Heightened self-reactivity associated with selective survival, but not expansion, of naïve virus-specific CD8+ T cells in aged mice

Kylie M. Quinn, Sophie G. Zaloumis, Tania Cukalac, Wan-Ting Kan, Xavier Y. X. Sng, Michiko Mirams, Katherine A. Watson, James M. McCaw, Peter C. Doherty, Paul G. Thomas, Andreas Handel, Nicole L. La Gruta

    Research output: Contribution to journalArticleResearchpeer-review

    16 Citations (Scopus)

    Abstract

    In advanced age, decreased CD8+ cytotoxic T-lymphocyte (CTL) responses to novel pathogens and cancer is paralleled by a decline in the number and function of naïve CTL precursors (CTLp). Although the age-related fall in CD8+ T-cell numbers is well established, neither the underlying mechanisms nor the extent of variation for different epitope specificities have been defined. Furthermore, naïve CD8+ T cells expressing high levels of CD44 accumulate with age, but it is unknown whether this accumulation reflects their preferential survival or an age-dependent driver of CD8+ T-cell proliferation. Here, we track the number and phenotype of four influenza A virus (IAV)-specific CTLp populations in naïve C57BL/6 (B6) mice during aging, and compare T-cell receptor (TCR) clonal diversity for the CD44hi and CD44lo subsets of one such population. We show differential onset of decline for several IAV-specific CD8+ T-cell populations with advanced age that parallel age-associated changes in the B6 immunodominance hierarchy, suggestive of distinct impacts of aging on different epitope-specific populations. Despite finding no evidence of clonal expansions in an aged, epitope-specific TCR repertoire, nonrandom alterations in TCR usage were observed, along with elevated CD5 and CD8 coreceptor expression. Collectively, these data demonstrate that naïve CD8+ T cells expressing markers of heightened self-recognition are selectively retained, but not clonally expanded, during aging.

    Original languageEnglish
    Pages (from-to)1333-1338
    Number of pages6
    JournalProceedings of the National Academy of Sciences of the United States of America
    Volume113
    Issue number5
    DOIs
    Publication statusPublished - 2 Feb 2016

    Keywords

    • Aging
    • CD44 virtual memory
    • CD5
    • Influenza A virus
    • Naive CD8 T cells

    Cite this