| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Laboratory of Tumor Immunology and Biology, Division of Basic Science, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
|
Introduction |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
9–10 amino acids long)
associated with class I molecules of the MHC (1, 2). Much progress has
recently been made in the identification of tumor Ags that can be
recognized by human T cells. A number of tumor Ags recognized by CTLs
have been characterized, including members of the MAGE gene family (3),
BAGE (4), GAGE (5), MART-1/melan-A (6, 7), tyrosinase (8, 9, 10, 11), gp-100
(12, 13), ß-catenin (14), HER-2/neu (15, 16, 17),
p21ras (18, 19, 20, 21), p53 (22, 23), HPVE6 (24),
carcinoembryonic Ag
(CEA)2 (25), and
prostate-specific Ag (PSA) (26, 27). Prostate cancer is one of the most common cancers found in man and is associated with increased serum levels of PSA (28). The expression of PSA is cell type specific and is thought to be produced exclusively in males by the epithelial cells of the prostate (29). PSA is also a kallikrein-like serine protease, and human PSA has a high degree of homology with human pancreatic kallikrein (30). The majority of prostate cancers and epithelial cells lining the acini and ducts of the prostate gland express PSA (31). Immunoperoxidase staining indicates that PSA is found in the cytoplasmic portion of these cells (31). For this reason, PSA is a potential target for the induction of T cell-directed immunity against prostate cancer. One human PSA peptide, which consists of amino acids 146–154 of PSA molecules, is recognized by CTLs and has been described; however, CTLs generated in response to this peptide have not been shown to lyse prostate cancer cells (26). The identification of two HLA-A2-binding PSA peptides capable of eliciting cytotoxic T cell responses has recently been reported (27). These peptides were designated PSA-1 (amino acids 141–150) and PSA-3 (amino acids 154–163). The T cell lines were capable of lysing PSA-positive, HLA-A2-positive LNCaP human prostate carcinoma cells (27).
The identification of peptides that conform to HLA-class I A2
motifs was pursued in the previous study (27) because the HLA-A2 allele
is the most common class I allele, represented in 50% of North
American Caucasians and 34% of African-Americans (32). Other common
HLA class I alleles of North American populations are HLA-A3, -A11,
-A24, and -B53. Indeed, these class I molecules, along with A2, are
present in 90% of the human population.
Herein we report identification of a PSA oligoepitope peptide (designated PSA-OP) that contains motifs for HLA class I-A2, -A3, -A11, and B53 alleles. The ability of this oligoepitope peptide to induce cytotoxic T cell activity to multiple epitopes in vitro and in vivo in HLA-A2.1/Kb transgenic mice was investigated. Our results suggest that PSA-OP may be a potential candidate for use in peptide-based vaccines for human prostate carcinoma.
|
Materials and Methods |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
The human prostate carcinoma cell line LNCaP (HLA-A2-positive and PSA-positive) and K562 chronic myelogenous leukemia cells were purchased from American Type Culture Collection (Manassas, VA). The cultures were free of mycoplasma and were maintained in complete medium (RPMI 1640; Life Technologies, Grand Island, NY) supplemented with 10% FBS, 2 mM glutamine, 100 U/ml penicillin, and 100 µg/ml streptomycin (Life Technologies). The 174CEM-T2 cell line (T2; transport deletion mutant) (33) was provided by Dr. Peter Cresswell (Yale University School of Medicine, New Haven, CT). The C1R cell line is a human plasma leukemia cell line that does not express endogenous HLA-A or -B Ags (34). The C1R-A2 cells express a transfected genomic clone of HLA-A2.1 (35) and were obtained from Dr. William E. Biddison (National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD). T2 cells and C1R-A2 cells were mycoplasma free and maintained in Iscove’s modified Dulbecco’s complete medium and RPMI 1640 complete medium (Life Technologies), respectively.
Peptide synthesis
The PSA-OP 30-mer oligopeptide was synthesized on a
peptide synthesizer (model 432A; Applied Biosystems, Foster City, CA).
It operates on a 25-µmol scale and employed f-moc chemistry and
feedback monitoring to control the coupling of each successive amino
acid to the growing chain. The completed peptide was cleaved off the
synthesis resin with trifluoroacetic acid and thioanisole/ethanedithiol
as scavengers. Acid salts were extracted with tert-butyl methyl ether,
and the peptide was lyophilized from water to give 64 mg of powder.
The powder was dissolved in aqueous solution, sterile filtered, and
frozen at -70°C at a concentration of 2 mg/ml. The purity of the
peptides was >90% as analyzed by HPLC. CAP-1, PSA-1, PSA-3, and PSA-9
peptides were generated as described previously (25, 27, 36).
