Investigação da ligação do Fator H de mamíferos ao epitélio intestinal de Lutzomyia longipalpis e à superfície de diferentes espécies de Leishmania do velho e novo mundo

• Ano de defesa: 2018
• Autor(a) principal: Natalia Alvim Araujo Saab
• 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-B44QDG

Complement is an immune system element that acts against foreign intruders by recognizing, binding and eliminating them. It can be triggered through different pathways that promote lysis of foreign microorganisms and can harms hematophagous digestive system, as Leishmania and sandflies. Complement system can be evaded by capturing Factor H from plasma resulting in the inhibition of the alternative pathway. This is a mechanism established in several pathogens. Recently, it was detected in Anopheles mosquitoes and by our research group in Leishmania infantum assayed with human serum. Since phlebotomines feed on distinct hosts and are able to transmit Leishmania to these vertebrates, its not sufficient that the majority of researches are developed only on human. Thereby, our studies purpose was to investigate the capacity of humans, dogs and rats Factor H to bind in phlebotomines Lutzomyia longipalpis midgut epithelium as immune complement system evasion mechanism. Sandflies midguts and Leishmania promatisgotes were incubated in those mammalians serum and analysed using ELISA methodology. Our results show that humans, dogs and rats FH is able to bind to L. longipalpis midgut epithelium. Only humans FH binds to L. infantum cellular surface. Other Leishmania species were analysed but the results are preliminary. The present work also explored aspects about complement classic pathway activation inside sandflies midgut. Through the same ELISA methodology we verified the possibility of IgG antibodies and C1 protein binding to L. longipalpis midgut epithelium. No IgG binding was detected but C1 molecule from humans, dogs and rats indeed binds to sandflies midgut epithelium. Besides scientific value, this research enables the development of novel sandflies control strategies and contributes to a greater knowledge of the blood feeding mechanisms which are pivotal to sandflies reproductive and vectorial capacity.