HIV-1 cure strategy by means of proviral knock-out using CRISPR-Cas9 has been hampered by the emergence of viral resistance against d2 fleshripper the targeting guide RNA (gRNA).Here, we proposed multiple, concentrated gRNA attacks against HIV-1 regulatory genes to block viral escape.The T cell line were transduced with single and multiple gRNAs targeting HIV-1 tat and rev using lentiviral-based CRISPR-Cas9, followed by replicative HIV-1NL4-3 challenge in vitro.
Viral p24 rebound was observed for almost all gRNAs, but multiplexing three tat-targeting gRNAs maintained p24 suppression and cell viability, indicating the inhibition of viral escape.Multiplexed tat gRNAs inhibited acute viral replication in the 2nd round of infection, abolished cell-associated transmission to unprotected T cells, and maintained protection through 45 days, post-infection (dpi) after a higher dose of HIV-1 infection.Finally, we describe here for the first time the assembly of all-in-one lentiviral vectors containing three and six gRNAs targeting tat and rev.
A single-vector tat-targeting construct shows non-inferiority to the tat-targeting frondescence boise multi-vector in low-dose HIV-1 infection.We conclude that Cas9-induced, DNA repair-mediated mutations in tat are sufficiently deleterious and deplete HIV-1 fitness, and multiplexed disruption of tat further limits the possibility of an escape mutant arising, thus elevating the potential of CRISPR-Cas9 to achieve a long-term HIV-1 cure.