Human monoclonal antibodies against chikungunya virus target multiple distinct epitopes in the E1 and E2 glycoproteins

Chikungunya virus (CHIKV) is a mosquito-Transmitted alphavirus that causes persistent arthritis in a subset of human patients. We report the isolation and functional characterization of monoclonal antibodies (mAbs) from two patients infected with CHIKV in the Dominican Republic. Single B cell sorting yielded a panel of 46 human mAbs of diverse germline lineages that targeted epitopes within the E1 or E2 glycoproteins. MAbs that recognized either E1 or E2 proteins exhibited neutralizing activity. Viral escape mutations localized the binding epitopes for two E1 mAbs to sites within domain I or the linker between domains I and III; and for two E2 mAbs between the β-connector region and the B-domain. Two of the E2-specific mAbs conferred protection in vivo in a stringent lethal challenge mouse model of CHIKV infection, whereas the E1 mAbs did not. These results provide insight into human antibody response to CHIKV and identify candidate mAbs for therapeutic intervention. no available vaccines or therapies to treat CHIKV infection. In this report, we identified and characterized a large panel of antibodies against CHIKV from two donors that contracted the viral infection in the Dominican Republic. These antibodies target a number of different regions of the membrane proteins that coat the surface of the virus, and many can inhibit the ability of CHIKV to infect cells. Two of the antibodies were shown to protect mice from a lethal dose of CHIKV. These antibodies have therapeutic potential, and provide insight into the human immune response that may facilitate vaccine development.