Polimorfismos de lipofosfoglicanos (LPGs) de Leishmania (Leishmania) major-like isoladas no Brasil e seu papel na interação com Lutzomyia longipalpis e Phlebotomus papatasi

• Ano de defesa: 2017
• Autor(a) principal: Agna Cristina Guimarães
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Parasitologia
• Link de acesso: http://hdl.handle.net/1843/BUOS-AQ2NDA

Leishmania (L.) major is an Old World species of causing cutaneous leishmaniasis (LC). It is mainly transmitted by Phlebotomus papatasi and P. duboscqi. In the Americas (Ecuador, Peru, Paraguay, Mexico and Venezuela) some isolates similar to L. (L.) major have been described as L. major-like. In Brazil, three isolates from patients who never left the country, were characterized as L. major-like (BH49, BH121 and BH129), due to genetic linkage to the reference strain of L. major (Friedlin FV1). Several studies have characterized those strains using biochemical, biological and molecular techniques. However, aspects of glycobiology and interaction with vectors are still unknown for these strains. In the present study, we preliminarly characterized the repeat units of lipophosphoglycans (LPGs) of L. major-like strains and detected intraspecific variations in their levels of galactosylation/arabinosylation. Strains BH49 and BH129 as well as the FV1 control were more galactosylated than strain BH121. However, only strains BH129 and FV1 were arabinosylated. Galactose is an important sugar in the parasite-host interaction, since it recognizes a receptor in the P. papatasi midgut (PpGalec). In order to evaluate whether different levels of galactosylation would affect the interaction with vectors, in vivo infection assays were performed in Lutzomyia longipalpis (permissive vector) and P. papatasi (restrictive vector). The strains were artificially offered to the vectors and evaluated 1, 5 and 8 days post-infection. All strains were able to infect both vectors, with succesfull colonization of the stomodeal valve and metacylcogenesis. Although, BH121 strains (less galactosylated) exhibited lower infection intensity, it also managed to colonize the midgut of both vectors. The data obtained suggest that polymorphisms in L. major-like LPG may affect the interaction with the invertebrate host.