HIV-1 envelope gp41 antibodies can originate from terminal ileum B cells that share cross-reactivity with commensal bacteria
Monoclonal antibodies derived from blood plasma cells of acute HIV-1-infected individuals are predominantly targeted to the HIV Env gp41 and cross-reactive with commensal bacteria. To understand this phenomenon, we examined anti-HIV responses in ileum B cells using recombinant antibody technology and probed their relationship to commensal bacteria. The dominant ileum B cell response was to Env gp41. Remarkably, a majority (82%) of the ileum anti-gp41 antibodies cross-reacted with commensal bacteria, and of those, 43% showed non-HIV-1 antigen polyreactivity. Pyrosequencing revealed shared HIV-1 antibody clonal lineages between ileum and blood. Mutated immunoglobulin G antibodies cross-reactive with both Env gp41 and microbiota could also be isolated from the ileum of HIV-1 uninfected individuals. Thus, the gp41 commensal bacterial antigen cross-reactive antibodies originate in the intestine, and the gp41 Env response in HIV-1 infection can be derived from a preinfection memory B cell pool triggered by commensal bacteria that cross-react with Env.
Trama, A. M., Moody, M. A., Alam, S. M., Jaeger, F. H., Lockwood, B., Parks, R., ... Haynes, B. F. (2014). HIV-1 envelope gp41 antibodies can originate from terminal ileum B cells that share cross-reactivity with commensal bacteria. Cell Host and Microbe, 16(2), 215-226. https://doi.org/10.1016/j.chom.2014.07.003