| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
*
Wisconsin Regional Primate Research Center and
Department of Pathology and Laboratory Medicine, University of Wisconsin, Madison, WI 53715;
Eppimune, San Diego, CA 92121;
§
Division of Immunology, New England Regional Primate Research Center, Harvard Medical School, Southborough, MA 01772; and
¶
Infectious Disease Unit and Partners AIDS Research Center, Massachusetts General Hospital, Charlestown, MA 02129;
||
Laboratory of Genetics, University of Wisconsin, Madison, WI 53706
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
|
Introduction |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Because of the similarity of the immune systems of macaques and humans, SIV infection of macaques is also an excellent model to study the immunology of HIV infection of humans. Many macaque genes that encode proteins important in the functioning of the immune system are remarkably similar to their human homologues. Specifically, homologues of the human MHC class I (8, 9), class II (10), and TCR genes (11, 12) are all found in the macaque. Interestingly, macaque and human MHC class I molecules bind peptides derived from similar regions of the gag and env proteins of HIV and SIV (13, 14, 15, 16, 17, 18, 19). Similarities in peptide binding ability of MHC proteins are also evident at the class II loci, with rhesus macaque lymphocytes able to present a mycobacterially derived peptide to a human T cell clone (20). Taken together, these data suggest that some elements of Ag processing as well as the peptide binding specificities of MHC molecules may have been conserved between humans and macaques.
The cell-mediated immune response may play an important role in the containment of HIV in infected individuals, especially during the first few weeks postinfection (21, 22, 23). Recent evidence from studies of HIV-infected patients also implicates the role of CTL in containing the virus later in infection (24, 25, 26). Evidence for transient CTL activity in several infants born to HIV-infected mothers suggests that CTLs may also be important in protection against infection with HIV (27, 28). More recently, it has been shown that mutation of an immunodominant HLA-B*27-restricted gag CTL epitope, after 9 to 12 yr of stability in two HLA-B*27-positive HIV-infected individuals, coincided with an increase in viral load, a decline in CD4+ T cells, and progression to AIDS (29). Rapid escape from CTL recognition has also recently been demonstrated in an individual that made a strong response to an immunodominant gp160 peptide (30). The rapid evolution of unrecognized variants in this and other HIV-infected individuals (31, 32) provides strong evidence for the ability of CTL to suppress viral replication in vivo.
Several studies in humans, chimpanzees, and macaques have suggested that strong humoral and cellular immune responses to HIV and SIV can be generated through several different vaccination strategies (33, 34, 35, 36, 37, 38, 39). Indeed, DNA-encoded subunit vaccines have protected chimpanzees from high dose HIV-1 challenge (40). Infection of rhesus macaques with attenuated nef deletion mutants of SIV or previous exposure to HIV-2 has also been shown to protect these animals from subsequent challenges with pathogenic viruses (35, 41, 42). Furthermore, vaccination of cynomologus macaques with vaccinia-expressing nef elicited high levels of CTLs in several animals, with one animal being protected against SIV challenge (43). These studies suggest that it may be possible to induce a protective immune response and provide the rationale to further explore whether CTLs can protect against AIDS virus infection in an animal model.
The majority of vaccine strategies designed against HIV and SIV induce both cellular and humoral immune responses. As such, it has been difficult to distinguish between the role of antiviral CTLs and virus-specific Abs in protection from infection or in controlling viral loads. To address this issue it will be important to stimulate CTLs in the absence of an Ab response through vaccination with those minimal regions of the virus that encode CTL epitopes. The rhesus macaque MHC class I molecule Mamu (Macacamulatta)3-A*01 presents a peptide from the SIV gag protein (16). This epitope has been used as a 12 mer in vaccination strategies and for stimulating CTLs to viral variants from SIV-infected animals (44, 45). However, the optimal epitope, defined as the peptide that binds with the highest affinity or that is able to sensitize target cells for lysis at low concentrations, has not been identified. In most cases, immunogenic peptides seem to be high affinity binders, and peptides that are shorter or longer than the optimal epitope generally bind with lower affinity (46, 47). Vaccination with the optimal CTL epitope, therefore, may be more efficient at inducing a strong CTL response than vaccination with longer peptides. In this study we have identified the peptide binding motif of Mamu-A*01 using peptide elution. Additionally, we have defined the optimal Mamu-A*01-restricted CTL epitope contained in the SIV gag protein using sets of overlapping peptides in live cell binding assays and in CTL assays. Identification of the SIV gag-derived CTL epitope, bound and presented by Mamu-A*01, will be important to the development of vaccine strategies designed to induce CD8+ CTL responses against SIV in the rhesus macaque.
|
Materials and Methods |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
LP XhoI (5'-GCC TCG AGA TGS CSG TCA YGG CKC CCC GAA SYS TC-3') and 3'H3 (GCA AGC TTA GTC CCA CAC AAG GCA GCT G-3') primers were used to amplify Mamu-A*01 using the PCR from a previously described plasmid containing the rhesus MHC class I cDNA (16). After amplification, the PCR product was ligated into pSP72 (Promega, Madison, WI), which was used to transform bacterial SCS1 cells. Plasmid minipreps were then sequenced using an Applied Biosystems 373 automated sequencer (Applied Biosystems, Foster City, CA) to obtain full-length sequence. A minimum of three copies of numerous cDNAs were sequenced and analyzed with the use of software from IBI (New Haven, CT) and Applied Biosystems. A clone containing the consensus sequence for Mamu-A*01 was selected for transfection, and the cDNA was then subcloned into the pKG5 expression vector (gift from Andrew McMichael, Oxford University, Oxford, U.K.).
Stable transfection of Mamu-A*01 into the 721.221 cell line
The pKG5 vector encoding Mamu-A*01 was electroporated into the 721.221 cell line, a cloned EBV-transformed B LCL with homozygous deletions of the MHC class I loci (48). 721.221 cells (5 x 106) were transfected in a 1-cm electroporation cuvette with 10 µg of plasmid DNA. Electroporation was conducted with a Zapper (Medical Electronics Shop, University of Wisconsin, Madison, WI) at 1250 V and a capacitance of 450 µF. The cells were then incubated for 2 days at 37°C in RPMI 1640 culture medium supplemented with penicillin (50 U/ml), streptomycin (50 µg/ml), L-glutamine (2 mM), 5% defined FBS (HyClone, Logan, UT), and 10% defined/supplemented bovine calf serum (HyClone). On day 3 the cells were placed under selection by feeding with culture medium containing 1.5 mg/ml G418 (Life Technologies, Grand Island, NY). Approximately 4 wk later, viable transfectants were tested for HLA surface expression by flow cytometry using the W6/32 mAb directly conjugated to FITC (Sigma, St. Louis, MO). The transfectant with the highest level of MHC class I expression was selected to be grown for peptide elution studies.
Affinity purification of Mamu-A*01
MHC class I molecules were purified from the surface of Mamu-A*01-transfected 721.221 cells according to a modified protocol (49). Briefly, 4 x 109 transfected 721.221 cells were washed in cold HBSS (Life Technologies), harvested, and then frozen until needed. Thawed cells were then resuspended in 100 ml of 1% Nonidet P-40 lysis buffer containing 0.25% sodium deoxycholate, 174 µg/ml PMSF, 5 µg/ml aprotonin, 10 µg/ml leupeptin, 10 µg/ml pepstatin A, 20 µg/ml iodoacetamide, 0.2% sodium azide, and 0.003 µg/ml EDTA. Cell lysates were incubated at 4°C for 1 h, centrifuged at 100,000 x g at 4°C to remove cellular debris, and then filtered sequentially through 0.8- and 0.22-µm pore size Nalgene filters (Nalge, Rochester, NY) to remove any remaining lipids. Filtered lysates were then passed twice over an LB3.1 (anti-class II Ab)-coupled protein A-Sepharose column to preclear the lysate. The flowthough was passed twice over two consecutive W6/32-coupled columns (mAb W6/32, a gift from D. Geraghty, Fred Hutchinson Cancer Research Center, Seattle, WA) to specifically bind MHC class I molecules. The protein A beads of the W6/32 columns were then washed separately: twice with lysis buffer (without protease inhibitors), twice with a high salt buffer (1 M NaCl and 20 mM Tris, pH 8.0), and twice with a no salt buffer (20 mM Tris, pH 8.0).
Purification of MHC class I bound peptides
The MHC heavy chain ß2m/peptide complexes were eluted from the protein A beads by incubation in 0.2 N acetic acid (49). The beads were then briefly centrifuged, the supernatant transferred to a new tube, and the process was repeated. One hundred microliters of glacial acetic acid was then added to each tube to allow for dissociation of the MHC heavy chain/ß2m/peptide complexes. MHC class I heavy chains, ß2m, and W6/32 Abs were then separated from the peptides by centrifugation through an Ultrafree-CL filter (5000 NMWL, Millipore, Bedford, MA). Peptide yields were determined by quantitation of Mamu-A*01 heavy chain using SDS-PAGE.
