Investigations into how Anopheles-specific flaviviruses affect arbovirus and Plasmodium transmission
Wellcome Trust
International Centre of Insect Physiology and Ecology
Despite the vast diversity of arboviruses endemic in East Africa, most research efforts have focused on just a few key viral pathogens. Additionally, estimates of arbovirus diversity in the tropics are likely to be underestimated, especially in Anopheles spp. Many arboviruses are vertically transmitted in mosquitoes, as are recently identified clades of insect-specific flaviviruses (ISFVs). Some ISFVs can either inhibit or enhance replication of other arboviruses in mosquitoes and thus impact both horizontal and vertical transmission of arboviruses. However, whether Anopheles-specific flaviviruses affect arbovirus or malaria (Plasmodium) transmission remains unknown. This study will 1) culture these viruses in Anopheles cell lines and examine their effect on secondary arbovirus inoculations; 2) secondarily infect Anopheles gambiae with arboviruses (Wesselsbron , Semliki Forest, and o’nyong-nyong viruses) after infection with ANFV; 3) characterise vector and viral gene expression responses to primary AnFV infections and with arbovirus infections using transcriptome sequencing; and 4) investigate the effects of AnFVs on Plasmodium transmission. The results from this study will inform on the potential utility of vertically transmitted AnFVs for blocking the transmission of arboviruses and or malaria parasites in Anopheles mosquitoes.
2.2 Factors relating to physical environment