Reprogramming the antigen specificity of B cells using genome-editing technologies

Abstract

HIV infection is a global health concern affecting roughly 37 million people and still no effective vaccine is available for prevention. While rare, HIV broadly neutralizing antibodies (bnAbs) have been isolated from patients. These antibodies have been shown to be protective in animal models if present at the time of challenge in passive transfer experiments. Thus, elicitation of HIV bnAbs is a central goal for vaccine design. These antibodies, however, contain rare features not present in the naïve human antibody repertoire. We have developed a universal genome editing strategy to introduce novel paratopes into the human repertoire. We used CRISPR-Cas9 in a homology directed repair strategy, to replace the heavy chain (HC) variable region in B cell lines and human primary B cells with that from an HIV broadly neutralizing antibody, PG9. The modified locus expresses PG9 HC which pairs with native light chains resulting in the cell surface expression of HIV specific BCRs. The engineered B cells are subject to class switch recombination and somatic hypermutation to generate HIV-specific BCRs with improved neutralizing breath and potency.