HPLC fractionation and automated Edman degradation sequencing of peptides
The peptide-containing eluate that passed through the 5000 m.w. filter was dried down to 100 µl. Acid-eluted peptides were separated by HPLC using a reverse-phase Beckman Ultrasphere C18 4.6-mm x 250-mm column and a trifluoroacetic acid (TFA)/acetonitrile water gradient consisting of a mixture of two mobile phases. Mobile phase A consisted of 5% acetonitrile in water with 0.1% TFA, while phase B consisted of 50% acetonitrile in water with 0.1% TFA. The gradient varied from 100% mobile phase A to 100% phase B over 70 min at a flow rate of 1 ml/min. Fractions were collected at 1-min intervals, and peptides eluting between fractions 15 and 55 were collected, pooled, and subjected to Edman degradation sequencing on a high sensitivity Procise cLC sequencer (W. M. Keck Foundation, Biotechnology Resource Laboratory, New Haven, CT). Residue preferences at each position were originally assessed according to previously outlined methods (50, 51). Only signals that demonstrated a >50% increase in the absolute amount (picomoles) compared with the previous (or pre-previous) cycle were considered to indicate significant residues. Depending on the magnitude of signal increase seen for a given residue, these residues were classified as strong (>100%) or weak (>50%) residues (50, 51). A second pool of peptides that eluted as a predominant HPLC peak between 35 and 37 min was also separately collected and subjected to Edman degradation. An average relative frequency table was then generated by combining and converting the raw data from the two Edman degradation experiments (15–55 pool and 35–37 pool) according to the method of Kubo et al. (Ref. 52; data now shown). This average relative frequency table allowed for standardized values to be generated for individual runs and combined for comparison. No assignment of preferred amino acids was made for position 1 (P1), since this cycle tends to contain high levels of background signal, making proper assignments difficult. Cysteine was not modified during sequencing and therefore could not be detected.
Live cell binding assays
The live cell binding assays were performed as previously
described (53). Briefly, Mamu-A*01-transfected 721.221 cells
(106 cells/ml) were preincubated overnight in 5% FCS with
3 µg/ml human ß2m (Scripps Clinic and Research
Foundation, La Jolla, CA) at 26°C. Cells were washed twice in RPMI
1640 and resuspended to a concentration of 107 cells/ml.
Cells (2 x 106 cells; 200 µl/data point) were then
incubated in the presence of 105 cpm (10 µl) of a
radiolabeled peptide, ß2m (3 µg/ml), and where tested,
20 µl of various concentrations of unlabeled inhibitor peptide at
20°C for 4 h. Peptides were HPLC purified and radiolabeled with
125I according to the chloramine-T method (54). Following
incubation, free and cell-bound peptides were separated by washing
three times with serum-free medium and then passed through a FCS
gradient. Pelleted fractions were counted on a gamma scintillation
counter. In the case of competitive assays, the concentration of
peptide yielding 50% inhibition of the binding of the radiolabeled
probe peptide was also calculated (IC50) (55).
JA2-Kb cells were used as a negative control cell line.
These cells are stable transfectants of the human T cell leukemia line,
Jurkat, expressing an HLA-A*0201/Kb fusion protein
(
1 and 2 domains of HLA-A*0201 and 3 domain of H-2
Kb) (56).
Animals
Rhesus macaque rh95024 was identified as Mamu-A*01
positive by PCR-SSP and direct sequencing as previously described (57).
Briefly, for allele-specific PCR, genomic DNA was isolated from
peripheral blood using a QIAamp Blood Kit (Qiagen, Chatsworth, CA). DNA
(50–150 ng) was then amplified in a single PCR reaction using two sets
of Mamu-A*01-specific primers, Mamu-A*01F and Mamu-A*01R.
rh95024 was then infected i.v. with 40 tissue culture infectious doses
(TCID) of amplified SIVmac isolate 251. This animal was maintained in
accordance with the National Institutes of Health Guide to the Care and
Use of Laboratory Animals and under the approval of the University of
Wisconsin Research Animal Resource Center review committee. Rhesus
macaque rh118.87 was vaccinated with the live attenuated SIV strain
SIVmac239
nef (58) and housed at the New England Regional
Primate Center (Southborough, MA).
Generation of B LCL lines
B LCL lines from rh95024 were generated by transformation of 1 x 106 freshly Ficoll/diatrizoate gradient purified PBL with equal volumes of S594 supernatant and R10 medium consisting of RPMI 1640 supplemented with penicillin (50 U/ml), streptomycin (50 µg/ml), L-glutamine (2 mM), and 10% FBS (Biocell, Carson, CA). S594 supernatant was derived from a cell line productively infected with baboon Herpes virus papio (59).
Generation of cultured bulk CTL effector cells
PBL were isolated from whole blood using Ficoll/diatrizoate gradient centrifugation and then washed twice in R10 medium. CTL cultures were initiated by coculture of PBL with autologous B LCL stimulators expressing the SIV gag protein as previously described (60, 61). Stimulators were prepared by infecting 1 x 107 autologous B LCLs with a recombinant vaccinia virus construct expressing the gag gene of SIVmac 251 (vAbT252, a gift from D. Panicali and G. Mazzara, Therion Biologics, Cambridge, MA). Four plaque-forming units per cell of recombinant vaccinia virus were used to infect B LCLs for 2 h in serum-free RPMI medium. Cells were then incubated in 10 ml of R10 medium, and the infection was allowed to continue for 14 h, at which time viable infected cells were collected by Ficoll/diatrizoate gradient centrifugation. Cells were then washed in HBSS (Life Technologies) and resuspended in 5 ml of 1.5% paraformaldehyde for 30 min at room temperature. Stimulators were spun down, resuspended in 5 ml of 0.2 M glycine in PBS, and incubated at room temperature for 15 min. Centrifuged cells were then washed once in 5 ml of FBS, and 5 x 106 stimulators were cocultured with 5 x 106 PBL in a 24-well plate (Corning, Corning, NY). Remaining stimulators were resuspended in FBS to a final cell concentration of 1 x 107/ml and stored at 4°C until needed.
On day 3, 1 ml of the medium was replaced with R10 medium containing 20 U of rIL-2/ml (provided by M. Gately, Hoffmann-La Roche, Nutley, NJ). Medium was changed every other day with rIL-2 medium until day 7 when viable cells were purified on a Ficoll/diatrizoate gradient and resuspended in 2 ml of R10. Additional stimulators (5 x 106) were then added to the CTL cultures and incubated for an another 3 days, after which half the medium was again replaced with rIL-2 medium every 2 days. On day 14 the CTL activity of the cultures was assessed in a standard 51Cr release assay.
Isolation of CTL clones specific for the Mamu-A*01-restricted gag epitope
PBMC were obtained from rhesus macaque rh118.87. This animal,
which had been vaccinated with the live attenuated SIV strain
SIVmac239nef, had previously been shown to have strong
CTL activity against the SIV gag protein (58). PBMC were stimulated
initially with an autologous B LCL infected overnight with a
recombinant vaccinia virus vector expressing SIV gag, pol, and env and
then inactivated using UV light and psoralen. After 10 to 14 days,
stimulated PBMC were depleted of CD4+ T cells using
immunomagnetic beads as previously described (58). CD8+ T
cells were then cloned by culturing them at 10, 3, and 1 cells/well in
96-well U-bottom plates in 200 µl of RPMI supplemented with 5 µg/ml
Con A (Sigma), 20% FBS, 10 mM HEPES, 2 mM L-glutamine, 50
IU/ml penicillin, 50 µg/ml streptomycin, and 100 U/ml recombinant
human IL-2 (provided by M. Gately, Hoffmann-La Roche) in the presence
of 1 x 105 irradiated (3,000 rad) human PBMC and
1 x 104 irradiated (10,000 rad) autologous B LCL as
feeder cells. After 2 wk, wells exhibiting growth were restimulated
with Con A, irradiated human PBMC, autologous B LCL, and IL-2 using a
modification of techniques previously employed for the propagation of
human HIV-specific CTL clones (17).
Peptides
Peptides were obtained as lyophilized products from Biosynthesis (Lexisville, TX) or Chiron Mimotopes (San Diego, CA) or were synthesized at Cytel using standard t-Boc or F-moc solid phase synthesis methods. Peptides synthesized at Cytel were reverse phase HPLC purified to >95% homogeneity. For CTL assays, lyophilized aliquots were resuspended in HBSS with 10% DMSO (Sigma) to a final concentration of 1 mg/ml. For live cell binding assays, peptides were resuspended at 20 mg/ml in 100% DMSO, then diluted with PBS.
