| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
*
Laboratory of Viral Oncology, Aichi Cancer Center Research Institute, Nagoya, Japan;
Department of Pediatrics, Nagoya University School of Medicine, Nagoya, Japan; and
Department of Pediatrics, Nagoya Ekisaikai Hospital, Nagoya, Japan
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
in EBV-reactive T cells by FACS, we have
demonstrated that 34–54% of HLA-DR+/CD8+ and
34–60% of CD45RO+/CD8+ T cells in the PBMCs
of febrile patients suffering from IM are EBV-specific. The
EBV-specific CD8+ T cell counts in the PBMCs of four
febrile patients suffering from IM ranged between 2260 and 8200/µl,
decreasing to 5.1% and 7.9% of the counts in the first samples over
10 days in two donors. The decline of CD8+ T cell
subpopulations, namely HLA-DR+, CD45RO+, and
EBV-specific T cells, was in parallel with the drop in the EBV genome
load. These data indicate that the Ag-driven expansion of
CD8+ T cells and subsequent contraction with the Ag decline
in vivo in humans is effective for clearing virus-infected cells with
minimal disturbance of the homeostasis of the immune
system. |
Introduction |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
In the PBMCs of IM patients, there are large numbers of atypical
lymphocytes, the majority being activated CD8+ T
cells ex- pressing HLA-DR and CD45RO Ags (5, 6, 7).
Such T cell proliferation during viral infections in vivo could
theoretically result by several mechanisms: 1) Ag-driven expansion of
specific T cells, 2) stimulation of cell division by cross-reactive
Ags, or 3) cytokine-mediated bystander activation (8, 9, 10, 11).
Recent work using mice challenged with lymphocytic choriomeningitis
virus (LCMV) revealed that 50–70% of the activated
CD8+ T cells in the primary infection were
virus-specific (12). This unexpectedly high Ag-specific
CD8+ T cell frequency was disclosed by means of
sensitive assays, such as binding to tetrameric MHC class I
molecule-peptide complexes or measuring IFN- production at the
single-cell level, whereas a classical limiting dilution analysis (LDA)
to quantify virus-specific CTLs indicated that only a small fraction
(1–5% most) of the activated CD8+ T cells were
Ag-specific at the peak of the primary response (13, 14, 15).
The differential may result from in vitro outgrowth underestimating the
true magnitude of the Ag-induced primary response, because only cells
that are capable of dividing and surviving the 2-week in vitro culture
period will score as positive (12).
As a natural situation to study the development of the
CD8+ T cells immune response and their fate in
vivo in humans, EBV-specific T cells in the case of IM have been
analyzed (3, 15, 16, 17). Callan et al.(16)
demonstrated biased TCR Vß usage in most of the IM patients studied.
In selected individuals, 
25% of CD8+ T cells
expressed a single Vß chain, suggesting Ag-driven expansion
(16). The authors also demonstrated, using tetrameric
MHC-peptide complexes, that T cells specific for a single peptide
derived from an EBV lytic protein comprised 44% of the total
CD8+ T cells in the PBMCs of an
HLA-B8+ patient (17). Their data
strongly support the notion that a massive expansion of
CD8+ T cells in IM is Ag-driven. However due to
the HLA-restricted reagents used to detect Ag-specific T cells, there
is still debate regarding whether such expansion is restricted to some
HLA alleles or happens in unselected IM patients.
Recently we have developed an efficient method for the detection of
EBV-specific class I-restricted CD8+ T cells in
PBMCs irrespective of HLA typing (18). During IM,
CD8+ T cells are directed not only to EBV latent
proteins but also to lytic cycle proteins (3, 15, 17).
Here we applied autologous lymphoblastoid cell lines (LCLs), which are
B cell lines that have been transformed with a laboratory EBV strain,
as APCs, because a small portion of LCLs are known to express lytic
cycle proteins and effectively stimulate T cells specific for such
proteins (3, 19) in addition to latent proteins. PBMCs of
the patients are thereby incubated with autologous LCLs in the presence
of an intracellular transport blocker, brefeldin A (BFA), for 6 h,
and the accumulation of IFN- is detected by multiparameter FACS
analysis. The results demonstrate that 34–54% of
HLA-DR+/CD8+ and 34–60%
of CD45RO+/CD8+ T cells in
the PBMCs of unselected patients suffering with IM are EBV-specific.
