Aedes aegypti AgBR1 antibodies modulate early Zika virus infection of mice

A recent epidemic of Zika virus in the Americas, affecting well over a million people, caused substantial mortality and morbidity, including Guillain–Barre syndrome, microcephaly and other fetal developmental defects1,2. Preventive and therapeutic measures that specifically target the virus are not readily available. The transmission of Zika virus is predominantly mosquito-borne, and Aedes aegypti mosquitoes serve as a key vector for Zika virus3. Here, to identify salivary factors that modulate mosquito-borne Zika virus infection, we focused on antigenic proteins in mice that were repeatedly bitten by mosquitoes and developed antibodies against salivary proteins. Using a yeast surface display screen, we identified five antigenic A. aegypti salivary proteins in mice. Antiserum against one of these five proteins—A. aegypti bacteria-responsive protein 1 (AgBR1)—suppressed early inflammatory responses in the skin of mice bitten by Zika-virus-infected mosquitoes. AgBR1 antiserum also partially protected mice from lethal mosquito-borne—but not needle-injected—Zika virus infection. These data suggest that AgBR1 is a target for the prevention of mosquito-transmitted Zika virus infection.