Cytotoxicity assay
Testing of bulk CTL cultures required 5 x 105 autologous B LCL to be incubated for 1 h with 80 µCi of Na251Cr04 (New England Nuclear Life Sciences Products) in a 200-µl volume of R10 medium at 37°C in a 5% CO2 humidified incubator. Target cells were then washed five times and resuspended to a concentration of 5 x 104/ml in R10 medium. One hundred microliters of the target cell suspension was then plated into individual wells of a 96-well U-bottom microtiter plate. Peptide titrations were conducted by incubating the 51Cr-labeled target cells with the indicated concentration of peptide for 1 h in individual wells of the 96-well plate before the addition of effector cells. Tenfold dilutions of peptides were made in HBSS with 10% DMSO. Effector CTLs were then added to duplicate wells of target cells and allowed to coincubate for 5 h before supernatants were harvested with a harvesting press (Skatron, Sterling, VA). 51Cr release was measured on a Searle gamma counter (model 1185, Searle, Skokie, IL). Spontaneous 51Cr release was measured for each target cell line using four wells of target cells that received 100 µl of R10. Four additional wells received 100 µl of 5% Triton X-100 (Sigma) and were used to measure maximum 51Cr release. The percent specific lysis was determined using the following equation: % specific lysis = [(experimental release - spontaneous release)/(maximum release - spontaneous release)] x 100. Spontaneous release was always <25% of maximal release. Data reported for bulk CTL cultures are based on single CTL assays tested at various E:T cell ratios.
CTL clones were tested for SIV-specific CTL activity using autologous B LCL or Mamu-A*01-transfected C1R cells (62), infected either with a recombinant vaccinia virus vector expressing SIV gag and protease genes or with the unmodified vaccinia virus NYCBH as a control. Clones exhibiting SIV gag-specific activity were then screened for their ability to recognize autologous B LCL sensitized with the SIV gag peptide TPYDINQML incubated with the B LCL during 51Cr labeling at 100 µg/ml. Peptide titrations were conducted by incubating the 51Cr-labeled target cells with the indicated concentration of peptide for 45 min in individual wells of the 96-well plate before the addition of effector cells as previously described (63). For each CTL clone the pattern of recognition of these different peptides was confirmed in three or more CTL assays.
|
Results |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
To assist in the correct identification of additional
Mamu-A*01-restricted CTL epitopes, we were interested in determining
the anchor residues of peptides bound by Mamu-A*01. To accomplish this,
Mamu-A*01 was transfected into the human MHC class
I-deficient B LCL line 721.221. Peptides bound by this molecule were
then eluted and sequenced by Edman degradation. Sequence analysis of
the first set of pooled peptides, which eluted between fractions 15 and
55, revealed a striking enrichment of the signal for proline at
position 3 (P3), which was greater than any other signal identified
(data not shown). From the combined data of this and an Edman
degradation run of a second pool of peptides, other weaker enrichments,
possibly reflecting secondary anchor residues, were confirmed for
threonine at P2, for proline at P4, for isoleucine at P6, for
asparagine at P7, and for glutamine at P8 (Fig. 1
A). Increases in
signal for other amino acids were also observed at other positions;
however, these signals were not consistently elevated in the two Edman
degradation experiments and were not considered significant. Therefore,
the proline residue that occupies P3 of the SIV gag CTL epitope appears
to represent the anchor residue critical for the binding of the SIV gag
epitope to Mamu-A*01. These findings suggest that the naturally
processed peptide may span residues 181 to 190 (or possibly 181–189).
This differs from the previously described SIV gag Mamu-A*01-restricted
CTL epitope (TPYDINQML182–190) in that the redefined
epitope possesses an additional NH2-terminal residue
(C181; Fig. 1B).
|
Since the peptide binding motif data suggested that the Mamu-A*01-restricted SIV gag CTL epitope possessed a proline residue at P3 rather than at P2, as previously described, we were interested in using binding assays to test the validity of these findings. We examined the binding abilities of a panel of SIV gag181–191-derived peptides in a direct live cell binding assay specific for Mamu-A*01. Since a cysteine residue can interfere with proper radiolabeling of these peptides, all the analogues tested contain an alanine to cysteine substitution at P1. The 10 mer peptide (ATPYDINQML) bound to 721.221 cells transfected with Mamu-A*01, but not to untransfected 721.221 cells or 721.221/A2-Kb cells. Furthermore, when an excess of unlabeled homologous peptide was added to inhibit binding, it was determined that binding of the labeled ATPYDINQML peptide was of high affinity (IC50 = 3.1 nM; data not shown). Other unrelated peptides also inhibited binding of the radiolabeled peptide to various degrees, but with binding affinities ranging from about 100 nM for the HBV18–27 analogue (FLPSDYFPSV), which also carries a proline in position 3, to undetectable levels in the case of the rat 60s L28 peptide (FRYNGLIHR; data not shown).
We then analyzed the abilities of several SIV
gag181–191-derived peptides to bind to Mamu-A*01 as
measured by inhibition assays. Since MHC class I molecules are able to
bind peptides of variable length, it was necessary to define the length
of this epitope using additional truncated peptides. It was first
determined that the natural peptide (CTPYDINQML) bound Mamu-A*01 as
well as the C > A analogue, demonstrating an IC50
value of 5.9 nM (Table I). Examination of
COOH-terminal truncated SIV gag peptides revealed optimal binding with
either 9 mer (CTPYDINQM) or 10 mer (CTPYDINQML) peptides. This may
indicate that both M189 or L190 are capable of
being bound by the F pocket of Mamu-A*01. Elongation of the peptide to
include an additional COOH-terminal residue (N191),
however, dramatically increased the IC50 value, thereby
decreasing the binding affinity. Likewise, further truncation of the 9
mer peptide by removal of the COOH-terminal M189 residue
dramatically reduced binding to Mamu-A*01.
|
Binding of single substitution analogues reveals that the P3 proline represents the dominant anchor residue
To verify the peptide binding motif determined for Mamu-A*01,
single substitution analogues of the C > A peptide analogue
(ATPYDINQML) were tested in live cell binding assays. Initially,
lysine residues were substituted at all positions to determine whether
substitution with this larger, charged residue affected binding. As
illustrated in Table II, analogues with
lysine substitutions at P2, P3, P8, and P10 had significantly reduced
binding capacity. Additional analogues tested at P2 revealed that a
variety of amino acid substitutions at this position were not well
accommodated and resulted in reduced binding. However, a few
substitutions, including alanine, proline, and valine were
accommodated. This was not unexpected, since valine was also revealed
as a possible weak P2 anchor in the peptide binding motif of Mamu-A*01
(data not shown), and alanine often accompanies motifs with
threonine/valine anchors. However, similar analogues tested at P3
revealed that no residue could replace proline, underlying the role of
proline as a crucial anchor residue. P8 and P10 lysine substitution
analogues were the only other analogues that revealed decreased binding
capacity. However, unlike the P2 and P3 analogues, only those P8 and
P10 analogues containing lysine (as well as glutamine for P10) had
reduced binding. Many other P8 and P10 analogues tested did not
significantly alter IC50 values, suggesting that,
while P8 and P10 residues are important for binding to Mamu-A*01, it is
unlikely that strong anchor residues exist at these positions.
|
It is often difficult to appreciate even dramatic differences in peptide recognition by CTLs among sets of peptides if high peptide concentrations are used to pulse target cells. At these high concentrations, even suboptimal peptides may be capable of inducing appreciable levels of specific lysis in the CTL assays. Therefore, in the next series of experiments we used bulk CTL lines derived from a Mamu-A*01-positive SIV-infected rhesus macaque to determine the optimal CTL epitope through testing of various dilutions of peptides for their ability to induce lysis of target cells.
Initially we tested the ability of the 9-mer (CTPYDINQM) and 10 mer
(CTPYDINQML) peptides, the optimal Mamu-A*01 binders, for this capacity
to sensitize Mamu-A*01-transfected 721.221 target cells for
lysis. As illustrated in Figure 2,
A and B, only minor differences in the percent
specific lysis were observed at high peptide concentrations. However,
when nanogram amounts of these peptides were tested, the 9 mer was
>100-fold more active than the 10-mer. Bulk CTL lines were also shown
to recognize autologous B LCLs equally as well as
Mamu-A*01-transfected 721.221 cells when pulsed with high
concentrations of peptide. These peptides were then retested along with
the 8-mer TPYDINQM, 9-mer TPYDINQML, and 12-mer EGCTPYDINQML
peptides (Fig. 2C). The 9-mer CTPYDINQM yielded the
highest levels of CTL activity at low peptide concentrations and was
almost 1,000-fold more active than the 10-mer CTPYDINQML.
Furthermore, the 9-mer CTPYDINQM peptide appeared to be recognized 100-
to 10,000-fold better than the two other truncated peptides,
TPYDINQM and TPYDINQML, which were missing the crucial cysteine
residue at position 1. The p11C 12-mer (EGCTPYDINQML), originally
used to map the Mamu-A*01-restricted SIV gag epitope, was also poorly
recognized at low peptide concentrations. These findings suggest that
the SIV gag CTL epitope ends in a methionine residue and identifies the
SIV gag CTPYDINQM peptide as the optimal CTL epitope for recognition by
bulk CTL lines.
|
We next examined recognition of a panel of SIV gag peptides by
three SIV-specific CTL clones obtained from a Mamu A*01-positive rhesus
macaque that developed a CTL response dominated by the specificity for
the 25-mer gag peptide 11, spanning residues 171 to 195 (16, 58).