Generation of T cell lines
The protocol described by Tsang et al. (25) was used for the generation of T cell lines. PBMCs were obtained from the heparinized blood of apparently normal HLA-A2 and HLA-A3 donors by the use of lymphocyte separation medium gradients (Organon Teknika, Durham, NC) as described previously (37). Washed PBMCs were resuspended in complete medium (RPMI 1640, Life Technologies) supplemented with 10% pooled human AB serum (Valley Biomedical, Winchester, VA), 2 mM glutamine, 100 U/ml penicillin, and 100 µg/ml of streptomycin (Life Technologies). Cells (2 x 105) in complete medium in a volume of 100 µl were put into each well of a 96-well flat-bottom assay plate (Corning Costar, Cambridge, MA). PSA-OP peptide was added to cultures at a final concentration of 50 µg/ml. Cultures were incubated for 5 days at 37°C in a humidified atmosphere containing 5% CO2. After removal of the peptide-containing medium, the cultures were then supplemented with human rIL-2 (provided by the National Cancer Institute Surgery Branch) (10 U/ml) for 11 days, with IL-2-containing medium being replenished every 3 days. The 5-day incubation with peptide and 11 days with IL-2 constituted one in vitro stimulation (IVS) cycle. Primary cultures were restimulated with PSA-OP peptide (50 µg/ml) on day 16 to begin the next IVS. Irradiated (4000 rad) autologous PBMCs (5 x 105) were added in a volume of 50 µl in complete medium as APCs. The T cell lines derived from two HLA-A2 donors were designated T1-PSA-OP and T2-PSA-OP. The T cell lines derived from two HLA-A3 donors were designated T3-PSA-OP and T4-PSA-OP.
Cytotoxicity assays
Target cells were labeled with 50 µCi of 111In-labeled oxyquinoline (Medi-Physics, Arlington, IL) for 15 min at room temperature. Target cells (0.5 x 104) in 100 µl of complete medium were added to each of 96 wells in U-bottom assay plates (Corning Costar). The labeled target cells were incubated with peptides at various concentrations for 60 min at 37°C in 5% CO2 before adding effector cells. Effector cells were suspended in 100 µl of complete medium supplemented with 10% pooled human AB serum and added to target cells. The plates were then incubated at 37°C in 5% CO2 for 4 or 16 h. Supernatant was harvested for gamma counting with the use of harvester frames (Skatron, Sterling, VA). Determinations were conducted in triplicate, and SDs were calculated. All experiments were conducted three times. Specific lysis was calculated with the following formula: % specific lysis = {[observed release (cpm) - spontaneous release (cpm)]/[total release (cpm) - spontaneous release (cpm)]} x 100.
Spontaneous release was determined from wells to which 100 µl of complete medium was added. Total releasable radioactivity was obtained after treatment of targets with 2.5% Triton X-100.
Exopeptidases and inhibitors
Captopril (Sigma Chemical, St. Louis, MO) and potato carboxypeptidase inhibitor (Calbiochem, La Jolla, CA) were dissolved in PBS and used at a concentration of 10-6 M and 10-5 M, respectively. E64 and Plummer’s inhibitor (Calbiochem) were dissolved in acidified deionized water and 33% DMSO (final DMSO concentration, 1.7%), respectively. Both E64 and Plummer’s inhibitor were used at a concentration of 10-6 M.
Flow cytometry
Single-color flow cytometric analysis. The method for single-color flow cytometric analysis has been described previously (38). Briefly, cells were washed three times with cold Ca2+- and Mg2+-free Dulbecco’s phosphate-buffered saline (DPBS) and then stained for 1 h with mAb against CD3, CD4, CD8, CD56, CD19, HLA-DR (Becton Dickinson, San Jose, CA), and HLA class I (W6/32) (Serotec, Sussex, U.K.). MOPC-21 (Cappel/Organon Teknika, West Chester, PA) was used as isotype control. The cells were then washed three times and incubated with 1:100 dilution of FITC-labeled goat anti-mouse IgG (Kirkegaard & Perry, Gaithersburg, MD). The cells were again washed three times with DPBS and resuspended in DPBS at a concentration of 1 x 106 cells/ml. The cells were immediately analyzed using a Becton Dickinson FACScan equipped with a blue laser with an excitation of 15 nW at 488 nm. Data were gathered from 10,000 live cells, stored, and used to generate results.
