Detection of promastigote stage-specific antigens on Leishmania mexicana amazonensis developing in the midgut of Lutzomyia longipalpis.

Previously described monoclonal antibodies IX-IF9-D8, IX-2H7-E10 and IX-5H9-C1 recognize promastigote stage-specific determinants present on externally exposed membrane proteins of axenically cultured Leishmania mexicana amazonensis. In the present study, these antigens were demonstrated by indirect immunofluorescence to be present on promastigotes found in the gut lumen of infected Lutzoymia longipalpis. The presence of these antigens on promastigotes found in infected sandflies suggests that the same antigens should be relevant for protective immunity studies and for species identification of Leishmania encountered in epidemiological studies.