PGF2α Synthase-Like Proteins are Expressed in Promastigotes of Old World Leishmania Species but not in New World Species

Abstract

Background: Leishmaniasis is a disease caused by protozoan parasites of the genus Leishmania and spread by the bite of infected sand fly species. The disease is characterized by an increase in prostaglandin production in the host. PGF_2α is among the prostaglandins that are synthesized by Leishmania sp.

Objectives: To compare the expression profiles of PGF_2α synthase-like proteins in Old and New World species of Leishmania so as to provide insight into the role of these proteins.

Methodology: To detect gene expression at transcription level, polymerase chain reaction was carried out using L. major PGF_2α synthase gene specific primers and cDNA from L. major, L. donovani, L. tropica, L. amazonensis, L. braziliensis, L. mexicana and L. chagasi promastigotes. To detect expression at translation level, total protein from promastigotes of the above parasites was analyzed on a Western blot using T. brucei-specific rabbit anti-PGF_2α synthase polyclonal antibodies.

Results: At the transcription level, PGF_2α synthase gene expression was detected in Old World species L. major, L. donovani and L. tropica, but was absent in the New World  L. amazonensis and L. mexicana. It was expressed at low levels in the New World L. chagasi. Western blot analysis confirmed the presence of PGF_2α synthase - like proteins in Old World and not in New World species.

Discussion: These findings suggest that New World Leishmania may have evolved new ortholog genes to produce PGF_2α. Alternatively, the ancestral PGF_2α synthase gene may be present in the New World species but has mutated or been lost due to speciation during evolution.

Key words: Prostaglandins; PGF_2α synthase; Leishmania