Stabilization of the V2 loop improves the presentation of V2 loop-associated broadly neutralizing antibody epitopes on HIV-1 envelope trimers.
A successful HIV-1 vaccine will likely need to elicit broadly neutralizing antibodies (bNAbs) that target the envelope glycoprotein (Env) spike on the virus. Native-like recombinant Env trimers of the SOSIP design now serve as a platform for achieving this challenging goal. However, SOSIP trimers usually do not bind efficiently to the inferred germline precursors of bNAbs (gl-bNAbs). We hypothesized that the inherent flexibilities of the V1 and V2 variable loops in the Env trimer contribute to the poor recognition of gl-bNAb epitopes at the trimer apex that extensively involve V2 residues. To reduce local V2 flexibility and improve the binding of V2-dependent bNAbs and gl-bNAbs, we designed BG505 SOSIP.664 trimer variants containing newly created disulfide bonds intended to stabilize the V2 loop in an optimally antigenic configuration. The first variant, I184C/E190C, contained a new disulfide bond within the V2 loop, whereas the second variant, E153C/R178C, had a new disulfide bond that cross-linked V2 and V1. The resulting engineered native-like trimer variants were both more reactive with and were neutralized by V2 bNAbs and gl-bNAbs, a finding that may be valuable in the design of germline targeting and boosting trimer immunogens to create an antigenic conformation optimal for HIV vaccine development.
['de Taeye|Steven W|SW|', 'Go|Eden P|EP|', 'Sliepen|Kwinten|K|', 'de la Peña|Alba Torrents|AT|', 'Badal|Kimberly|K|', 'Medina-Ramírez|Max|M|', 'Lee|Wen-Hsin|WH|0000-0001-9445-6671', 'Desaire|Heather|H|', 'Wilson|Ian A|IA|', 'Moore|John P|JP|', 'Ward|Andrew B|AB|', 'Sanders|Rogier W|RW|']
D016915:AIDS Vaccines D057134:Antibodies, Neutralizing D000939:Epitopes D015483:HIV Antibodies D015497:HIV-1 D055503:Protein Multimerization D017433:Protein Structure, Secondary D054299:env Gene Products, Human Immunodeficiency Virus
antibody vaccine development HIV-1 envelope glycoprotein trimer glycoprotein structure human immunodeficiency virus (HIV) protein design structure-function