Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2002 Apr;76(8):3748-55.
doi: 10.1128/jvi.76.8.3748-3755.2002.

Sustained high frequencies of specific CD4 T cells restricted to a single persistent virus

Affiliations

Sustained high frequencies of specific CD4 T cells restricted to a single persistent virus

Martina Sester et al. J Virol. 2002 Apr.

Abstract

Replication of cytomegalovirus (CMV) is largely controlled by the cellular arm of the immune response. In this study the CMV-specific CD4 T-cell response was characterized in a cohort of apparently healthy individuals. In 11% of all individuals, extremely high frequencies, between 10 and 40%, were found. High-level frequencies of CMV-specific CD4 T cells persisted over several months and were not the result of an acute infection. Specific T cells were oligoclonal and were phenotypically and functionally characterized as mature effector cells, with both cytokine-secreting and proliferative potential. These high-level frequencies do not seem to compromise the immune response towards heterologous infections, and no signs of immunopathology were observed. Whereas a large temporary expansion of virus-specific T cells is well known to occur during acute infection, we now show that extremely high frequencies of virus-specific T cells may continuously exist in chronic CMV infection without overtly compromising the remaining protective immunity.

PubMed Disclaimer

Figures

FIG. 1.
FIG. 1.
Heterogeneous frequencies of CMV-specific CD4 T cells in healthy seropositive individuals (n = 50) (black circles) and long-term renal transplant recipients (n = 111) (open circles). Frequencies of CMV-specific CD4 T cells were analyzed using flow cytometry and may range from 0.1 to up to 43.8% (median, 1.87%). Neither median T-cell frequencies nor the frequency distribution differed between control individuals (median, 1.57%) and long-term transplant patients (median, 1.90%; P = 0.11). Renal transplant recipients tested negative for CMV DNA. No CMV-specific T cells were detectable in CMV-seronegative individuals (n = 77).
FIG. 2.
FIG. 2.
Detection of CMV-specific CD4 T cells. (A) Whole blood of a CMV-positive individual (#0320) was stimulated with control antigen, CMV antigen, or SEB, and specifically induced cytokine induction in CD4 and CD8 T cells was analyzed using flow cytometry. Numbers indicate percentages of specifically stimulated CD4 T cells. (B) Determination of CMV-specific T cells using the ELISPOT assay. IFN-γ secretion from 2 × 105 PBMC/well stimulated with control antigen, CMV antigen, or SEB was analyzed. The lower panel shows IFN-γ secretion from CD8-depleted PBMC. The mean numbers of spot-forming units per well after stimulation with control antigen, CMV antigen, and SEB were 23, ≫500, and >>500 (upper panel) and 19, ≫500, and 404 (lower panel), respectively. Given the percentage of 52% CD4 T cells among CD8-depleted PBMC, 404 spots correspond to an SEB-reactive CD4 T-cell frequency of 0.4%. Thus, the ELISPOT assay leads to an approximately sevenfold underestimation of frequencies compared to the respective frequencies obtained by flow cytometry (A) 2.85%). (C) PBMC were stimulated with control antigen (o), CMV antigen (•), and SEB (▪), and proliferative responses were assayed after 1, 2, 3, 4, or 5 days. The left diagram corresponds to the individual analyzed in panels A and B, and the middle and right panels represent proliferative responses in individuals with CMV-specific CD4 T-cell frequencies of 2.9 and 0%, respectively.
FIG. 3.
FIG. 3.
Lack of antigen-nonspecific CD4 T-cell activation. PBMC from pairs of three CMV-positive and three CMV-negative blood donors in all combinations were mixed and stimulated for 6 h using CMV antigen and control antigen. To distinguish cells of the respective donor within the mixture, PBMC of one donor were prestained using FITC-conjugated anti-CD45 antibody (prestained cells are denoted with an asterisk). After stimulation, IFN-γ production was flow-cytometrically analyzed in T cells from each donor in the mixture. (A) PBMC from a CMV-negative (n) and a CMV positive (p) donor were mixed (*p/p, *n/n, *p/n; 106 PBMC from each donor) and stimulated. (B) PBMC from three CMV-positive (prestained) and three CMV-negative donors were mixed in all possible combinations (n = 9; *CMV+/CMV−). Six different combinations of PBMC from CMV-negative (*CMV−/CMV−) and CMV positive donors (*CMV+/CMV+) were stimulated as controls.
FIG. 4.
FIG. 4.
Extremely high frequencies of CMV-reactive T cells are stable over time. Respective T cells in eight individuals were followed during at least 1.2 to up to 2.3 years using flow cytometry. CMV-DNA was not detectable in any of the patients (hybrid capture assay; data not shown).
FIG. 5.
FIG. 5.
CMV-specific CD4 T cells are oligoclonal. CMV-specific T cells were found among T cells expressing different T-cell receptors. (A) Shown are the respective specific T cells among cells expressing TCR-Vβ5.2, -Vβ8.0, -Vβ13.1, -Vβ16, -Vβ20, and -Vβ21.3 in a representative example (individual #0320). A particularly high percentage of CMV-specific T cells express TCR-Vβ13.1 or -Vβ16, whereas no specific T cell expresses TCR-Vβ8.0. The two numbers in each diagram indicate the percentages of TCR-Vβ-positive cells among all CD4 T cells and among CMV-specific CD4 T cells, respectively. (B) TCR-Vβ distribution among CMV-specific CD4 T cells in different individuals. + and / indicate the presence or absence, respectively, of IFN-γ-positive CD4 T cells within the respective T-cell population bearing a particular TCR-Vβ subunit.
FIG. 6.
FIG. 6.
Characterization of CMV-specific CD4 T cells. CMV-specific CD4 T cells are mainly positive for CD45RO and are largely negative for CD27, CD62L, and CCR7. In contrast, a considerable percentage of SEB-responsive T cells are CD27 positive (16.8%). Numbers indicate percentages of T cells positive (CD45R) or negative (CD27, CD62L, and CCR7) for the respective cell surface molecule among IFN-γ-positive CD4 T cells. The percentage of Th1 cells was determined after polyclonal stimulation with PMA-ionomycin (lower right diagram).