Initial screening of 106 gag-specific CTL clones from this animal with
the previously reported 9-mer (TPYDINQML182–190)
revealed that 92 clones (87%) recognized this peptide. Two of these
clones (no. 8 and 20) were randomly selected for further study as
representative clones. An additional clone (no. 125), which did not
recognize the previously described minimal epitope (TPYDINQML) but did
recognize the 25-mer gag peptide 11 (data not shown), was also used for
these studies. Recognition of various gag peptides over a range of
peptide concentrations was examined using autologous B LCLs and
Mamu-A*01-transfected C1R cells. Although each of the CTL
clones presented a distinct pattern of recognition with this panel of
peptides, for all clones the optimal epitope consisted of either the
9-mer CTPYDINQM or the 10 mer CTPYDINQML (Fig. 3, A and B).
In general, the 9-mer TPYDINQML was recognized by these clones 100- to
10,000-fold less efficiently than the CTPYDINQM or CTPYDINQML
peptides. Clone 125 did not recognize the 9-mer peptide TPYDINQML at
any concentration tested, except when tested on
Mamu-A*01-transfected C1R cells at very high peptide
concentrations (Fig. 3B). Interestingly, clone 8 did
not recognize the 9-mer CTPYDINQM peptide at all, while it recognized
the 10-mer CTPYDINQML with a sensitizing dose of peptide required
for 50% maximal lysis of 0.001 µg/ml. This finding is in agreement
with the peptide binding data examining lysine analogues (Table II
),
which suggested that the P10 leucine of the 10-mer (CTPYDINQML)
could also be bound by the F pocket of Mamu-A*01. However, both clones
125 and 20 recognized the CTPYDINQM peptide as the optimal epitope.
Thus, while there was variation in the optimal epitope recognized by
each of these clones, the consensus optimal epitope consisted of either
the 9-mer CTPYDINQM or the 10-mer CTPYDINQML with the proline residue
at position 3.
|
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
CTLs from Mamu-A*01-positive rhesus macaques were previously shown to recognize two overlapping 12-mer peptides, p11C and p11D (16). These two 12-mers overlapped by nine residues, and it was therefore concluded that the minimal CTL epitope was TPYDINQML182–190 (16, 45, 64). However, we have demonstrated that gag-specific bulk CTL cultures recognized Mamu-A*01-positive target cells pulsed with the SIV gag CTPYDINQM peptide even at nanogram amounts, whereas much greater concentrations of the TPYDINQML, or the longer CTPYDINQML, peptides were required to obtain similar levels of recognition. Studies with cloned CTL confirmed this hierarchy of CTL recognition, with the CTPYDINQM peptide being recognized by the majority of the CTL clones at low peptide concentrations.
It is interesting that one CTL clone (no. 8) preferentially recognized the longer CTPYDINQML peptide and, in fact, failed to recognize the CTPYDINQM peptide even at concentrations up to 10 µg/ml. This finding combined with our peptide binding data that demonstrated little difference between binding of this 10-mer and the minimal epitope CTPYDINQM, as well as data demonstrating a role for the P10 leucine in binding of the 10-mer, suggest that Mamu-A*01 may be capable of binding and presenting both of these peptides. Therefore, SIV-infected Mamu-A*01-positive rhesus macaques may be capable of mounting significant CTL responses against both these epitopes. The preferential reactivity of bulk CTL cultures toward the shorter epitope, however, may be a reflection of higher precursor frequencies of circulating CTLs specific for the shorter CTPYDINQM peptide. This may be due to subtle differences in the MHC class I Ag processing pathway that might favor production of the shorter epitope from the SIV gag protein.
Identification of this first rhesus macaque MHC class I peptide motif (Mamu-A*01), proved to be interesting in that peptides bound by Mamu-A*01 possess a single dominant anchor residue at position 3 (P3). The majority of human MHC class I molecules, however, bind peptides with anchor residues at positions 2 (P2) and 9 (P9) that interact with the B and F pockets of an MHC class I molecule’s peptide binding groove (65). The presence of a P3 anchor for Mamu-A*01 suggests that the D pocket, which binds P3 residues, is responsible for tight binding of peptides to this molecule (66, 67, 68). Interestingly, the D pocket is rather shallow for the majority of human MHC class I molecules and is believed to provide less binding energy than the B and F pockets for the peptide/MHC complex (66, 67, 68). Position 3, however, does appear to be an important secondary anchor site for a number of HLA alleles (69, 70, 71). Furthermore, despite the shallowness of the D pocket, a few mouse (H-2Dd) and human (HLA-A*01, -B*08) MHC class I molecules possess a dominant anchor motif at P3. Analysis of the B pockets of Mamu-A*01 and these other mouse and human MHC class I molecules, which do not possess P2 anchor motifs, reveals that some of the residues forming their B pockets are unique to these molecules and may interfere with the ability of their B pockets to tightly bind P2 residues (data not shown). As such, in these molecules the D pocket may supplant the role of the B pocket by tightly binding P3 residues. Determination of the peptide binding motifs of additional rhesus macaque MHC class I molecules will be necessary to determine whether the absence of P2 anchor motifs is a general characteristic of these molecules.
The absence of a strong COOH-terminal anchor, usually at P9, in the defined peptide binding motif of Mamu-A*01 is surprising. However, live cell binding assays indicated that loss of the COOH-terminal methionine of the shorter peptide (CTPYDINQM) dramatically reduced the ability of this peptide to bind Mamu-A*01. This strongly supports a role for COOH-terminal residues of peptides in binding to Mamu-A*01. Indeed, preliminary analysis of the F pockets of various rhesus MHC class I molecules, including Mamu-A*01, suggests that residues forming the F pockets of these molecules are very similar to those of their human counterparts and, therefore, would be expected to possess strong P9 anchors.
It has been observed that human and rhesus macaque MHC class I molecules bind CTL epitopes from similar regions of HIV and SIV, respectively. For example, the rhesus Mamu-A*01-restricted SIV gag epitope was originally believed to be identical with the HLA-B*53-restricted epitope from the HIV-2 gag protein (TPYDINQML) (15). Similarly, other SIV epitopes bound by Mamu-A*08, -B*01 and -A*02 (18, 19, 72) overlap significantly with previously described HIV epitopes restricted by the human MHC class I molecule HLA-A*02. However, closer examination of the residues forming the B (and D) pockets these MHC class I molecules reveals that these human and rhesus molecules do not possess similar pockets and would not be expected to bind the same minimal epitopes. Therefore, basing assumptions regarding SIV CTL epitopes on closely related HIV epitopes may be misleading, and defining the peptide binding motifs of these rhesus MHC class I molecules will be necessary for the accurate identification of their minimal SIV CTL epitopes.
Peptide immunizations of Mamu-A*01-positive rhesus macaques have been attempted previously on several occasions (44, 73, 74). However, although these peptide immunizations generated a CTL response, they were never able to protect rhesus macaques from subsequent infection with pathogenic virus. Unfortunately, in all these experiments, a 12-amino acid peptide (p11C) was used to immunize these rhesus macaques. We have now determined that the optimal peptide bound by Mamu-A*01 is only 9 to 10 amino acids in length. Since the immunogenicity of a peptide is crucially dependent on its affinity for MHC class I molecules (75), it is possible that in these previous experiments the CTL responses generated were not optimal. Thus, immunization with smaller peptides that bind to MHC class I molecules with higher affinity may improve CTL responses compared with immunization with longer peptides that have a much lower affinity for the MHC class I molecule.
Mamu-A*01-positive rhesus macaques make an immunodominant response to
the SIV gag protein. In previous studies, each of five SIVmac-infected
rhesus macaques developed CTLs against this protein of the virus, and
in each case Mamu-A*01 was the restricting MHC class I molecule (16).
Furthermore, only a single peptide (p11, a 25 mer) was recognized
significantly. These findings, combined with the frequency of
Mamu-A*01, which is >22% in rhesus macaques originating from India
(16, 57, 76), make this epitope an obvious choice for vaccines designed
to induce CTLs against this region of the virus. Indeed, this region of
the SIV gag protein appears to be well conserved in nine different SIV
isolates derived from rhesus macaques, stump-tailed macaques, and sooty
mangabeys, with only a single position 9 (M
L) variant existing in a
stump-tailed macaque isolate (data not shown). In this study we have
redefined a previously reported CTL epitope from the SIV gag protein.
This epitope can now be used to develop epitope-based vaccines, to
detect viral escape mutants, or to form soluble peptide-MHC dimers or
tetramers (77, 78) for the identification and characterization of
peptide-specific CTL.
|
Acknowledgments |
|---|
nef-infected animal, Maurice Gately for providing
recombinant IL-2, Suqin He for synthesis of SIV peptides, and Dan
Geraghty for providing the W6/32 mAb for MHC class I affinity
purification. We also thank Ken Williams and Kathy Stone from the
W. M. Keck Foundation (New Haven, CT) for HPLC and Edman
degradation analysis, and Douglas Nixon for his advice on and critical
review of this manuscript. This paper is WRPRC publication 37-043. |
Footnotes |
|---|
2 Address correspondence and reprint requests to Todd M. Allen, Wisconsin Regional Primate Research Center and Program in Cellular and Molecular Biology, University of Wisconsin, Madison, WI 53715.
