Abstract
C-C chemokine receptor type 5 (CCR5) is the main co-receptor for HIV entry into the target CD4+ cells, and homozygous CCR5Δ32/Δ32 cells are resistant to CCR5-tropic HIV infection. However, the CCR5Δ32/Δ32 homozygous donors in populations are rare. Here we developed a simple approach to induce CCR5Δ32/Δ32 homozygotes through CRISPR-Cas9 genome-editing technology. Designing a pair of single-guide RNA targeting the flank region of the CCR5Δ32 mutation locus, we applied the CRISPR-Cas9 and lentiviral packaging system to successfully convert wild-type CCR5 into CCR5Δ32/Δ32 homozygotes in the human Jurkat CD4+ cell line and primary CD4+ cells, exactly the same as the naturally occurring CCR5Δ32/Δ32 mutation. The successful rate is up to 20% in Jurkat cells but less in primary CD4+ cells. The modified CCR5Δ32/Δ32 CD4+ cells are resistant to CCR5-tropic HIV infection. Whole-genome sequencing revealed no apparent off-target sites. This approach has the promise to promote HIV/AIDS therapy from the only cured unique Berlin patient to a routine autologous cell-based therapy.