Vaccine elicitation of HIV broadly neutralizing antibodies from genome-edited B cells in non-human primates and derived lymphoid organoids.

HIV broadly neutralizing antibodies (bnAbs) are promising reagents for prevention and therapy of disease; however, their elicitation is constrained by genetic limitations of the human B cell antigen-receptor (BCR) repertoire. Precision genome-editing offers a potential solution by enabling bnAb genes to be programmed into the BCR repertoire as IgH-modified B cells. Such cells can be vaccinated to elicit durable bnAb memory responses in mice; however, extending this success to non-human primates (NHPs) would be a major advance towards clinical translation. Here, we show that ex vivo reprogrammed NHP B cells can survive autologous infusion and respond to immunization, differentiating into antibody-secreting cells (ASCs) that can produce up to 1 µg/ml of a bnAb in serum following vaccination prime. Although durable transgenic memory responses were not generated, vaccination of engineered cells in secondary lymphoid organoid (SLO) cultures recapitulated transient ASC responses in vitro. These findings suggest that NHP-derived SLOs could provide a platform to optimize engineering and vaccination conditions that drive germinal center maturation of IgH-reprogrammed B cells in a clinically relevant NHP model, supporting the development of engineered B-cell vaccines that generate durable bnAb responses as a potential functional cure for HIV.