Fly gut’s ’sticky spot’ for leishmaniasis parasite

Insect-borne parasites usually like to “stick” around inside their hosts while they mature and prepare to infect again. Now, Jesus Valenzuela and colleagues have identified the molecular receptor inside the midgut of the sand fly Phlebotomus papatasi that provides the “flypaper” for the parasite that causes the major form of leishmaniasis, a tropical disease with both mild and fatal forms. PpGalec is the receptor protein that the parasite uses to bind to the fly’s midgut and avoid being excreted at a particularly vulnerable stage of its development.

“Identifying and targeting midgut molecules essential for parasite survival represents a novel strategy for development of transmission-blocking vaccines against vector-borne diseases,” Valenzuela and colleagues conclude. As Stephen Beverley and Deborah Dobson point out in an accompanying article, leishmaniasis is a common opportunistic infection in people with AIDS and has also been a recent concern for foreign soldiers serving in Iraq.