Lens epithelium-derived growth factor/p75 qualifies as a target for HIV gene therapy in the NSG mouse model

Abstract

Lens epithelium-derived growth factor (LEDGF/p75) is an essential cofactor of HIV integration. Both stable overexpression of the C-terminal part of LEDGF/p75 (LEDGF325-530) containing the integrase (IN)-binding domain (IBD) and stable knockdown (KD) of LEDGF/p75 are known to inhibit HIV infection in laboratory cell lines. Here, primary human CD4+ T-cells were transduced with lentiviral vectors encoding LEDGF 32525-530, the interaction-deficient mutant LEDGF325-530 D366N, or a hairpin depleting LEDGF/p75 and challenged with HIV. Maximal protection of primary T-cells from HIV infection was obtained after LEDGF 325-530 overexpression reducing HIV replication 40-fold without evidence of cellular toxicity. This strategy was subsequently evaluated in the NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mouse model. Threefold reduction in mean plasma viral load was obtained in mice engrafted with CD4+ T-cells expressing LEDGF325-530 in comparison with engraftment with LEDGF325-530 D366N cells. Four weeks after transplantation with LEDGF325-530 D366N cells, 70% of the CD4+ cells were lost due to ongoing HIV replication. However, in mice transplanted with LEDGF325-530 cells only a 20% decrease in CD4+ cells was measured. Liver and spleen sections of LEDGF325-530 mice contained less HIV than LEDGF 325-530 D366N mice as measured by p24 antigen detection. LEDGF 325-530 overexpression potently inhibits HIV replication in vivo and protects against HIV mediated cell killing of primary CD4+ T-cells. © The American Society of Gene & Cell Therapy.