Generation of HIY-resistant cells with a single-domain antibody:implications for HIV-1 gene therapy

The cure or functional cure of the"Berlin patient"and"London patient"indicates that infusion of HIV-resistant cells could be a viable treatment strategy.Very recently,we genetically linked a short-peptide fusion inhibitor with a glycosylphosphatidylinositol(GPI)attachment signal,rendering modified cells fully resistant to HIV infection.In this study,GPI-anchored m36.4,a single-domain antibody(nanobody)targeting the coreceptor-binding site of gp120,was constructed with a lentiviral vector.We verified that m36.4 was efficiently expressed on the plasma membrane of transduced TZM-bl cells and targeted lipid raft sites without affecting the expression of HIV receptors(CD4,CCR5,and CXCR4).Significantly,TZM-bl cells expressing GPI-m36.4 were highly resistant to infection with divergent HIV-1 subtypes and potently blocked HIV-1 envelope-mediated cell-cell fusion and cell-cell viral transmission.Furthermore,we showed that GPI-m36.4-modified human CEMss-CCR5 cells were nonpermissive to both CCR5-and CXCR4-tropic HIV-1 isolates and displayed a strong survival advantage over unmodified cells.It was found that GPI-m36.4 could also Impair HIV-1 Env processing and viral infectivity in transduced cells,underlying a multifaceted mechanism of antiviral action.In conclusion,our studies characterize m36.4 as a powerful nanobody that can generate HIV-resistant cells,offering a novel gene therapy approach that can be used alone or in combination.