ADAPTATION OF CHIKUNGUNYA VIRUS TO Ae. Albopictus MOSQUITOES: ROLE OF THE MUTATIONS IN E2 PROTEIN

Konstantin Tsetsarkin, and S. Higgs, Ph.D.

Department of Pathology, UTMB

Background: Chikungunya virus is an emerging arbovirus associated with several recent large-scale epidemics. A single mutation E1 A226V in CHIKV significantly changes the ability of the virus to infect and be transmitted by Ae. albopictus mosquitoes when expressed in the background of well characterized CHIKV strains OPY-1 and 37997 but not in Ag41855. Objective and Methods: In order to elucidate the genetic determinates which affect CHIKV sensitivity for the E1 A226V mutation in Ae. albopictus, genomes of the OPY-1 and Ag41855 strains were used for construction of chimeric viruses and viruses with a specific combination of point mutations in the E2 protein. Results: The determination of the midgut infection rates of the derived virus in Ae. albopictus and Ae. aegypti mosquitoes revealed a crucial role of the E2 G60D and E2 I211T mutations on CHIKV infectivity for Ae. albopictus and Ae. aegypti, and specific roles of these positions in determining the CHIKV sensitivity for the E1 A226V mutation in Ae. albopictus. Conclusions: Newly described determinants of CHIKV mosquito infectivity for Ae. albopictus and Ae. aegypti will be of particular importance in the studies aimed at the investigation of the detailed mechanisms of CHIKV adaptations to its vector species. Supported by the McLaughlin Predoctoral Fellowship and NIH R21AI073389.