Nitesh Mishra, Bo Liang, Ryan S. Roark, Amrit Raj Ghosh, Sean Callaghan, Wen-Hsin Lee, Xuduo Li, Anh L. Vo, Gabriel Avillion, Rohan Roy Chowdhury, Rumi Habib, Frederic Bibollet-Ruche, Gabriella Giese, Prabhgun Oberoi, Khaled Amereh, Anjali Somanathan, Yuxin Zhu, Yuexiu Zhang, Muzaffer Ahmad Kassab, Lifei Tjio, Sharaf Andrabi, Raphael A. Reyes, Joel D. Allen, Nicole E. James, Kipchoge N. Randall, Lara van der Maas, Elana Ben‐Akiva, Kasia Kacmarek-Michaels, Samantha J. Plante, Christian L. Martella, Ashwin N. Skelly, Ajay Veer Singh, Jonathan Hurtado, Katharina Dueker, Tazio Capozzola, Rebecca Nedellec, Gabriel Ozorowski, Mark G. Lewis, Samantha Falcone, Andrea Carfı́, Sunny Himansu, Lawrence Shapiro, Max Crispin, Beatrice H. Hahn, Bryan Briney, Darrell J. Irvine, Dennis R. Burton, Andrew B. Ward, Facundo D. Batista, Peter D. Kwong, George M. Shaw, Andrabi Raiees
SUMMARY Germline-targeting-(GT) is a promising strategy to activate rare broadly neutralizing antibody (bnAb)-producing B cells against HIV, but induction of such responses in outbred animals has not been achieved. Using antibody-guided structure-based design, we engineered a germline-targeting trimer immunogen Q23-APEX-GT2 that primes diverse V2-apex bnAb precursors. Q23-APEX-GT2 efficiently activated V2-apex-specific B cells in humanized knock-in mice and consistently elicited immunofocused antibody responses in rhesus macaques, priming multiple long CDRH3-loop bnAb-B cell lineages. Monoclonal antibodies from immunized macaques exhibited broad heterologous HIV trimer binding and cross-neutralization. Atomic-level structural studies confirmed precise epitope targeting and revealed CDRH3-paratope configurations that mirrored those of human V2-apex bnAbs. This study provides proof-of-principle for successful priming and maturation of authentic V2-apex bnAb precursors in outbred macaques, underscoring the potential of V2-apex-targeted vaccines. HIGHLIGHTS Engineered Q23-APEX-GT2 trimer to stimulate diverse V2-apex bnAb B cell precursors Q23-APEX-GT2 primed rare V2-apex bnAb B cells in mice and outbred rhesus macaques Q23-APEX-GT2 elicited immunofocused antibody responses and diverse V2-apex B cell lineages with desirable long-CDRH3 paratope properties Q23-APEX-GT2 alone induced V2-apex antibodies with broad HIV trimer binding and modest neutralization breadth Structural analysis confirmed bnAb site targeting, mirroring human and rhesus V2-apex bnAbs