3 Abbreviations used in this paper: Mamu, Macaca mulatta; B LCL, B lymphoblastoid cell line; TFA, trifluoroacetic acid.
Received for publication November 4, 1997. Accepted for publication February 13, 1998.
|
References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
This article has been cited by other articles:
|
|
 |
|
  E. R. Manuel, W. W. Yeh, M. S. Seaman, K. Furr, M. A. Lifton, S. L. Hulot, P. Autissier, and N. L. Letvin Dominant CD8+ T-Lymphocyte Responses Suppress Expansion of Vaccine-Elicited Subdominant T Lymphocytes in Rhesus Monkeys Challenged with Pathogenic Simian-Human Immunodeficiency Virus J. Virol., October 1, 2009; 83(19): 10028 - 10035. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. J. Burwitz, C. J. Pendley, J. M. Greene, A. M. Detmer, J. J. Lhost, J. A. Karl, S. M. Piaskowski, R. A. Rudersdorf, L. T. Wallace, B. N. Bimber, et al. Mauritian Cynomolgus Macaques Share Two Exceptionally Common Major Histocompatibility Complex Class I Alleles That Restrict Simian Immunodeficiency Virus-Specific CD8+ T Cells J. Virol., June 15, 2009; 83(12): 6011 - 6019. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. T. Loffredo, J. Sidney, A. T. Bean, D. R. Beal, W. Bardet, A. Wahl, O. E. Hawkins, S. Piaskowski, N. A. Wilson, W. H. Hildebrand, et al. Two MHC Class I Molecules Associated with Elite Control of Immunodeficiency Virus Replication, Mamu-B*08 and HLA-B*2705, Bind Peptides with Sequence Similarity J. Immunol., June 15, 2009; 182(12): 7763 - 7775. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Genesca, P. J. Skinner, J. J. Hong, J. Li, D. Lu, M. B. McChesney, and C. J. Miller With Minimal Systemic T-Cell Expansion, CD8+ T Cells Mediate Protection of Rhesus Macaques Immunized with Attenuated Simian-Human Immunodeficiency Virus SHIV89.6 from Vaginal Challenge with Simian Immunodeficiency Virus J. Virol., November 15, 2008; 82(22): 11181 - 11196. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. R. Reynolds, A. M. Weiler, K. L. Weisgrau, S. M. Piaskowski, J. R. Furlott, J. T. Weinfurter, M. Kaizu, T. Soma, E. J. Leon, C. MacNair, et al. Macaques vaccinated with live-attenuated SIV control replication of heterologous virus J. Exp. Med., October 27, 2008; 205(11): 2537 - 2550. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. R. Kaufman, J. Liu, A. Carville, K. G. Mansfield, M. J. E. Havenga, J. Goudsmit, and D. H. Barouch Trafficking of Antigen-Specific CD8+ T Lymphocytes to Mucosal Surfaces following Intramuscular Vaccination J. Immunol., September 15, 2008; 181(6): 4188 - 4198. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E.-Y. Kim, R. S. Veazey, R. Zahn, K. J. McEvers, S. H. C. Baumeister, G. J. Foster, M. D. Rett, M. H. Newberg, M. J. Kuroda, E. P. Rieber, et al. Contribution of CD8+ T Cells to Containment of Viral Replication and Emergence of Mutations in Mamu-A*01-Restricted Epitopes in Simian Immunodeficiency Virus-Infected Rhesus Monkeys J. Virol., June 1, 2008; 82(11): 5631 - 5635. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. T. Loffredo, A. T. Bean, D. R. Beal, E. J. Leon, G. E. May, S. M. Piaskowski, J. R. Furlott, J. Reed, S. K. Musani, E. G. Rakasz, et al. Patterns of CD8+ Immunodominance May Influence the Ability of Mamu-B*08-Positive Macaques To Naturally Control Simian Immunodeficiency Virus SIVmac239 Replication J. Virol., February 15, 2008; 82(4): 1723 - 1738. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Sen, W. A. Charini, R. A. Subbramanian, E. R. Manuel, M. J. Kuroda, P. A. Autissier, and N. L. Letvin Clonal Focusing of Epitope-Specific CD8+ T Lymphocytes in Rhesus Monkeys following Vaccination and Simian-Human Immunodeficiency Virus Challenge J. Virol., January 15, 2008; 82(2): 805 - 816. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. M. Mueller, D. H. Do, S. R. Altork, C. M. Artlett, E. J. Gracely, C. D. Katsetos, A. Legido, F. Villinger, J. D. Altman, C. R. Brown, et al. IL-15 Treatment during Acute Simian Immunodeficiency Virus (SIV) Infection Increases Viral Set Point and Accelerates Disease Progression despite the Induction of Stronger SIV-Specific CD8+ T Cell Responses J. Immunol., January 1, 2008; 180(1): 350 - 360. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. N. Mandl, R. R. Regoes, D. A. Garber, and M. B. Feinberg Estimating the Effectiveness of Simian Immunodeficiency Virus-Specific CD8+ T Cells from the Dynamics of Viral Immune Escape J. Virol., November 1, 2007; 81(21): 11982 - 11991. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. M. Mueller, C. Petrovas, D. H. Do, S. R. Altork, T. Fischer-Smith, J. Rappaport, J. D. Altman, M. G. Lewis, and P. D. Katsikis Early Establishment and Antigen Dependence of Simian Immunodeficiency Virus-Specific CD8+ T-Cell Defects J. Virol., October 15, 2007; 81(20): 10861 - 10868. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. J. Miller, M. Genesca, K. Abel, D. Montefiori, D. Forthal, K. Bost, J. Li, D. Favre, and J. M. McCune Antiviral Antibodies Are Necessary for Control of Simian Immunodeficiency Virus Replication J. Virol., May 15, 2007; 81(10): 5024 - 5035. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Chu, Z. Lou, Y. W. Chen, Y. Liu, B. Gao, L. Zong, A. H. Khan, J. I. Bell, Z. Rao, and G. F. Gao First Glimpse of the Peptide Presentation by Rhesus Macaque MHC Class I: Crystal Structures of Mamu-A*01 Complexed with Two Immunogenic SIV Epitopes and Insights into CTL Escape J. Immunol., January 15, 2007; 178(2): 944 - 952. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. R. Manuel, W. A. Charini, P. Sen, F. W. Peyerl, M. J. Kuroda, J. E. Schmitz, P. Autissier, D. A. Sheeter, B. E. Torbett, and N. L. Letvin Contribution of T-Cell Receptor Repertoire Breadth to the Dominance of Epitope-Specific CD8+ T-Lymphocyte Responses J. Virol., December 15, 2006; 80(24): 12032 - 12040. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. M. Belyakov, V. A. Kuznetsov, B. Kelsall, D. Klinman, M. Moniuszko, M. Lemon, P. D. Markham, R. Pal, J. D. Clements, M. G. Lewis, et al. Impact of vaccine-induced mucosal high-avidity CD8+CTLs in delay of AIDS viral dissemination from mucosa Blood, April 15, 2006; 107(8): 3258 - 3264. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. H. Newberg, K. J. McEvers, D. A. Gorgone, M. A. Lifton, S. H. C. Baumeister, R. S. Veazey, J. E. Schmitz, and N. L. Letvin Immunodomination in the Evolution of Dominant Epitope-Specific CD8+ T Lymphocyte Responses in Simian Immunodeficiency Virus-Infected Rhesus Monkeys J. Immunol., January 1, 2006; 176(1): 319 - 328. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. B. McDermott, D. H. O'Connor, S. Fuenger, S. Piaskowski, S. Martin, J. Loffredo, M. Reynolds, J. Reed, J. Furlott, T. Jacoby, et al. Cytotoxic T-Lymphocyte Escape Does Not Always Explain the Transient Control of Simian Immunodeficiency Virus SIVmac239 Viremia in Adenovirus-Boosted and DNA-Primed Mamu-A*01-Positive Rhesus Macaques J. Virol., December 15, 2005; 79(24): 15556 - 15566. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. T. Loffredo, J. Sidney, S. Piaskowski, A. Szymanski, J. Furlott, R. Rudersdorf, J. Reed, B. Peters, H. D. Hickman-Miller, W. Bardet, et al. The High Frequency Indian Rhesus Macaque MHC Class I Molecule, Mamu-B*01, Does Not Appear to Be Involved in CD8+ T Lymphocyte Responses to SIVmac239 J. Immunol., November 1, 2005; 175(9): 5986 - 5997. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. D. Hickman-Miller, W. Bardet, A. Gilb, A. D. Luis, K. W. Jackson, D. I. Watkins, and W. H. Hildebrand Rhesus Macaque MHC Class I Molecules Present HLA-B-Like Peptides J. Immunol., July 1, 2005; 175(1): 367 - 375. