Ex vivo analysis identifies effective HIV-1 latency–reversing drug combinations

Engineering HIV-Resistant, Anti-HIV Chimeric Antigen Receptor T Cells

“…We envision addressing this concern by adoptive transfer of anti-HIV CAR T cells to individuals who are initially on ART and by combining CAR T cells targeting distinct epitopes on HIV Env, potentially in concert with agents that promote viral activation in latently infected cells. 63 In summary, we have demonstrated the feasibility and utility of a novel strategy for HIVCAR therapy that not only targets HIV-infected cells in the presence of ART but also protects the effector cells from HIV infection. This approach leverages recent advances in the ability to identify potent bNAbs, CAR technology, and the field of gene therapy, including the ability to perform high-efficiency gene editing of primary cells, and warrants further preclinical testing in animal models.…”

Measuring the latent reservoir in vivo

“…These new assays reduce the contribution of most defective genomes, do not rely on an amplification step with virus propagation by coculture, and may have several advantages for measuring the HIV reservoir. First, many latency-reversing agents (LRAs) show a posttranscriptional block (72); therefore, the activity of these compounds requires measurement of HIVinducible transcription ex vivo (73,74). Additionally, because the assays that quantify the inducible HIV reservoir have a higher dynamic range than QVOA, such assays could make it easier to detect reductions in the reservoir ex vivo following effective in vivo interventions (75).…”

“…In general, CD4 + T cells are maximally activated as they are for QVOA, and then HIV RNA is directly measured from cell extracts (caRNA) (51,69,(73)(74)(75) or cell supernatants (cell-free RNA [cfRNA]) (69,73,74). While caRNA measures transcriptionally competent provirus, it might also detect defective transcripts.…”

“…cfRNA reflects the capacity to induce translation and form and release virions. In contrast to QVOA, various activation stimuli have been used in these assays, including anti-CD3/CD28 costimulation (17,73), phorbol myristate acetate (PMA) and ionomycin (74)(75)(76), or PHA (51). Moreover, depending on the aim of the study, the format of the assay can be adapted easily.…”

Recent developments in the effort to cure HIV infection: going beyond N = 1

“…One of the major problems in the search for effective LRAs is that, despite impressive activity in various in vitro models, most LRAs, including the HDAC inhibitors, have weak activity in ex vivo studies using resting CD4 + T cells from patients on ART (74). Fortunately, some combinations of LRAs are now beginning to show levels of latency reversal comparable to global T cell activation (75,76). In clinical trials, no reduction in the reservoir has yet been demonstrated, but there is evidence for increases in cell-associated HIV RNA and for slight transient increases in plasma HIV RNA with certain HDAC inhibitors (17,18).…”