Immunology 2017 02 23() doi 10.1111/imm.12730
T follicular helper (Tfh) cells are essential for B cell differentiation and the subsequent antibody responses. Their numbers and functions are altered during human and simian immunodeficiency virus (HIV/SIV) infections. In lymphoid tissues, Tfh cells are present in germinal center, where they are the main source of replicative HIV-1 and represent a major reservoir. Paradoxically, Tfh numbers are increased in chronically infected individuals. Understanding the fate of Tfh cells in the course of HIV-1 infection is essential for the design of efficient strategies toward a protective HIV vaccine or a cure. The purpose of this review is to summarise the recent advance in our understanding of Tfh-cell dynamics during HIV/SIV infection. In particular, to explore the possible causes of their expansion in lymphoid tissues by discussing the impact of HIV-1 infection on dendritic cells, to identify the molecular players rendering Tfh cells highly susceptible to HIV-1 infection, and to consider the contribution of regulatory follicular T cells in shaping Tfh cell functions. This article is protected by copyright. All rights reserved.