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. T. Evans, J. E. Bricker, H. B. Sanford, S. Lang, A. Carville, B. A. Richardson, M. Piatak Jr., J. D. Lifson, K. G. Mansfield, and R. C. Desrosiers Immunization of Macaques with Single-Cycle Simian Immunodeficiency Virus (SIV) Stimulates Diverse Virus-Specific Immune Responses and Reduces Viral Loads after Challenge with SIVmac239 J. Virol., June 15, 2005; 79(12): 7707 - 7720. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Su, M. A. Luscher, Y. Xiong, T. Rustam, R. R. Amara, E. Rakasz, H. L. Robinson, and K. S. MacDonald Novel simian immunodeficiency virus CTL epitopes restricted by MHC class I molecule Mamu-B*01 are highly conserved for long term in DNA/MVA-vaccinated, SHIV-challenged rhesus macaques Int. Immunol., May 1, 2005; 17(5): 637 - 648. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Nacsa, Y. Edghill-Smith, W.-P. Tsai, D. Venzon, E. Tryniszewska, A. Hryniewicz, M. Moniuszko, A. Kinter, K. A. Smith, and G. Franchini Contrasting Effects of Low-Dose IL-2 on Vaccine-Boosted Simian Immunodeficiency Virus (SIV)-Specific CD4+ and CD8+ T Cells in Macaques Chronically Infected with SIVmac251 J. Immunol., February 15, 2005; 174(4): 1913 - 1921. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Otting, C. M. C. Heijmans, R. C. Noort, N. G. de Groot, G. G. M. Doxiadis, J. J. van Rood, D. I. Watkins, and R. E. Bontrop Unparalleled complexity of the MHC class I region in rhesus macaques PNAS, February 1, 2005; 102(5): 1626 - 1631. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Z. Smith, C. J. Dale, R. De Rose, I. Stratov, C. S. Fernandez, A. G. Brooks, J. Weinfurter, K. Krebs, C. Riek, D. I. Watkins, et al. Analysis of Pigtail Macaque Major Histocompatibility Complex Class I Molecules Presenting Immunodominant Simian Immunodeficiency Virus Epitopes J. Virol., January 15, 2005; 79(2): 684 - 695. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. T. Loffredo, J. Sidney, C. Wojewoda, E. Dodds, M. R. Reynolds, G. Napoe, B. R. Mothe, D. H. O'Connor, N. A. Wilson, D. I. Watkins, et al. Identification of Seventeen New Simian Immunodeficiency Virus-Derived CD8+ T Cell Epitopes Restricted by the High Frequency Molecule, Mamu-A*02, and Potential Escape from CTL Recognition J. Immunol., October 15, 2004; 173(8): 5064 - 5076. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. A. Sharpe, A. Cope, S. Dowall, N. Berry, C. Ham, J. L. Heeney, D. Hopkins, L. Easterbrook, M. Dennis, N. Almond, et al. Macaques infected long-term with attenuated simian immunodeficiency virus (SIVmac) remain resistant to wild-type challenge, despite declining cytotoxic T lymphocyte responses to an immunodominant epitope J. Gen. Virol., September 1, 2004; 85(9): 2591 - 2602. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Izumi, Y. Ami, K. Matsuo, K. Someya, T. Sata, N. Yamamoto, and M. Honda Intravenous Inoculation of Replication-Deficient Recombinant Vaccinia Virus DIs Expressing Simian Immunodeficiency Virus Gag Controls Highly Pathogenic Simian-Human Immunodeficiency Virus in Monkeys J. Virol., December 15, 2003; 77(24): 13248 - 13256. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. U. Vogel, M. R. Reynolds, D. H. Fuller, K. Vielhuber, T. Shipley, J. T. Fuller, K. J. Kunstman, G. Sutter, M. L. Marthas, V. Erfle, et al. Multispecific Vaccine-Induced Mucosal Cytotoxic T Lymphocytes Reduce Acute-Phase Viral Replication but Fail in Long-Term Control of Simian Immunodeficiency Virus SIVmac239 J. Virol., December 15, 2003; 77(24): 13348 - 13360. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Sidney, S. Southwood, V. Pasquetto, and A. Sette Simultaneous Prediction of Binding Capacity for Multiple Molecules of the HLA B44 Supertype J. Immunol., December 1, 2003; 171(11): 5964 - 5974. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. H. O'Connor, B. R. Mothe, J. T. Weinfurter, S. Fuenger, W. M. Rehrauer, P. Jing, R. R. Rudersdorf, M. E. Liebl, K. Krebs, J. Vasquez, et al. Major Histocompatibility Complex Class I Alleles Associated with Slow Simian Immunodeficiency Virus Disease Progression Bind Epitopes Recognized by Dominant Acute-Phase Cytotoxic-T-Lymphocyte Responses J. Virol., August 15, 2003; 77(16): 9029 - 9040. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. C. McGuire, S. R. Leib, R. H. Mealey, D. G. Fraser, and D. J. Prieur Presentation and Binding Affinity of Equine Infectious Anemia Virus CTL Envelope and Matrix Protein Epitopes by an Expressed Equine Classical MHC Class I Molecule J. Immunol., August 15, 2003; 171(4): 1984 - 1993. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. A. P. Lafont, A. Buckler-White, R. Plishka, C. Buckler, and M. A. Martin Characterization of Pig-Tailed Macaque Classical MHC Class I Genes: Implications for MHC Evolution and Antigen Presentation in Macaques J. Immunol., July 15, 2003; 171(2): 875 - 885. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. H. Barouch, J. Kunstman, J. Glowczwskie, K. J. Kunstman, M. A. Egan, F. W. Peyerl, S. Santra, M. J. Kuroda, J. E. Schmitz, K. Beaudry, et al. Viral Escape from Dominant Simian Immunodeficiency Virus Epitope-Specific Cytotoxic T Lymphocytes in DNA-Vaccinated Rhesus Monkeys J. Virol., July 1, 2003; 77(13): 7367 - 7375. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Malkevitch, L. J. Patterson, K. Aldrich, E. Richardson, W. G. Alvord, and M. Robert-Guroff A Replication Competent Adenovirus 5 Host Range Mutant-Simian Immunodeficiency Virus (SIV) Recombinant Priming/Subunit Protein Boosting Vaccine Regimen Induces Broad, Persistent SIV-Specific Cellular Immunity to Dominant and Subdominant Epitopes in Mamu-A*01 Rhesus Macaques J. Immunol., April 15, 2003; 170(8): 4281 - 4289. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. T. Evans, L.-M. Chen, J. Gillis, K.-C. Lin, B. Harty, G. P. Mazzara, R. O. Donis, K. G. Mansfield, J. D. Lifson, R. C. Desrosiers, et al. Mucosal Priming of Simian Immunodeficiency Virus-Specific Cytotoxic T-Lymphocyte Responses in Rhesus Macaques by the Salmonella Type III Secretion Antigen Delivery System J. Virol., February 15, 2003; 77(4): 2400 - 2409. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. R. Mothe, J. Weinfurter, C. Wang, W. Rehrauer, N. Wilson, T. M. Allen, D. B. Allison, and D. I. Watkins Expression of the Major Histocompatibility Complex Class I Molecule Mamu-A*01 Is Associated with Control of Simian Immunodeficiency Virus SIVmac239 Replication J. Virol., February 15, 2003; 77(4): 2736 - 2740. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Tryniszewska, J. Nacsa, M. G. Lewis, P. Silvera, D. Montefiori, D. Venzon, Z. Hel, R. W. Parks, M. Moniuszko, J. Tartaglia, et al. Vaccination of Macaques with Long-Standing SIVmac251 Infection Lowers the Viral Set Point After Cessation of Antiretroviral Therapy J. Immunol., November 1, 2002; 169(9): 5347 - 5357. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. U. Vogel, H. Horton, D. H. Fuller, D. K. Carter, K. Vielhuber, D. H. O'Connor, T. Shipley, J. Fuller, G. Sutter, V. Erfle, et al. Differences Between T Cell Epitopes Recognized After Immunization and After Infection J. Immunol., October 15, 2002; 169(8): 4511 - 4521. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Baig, D. B. Levy, P. F. McKay, J. E. Schmitz, S. Santra, R. A. Subbramanian, M. J. Kuroda, M. A. Lifton, D. A. Gorgone, L. S. Wyatt, et al. Elicitation of Simian Immunodeficiency Virus-Specific Cytotoxic T Lymphocytes in Mucosal Compartments of Rhesus Monkeys by Systemic Vaccination J. Virol., October 11, 2002; 76(22): 11484 - 11490. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. U. Vogel, T. C. Friedrich, D. H. O'Connor, W. Rehrauer, E. J. Dodds, H. Hickman, W. Hildebrand, J. Sidney, A. Sette, A. Hughes, et al. Escape in One of Two Cytotoxic T-Lymphocyte Epitopes Bound by a High-Frequency Major Histocompatibility Complex Class I Molecule, Mamu-A*02: a Paradigm for Virus Evolution and Persistence? J. Virol., October 11, 2002; 76(22): 11623 - 11636. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. M. Allen, P. Jing, B. Calore, H. Horton, D. H. O'Connor, T. Hanke, M. Piekarczyk, R. Ruddersdorf, B. R. Mothe, C. Emerson, et al. Effects of Cytotoxic T Lymphocytes (CTL) Directed against a Single Simian Immunodeficiency Virus (SIV) Gag CTL Epitope on the Course of SIVmac239 Infection J. Virol., September 11, 2002; 76(20): 10507 - 10511. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. R. Mothe, J. Sidney, J. L. Dzuris, M. E. Liebl, S. Fuenger, D. I. Watkins, and A. Sette Characterization of the Peptide-Binding Specificity of Mamu-B*17 and Identification of Mamu-B*17-Restricted Epitopes Derived from Simian Immunodeficiency Virus Proteins J. Immunol., July 1, 2002; 169(1): 210 - 219. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Horton, T. U. Vogel, D. K. Carter, K. Vielhuber, D. H. Fuller, T. Shipley, J. T. Fuller, K. J. Kunstman, G. Sutter, D. C. Montefiori, et al. Immunization of Rhesus Macaques with a DNA Prime/Modified Vaccinia Virus Ankara Boost Regimen Induces Broad Simian Immunodeficiency Virus (SIV)-Specific T-Cell Responses and Reduces Initial Viral Replication but Does Not Prevent Disease Progression following Challenge with Pathogenic SIVmac239 J. Virol., June 14, 2002; 76(14): 7187 - 7202. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Santra, D. H. Barouch, M. J. Kuroda, J. E. Schmitz, G. R. Krivulka, K. Beaudry, C. I. Lord, M. A. Lifton, L. S. Wyatt, B. Moss, et al. Prior Vaccination Increases the Epitopic Breadth of the Cytotoxic T-Lymphocyte Response That Evolves in Rhesus Monkeys following a Simian-Human Immunodeficiency Virus Infection J. Virol., May 13, 2002; 76(12): 6376 - 6381. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Santra, J. E. Schmitz, M. J. Kuroda, M. A. Lifton, C. E. Nickerson, C. I. Lord, R. Pal, G. Franchini, and N. L. Letvin Recombinant Canarypox Vaccine-Elicited CTL Specific for Dominant and Subdominant Simian Immunodeficiency Virus Epitopes in Rhesus Monkeys J. Immunol., February 15, 2002; 168(4): 1847 - 1853. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. G.-T. Wee, S. Patel, A. J. McMichael, and T. Hanke A DNA/MVA-based candidate human immunodeficiency virus vaccine for Kenya induces multi-specific T cell responses in rhesus macaques J. Gen. Virol., January 1, 2002; 83(1): 75 - 80. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. U. Vogel, B. E. Beer, J. zur Megede, H.-G. Ihlenfeldt, G. Jung, S. Holzammer, D. I. Watkins, J. D. Altman, R. Kurth, and S. Norley Induction of anti-simian immunodeficiency virus cellular and humoral immune responses in rhesus macaques by peptide immunogens: correlation of CTL activity and reduction of cell-associated but not plasma virus load following challenge J. Gen. Virol., January 1, 2002; 83(1): 81 - 91. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z. Hel, W.-P. Tsai, A. Thornton, J. Nacsa, L. Giuliani, E. Tryniszewska, M. Poudyal, D. Venzon, X. Wang, J. Altman, et al. Potentiation of Simian Immunodeficiency Virus (SIV)-Specific CD4+ and CD8+ T Cell Responses by a DNA-SIV and NYVAC-SIV Prime/Boost Regimen J. Immunol., December 15, 2001; 167(12): 7180 - 7191. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. L. Dzuris, J. Sidney, H. Horton, R. Correa, D. Carter, R. W. Chesnut, D. I. Watkins, and A. Sette Molecular Determinants of Peptide Binding to Two Common Rhesus Macaque Major Histocompatibility Complex Class II Molecules J. Virol., November 15, 2001; 75(22): 10958 - 10968. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Robinson, W. A. Charini, M. H. Newberg, M. J. Kuroda, C. I. Lord, and N. L. Letvin A Commonly Recognized Simian Immunodeficiency Virus Nef Epitope Presented to Cytotoxic T Lymphocytes of Indian-Origin Rhesus Monkeys by the Prevalent Major Histocompatibility Complex Class I Allele Mamu-A*02 J. Virol., November 1, 2001; 75(21): 10179 - 10186. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. A. Charini, M. J. Kuroda, J. E. Schmitz, K. R. Beaudry, W. Lin, M. A. Lifton, G. R. Krivulka, A. Necker, and N. L. Letvin Clonally Diverse CTL Response to a Dominant Viral Epitope Recognizes Potential Epitope Variants J. Immunol., November 1, 2001; 167(9): 4996 - 5003. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Sharpe, N. Polyanskaya, M. Dennis, G. Sutter, T. Hanke, V. Erfle, V. Hirsch, and M. Cranage Induction of simian immunodeficiency virus (SIV)-specific CTL in rhesus macaques by vaccination with modified vaccinia virus Ankara expressing SIV transgenes: influence of pre-existing anti-vector immunity J. Gen. Virol., September 1, 2001; 82(9): 2215 - 2223. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. H. Barouch, S. Santra, M. J. Kuroda, J. E. Schmitz, R. Plishka, A. Buckler-White, A. E. Gaitan, R. Zin, J.-H. Nam, L. S. Wyatt, et al. Reduction of Simian-Human Immunodeficiency Virus 89.6P Viremia in Rhesus Monkeys by Recombinant Modified Vaccinia Virus Ankara Vaccination J. Virol., June 1, 2001; 75(11): 5151 - 5158. [Abstract] [Full Text]
|
|
|
|
|
|
M. Rosenzweig, M. Connole, R. Glickman, S.-P. S. Yue, B. Noren, M. DeMaria, and R. P. Johnson Induction of cytotoxic T lymphocyte and antibody responses to enhanced green fluorescent protein following transplantation of transduced CD34+ hematopoietic cells Blood, April 1, 2001; 97(7): 1951 - 1959. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Xiong, M. A. Luscher, J. D. Altman, M. Hulsey, H. L. Robinson, M. Ostrowski, B. H. Barber, and K. S. MacDonald Simian Immunodeficiency Virus (SIV) Infection of a Rhesus Macaque Induces SIV-Specific CD8+ T Cells with a Defect in Effector Function That Is Reversible on Extended Interleukin-2 Incubation J. Virol., March 15, 2001; 75(6): 3028 - 3033. [Abstract] [Full Text]
|
|
|
|
|
|
T. U. Vogel, T. M. Allen, J. D. Altman, and D. I. Watkins Functional Impairment of Simian Immunodeficiency Virus-Specific CD8+ T Cells during the Chronic Phase of Infection J. Virol., March 1, 2001; 75(5): 2458 - 2461. [Abstract] [Full Text]
|
|
|
|
|
|
D. H. Barouch, A. Craiu, S. Santra, M. A. Egan, J. E. Schmitz, M. J. Kuroda, T.-M. Fu, J.-H. Nam, L. S. Wyatt, M. A. Lifton, et al. Elicitation of High-Frequency Cytotoxic T-Lymphocyte Responses against both Dominant and Subdominant Simian-Human Immunodeficiency Virus Epitopes by DNA Vaccination of Rhesus Monkeys J. Virol., March 1, 2001; 75(5): 2462 - 2467. [Abstract] [Full Text]
|
|
|
|
|
|
J. A. Urvater, H. Hickman, J. L. Dzuris, K. Prilliman, T. M. Allen, K. J. Schwartz, D. Lorentzen, C. Shufflebotham, E. J. Collins, D. L. Neiffer, et al. Gorillas with Spondyloarthropathies Express an MHC Class I Molecule with Only Limited Sequence Similarity to HLA-B27 that Binds Peptides with Arginine at P2 J. Immunol., March 1, 2001; 166(5): 3334 - 3344. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. M. Allen, B. R. Mothé, J. Sidney, P. Jing, J. L. Dzuris, M. E. Liebl, T. U. Vogel, D. H. O'Connor, X. Wang, M. C. Wussow, et al. CD8+ Lymphocytes from Simian Immunodeficiency Virus-Infected Rhesus Macaques Recognize 14 Different Epitopes Bound by the Major Histocompatibility Complex Class I Molecule Mamu-A*01: Implications for Vaccine Design and Testing J. Virol., January 15, 2001; 75(2): 738 - 749. [Abstract] [Full Text]
|
|
|
|
|
|