Dual-color flow cytometric analysis. The procedure for dual-color flow cytometric analysis was similar to that for single-color analysis, with the following exceptions. The Abs used were anti-CD4 FITC/anti-CD8 phycoerythrin conjugate and anti-IgG1 FITC/anti-IgG2a phycoerythrin (isotype controls). All of the Abs mentioned above were purchased from Becton Dickinson. Staining was done simultaneously for 1 h, after which cells were washed three times, resuspended as described above, and immediately analyzed using a Becton Dickinson FACSort equipped with a blue laser with an excitation of 15 nW at 488 nm and equipped with the CellQuest program.
HLA typing
HLA phenotyping was performed on PBMCs by the Blood Bank of the National Institutes of Health with a standard Ab-dependent microcytotoxicity assay and a defined panel of anti-HLA antisera or with a DNA assay. The following HLA phenotypes were found for donors in this study: donor 1: HLA-A2, 24; B50, 62; Cw - -; DR ß1*0701,0901; DQ ß1*0201,0303; DR ß4*0101; donor 2: HLA-A2,-; B7, 60; Cw3,-; DR ß1*0405, 0801; DQ ß1*0302,04; Drß4*0101; donor 3: HLA-A3, 34; B14, 58; Cw6,-; DRß1*0102, 1102; DQß1*0501, 0301; DRß3*0202; and donor 4: HLA-A3, 11; B7, 51; Cw7,-; DRß1*04,09; DQß1*03,03; DRß4*01.
Peptide binding to HLA-A2
Binding of the PSA-OP peptide to HLA-A2 molecules was evaluated by up-regulation of these molecules’ expression on the surface of T2 cells as demonstrated by flow cytometry. The method described by Nijman et al. (39) was used for T2 cell peptide binding assays. Briefly, 1 x 106 cells in serum-free Iscove’s modified Dulbecco’s complete medium were incubated with peptides at a concentration of 50 µg/ml in 24-well culture plates at 37°C in 5% CO2. Flow cytometry for peptide binding was performed using T2 cells and single-color analysis. After cells were washed three times in DPBS as described above, they were incubated for 1 h with HLA-A2-specific mAb (One Lambda, Canoga Park, CA), using 10 µl of a 1x working dilution per 106 cells. UPC-10 (Cappel/Organon Teknika) was used as isotype control. The cells were then washed three times and incubated with a 1:100 dilution of FITC-labeled anti-mouse IgG (Becton Dickinson). A similar method was used for the analysis of PSA-OP, PSA-3, and PSA-9 binding to HLA-A3 molecules using T2A3 cells and anti-HLA-A3-specific mAb (One Lambda). Analysis was conducted with the FACScan, as described above. Cells were maintained on ice during all cell preparation and staining, unless otherwise stated.
Transgenic mice
HLA-A2.1/Kb transgenic mice were kindly provided by
Dr. L. Sherman (Scripps Laboratories, San Diego, CA). Transgenic mice
express the product of the HLA-A2.1Kb chimeric gene in
which the 
3 domain of the heavy chain is replaced by the mouse
H-2.1/Kb domain, but the HLA-A2.1 1 and 2 domains are
unaltered (40, 41).
In vivo immunization and murine T cell cultures
Groups of HLA-A2.1/Kb transgenic mice (three mice per group) were immunized s.c. in the base of the tail with 250 µg of PSA-OP emulsified in Detox adjuvant. Detox adjuvant was formulated as a stable emulsion with either Sequalene (C30H62) or Sequalene (C30H50) plus cell wall skeleton and monophosphoryl lipid A in a 10:1 ratio, with an emulsifier (provided by RIBI ImmunoChem Research, Hamilton, MT). Mice injected with adjuvant were used as controls. A total of three injections of PSA-OP were given 2 wk apart. Mice were killed 7 days after the last injection, and spleen cells were restimulated in vitro with 50 µg/ml of PSA-OP with irradiated syngeneic spleen cells for 6 days. The cytotoxicity of these bulk cultures was tested. Peptide-pulsed Jurkat A2 (JA2Kb) cells (Jurkat 0201Kb cells stable transfectant of the human T cell leukemia line, Jurkat, which express the product of the HLA-A0201Kb chimeric gene (42)) were used as target cells.
Vaccinia virus infection of C1R cells
A recombinant vaccinia virus expressing PSA (designated rV-PSA) was generated as described previously (43). C1R-A2 and C1R-A3 target cells at a concentration of 1 x 107 cells/ml in complete RPMI 1640 medium supplemented with 0.1% BSA were incubated with an equal volume of either wild-type vaccinia virus or rV-PSA (multiplicity of infection = 10) in the same medium at 37°C for 1.5 h. The cells were then seeded at 105 cells/ml in complete medium with 10% FBS into 24-well culture plates at 37°C in 5% CO2 for 24 h before being used as targets in cytotoxic assay experiments. PSA production from the rV-PSA vaccinia virus was evaluated using a RIA kit purchased from Tandem (Hybritech, San Diego, CA).
