Type 1-programmed dendritic cells drive antigen-specific latency reversal and immune elimination of persistent HIV-1

Background: Despite the success of antiretroviral therapy (ART), latent HIV-1 continues to persist in a long-lived population of resting memory CD4(+) T cells within those who are infected. Finding a safe and effective means to induce latency reversal (LR) during ART to specifically expose this latent HIV-1 cellular reservoir for immune elimination has been a major barrier to a functional cure. Methods: In this study, we test the use of antigen-presenting type 1-polarized, monocyte-derived dendritic cells (MDC1) generated from chronic HIV-1-infected individuals on ART as a means to induce HIV-1 latency reversal in autologous CD4(+) T cells harboring replication-competent provirus. We use the same MDC1 for ex-vivo generation of autologous HIV-1 antigen-specific CD8(+) cytotoxic T cells (CTL) and test their effector responses against the MDC1-exposed HIV-1- infected CD4(+) T cell targets. Findings: MDC1 presentation of either HIV-1 or cytomegalovirus (CMV) antigens to CD4(+) T cells facilitated HIV-1 LR. This antigen-driven MDC1-mediated LR was sharply diminished with blockade of the CD40L/CD40 'helper' signaling pathway. Importantly, these antigen-presenting MDC1 also activated the expansion of CTL capable of killing the exposed HIV-1-infected targets. Interpretation: Inclusion of virus-associated MHC class II 'helper' antigens in MDC1-based HIV-1 immunotherapies could serve both as a targeted means to safely unmask antigen-specific CD4(+) T cells harboring HIV-1, and to support CTL responses that can effectively target the MDC1-exposed HIV-1 cellular reservoir as a functional cure strategy. (C) 2019 The Authors. Published by Elsevier B.V.