BACKGROUND Arginase is an enzyme that converts L-arginine to urea and L-ornithine, an essential substrate for the polyamine pathway supporting Leishmania (Leishmania) amazonensis replication and its survival in the mammalian host. L-arginine is also the substrate of macrophage nitric oxide synthase 2 (NOS2) to produce nitric oxide (NO) that kills the parasite. This competition can define the fa...

Upon their internalization by macrophages, Leishmania promastigotes inhibit phagolysosome biogenesis. The main factor responsible for this inhibition is the promastigote surface glycolipid lipophosphoglycan (LPG). This glycolipid has a profound impact on the phagosome, causing periphagosomal accumulation of F-actin and disruption of phagosomal lipid microdomains. Functionally, this LPG-mediated...

Leishmania are protozoan parasites that cause several human diseases called leishmaniases, which can display very different clinical aspects (Peters and Killick-Kendrick, 1987b). The life cycle of Leishmania involves two kinds of hosts: dipteran insects (sandflies) and several mammals, in which they adopt a motile, flagellated, promastigote form and a non-motile, amastigote form with a very sho...

The presence of different derivatives of sialic acids (SA) on Leishmania donovani instigated us to investigate their status on different strains of Leishmania sp. causing different forms of the disease. Leishmania tropica (K27), Leishmania major (JISH118) and Leishmania mexicana (LV4) responsible for cutaneous, Leishmania braziliensis (L280) and Leishmania amazonensis (LV81) causing diffuse and...

Leishmania promastigotes synthesize an abundance of phosphoglycans, either attached to the cell surface through phosphatidylinositol anchors (lipophosphoglycan, LPG) or secreted as protein-containing glycoconjugates. These phosphoglycans are thought to promote the survival of the parasite within both its vertebrate and invertebrate hosts. The relative contributions of different phosphoglycan-co...

Serum from healthy, nonimmune humans contained immunoglobulin M (IgM) antibodies that agglutinated Leishmania donovani promastigotes, activated complement, and enhanced promastigote ingestion by human monocytes. The findings indicate that IgM antibodies have the capacity to affect the initial interaction of L. donovani promastigotes with human host defenses.

background: leishmania homologue of receptors for activated c kinase(lack) antigen is a 36-kda protein, which provokes a very early immune response against leishmania infection. there are several reports on the expression of lack through different life-cycle stages of genus leishmania , but only a few of them have focused on l.tropica . methods: the present study provides details of the cloning...

background: different methods have been used for characterization of leishmania promastigotes. monoclonal antibodies are useful in characterization of   leishmania spp . both amastogotes and promastigotes. objective: comparing the characterization of   leishmania spp. promastigotes with immunoperoxidase test (avidin-biotin) techniques and an indirect immunofluorescent assay (ifa).   methods: ap...