Similar articles

Cited by

References

    1. Alcami, A., and U. H. Koszinowski. 2000. Viral mechanisms of immune evasion. Immunol. Today 21:447-455. - PMC - PubMed
    1. Alexander Miller, M. A., G. R. Leggatt, and J. A. Berzofsky. 1996. Selective expansion of high- or low-avidity cytotoxic T lymphocytes and efficacy for adoptive immunotherapy. Proc. Natl. Acad. Sci. USA 93:4102-4107. - PMC - PubMed
    1. Appay, V., D. F. Nixon, S. M. Donahoe, G. M. Gillespie, T. Dong, A. King, G. S. Ogg, H. M. Spiegel, C. Conlon, C. A. Spina, D. V. Havlir, D. D. Richman, A. Waters, P. Easterbrook, A. J. McMichael, and S. L. Rowland-Jones. 2000. HIV-specific CD8+ T cells produce antiviral cytokines but are impaired in cytolytic function. J. Exp. Med. 192:63-75. - PMC - PubMed
    1. Butz, E. A., and M. J. Bevan. 1998. Massive expansion of antigen-specific CD8+ T cells during an acute virus infection. Immunity 8:167-175. - PMC - PubMed
    1. Callan, M. F., N. Steven, P. Krausa, J. D. Wilson, P. A. Moss, G. M. Gillespie, J. I. Bell, A. B. Rickinson, and A. J. McMichael. 1996. Large clonal expansions of CD8+ T cells in acute infectious mononucleosis. Nat. Med. 2:906-911. - PubMed

Publication types

Substances