Predominance of weakly cytotoxic, T-bet Low Eomes Neg CD8 + T-cells in human gastrointestinal mucosa: Implications for HIV infection

B. E. Kiniry, A. Ganesh, J. W. Critchfield, P. W. Hunt, F. M. Hecht, M. Somsouk, S. G. Deeks, Barbara Shacklett

Research output: Contribution to journalArticle

12 Scopus citations

Abstract

The gastrointestinal mucosa is an important site of HIV acquisition, viral replication, and pathogenesis. Immune cells in mucosal tissues frequently differ in phenotype and function from their non-mucosal counterparts. Although perforin-mediated cytotoxicity as measured in blood is a recognized correlate of HIV immune control, its role in gastrointestinal tissues is unknown. We sought to elucidate the cytotoxic features of rectal mucosal CD8 + T-cells in HIV infected and uninfected subjects. Perforin expression and lytic capacity were significantly reduced in rectal CD8 + T-cells compared with their blood counterparts, regardless of HIV clinical status; granzyme B (GrzB) was reduced to a lesser extent. Mucosal perforin and GrzB expression were higher in participants not on antiretroviral therapy compared with those on therapy and controls. Reduction in perforin and GrzB was not explained by differences in memory/effector subsets. Expression of T-bet and Eomesodermin was significantly lower in gut CD8 + T-cells compared with blood, and in vitro neutralization of TGF-β partially restored perforin expression in gut CD8 + T-cells. These findings suggest that rectal CD8 + T-cells are primarily non-cytotoxic, and phenotypically shaped by the tissue microenvironment. Further elucidation of rectal immune responses to HIV will inform the development of vaccines and immunotherapies targeted to mucosal tissues.

Original languageEnglish (US)
Pages (from-to)1008-1020
Number of pages13
JournalMucosal Immunology
Volume10
Issue number4
DOIs
StatePublished - Jul 1 2017

    Fingerprint

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

Cite this