Mosquito Spit Disturbs Human Immune Cells for Days

When mosquitoes take a blood meal, they deposit saliva into their host’s skin, provoking an immune response even in the absence of pathogens. The saliva alone, because of the proteins it contains, causes cytokine levels in the blood to rise, while altering the size of immune cell subpopulations. Such changes have been observed in studies with mouse models, but a new study goes a bit further. It describes the effects of mosquito bites on human immune cells in mice engrafted with human hematopoietic stem cells.

The new study, from scientists based at Baylor College of Medicine, shows that the number of immune cell types affected is much larger than previously described, and that some immune responses to mosquito bites can be detected up until seven days post-bite.

Although these findings are of uncertain biological significance, they could complement findings from earlier studies that mosquito saliva enhances the ...