TFH in HIV Latency and as Sources of Replication-Competent Virus

During untreated disease, HIV replication is concentrated within T follicular helper cells (T-FH). Heightened permissiveness, the presence of highly infectious virions on follicular dendritic cells (FDCs), low frequencies of virus-specific cytotoxic T lymphocytes (CTLs) in B cell follicles, expansions in T-FH, and T-FH dysfunction, all likely promote replication in T-FH. Limited data suggest that memory T-FH play a role in the latent or subclinical reservoir of HIV during antiretroviral therapy (ART), potentially for many of the same reasons. A better understanding of the role of memory T-FH and FDC-bound virions in promoting recrudescent viremia in the setting of ART cessation is essential. Studies that target follicular virus reservoirs are needed to determine their role in HIV latency and to suggest successful cure strategies.