CD8 T cells recruited early in mouse polyomavirus infection undergo exhaustion

J Immunol. 2012 May 1;188(9):4340-8. doi: 10.4049/jimmunol.1103727. Epub 2012 Mar 23.

Abstract

Repetitive Ag encounter, coupled with dynamic changes in Ag density and inflammation, imparts phenotypic and functional heterogeneity to memory virus-specific CD8 T cells in persistently infected hosts. For herpesvirus infections, which cycle between latency and reactivation, recent studies demonstrate that virus-specific T cell memory is predominantly derived from naive precursors recruited during acute infection. Whether functional memory T cells to viruses that persist in a nonlatent, low-level infectious state (smoldering infection) originate from acute infection-recruited naive T cells is not known. Using mouse polyomavirus (MPyV) infection, we previously showed that virus-specific CD8 T cells in persistently infected mice are stably maintained and functionally competent; however, a sizeable fraction of these memory T cells are short-lived. Further, we found that naive anti-MPyV CD8 T cells are primed de novo during persistent infection and contribute to maintenance of the virus-specific CD8 T cell population and its phenotypic heterogeneity. Using a new MPyV-specific TCR-transgenic system, we now demonstrate that virus-specific CD8 T cells recruited during persistent infection possess multicytokine effector function, have strong replication potential, express a phenotype profile indicative of authentic memory capability, and are stably maintained. In contrast, CD8 T cells recruited early in MPyV infection express phenotypic and functional attributes of clonal exhaustion, including attrition from the memory pool. These findings indicate that naive virus-specific CD8 T cells recruited during persistent infection contribute to preservation of functional memory against a smoldering viral infection.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • CD8-Positive T-Lymphocytes / immunology*
  • Immunologic Memory*
  • Mice
  • Mice, Knockout
  • Polyomavirus / immunology*
  • Polyomavirus Infections / genetics
  • Polyomavirus Infections / immunology*
  • Tumor Virus Infections / genetics
  • Tumor Virus Infections / immunology*