Active PD-L1 incorporation within HIV virions functionally impairs T follicular helper cells

PLoS Pathog. 2022 Jul 5;18(7):e1010673. doi: 10.1371/journal.ppat.1010673. eCollection 2022 Jul.

Abstract

The limited development of broadly neutralizing antibodies (BnAbs) during HIV infection is classically attributed to an inadequate B-cell help brought by functionally impaired T follicular helper (Tfh) cells. However, the determinants of Tfh-cell functional impairment and the signals contributing to this condition remain elusive. In the present study, we showed that PD-L1 is incorporated within HIV virions through an active mechanism involving p17 HIV matrix protein. We subsequently showed that in vitro produced PD-L1high but not PD-L1low HIV virions, significantly reduced Tfh-cell proliferation and IL-21 production, ultimately leading to a decreased of IgG1 secretion from GC B cells. Interestingly, Tfh-cell functions were fully restored in presence of anti-PD-L1/2 blocking mAbs treatment, demonstrating that the incorporated PD-L1 proteins were functionally active. Taken together, the present study unveils an immunovirological mechanism by which HIV specifically exploits the regulatory potential of PD-L1 to suppress the immune system during the course of HIV infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • B-Lymphocytes
  • HIV Infections*
  • Humans
  • T Follicular Helper Cells
  • T-Lymphocytes, Helper-Inducer*
  • Virion

Grants and funding

This work was supported by Swiss National Science Foundation Grant 320030_200912 and by Freedom Forever Association to M.P. and by an educational grant from FONDATION MACHAON to R.B. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.