Loss of Function of Intestinal IL-17 and IL-22 Producing Cells Contributes to Inflammation and Viral Persistence in SIV-Infected Rhesus Macaques

PLoS Pathogens

Kirk Easley¹  Rémi Fromentin²  Nicolas Chomont²  Colleen S. McGary³  Mirko Paiardini³  Sara Paganini³  Luca Micci³  Emily S. Ryan³ 

[1] Department of Biostatistics & Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America;Department of Microbiology, Infectiology and Immunology, Université de Montréal, Faculty of Medicine, and Centre de Recherche du CHUM, Montreal, Québec, Canada;Division of Microbiology & Immunology, Yerkes National Primate Research Center, Emory University School of Medicine, Atlanta, Georgia, United States of America

关键词: T cells;    SIV;    Gastrointestinal tract;    Cytokines;    Blood;    Immune activation;    HIV infections;    Antiretroviral therapy;   

DOI  :  10.1371/journal.ppat.1005412

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

In HIV/SIV-infected humans and rhesus macaques (RMs), a severe depletion of intestinal CD4+ T-cells producing interleukin IL-17 and IL-22 associates with loss of mucosal integrity and chronic immune activation. However, little is known about the function of IL-17 and IL-22 producing cells during lentiviral infections. Here, we longitudinally determined the levels and functions of IL-17, IL-22 and IL-17/IL-22 producing CD4+ T-cells in blood, lymph node and colorectum of SIV-infected RMs, as well as how they recover during effective ART and are affected by ART interruption. Intestinal IL-17 and IL-22 producing CD4+ T-cells are polyfunctional in SIV-uninfected RMs, with the large majority of cells producing four or five cytokines. SIV infection induced a severe dysfunction of colorectal IL-17, IL-22 and IL-17/IL-22 producing CD4+ T-cells, the extent of which associated with the levels of immune activation (HLA-DR+CD38+), proliferation (Ki-67+) and CD4+ T-cell counts before and during ART. Additionally, Th17 cell function during ART negatively correlated with residual plasma viremia and levels of sCD163, a soluble marker of inflammation and disease progression. Furthermore, IL-17 and IL-22 producing cell frequency and function at various pre, on, and off-ART experimental points associated with and predicted total SIV-DNA content in the colorectum and blood. While ART restored Th22 cell function to levels similar to pre-infection, it did not fully restore Th17 cell function, and all cell types were rapidly and severely affected—both quantitatively and qualitatively—after ART interruption. In conclusion, intestinal IL-17 producing cell function is severely impaired by SIV infection, not fully normalized despite effective ART, and strongly associates with inflammation as well as SIV persistence off and on ART. As such, strategies able to preserve and/or regenerate the functions of these CD4+ T-cells central for mucosal immunity are critically needed in future HIV cure research.

【 授权许可】

CC BY