Statistical analysis
Statistical analysis of differences between means was done using a two-tailed paired t test (StatView statistical software; Abacus Concepts, Berkeley, CA).
|
Results |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
PSA-OP is a 30-mer oligopeptide encompassing the shorter
HLA-A2-binding PSA-1, PSA-2, and PSA-3 peptides (27) (Table I
) and a potential HLA-A3-binding PSA-9
(amino acid 162–170) (38) peptide. PSA-OP did not bind to T2 cells
in the T2 binding assay (Table I), whereas peptides PSA-1, -2, and
-3 demonstrated binding. While peptide PSA-9 and an A3-binding CEA
peptide (CEA-27) both bound to HLA-A3 as expected, the PSA-OP did not.
PSA-3 was used as an additional negative control and also showed
background binding. Binding of peptides PSA-9 and PSA-OP to HLA-A3
molecules was evaluated by flow cytometry with T2A3 cells.
|
). These studies were
conducted at E:T ratios of 25:1. No lysis was observed when C1R-A2
cells were pulsed with the PSA-2 peptide or the control CEA CAP-1
peptide (25).
|
). No lysis was detected with these
two cell lines when C1R-A3 cells were pulsed with the control PSA-3
peptide, which was previously shown to bind HLA-A2, but not HLA-A3 (see
Table I
).
|
, A and B,
increased lysis of the C1R-A2 cells, pulsed with either PSA-OP or PSA-3
peptide, was seen with E:T ratios for both the T1-PSA-OP and the
T2-PSA-OP T cell lines. The control peptide CAP-1 elicited no lysis at
any of the E:T ratios. Similar results were seen when C1R-A3
cells were pulsed with either PSA-OP or the PSA-9 peptide. Increased
lysis was observed with increasing E:T ratios employing both the
T3-PSA-OP or the T4-PSA-OP T cell lines (Fig. 2, A and B). In
these studies, the PSA-3 peptide was used as a control peptide.
|
|
A, lysis by the
T1-PSA-OP line was greater at the E:T ratio of 25:1, increasing to 80%
lysis with increasing peptide. Similar results were seen employing the
T2-PSA-OP cell line (Fig. 3B). Titration experiments
employing the C1R-A3 cell line were also conducted. As seen
employing both the T3-PSA-OP T cell line (Fig. 4A) and the T4-PSA-OP T cell
line (Fig. 4B), lysis of C1R-A3 cells reached a plateau at
25 µg/ml oligopeptide at E:T ratios of 25:1.
|
|
). No
blocking was observed using the control UPC-10 mAb. Inhibition of
T3-PSA-OP and T4-PSA-OP activity was observed by employing the
anti-HLA-A3 antisera (Table IV); no inhibition was observed using
the control UPC-10 antisera.
|
Cytotoxicity of PSA-specific T cell lines against rV-PSA-infected target cells
Studies were conducted with HLA-matched target cells ±
rV-PSA infection to further demonstrate specificity of T cell lysis for
PSA. The ability of T1-PSA-OP, T2-PSA-OP, T3-PSA-OP, and T4-PSA-OP
cells to lyse target cells endogenously expressing PSA was
investigated. These T cell lines were tested for cytotoxicity against
C1R-A2 cells and C1R-A3 cells infected with either wild-type vaccinia
virus (Wyeth strain) or rV-PSA. C1R-A2 cells infected with
rV-PSA, and not with wild-type vaccinia, were lysed by T cell lines
T1-PSA-OP and T2-PSA-OP (Table V).
Similarly, C1R-A3 cells infected with rV-PSA were lysed by T cell lines
T3-PSA-OP and T4-PSA-OP (Table V). No lysis was observed of wild-type
vaccinia-infected cells by any of the T cell lines. These results
demonstrate that CTL lines generated with the PSA-OP oligopeptide
indeed recognize and mediate lysis via the product of the human PSA
gene.
|
Studies were conducted to determine whether T1-PSA-OP and
T2-PSA-OP cells could lyse the PSA-positive and HLA-A2-positive
prostate carcinoma cell line LNCaP. As shown in Table VI, LNCaP cells were lysed by the
T1-PSA-OP and T2-PSA-OP CTLs. The cytotoxic activity of these cell
lines against LNCaP cells was shown to be HLA-A2 restricted, as
indicated by the inhibition of lysis with the addition of
anti-HLA-A2, but not with the control Ab UPC-10 (Table VI).
|
). This result confirmed that
LNCaP cells endogenously process PSA to present PSA peptides
in the context of HLA-A2 for T cell-mediated lysis. Moreover, these
results demonstrate that PSA-1 and PSA-3 peptides can compete with
endogenously processed PSA peptides for T cell lysis by the
PSA-OP-induced CTLs.
|
To assess the in vivo immunogenicity of PSA-OP,
HLA-A2.1/Kb transgenic mice were injected with PSA-OP.