The decline of the subpopulations of CD8+ cells,
namely HLA-DR+, CD45RO+,
and EBV-specific T cells, is in parallel with reduction of the EBV
genome load in PBMCs. Our data clearly point to Ag-driven expansion of
the activated CD8+ T cell population and its
subsequent rapid contraction by a mechanism termed activation-induced
cell death (AICD) (13) in the natural course of primary
EBV infections.
|
Materials and Methods |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
A diagnosis of IM was made on the basis of typical clinical manifestations and a positive IgM Ab titer for EBV capsid Ag (1). The study design and purpose, which had been approved by the Institutional Review Board, were fully explained to all donors. Peripheral blood was only sampled after informed consent was obtained.
Preparation of PBMCs and LCLs
PBMCs were separated by centrifuging heparinized blood over Ficoll/Hypaque (Pharmacia Biotech, Uppsala, Sweden). Aliquots of PBMCs were frozen at -80°C until use. LCLs were prepared by transforming PBMCs with B95-8 cell culture supernatant as described previously (20). LCLs were cultured in Iscove’s modified Dulbecco’s medium (Life Technologies, Grand Island, NY) supplemented with 2 mM L-glutamine, 50 U/ml penicillin, 50 µg/ml streptomycin, 5 x 10-5 M 2-ME, and 10% heat-inactivated FCS (HyClone, Logan, UT) (referred to as culture medium).
Detection of IFN--producing CD8+ T cells in response
to LCLs by FACS
For determination of the CD8+ Ag-specific
T lymphocyte frequency, an intracellular cytokine assessment using FACS
was performed as described previously with slight modifications
(18). Briefly, thawed PBMCs were incubated over night in
culture medium containing rIL-2 (100 U/ml). On the following day, cells
were resuspended at a concentration of 4 x
105/ml in the same medium. Autologous LCLs were
resuspended at a concentration of 1.2 x 106/ml,
and 0.5-ml aliquots along with PBMCs (0.5 ml) were mixed in 16 x 125
mm culture tubes and incubated in a humidified 5%
CO2 incubator at 37°C for 1 h. BFA (Sigma,
St. Louis, MO) was added at 10 µg/ml and the cells were cultured for
an additional 5 h. For blocking experiments, an anti-HLA class
I mAb (clone W6/32, Cedarlane, Ontario, Canada) or an isotype-matched
control mAb was added at a final concentration of 50 µg/ml. After the
incubation, the cells were fixed in 4% paraformaldehyde for 10 min at
room temperature. As a control, the same numbers of responder cells and
LCLs were incubated separately in the presence of BFA and fixed before
mixing. After washing with PBS, cells were permeabilized with IC Perm
(Biosource International, Camarillo, CA) and stained with
PE-cyanin-5.1-labeled anti-CD8 (Coulter, Miami, FL), PE-labeled
anti-HLA-DR or anti-CD45RO (Coulter), and FITC-labeled
anti-human IFN- (Becton Dickinson, San Jose, CA) mAbs. Stained
cells were analyzed by FACScan (Becton Dickinson) using Lysis II
software. Live-gating of the CD8high T cell
subset was performed, and 5000 events were acquired for each analysis.
Compensation condition and the cutoff values for FACS analysis were
determined using isotype-matched control mAbs purchased from the same
companies.
Real-time quantitative PCR
Real-time quantitative PCR assays with a fluorogenic probe were performed as described previously (21) using a set of primers (5'-CGGAAGCCCTCTGGACTTC, 5'-CCCTGTTTATCCGATGGAATG) and a fluorogenic probe (5'-TGTACACGCACGAGAAATGCGCC) synthesized by Perkin Elmer Applied Biosystems (Foster City, CA). These oligonucleotides were selected in the BALF5 gene encoding the viral DNA polymerase. Briefly, DNA (250 ng) extracted from PBMCs was added to a PCR mixture containing 10 mM Tris (pH 8.3), 50 mM KCl, 10 mM EDTA, 5 mM MgCl2, 100 µM dATP, dCTP, dGTP, dTTP, 0.2 µM of each primer, 0.1 µM fluorogenic probe, and 1.25 U of AmpliTaq Gold (Perkin Elmer Applied Biosystems). After activation for 10 min at 95°C, 45–50 cycles of 15 s at 95°C and 1 min at 62°C were conducted with a Model 7700 Sequence Detector (Perkin Elmer Applied Biosystems). A threshold cycle value for each sample was calculated by determining the point at which fluorescence exceeded 10 times the SD of the baseline. For a positive control, a plasmid (pGEM-BALF5) containing the BALF5 gene was used (21). The threshold cycle values for clinical samples were plotted on the standard curve, and copy numbers were calculated automatically by Sequence Detector v1.6 software (Perkin Elmer Applied Biosystems). Each sample was tested in duplicate, and the mean of the two values was shown as the copy number of the sample. Samples were defined as negative when the values exceeded 50 cycles.
