How Innate Immunity affects CRISPR/Cas9 Gene Editing

Abstract

Clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein 9 (Cas9) systems are powerful gene-editing tools that may facilitate causative treatments of inherited retinal diseases. The immunogenic potential of Cas9, a peptide of bacterial origin, was assessed using cellular models of human immunocompetent cells, including macroglial and microglial cell lines. Transfection of human immortalized microglia (IMhu) with Streptococcus pyogenes-Cas9 led to Cas9 expression but did not induce a pro-inflammatory innate immune response, with no induction of pro-inflammatory cytokine production measured. These results demonstrate no evidence of an immunogenic effect of Cas9 transfection in models of human microglial cells, adding another layer of confidence in the immunological safety of possible Cas9-mediated retinal gene therapies.