Genetically-edited iPSCs derived from HIV-1 infected patients on therapy can give rise to immune cells resistant to HIV-1 infection.

Objective: To assess the in-vitro CCR5---tropic and CXCR4---tropic HIV---1 infectivity of immune cells, particularly macrophages, derived fromCCR5 gene---edited induced pluripotent stem cells (iPSCs) obtained from the peripheral blood mononuclear cells (PBMC) of HIV---infected patients on antiretroviral therapy (ART). Design: PBMC were obtained from six patients who had been HIV---infected for over 20 years and were on ART for 1---12 years prior to this study. Methods: The PBMC were derived into iPSCs and genetically edited with TALENs or CRISPR---cas9 endonucleases combined with PiggyBac technology to introduce the naturally occurring 32---bp deletion to theCCR5 gene. These iPSCs were differentiated into macrophages, and subsequently challenged with CCR5---tropic or CCR5/CXCR4 dual--- tropic HIV---1 strains. iPSC derivation, gene editing and immune cell differentiation were done in feeder---free, xeno---free in-vitro conditions. Results: Multiple unedited (wild---type) andCCR5 gene---edited (mutant) iPSCs were derived from patients' PBMC. When differentiated into immune cells and HIV---1 challenged, mutant iPSC lines were resistant to CCR5---tropic and to some extent to CCR5/CXCR4 dual---tropic HIV---1 infection when compared to wild---type iPSC lines. Conclusion: Our study demonstrates that iPSC---derived, gene---edited immune cells are resistant to distinct HIV---1 strains. These findings have important implications for both in-vitro stem cell development and therapeutic approaches to cure HIV infection.