|
Results |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
in EBV-specific
CD8+ T cells
We applied a strategy using tricolor analysis for the detection of
EBV-specific IFN--producing T cells. First, the
PE-cyanin-5.1-labeled anti-CD8 mAb was used to gate the population.
Second, the PE-labeled anti-CD45RO or anti-HLA-DR mAb was
employed to segregate the CD8+ population. Fig. 1
shows the results using PBMCs of a
donor. IFN- production was observed exclusively in the
CD45RO+ subpopulation. Sixty percent of
CD45RO+/CD8+ T cells
produced IFN- upon stimulation with autologous LCLs (Fig. 1B), indicating their EBV specificity. As an unstimulated
control, we used responder cells and LCLs that had been separately
incubated in the same medium with BFA and mixed and stained after
fixing (Fig. 1A). Only 0.47% of the unstimulated
CD45RO+/CD8+ T cells
produced IFN-. To confirm that the IFN- production was class
I-restricted, the same responder cells were stimulated with autologous
LCLs in the presence of anti-class I mAb (Fig. 1C), or
with isotype-matched mouse mAb (D) as a controls. The IFN--producing
population was drastically reduced (4.1%) with anti-class I mAb
but not with control mAb (57%). These results indicate that the
IFN- in the CD8+ T cells is produced
through authentic recognition of the Ags presented by class I molecules
but not stimulated by putative superantigens on LCLs (22)
or by IL-12, an IFN--inducing factor secreted by LCLs
(23).
|
-producing T cells reside in the
CD45RO+ fraction of CD8+ cells
It has been reported that there are large numbers of
CD45RO+/CD8+ T cells that
are prone to apoptosis in the PBMCs of IM patients (6, 7).
Blood samples were obtained from donors 1–4 in febrile periods. After
6 h of stimulation with autologous LCLs, the cells were stained
for CD8, CD45RO, and IFN-. CD8+ cells were
gated and analyzed by FACS. The percentages of the
CD45RO+ fraction were not significantly changed
before and after the LCL stimulation (data not shown). The vast
majority of the EBV-specific CD8+ T cells were
CD45RO+ (Fig. 2).
The percentages of EBV-specific CD8+ T cells per
CD45RO+ population of each donor in the febrile
period were 60%, 34%, 55%, and 57% (Fig. 2, A–C and
E). Second samples were obtained from donors 3 and 4 at 10
days after the first sample was obtained, and the percentages of
EBV-specific CD8+/CD45RO+ T
cells were found to be reduced to 34% and 41%, respectively (Fig. 2, D and F). The first sample from donor 5 was
obtained 2 wk after the symptoms of IM had resolved. At that time, the
percentage of EBV-specific
CD8+/CD45RO+ T cells was
28% (Fig. 2G). With the second sample, obtained 1 mo later,
the frequency was reduced to 20% (Fig. 2H).
|
-producing T cells in the HLA-DR+
fraction of CD8+ cells
The frequencies of EBV-specific T cells among the
HLA-DR+/CD8+ populations of
the same samples used in Fig. 2
were then examined. The percentages of
the HLA-DR+ fraction were not significantly
changed before and after the LCL stimulation (data not shown). The
values for donors in the febrile period were 53%, 34%, 53%, and 54%
(Fig. 3, A–C and
E). Those in the second samples obtained from donors 3 and 4
at 10 days after the first samples had been obtained were 26% and
45%, respectively (Fig. 3, D and F). The results
in Fig. 3 demonstrate that most EBV-specific CD8+
T cells in the febrile and acute convalescent periods of IM were
HLA-DR+, indicating their activation status (Fig. 3, A–G). In contrast, 6 wk after the symptoms had resolved,
the EBV-specific CD8+ T cells resided in the
HLA-DR- population, indicating their entry into
the resting or memory fraction (Fig. 3H).
