Increased mortality in antiretroviral (ARV)-treated, HIV-infected individuals has been attributed to persistent immune dysfunction, in part due to abnormalities at the gastrointestinal barrier. In particular, the poor reconstitution of gastrointestinal Th17 cells correlates with residual translocation of dysbiotic, immunostimulatory microflora across a compromised intestinal epithelial barrier. We have previously demonstrated that oral probiotics promote increased intestinal CD4 + T-cell reconstitution during ARV treatment in a non-human primate model of HIV infection; however, essential mucosal T-cell subsets, such as Th17 cells, had limited recovery. Here, we sought to promote Th17 cell recovery by administering interleukin (IL)-21 to a limited number of ARV-treated, probiotic-supplemented, Simian Immunodeficiency Virus (SIV)-infected pigtailed macaques. We demonstrate that probiotic and IL-21 supplementation of ARVs are associated with enhanced polyfunctional Th17 expansion and reduced markers of microbial translocation and dysbiosis as compared with infected controls receiving ARVs alone. Importantly, treatment resulted in fewer morbidities compared with controls, and was independent of increased immune activation or loss of viral suppression. We propose that combining ARVs with therapeutics aimed at restoring intestinal stasis may significantly improve disease prognosis of ARV-treated, HIV-infected individuals.
Bibliographical noteFunding Information:
We thank F. Villinger (Emory University) for providing the IL-21; D. Hazuda (Gilead), M. Miller (Merck), and J. Lifson (NCI) for providing the ARVs; C. de Simon (Sigma Tau Pharmaceuticals) for providing the VSL#3; H. Cronise, J. Swerczek, and R. Herbert for veterinary assistance; and the NIAID LMM-Core for assessing viral loads. Funding for this study was provided in part by the Division of Intramural Research/NIAID/NIH. This project has been funded in part with federal funds from the National Cancer Institute, National Institutes of Health, under Contract No. HHSN261200800001E to JDE. The content of this publication does not necessarily reflect the views or policies of DHHS, or does the mention of trade names, commercial products, or organizations imply endorsement by the US Government.