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Regulatory B cell frequency correlates with markers of HIV disease progression and attenuates anti-HIV CD8+ T cell function in vitro
Journal article   Open access   Peer reviewed

Regulatory B cell frequency correlates with markers of HIV disease progression and attenuates anti-HIV CD8+ T cell function in vitro

Basile Siewe, Jack T Stapleton, Jeffrey Martinson, Ali Keshavarzian, Nazia Kazmi, Patricia M Demarais, Audrey L French and Alan Landay
Journal of leukocyte biology, Vol.93(5), pp.811-818
05/2013
DOI: 10.1189/jlb.0912436
PMCID: PMC3629440
PMID: 23434518
url
https://doi.org/10.1189/jlb.0912436View
Published (Version of record) Open Access

Abstract

A role for regulatory B cells is shown in HIV-pathogenesis, potentially impacting HIV cell-mediated control. HIV infection is associated with elevated expression of IL-10 and PD-L1, contributing to impairment of T cell effector functions. In autoimmunity, tumor immunology, and some viral infections, Bregs modulate T cell function via IL-10 production. In this study, we tested the hypothesis that during HIV infection, Bregs attenuate CD8 + T cell effector function, contributing to immune dysfunction. We determined that in vitro, TLR2-, TLR9-, and CD40L-costimulated Bregs from HIV − individuals exhibited a high frequency of cells expressing IL-10 and PD-L1. Compared with Bregs from HIV − individuals, a significantly higher percentage of Bregs from HIV + individuals spontaneously expressed IL-10 ( P =0.0218). After in vitro stimulation with HIV peptides, Breg-depleted PBMCs from HIV + individuals exhibited a heightened frequency of cytotoxic (CD107a + ; P =0.0171) and HIV-specific CD8 + T cells compared with total PBMCs. Furthermore, Breg depletion led to enhanced proliferation of total CD8 + and CD107a + CD8 + T cells ( P =0.0280, and P =0.0102, respectively). In addition, augmented CD8 + T cell effector function in vitro was reflected in a 67% increased clearance of infected CD4 + T cells. The observed Breg suppression of CD8 + T cell proliferation was IL-10-dependent. In HIV + individuals, Breg frequency correlated positively with viral load ( r =0.4324; P =0.0095), immune activation ( r =0.5978; P =0.0005), and CD8 + T cell exhaustion (CD8 + PD-1 + ; r =0.5893; P =0.0101). Finally, the frequency of PD-L1-expressing Bregs correlated positively with CD8 + PD-1 + T cells ( r =0.4791; P =0.0443). Our data indicate that Bregs contribute to HIV-infection associated immune dysfunction by T cell impairment, via IL-10 and possibly PD-L1 expression.
Translational & Clinical Immunology immune exhaustion IL-10 immune activation

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