|
The absolute numbers of lymphocytes, CD8+ T
cells, and their subpopulations of the samples are shown in Table I. In the PBMCs of four febrile patients,
the absolute cell counts of EBV-specific CD8+,
HLA-DR+/CD8+, and
CD45RO+/CD8+ T cells ranged
between 2,260 and 8,200/µl, 3,380 and 13,100/µl, and 3,240 and
14,500/µl, respectively. The cell counts of the three subpopulations
decreased to 5.1%, 5.9%, and 8.3% of those in the first samples by
10 days in donor 3. They also decreased to 7.9%, 6.2%, and 11.8% of
those in the first samples by 10 days in donor 4 (Table I). In donor 5,
the same values decreased to 18%, 6.3%, and 16.6% of those in the
first samples over 1 mo. Thus, the three subpopulations expanded and
contracted in parallel. Finally, the kinetics of EBV-specific
CD8+ T cells of the three paired samples are
shown in Fig. 4, along with quantitative
data for EBV genome load. The decline of EBV-specific
CD8+ T cells paralleled that of the EBV
genome load.
|
|
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
25% of the
total CD8+ pool and whose monoclonal or
oligoclonal population of TCR usage implies that they are Ag-driven
(16). The conflict of the data between LDA and TCR usage
is partially due to the fact that LDA appears to underestimate the true
frequency of effector cells, which are highly activated and thus
sensitive to AICD (12, 13). In addition to differences due
to AICD, it is also possible that the vast majority of EBV-specific
CD8+ T cells can secrete IFN-, but that only a
subset of these cells can differentiate into CTLs.
One additional complexity of studying the CD8+ T
cell response to EBV is that EBV has two types of replication cycles,
namely lytic infection, in which infectious virions are produced, and
latent infection, which is represented by the majority of LCLs. Some
proteins expressed in either cycle are well recognized by
CD8+ T cells, which expand in IM (3, 17). Because 5% of LCLs have been found to express lytic
cycle proteins (3, 19), CTL precursors specific to the
lytic proteins may be stimulated and may expand in limiting dilution
cultures. However, at the end of the culture, the wells containing such
effector cells should be scored negative because a CTL assay is
insensitive if <10% of the target cells (in this case, the same LCLs
used for stimulation) express the relevant Ags. In contrast, in assays
using cytokine production or the proliferation of T cells as a marker
of Ag recognition, LCLs have been shown to work effectively as APCs for
CD8+ T cells specific to EBV lytic cycle proteins
(3, 19). In the current study and in previous studies
(18), we applied autologous LCLs as APCs for polyclonal
CD8+ EBV-specific T cells with the aim of
introducing as many epitopes as possible at the same time. Thus in our
system, both T cells specific for latent proteins and those specific
for lytic proteins should have contributed to the production of
IFN-, their relative proportions being unknown. Besides, we could
not deny the possibility that our assay may underestimate the
frequencies of T cells specific for lytic proteins, which are expressed
by small populations of LCLs.
We demonstrated here that 34–54% (mean: 48.5) of
HLA-DR+/CD8+ and 34–60%
(mean: 51.5) of
CD45RO+/CD8+ T cells in the
PBMCs of febrile patients suffering from IM were EBV-specific using an
efficient method developed recently in our laboratory for the detection
of EBV-specific class I-restricted CD8+ T cells
in PBMCs irrespective of HLA typing (18). Callan et al.
have similarly demonstrated, using tetrameric MHC-peptide complexes,
that T cells specific for a single peptide derived from an EBV lytic
protein comprised 44% of the total CD8+ T cells
in the PBMCs of an HLA-B8+ patient
(17). Thus, the data strongly support the notion that the
massive expansion of the CD8+ T cells in IM is
Ag-driven, not only in cases with restricted HLA alleles but also in
unselected IM patients. The appearance of atypical lymphocytes in
peripheral blood, a central diagnostic criteria of IM, would be an
expected result of morphological changes in such Ag-specific T cells.
