A study published in PLOS NTDs reports on a saliva protein with the opposite effect: D7, a protein present in Aedes aegypti saliva, binds to Dengue virus (DENV) and inhibits its transmission to human cells and mice. Antibodies against D7, which are present in humans exposed to mosquito bites, might therefore facilitate virus transmission and enhance disease severity.
Working on ways to reduce DENV transmission, Michael Conway, from Central Michigan University College of Medicine in Mt. Pleasant, USA, and colleagues, explore the targeting of mosquito saliva or midgut proteins to block transmission of DENV. This strategy has advantages compared with vaccines based on viral proteins because it does not need to take into account the different circulating DENV strains or adapt to rapidly evolving viruses.
The researchers had previously isolated proteins from the salivary glands of Aedes aegypti, the mosquito that transmits the Dengue, Zika, and Chikungunya viruses, and tested batches of proteins to see if they could either enhance or block DENV transmission to human cells. In this study, they focused on proteins that could inhibit DENV.