Env-antibody coevolution identifies B cell priming as the principal bottleneck to HIV V2 apex broadly neutralizing antibody development

Sci Immunol. 2026 Feb 13;11(116):eadz3933. doi: 10.1126/sciimmunol.adz3933. Epub 2026 Feb 13.

Abstract

Broadly neutralizing antibodies (bNAbs) are rarely elicited during HIV-1 infection. To identify obstacles to bNAb development, we longitudinally studied 122 rhesus macaques infected by 1 of 16 different simian-human immunodeficiency viruses (SHIVs). We identified the V2 apex region of the envelope (Env) as the most common bNAb target and a subset of Envs that preferentially elicited these antibodies. In 10 macaques, we delineated Env-antibody coevolution from B cell priming to bNAb development. Antibody phylogenies revealed permissive developmental pathways guided by evolving Envs that contained few mutations in or near the V2 apex C-strand, which were a sensitive indicator of apex-targeted responses. The absence of such mutations reflected a failure in bNAb priming. These results indicate that efficiency of B cell priming, and not complexities in Env-guided affinity maturation, is a primary obstacle to V2 apex bNAb elicitation in SHIV-infected macaques and identify specific HIV-1 Envs to advance as vaccine platforms.

MeSH terms

  • Animals
  • Antibodies, Neutralizing* / immunology
  • B-Lymphocytes* / immunology
  • HIV Antibodies* / immunology
  • HIV Infections* / immunology
  • HIV-1* / immunology
  • Humans
  • Macaca mulatta
  • Simian Acquired Immunodeficiency Syndrome / immunology
  • Simian Immunodeficiency Virus / immunology
  • env Gene Products, Human Immunodeficiency Virus* / genetics
  • env Gene Products, Human Immunodeficiency Virus* / immunology

Substances

  • HIV Antibodies
  • Antibodies, Neutralizing
  • env Gene Products, Human Immunodeficiency Virus