We have shown previously that EBV-specific T cell frequencies in the
CD8+ PBMCs of seronegative individuals contribute
no more than 0.03% of total CD8+ T cells as determined by
the same assay (K. Kuzushima, unpublished observations). As
demonstrated here, the EBV-specific T cell frequencies among the total
CD8+ PBMCs of IM patients at the febrile period
ranged from 29% to 54% (Table I). Taking into consideration the
finding that the number of absolute CD8+ T cells
in PBMCs during IM is four to eight times larger than that of control
subjects (5, 6, 25), a 3,000- to 14,000-fold expansion of
EBV-specific CD8+ T cells may occur during the
primary infection. This is comparable with the 2300-fold increase in
the LCMV nucleoprotein-specific CD8+ T cells of
mice with a primary infection during the first 8 days after virus
challenge (12).
Activated CD8+ T cells expressing
HLA-DR+ and CD45RO+ in
PBMCs during IM have been shown to rapidly undergo apoptosis upon
incubation in vitro in the absence of inhibitory cytokines such as IL-2
(6, 7). In LCMV-infected mice, it has been shown that
there is a precipitous drop in the number of Ag-specific
CD8+ T cells after viral clearance
(26). We have demonstrated a decline of EBV-specific
CD8+ T cells along with a drop in the EBV genome
load in PBMCs. Because EBV-specific CD8+ T cell
frequencies in the PBMCs of long-term EBV carriers are 
1% as
determined by our assay (18), >99% of the EBV-specific
CD8+ T cells generated during IM should disappear
before entering the memory state to maintain homeostasis
(13). Apoptosis due to Fas-Fas ligand interactions
(27) and TNF (28) have been implicated in
such an AICD-associated disappearance.
Our current data allow the dynamics of CD8+ Ag-specific T cells during virus challenge in IM to be outlined as a model of primary virus infection in vivo in humans. The rapid Ag-driven expansion of CD8+ T cells is followed by a subsequent decline due to AICD as an effective mechanism for clearing virus-infected cells with minimal disturbance of homeostasis of the immune system. Understanding the CD8+ T cell response from the primary EBV challenge toward recovery is essential for designing effective CTL therapies for various EBV-associated malignancies, such as immunoblastic B cell lymphomas seen in immunocompromised patients (29, 30), Hodgkin’s disease (31), nasopharyngeal carcinomas (2), and EBV-associated gastric carcinomas (32), in which some EBV Ags recognized by CTLs are expressed. In addition, our methodology to study the dynamics of quantitative viral load and the CD8+ Ag-specific T cell response should provide a useful approach to assess the pathogenesis of the diseases for which impaired cell-mediated immunity to EBV is postulated, such as EBV-associated hemophagocytic syndrome (33) and chronic active EBV infection (20, 34, 35).
|
Footnotes |
|---|
2 Address correspondence and reprint requests to Dr. Kiyotaka Kuzushima, Laboratory of Viral Oncology, Aichi Cancer Center Research Institute, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-0021 Japan. E-mail address:
3 Abbreviations used in this paper: IM, infectious mononucleosis; LCMV, lymphocytic choriomeningitis virus; LDA, limiting dilution analysis; LCL, lymphoblastoid cell line; BFA, brefeldin A; AICD, activation-induced cell death.
Received for publication July 8, 1999. Accepted for publication September 7, 1999.
