We study the biology and invasiveness of the sporozoite, malaria's infectious agent. Because malaria is the most critically infectious disease in the world, the sporozoite can well be considered the most important infectious cell. Mosquitoes introduce sporozoites into a host by injecting them into nonvascular skin tissue as they secrete saliva while probing for a blood source. To infect the host, these sporozoites must then reach a blood vessel. We are interested in how sporozoites move through the tissue to recognize and invade a blood vessel. The mosquito s saliva is necessary for it to take a blood meal. Therefore, we investigate whether host immunity to mosquito saliva affects the mosquito s ability to take a blood meal or the sporozoite s ability to migrate through the bite region to a blood vessel.

We also study a strain of the African mosquito vector of malaria that has the ability to reject the malaria parasite by means of a melanization response around the parasite. We are interested in determining the molecular basis for the ability of this strain to recognize malaria parasites as nonself and to initiate the biochemical cascade that leads to parasite killing within the mosquito. The long-range aim is to create transgenic mosquito vectors that can no longer transmit malaria.