CCR5 editing by Staphylococcus aureus Cas9 in human primary CD4(+) T cells and hematopoietic stem/progenitor cells promotes HIV-1 resistance and CD4(+) T cell enrichment in humanized mice

BACKGROUND: The chemokine receptor CCR5, which belongs to the superfamily of G protein-coupled receptors, is the major co-receptor for HIV-1 entry. Individuals with a homozygous CCR5Δ32 mutation have a long lasting and increased resistance to HIV-1 infection. Therefore, CCR5 represents an optimal target for HIV-1/AIDS gene therapy. The CRISPR/Cas9 system has been developed as one of the most efficacious gene editing tools in mammalian cells and the small-sized version from Staphylococcus aureus (SaCas9) has an advantage of easier delivery compared to the most commonly used version from Streptococcus pyogenes Cas9 (SpCas9). RESULTS: Here, we demonstrated that CCR5 could be specifically and efficiently edited by CRISPR/SaCas9 together with two sgRNAs, which were identified through a screening of 13 sgRNAs. Disruption of CCR5 expression by lentiviral vector-mediated CRISPR/SaCas9 led to increased resistance against HIV-1 infection in human primary CD4(+) T cells. Moreover, humanized mice engrafted with CCR5-disrupted CD4(+) T cells showed selective survival and enrichment when challenged with CCR5 (R5)-tropic HIV-1 in comparison to mock-treated CD4(+) T cells. We also observed CCR5 could be targeted by CRISPR/SaCas9 in human CD34(+) hematopoietic stem/progenitor cells without obvious differentiation deficiencies. CONCLUSIONS: This work provides an alternative approach to disrupt human CCR5 by CRISPR/SaCas9 for a potential gene therapy strategy against HIV-1/AIDS. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12977-019-0477-y) contains supplementary material, which is available to authorized users.