Leishmania chitinase facilitates colonization of sand fly vectors and enhances transmission to mice.

Chitinases of trypanosomatid parasites have been proposed to fulfil various roles in their blood-feeding arthropod vectors but so far none have been directly tested using a molecular approach. We characterized the ability of Leishmania mexicana episomally transfected with LmexCht1 (the L. mexicana chitinase gene) to survive and grow within the permissive sand fly vector, Lutzomyia longipalpis.

Down-regulation of gp63 in Leishmania amazonensis reduces its early development in Lutzomyia longipalpis.

The zinc protease (gp63) of promastigotes was found to play a role in the sand fly part of the Leishmania life cycle. Lutzomyia longipalpis females were fed with promastigotes (10(6) per ml) of a Leishmania amazonensis clone whose gp63 was up- and down-regulated by directional cloning into P6.5 for sense- and anti-sense transcription.