|
References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
This article has been cited by other articles:
|
|
 |
|
  M. J. Callahan, Z. Nagymanyoki, T. Bonome, M. E. Johnson, B. Litkouhi, E. H. Sullivan, M. S. Hirsch, U. A. Matulonis, J. Liu, M. J. Birrer, et al. Increased HLA-DMB Expression in the Tumor Epithelium Is Associated with Increased CTL Infiltration and Improved Prognosis in Advanced-Stage Serous Ovarian Cancer Clin. Cancer Res., December 1, 2008; 14(23): 7667 - 7673. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Li, C. W. Cunha, C. J. Davies, K. L. Gailbreath, D. P. Knowles, J. L. Oaks, and N. S. Taus Ovine herpesvirus 2 replicates initially in the lung of experimentally infected sheep J. Gen. Virol., July 1, 2008; 89(7): 1699 - 1708. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Williams and D. H. Crawford Epstein-Barr virus: the impact of scientific advances on clinical practice Blood, February 1, 2006; 107(3): 862 - 869. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Nikiforow, K. Bottomly, G. Miller, and C. Munz Cytolytic CD4+-T-Cell Clones Reactive to EBNA1 Inhibit Epstein-Barr Virus-Induced B-Cell Proliferation J. Virol., November 15, 2003; 77(22): 12088 - 12104. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Sester, U. Sester, B. C. Gartner, M. Girndt, A. Meyerhans, and H. Kohler Dominance of Virus-Specific CD8 T Cells in Human Primary Cytomegalovirus Infection J. Am. Soc. Nephrol., October 1, 2002; 13(10): 2577 - 2584. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Uda, T. Mima, N. Yamaguchi, Y. Katada, M. Fukuda, N. Fujii, K. Nakamura, and O. Saiki Expansion of a CD28-Intermediate Subset among CD8 T Cells in Patients with Infectious Mononucleosis J. Virol., June 5, 2002; 76(13): 6602 - 6608. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. C. Jaimes, O. L. Rojas, A. M. Gonzalez, I. Cajiao, A. Charpilienne, P. Pothier, E. Kohli, H. B. Greenberg, M. A. Franco, and J. Angel Frequencies of Virus-Specific CD4+ and CD8+ T Lymphocytes Secreting Gamma Interferon after Acute Natural Rotavirus Infection in Children and Adults J. Virol., April 16, 2002; 76(10): 4741 - 4749. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Sester, U. Sester, B. Gartner, B. Kubuschok, M. Girndt, A. Meyerhans, and H. Kohler Sustained High Frequencies of Specific CD4 T Cells Restricted to a Single Persistent Virus J. Virol., March 19, 2002; 76(8): 3748 - 3755. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. L. Silins, M. A. Sherritt, J. M. Silleri, S. M. Cross, S. L. Elliott, M. Bharadwaj, T. T. T. Le, L. E. Morrison, R. Khanna, D. J. Moss, et al. Asymptomatic primary Epstein-Barr virus infection occurs in the absence of blood T-cell repertoire perturbations despite high levels of systemic viral load Blood, December 15, 2001; 98(13): 3739 - 3744. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Kimura, Y. Hoshino, H. Kanegane, I. Tsuge, T. Okamura, K. Kawa, and T. Morishima Clinical and virologic characteristics of chronic active Epstein-Barr virus infection Blood, July 15, 2001; 98(2): 280 - 286. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Ogawa, K. Tanaka, A. Ishii, Y. Nakamura, S. Kondo, K. Sugamura, S. Takano, M. Nakamura, and K. Nagata A Novel Serum Protein That Is Selectively Produced by Cytotoxic Lymphocytes J. Immunol., May 15, 2001; 166(10): 6404 - 6412. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Nikiforow, K. Bottomly, and G. Miller CD4+ T-Cell Effectors Inhibit Epstein-Barr Virus-Induced B-Cell Proliferation J. Virol., April 15, 2001; 75(8): 3740 - 3752. [Abstract] [Full Text]
|
|
|
|
|
|
Q. J. Wang, F. J. Jenkins, L. P. Jacobson, L. A. Kingsley, R. D. Day, Z.-W. Zhang, Y.-X. Meng, P. E. Pellet, K. G. Kousoulas, A. Baghian, et al. Primary human herpesvirus 8 infection generates a broadly specific CD8+ T-cell response to viral lytic cycle proteins Blood, April 15, 2001; 97(8): 2366 - 2373. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. D. Hislop, N. E. Annels, N. H. Gudgeon, A. M. Leese, and A. B. Rickinson Epitope-specific Evolution of Human CD8+ T Cell Responses from Primary to Persistent Phases of Epstein-Barr Virus Infection J. Exp. Med., April 1, 2002; 195(7): 893 - 905. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
). 1st; the first samples.
2nd; the second samples. The first samples from donors 3 and 4 were
obtained in the febrile period; the second samples were obtained 10
days after the first sampling (A and B).
The first sample from donor 5 was obtained 2 wk after the symptoms of
IM had resolved; the second sample was obtained 1 mo after the first
sampling (C).