T.-M. Fu, D. C. Freed, W. L. Trigona, L. Guan, L. Zhu, R. Long, N. V. Persaud, K. Manson, S. Dubey, and J. W. Shiver Evaluation of Cytotoxic T-Lymphocyte Responses in Human and Nonhuman Primate Subjects Infected with Human Immunodeficiency Virus Type 1 or Simian/Human Immunodeficiency Virus J. Virol., January 1, 2001; 75(1): 73 - 82. [Abstract] [Full Text]
|
|
|
|
|
|
J. Sidney, J. L. Dzuris, M. J. Newman, R. P. Johnson, K. Amitinder, C. M. Walker, E. Appella, B. Mothe, D. I. Watkins, and A. Sette Definition of the Mamu A*01 Peptide Binding Specificity: Application to the Identification of Wild-Type and Optimized Ligands from Simian Immunodeficiency Virus Regulatory Proteins J. Immunol., December 1, 2000; 165(11): 6387 - 6399. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. H. Barouch, S. Santra, J. E. Schmitz, M. J. Kuroda, T.-M. Fu, W. Wagner, M. Bilska, A. Craiu, X. X. Zheng, G. R. Krivulka, et al. Control of Viremia and Prevention of Clinical AIDS in Rhesus Monkeys by Cytokine-Augmented DNA Vaccination Science, October 20, 2000; 290(5491): 486 - 492. [Abstract] [Full Text]
|
|
|
|
|
|
M. A. Cromwell, R. S. Veazey, J. D. Altman, K. G. Mansfield, R. Glickman, T. M. Allen, D. I. Watkins, A. A. Lackner, and R. P. Johnson Induction of Mucosal Homing Virus-Specific CD8+ T Lymphocytes by Attenuated Simian Immunodeficiency Virus J. Virol., September 15, 2000; 74(18): 8762 - 8766. [Abstract] [Full Text]
|
|
|
|
|
|
D. T. Evans, P. Jing, T. M. Allen, D. H. O'Connor, H. Horton, J. E. Venham, M. Piekarczyk, J. Dzuris, M. Dykhuzen, J. Mitchen, et al. Definition of Five New Simian Immunodeficiency Virus Cytotoxic T-Lymphocyte Epitopes and Their Restricting Major Histocompatibility Complex Class I Molecules: Evidence for an Influence on Disease Progression J. Virol., August 15, 2000; 74(16): 7400 - 7410. [Abstract] [Full Text]
|
|
|
|
|
|
M. A. Egan, W. A. Charini, M. J. Kuroda, J. E. Schmitz, P. Racz, K. Tenner-Racz, K. Manson, M. Wyand, M. A. Lifton, C. E. Nickerson, et al. Simian Immunodeficiency Virus (SIV) gag DNA-Vaccinated Rhesus Monkeys Develop Secondary Cytotoxic T-Lymphocyte Responses and Control Viral Replication after Pathogenic SIV Infection J. Virol., August 15, 2000; 74(16): 7485 - 7495. [Abstract] [Full Text]
|
|
|
|
|
|
M. J. Kuroda, J. E. Schmitz, A. Seth, R. S. Veazey, C. E. Nickerson, M. A. Lifton, P. J. Dailey, M. A. Forman, P. Racz, K. Tenner-Racz, et al. Simian immunodeficiency virus-specific cytotoxic T lymphocytes and cell-associated viral RNA levels in distinct lymphoid compartments of SIVmac-infected rhesus monkeys Blood, August 15, 2000; 96(4): 1474 - 1479. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. J. R. Goulder, C. Brander, K. Annamalai, N. Mngqundaniso, U. Govender, Y. Tang, S. He, K. E. Hartman, C. A. O'Callaghan, G. S. Ogg, et al. Differential Narrow Focusing of Immunodominant Human Immunodeficiency Virus Gag-Specific Cytotoxic T-Lymphocyte Responses in Infected African and Caucasoid Adults and Children J. Virol., June 15, 2000; 74(12): 5679 - 5690. [Abstract] [Full Text]
|
|
|
|
|
|
Z. W. Chen, A. Craiu, L. Shen, M. J. Kuroda, U. C. Iroku, D. I. Watkins, G. Voss, and N. L. Letvin Simian Immunodeficiency Virus Evades a Dominant Epitope-Specific Cytotoxic T Lymphocyte Response Through a Mutation Resulting in the Accelerated Dissociation of Viral Peptide and MHC Class I J. Immunol., June 15, 2000; 164(12): 6474 - 6479. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. J. R. Goulder, Y. Tang, S. I. Pelton, and B. D. Walker HLA-B57-Restricted Cytotoxic T-Lymphocyte Activity in a Single Infected Subject toward Two Optimal Epitopes, One of Which Is Entirely Contained within the Other J. Virol., June 1, 2000; 74(11): 5291 - 5299. [Abstract] [Full Text]
|
|
|
|
|
|
T. M. Allen, T. U. Vogel, D. H. Fuller, B. R. Mothe, S. Steffen, J. E. Boyson, T. Shipley, J. Fuller, T. Hanke, A. Sette, et al. Induction of AIDS Virus-Specific CTL Activity in Fresh, Unstimulated Peripheral Blood Lymphocytes from Rhesus Macaques Vaccinated with a DNA Prime/Modified Vaccinia Virus Ankara Boost Regimen J. Immunol., May 1, 2000; 164(9): 4968 - 4978. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. L. Dzuris, J. Sidney, E. Appella, R. W. Chesnut, D. I. Watkins, and A. Sette Conserved MHC Class I Peptide Binding Motif Between Humans and Rhesus Macaques J. Immunol., January 1, 2000; 164(1): 283 - 291. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Furchner, A. L. Erickson, T. Allen, D. I. Watkins, A. Sette, P. R. Johnson, and C. M. Walker The Simian Immunodeficiency Virus Envelope Glycoprotein Contains Two Epitopes Presented by the Mamu-A*01 Class I Molecule J. Virol., October 1, 1999; 73(10): 8035 - 8039. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. W. Blake, A. Moghaddam, P. Rao, A. Kaur, R. Glickman, Y.-g. Cho, A. Marchini, T. Haigh, R. P. Johnson, A. B. Rickinson, et al. Inhibition of Antigen Presentation by the Glycine/Alanine Repeat Domain Is Not Conserved in Simian Homologues of Epstein-Barr Virus Nuclear Antigen 1 J. Virol., September 1, 1999; 73(9): 7381 - 7389. [Abstract] [Full Text]
|
|
|
|
|
|
T. Hanke, R. V. Samuel, T. J. Blanchard, V. C. Neumann, T. M. Allen, J. E. Boyson, S. A. Sharpe, N. Cook, G. L. Smith, D. I. Watkins, et al. Effective Induction of Simian Immunodeficiency Virus-Specific Cytotoxic T Lymphocytes in Macaques by Using a Multiepitope Gene and DNA Prime-Modified Vaccinia Virus Ankara Boost Vaccination Regimen J. Virol., September 1, 1999; 73(9): 7524 - 7532. [Abstract] [Full Text]
|
|
|
|
|
|
M. A. Egan, M. J. Kuroda, G. Voss, J. E. Schmitz, W. A. Charini, C. I. Lord, M. A. Forman, and N. L. Letvin Use of Major Histocompatibility Complex Class I/Peptide/beta 2M Tetramers To Quantitate CD8+ Cytotoxic T Lymphocytes Specific for Dominant and Nondominant Viral Epitopes in Simian-Human Immunodeficiency Virus-Infected Rhesus Monkeys J. Virol., July 1, 1999; 73(7): 5466 - 5472. [Abstract] [Full Text]
|
|
|
|
|
|
H. L. Jordan, M. J. Kuroda, J. E. Schmitz, T. Steenbeke, M. A. Forman, and N. L. Letvin Detection of Simian Immunodeficiency Virus Gag-Specific CD8+ T Lymphocytes in Semen of Chronically Infected Rhesus Monkeys by Cell Staining with a Tetrameric Major Histocompatibility Complex Class I-Peptide Complex J. Virol., May 1, 1999; 73(5): 4508 - 4512. [Abstract] [Full Text]
|
|
|
|
|
|
M. J. Kuroda, J. E. Schmitz, W. A. Charini, C. E. Nickerson, M. A. Lifton, C. I. Lord, M. A. Forman, and N. L. Letvin Emergence of CTL Coincides with Clearance of Virus During Primary Simian Immunodeficiency Virus Infection in Rhesus Monkeys J. Immunol., May 1, 1999; 162(9): 5127 - 5133. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. J. Kuroda, J. E. Schmitz, W. A. Charini, C. E. Nickerson, C. I. Lord, M. A. Forman, and N. L. Letvin Comparative Analysis of Cytotoxic T Lymphocytes in Lymph Nodes and Peripheral Blood of Simian Immunodeficiency Virus-Infected Rhesus Monkeys J. Virol., February 1, 1999; 73(2): 1573 - 1579. [Abstract] [Full Text]
|
|
|
|
|
|
A. Seth, I. Ourmanov, M. J. Kuroda, J. E. Schmitz, M. W. Carroll, L. S. Wyatt, B. Moss, M. A. Forman, V. M. Hirsch, and N. L. Letvin Recombinant modified vaccinia virus Ankara-simian immunodeficiency virus gag pol elicits cytotoxic T lymphocytes in rhesus monkeys detected by a major histocompatibility complex class I/peptide tetramer PNAS, August 18, 1998; 95(17): 10112 - 10116. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. H. Barouch, A. Craiu, M. J. Kuroda, J. E. Schmitz, X. X. Zheng, S. Santra, J. D. Frost, G. R. Krivulka, M. A. Lifton, C. L. Crabbs, et al. Augmentation of immune responses to HIV-1 and simian immunodeficiency virus DNA vaccines by IL-2/Ig plasmid administration in rhesus monkeys PNAS, April 11, 2000; 97(8): 4192 - 4197. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