Cytotoxic T cells derived from PSA-OP-immunized mice specifically lysed
PSA-OP-pulsed Jurkat A2/Kb target cells (Table VIII), whereas no cytotoxic T cell
responses were observed when the control CAP-1 peptide-pulsed Jurkat
A2/Kb cells were used as targets. No lysis was
detected in bulk T cell cultures from control mice (Table VIII).
|
Studies were undertaken to investigate the mechanism by which a
30-mer oligopeptide can mediate MHC-restricted lysis by CTLs. We
investigated the possibility that PSA-OP was cleaved into shorter
peptides that can interact with HLA-A2 molecules. Four protease
inhibitors—potato carboxypeptidase, captopril, E-64, and Plummer’s
inhibitor—were used in CTL-blocking experiments. T1-PSA-OP cells were
used as effectors. Inhibition of T1-PSA-OP cytotoxic activity against
PSA-OP-pulsed target cells was detected when E64, captopril, or potato
carboxypeptidase were added (Table IX).
Addition of these inhibitors did not inhibit the cytotoxic activity of
T1-PSA-OP CTL against PSA-3 peptide-pulsed C1R-A2 cells. This result
suggested that PSA-OP can be processed by human serum and that the
processing can be inhibited by E64, potato carboxypeptidase, and
captopril, resulting in inhibited CTL activity.
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
The potential advantages of using an oligoepitope peptide rather than a combination of single-epitope peptides to induce immune responses are: 1) oligoepitope peptides are useful in generating cellular responses in a broad segment of the human population with different HLA-class I molecules; 2) the number of precursors to different single epitope peptides vary in different individuals, as indicated by our data obtained from the PSA-1 and PSA-3 peptide studies (31); thus, utilization of PSA-OP containing three HLA-A2 epitopes may activate the maximum number of PSA-specific precursors in different individuals; and (c) oligoepitope peptide may be constructed to contain both CD4+ and CD8+ T cell epitopes in an overlapping or nested configuration and, as a consequence, to form a more superior immunogen in comparison with a mixture of different peptides. For example, a single mutant 13-mer ras peptide has been shown to contain both a CD4+ and a nested CD8+ T cell epitope (46). Additional peptides recognized by CD4+ cells with MHC class II molecules and by CD8+ cells with MHC class I molecules have been described in the models of HIV (47), influenza (48, 49), and the p53 gene (50).
The use of an oligopeptide as an immunogen may thus be an appropriate compromise between the use of a 9-mer CTL peptide epitope and the entire protein. In the case of PSA, for example, there are regions of this gene product that share strong homology with normal tissue kallikrein genes. The region of the PSA-OP peptide was selected for its lack of any substantial homology for these normal sequences. Furthermore, from more practical considerations, the synthesis of a peptide is much more cost effective than the production of a recombinant protein.
The PSA-OP oligopeptide did not bind HLA-A2 and HLA-A3 molecules,
as indicated by the lack of up-regulation of HLA-A2 or HLA-A3
expression on T2A2 or T2A3 cells, respectively (Tables I and II). CTLs
recognize protein Ags as small peptides (9–10 amino acids long)
associated with class I molecules. There are a number of reports
regarding extracellular peptidases in the generation of optimal size
class I-binding peptides from larger protein fragments (51, 52, 53, 54). It has
been demonstrated that T cell stimulation by peptide p18, an HIV
gp160-derived peptide presented by murine H-2D MHC molecules, required
extracellular processing mediated by peptidases in FCS (54). This
peptide processing could be blocked by adding the
angiotensin-1-converting enzyme (ACE) inhibitor, captopril. Our data
suggest that proteolytic enzymes in FCS most likely degrade the 30-mer
PSA-OP to smaller active forms, resulting in the induction of immune
responses. To evaluate this hypothesis, four carboxypeptidase
inhibitors were used in the cytotoxic activity experiments. These were
E-64 (55), which blocks cathepsin B (peptidyldipeptidase B); Plummer’s
inhibitor (56), which blocks carboxypeptidase N (serum carboxypeptidase
B); captopril (57), which blocks an ACE or peptidyldipeptidase A; and
potato carboxypeptidase inhibitor (58), which blocks tissue
carboxypeptidases A and B. Results reported here (Table IX) indicate a
decrease in CTL activity in the presence of E-64, captopril, or potato
carboxypeptidase inhibitor, suggesting that the PSA-OP must be cleaved
into shorter peptides that, in turn, can interact with HLA-A2 molecules
and induce CTL lysis of target cells. It is also conceivable that other
extracellular proteases may be involved in the fragmentation of PSA-OP
into epitopes similar to PSA-1, PSA-3, and PSA-9. The data presented
here do not exclude the possible involvement of intracellular
processing of the PSA-OP peptide. The mechanism for processing PSA-OP,
extracellular and/or intracellular, will require further investigation.
