Initial antibodies binding to HIV-1 gp41 in acutely infected subjects are polyreactive and highly mutated
The initial antibody response to HIV-1 is targeted to envelope (Env) gp41, and is nonneutralizing and ineffective in controlling viremia. To understand the origins and characteristics of gp41-binding antibodies produced shortly after HIV-1 transmission, we isolated and studied gp41-reactive plasma cells from subjects acutely infected with HIV-1. The frequencies of somatic mutations were relatively high in these gp41-reactive antibodies. Reverted unmutated ancestors of gp41-reactive antibodies derived from subjects acutely infected with HIV-1 frequently did not react with autologous HIV-1 Env; however, these antibodies were polyreactive and frequently bound to host or bacterial antigens. In one large clonal lineage of gp41-reactive antibodies, reactivity to HIV-1 Env was acquired only after somatic mutations. Polyreactive gp41-binding antibodies were also isolated from uninfected individuals. These data suggest that the majority of gp41-binding antibodies produced after acute HIV-1 infection are cross-reactive responses generated by stimulating memory B cells that have previously been activated by non-HIV-1 antigens.
Liao, H-X., Chen, X., Munshaw, S., Zhang, R., Marshall, D. J., Vandergrift, N. A., ... Haynes, B. F. (2011). Initial antibodies binding to HIV-1 gp41 in acutely infected subjects are polyreactive and highly mutated. Journal of Experimental Medicine, 208(11), 2237-2249. DOI: 10.1084/jem.20110363