Leishmania (leishmania) amazonensis amastigote glycoshingolipids role in macrophage infectivity.

• Grant number: 07/01047-0
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: April 01, 2007
• End date: May 31, 2007
• Field of knowledge: Biological Sciences - Biochemistry - Biochemistry of Microorganisms
• Principal Investigator: Anita Hilda Straus Takahashi
• Grantee: Anita Hilda Straus Takahashi
• Host Institution: Departamento de Bioquímica. Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

The role of glycosphingolipids (GSLs) of amastigote forms of Leishmania (Leishmania) amazonensis in macrophage infection was analyzed. Our studies were focused particularly in GSLs presenting the terminal Galpb1-3Galpa; disaccharide. Macrophage invasion by L. (L.) amazonensis amastigotes was reduced by 37% when the disaccharide Galpb1-3Galp was added to culture medium. The putative macrophage receptor/lectin for beta-Gal-globotriaosylceramide (Galpb1-3Galpa1-3-Galpb1-4Glcpb1-1Cer) and other structurally related GSLs from L. (L.) amazonensis amastigotes were analyzed by binding assays with micelles containing purified parasite GSLs or intact amastigotes on Western blots of proteins extracted from resident peritoneal mouse macrophages. The putative macrophage receptor for micelles presenting amastigote GLSs or intact parasites was probed using mAb ST-3, which recognizes the glycoepitope Galpb1-3Galpa1-3-R present either in micelle preparation or on the amastigote surface. A macrophage doublet with molecular mass ~30 kDa was identified as the amastigote GSLs receptor. The specificity of this interaction was confirmed using fixed L. (L.) chagasi amastigotes, which do not express GSLs such as b-Galp-globotriaosylceramides, these parasites do not bind to 30 kDa protein. (AU)