Information obtained concerning the immunogenicity of PSA from
preclinical studies of mice and rhesus monkeys have limited
extrapolation to potential human immune T cell responses, since murine
and monkey MHC-binding motifs are different from the human motifs. The
MHC class I-binding affinity and stability of peptide-MHC complexes at
the cell surface contribute to the immunogenicity of CTL epitopes. In
view of this, HLA-A2.1/Kb transgenic mice provide a
potential model to evaluate the immunogenicity of HLA-A2-binding
peptides. HLA-A2.1/Kb transgenic mice express a chimeric
class I molecule composed of the 1 and 2 domains of HLA-A2.1 and
the 3 transmembrane and cytoplasmic domains of H-2Kb
(40, 41). Replacement of the 3 domain of the heavy chain allows
interaction of the murine CD8 molecule on CD8+ T cells with
the syngeneic 3 domain of the hybrid MHC class I molecule. The
HLA-A2.1/Kb transgenic mouse model has been used by many
investigators to examine the immunogenicity of HLA-A2 binding peptides
and the ability of human HLA-A2 molecules to present peptides to murine
T cells (33, 34). Results reported by other investigators using
influenza matrix peptides, HPV16 E6 and E7 peptides, and p53 peptides
in HLA-A2.1/Kb transgenic mice suggest that transgenic mice
are important models for the study of immunodominant peptides
recognized by human T cells (34, 59, 60). The immunogenicity of PSA-OP
in HLA-A2.1/Kb transgenic mice was investigated, and these
results (Table VIII) illustrate that PSA-OP can also induce CTL
responses in vivo.
Clinical trials employing PSA as a target are currently in progress in prostate carcinoma patients. PSA recombinant protein, encapsulated into liposomes, has resulted in the induction of PSA-specific lymphoproliferative responses and anti-PSA Ab responses (61). Phase I studies employing rV-PSA as an immunogen in prostate cancer patients are also in progress. In both studies, no unexpected toxicity has been observed thus far. The use of the PSA-OP oligopeptide as an immunogen, either in adjuvant or via pulsed dendritic cells, offers another approach to the induction of PSA-specific immunity. Moreover, the PSA-OP can be used potentially in the generation of PSA-specific CTL for adoptive transfer protocols or in the further experimental analysis of PSA-specific T cell responses.
|
|
Acknowledgments |
|---|
|
Footnotes |
|---|
2 Abbreviations used in this paper: CEA, carcinoembryonic Ag; PSA, prostate-specific Ag; PSA-OP, PSA oligoepitope peptide; IVS, in vitro stimulation; DPBS, Dulbecco’s phosphate-buffered saline; rv-PSA, recombinant vaccinia virus expressing PSA; ACE, angiotensin-1-converting enzyme.
Received for publication February 17, 1998. Accepted for publication May 13, 1998.
|
References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
. Cancer Res. 50:6248.This article has been cited by other articles:
|
|
 |
|
  C. Domschke, F. Schuetz, Y. Ge, T. Seibel, C. Falk, B. Brors, I. Vlodavsky, N. Sommerfeldt, H.-P. Sinn, M.-C. Kuhnle, et al. Intratumoral Cytokines and Tumor Cell Biology Determine Spontaneous Breast Cancer-Specific Immune Responses and Their Correlation to Prognosis Cancer Res., November 1, 2009; 69(21): 8420 - 8428. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Sommerfeldt, F. Schutz, C. Sohn, J. Forster, V. Schirrmacher, and P. Beckhove The Shaping of a Polyvalent and Highly Individual T-Cell Repertoire in the Bone Marrow of Breast Cancer Patients Cancer Res., August 15, 2006; 66(16): 8258 - 8265. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. M. Arlen, J. L. Gulley, C. Parker, L. Skarupa, M. Pazdur, D. Panicali, P. Beetham, K. Y. Tsang, D. W. Grosenbach, J. Feldman, et al. A Randomized Phase II Study of Concurrent Docetaxel Plus Vaccine Versus Vaccine Alone in Metastatic Androgen-Independent Prostate Cancer Clin. Cancer Res., February 15, 2006; 12(4): 1260 - 1269. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. P.F. Gade, W. Hassen, E. Santos, G. Gunset, A. Saudemont, M. C. Gong, R. Brentjens, X.-S. Zhong, M. Stephan, J. Stefanski, et al. Targeted Elimination of Prostate Cancer by Genetically Directed Human T Lymphocytes Cancer Res., October 1, 2005; 65(19): 9080 - 9088. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Matsueda, H. Takedatsu, A. Yao, M. Tanaka, M. Noguchi, K. Itoh, and M. Harada Identification of Peptide Vaccine Candidates for Prostate Cancer Patients with HLA-A3 Supertype Alleles Clin. Cancer Res., October 1, 2005; 11(19): 6933 - 6943. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. L. Gulley, P. M. Arlen, A. Bastian, S. Morin, J. Marte, P. Beetham, K.-Y. Tsang, J. Yokokawa, J. W. Hodge, C. Menard, et al. Combining a Recombinant Cancer Vaccine with Standard Definitive Radiotherapy in Patients with Localized Prostate Cancer Clin. Cancer Res., May 1, 2005; 11(9): 3353 - 3362. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. L. Kaufman, W. Wang, J. Manola, R. S. DiPaola, Y.-J. Ko, C. Sweeney, T. L. Whiteside, J. Schlom, G. Wilding, and L. M. Weiner Phase II Randomized Study of Vaccine Treatment of Advanced Prostate Cancer (E7897): A Trial of the Eastern Cooperative Oncology Group J. Clin. Oncol., June 1, 2004; 22(11): 2122 - 2132. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Oh, M. Terabe, C. D. Pendleton, A. Bhattacharyya, T. K. Bera, M. Epel, Y. Reiter, J. Phillips, W. M. Linehan, C. Kasten-Sportes, et al. Human CTLs to Wild-Type and Enhanced Epitopes of a Novel Prostate and Breast Tumor-Associated Protein, TARP, Lyse Human Breast Cancer Cells Cancer Res., April 1, 2004; 64(7): 2610 - 2618. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Takedatsu, S. Shichijo, K. Katagiri, H. Sawamizu, M. Sata, and K. Itoh Identification of Peptide Vaccine Candidates Sharing among HLA-A3+, -A11+, -A31+, and -A33+ Cancer Patients Clin. Cancer Res., February 1, 2004; 10(3): 1112 - 1120. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Gnjatic, D. Atanackovic, M. Matsuo, E. Jager, S. Y. Lee, D. Valmori, Y.-T. Chen, G. Ritter, A. Knuth, and L. J. Old Cross-Presentation of HLA Class I Epitopes from Exogenous NY-ESO-1 Polypeptides by Nonprofessional APCs J. Immunol., February 1, 2003; 170(3): 1191 - 1196. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. A. Herness and R. K. Naz A Novel Human Prostate-specific Gene-1 (HPG-1): Molecular Cloning, Sequencing, and Its Potential Involvement in Prostate Carcinogenesis Cancer Res., January 15, 2003; 63(2): 329 - 336. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Lu and E. Celis Recognition of Prostate Tumor Cells by Cytotoxic T Lymphocytes Specific for Prostate-specific Membrane Antigen Cancer Res., October 15, 2002; 62(20): 5807 - 5812. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Alexander, C. Oseroff, C. Dahlberg, M. Qin, G. Ishioka, M. Beebe, J. Fikes, M. Newman, R. W. Chesnut, P. A. Morton, et al. A Decaepitope Polypeptide Primes for Multiple CD8+ IFN-{gamma} and Th Lymphocyte Responses: Evaluation of Multiepitope Polypeptides as a Mode for Vaccine Delivery J. Immunol., June 15, 2002; 168(12): 6189 - 6198. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Terasawa, K.-Y. Tsang, J. Gulley, P. Arlen, and J. Schlom Identification and Characterization of a Human Agonist Cytotoxic T-Lymphocyte Epitope of Human Prostate-specific Antigen Clin. Cancer Res., January 1, 2002; 8(1): 41 - 53. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Miyagi, N. Imai, T. Sasatomi, A. Yamada, T. Mine, K. Katagiri, M. Nakagawa, A. Muto, S. Okouchi, H. Isomoto, et al. Induction of Cellular Immune Responses to Tumor Cells and Peptides in Colorectal Cancer Patients by Vaccination with SART3 Peptides Clin. Cancer Res., December 1, 2001; 7(12): 3950 - 3962. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Yamada, K. Kawano, M. Koga, T. Matsumoto, and K. Itoh Multidrug Resistance-associated Protein 3 Is a Tumor Rejection Antigen Recognized by HLA-A2402-restricted Cytotoxic T Lymphocytes Cancer Res., September 1, 2001; 61(17): 6459 - 6466. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. G. McNeel, L. D. Nguyen, and M. L. Disis Identification of T Helper Epitopes from Prostatic Acid Phosphatase Cancer Res., July 1, 2001; 61(13): 5161 - 5167. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Tsavaler, M. H. Shapero, S. Morkowski, and R. Laus Trp-p8, a Novel Prostate-specific Gene, Is Up-Regulated in Prostate Cancer and Other Malignancies and Shares High Homology with Transient Receptor Potential Calcium Channel Proteins Cancer Res., May 1, 2001; 61(9): 3760 - 3769. [Abstract] [Full Text]
|
|
|
|
|
|
M. Nouri-Shirazi, J. Banchereau, D. Bell, S. Burkeholder, E. T. Kraus, J. Davoust, and K. A. Palucka Dendritic Cells Capture Killed Tumor Cells and Present Their Antigens to Elicit Tumor-Specific Immune Responses J. Immunol., October 1, 2000; 165(7): 3797 - 3803. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Nishizaka, S. Gomi, K. Harada, K. Oizumi, K. Itoh, and S. Shichijo A New Tumor-Rejection Antigen Recognized by Cytotoxic T Lymphocytes Infiltrating into a Lung Adenocarcinoma Cancer Res., September 1, 2000; 60(17): 4830 - 4837. [Abstract] [Full Text]
|
|
|
|
|
|
K. Kawano, S. Gomi, K. Tanaka, N. Tsuda, T. Kamura, K. Itoh, and A. Yamada Identification of a New Endoplasmic Reticulum-resident Protein Recognized by HLA-A24-restricted Tumor-infiltrating Lymphocytes of Lung Cancer Cancer Res., July 1, 2000; 60(13): 3550 - 3558. [Abstract] [Full Text]
|
|
|
|
|
|
A. Heiser, P. Dahm, D. R. Yancey, M. A. Maurice, D. Boczkowski, S. K. Nair, E. Gilboa, and J. Vieweg Human Dendritic Cells Transfected with RNA Encoding Prostate-Specific Antigen Stimulate Prostate-Specific CTL Responses In Vitro J. Immunol., May 15, 2000; 164(10): 5508 - 5514. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. P. Eder, P. W. Kantoff, K. Roper, G. Xu, G. J. Bubley, J. Boyden, L. Gritz, G. Mazzara, W. K. Oh, P. Arlen, et al. A Phase I Trial of a Recombinant Vaccinia Virus Expressing Prostate-specific Antigen in Advanced Prostate Cancer Clin. Cancer Res., May 1, 2000; 6(5): 1632 - 1638. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Nakao, S. Shichijo, T. Imaizumi, Y. Inoue, K. Matsunaga, A. Yamada, M. Kikuchi, N. Tsuda, K. Ohta, S. Takamori, et al. Identification of a Gene Coding for a New Squamous Cell Carcinoma Antigen Recognized by the CTL J. Immunol., March 1, 2000; 164(5): 2565 - 2574. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Gomi, M. Nakao, F. Niiya, Y. Imamura, K. Kawano, S. Nishizaka, A. Hayashi, Y. Sobao, K. Oizumi, and K. Itoh A Cyclophilin B Gene Encodes Antigenic Epitopes Recognized by HLA-A24-Restricted and Tumor-Specific CTLs J. Immunol., November 1, 1999; 163(9): 4994 - 5004. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. W. Simons, B. Mikhak, J.-F. Chang, A. M. DeMarzo, M. A. Carducci, M. Lim, C. E. Weber, A. A. Baccala, M. A. Goemann, S. M. Clift, et al. Induction of Immunity to Prostate Cancer Antigens: Results of a Clinical Trial of Vaccination with Irradiated Autologous Prostate Tumor Cells Engineered to Secrete Granulocyte-Macrophage Colony-stimulating Factor Using ex Vivo Gene Transfer Cancer Res., October 1, 1999; 59(20): 5160 - 5168. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
