Glicoconjugados (GIPLs e LPGs) de Leishmania braziliensis e L. infantum: Modula????o do Sistema Imune Inato e varia????es na estrutura de carboidratos

Os glicoconjugados de Leishmaniatem sido extensivamente estudados, mas ainda pouco se sabe sobre o quanto polimorfismos intra e interespec??ficos contribuem com o desenvolvimento das diferentes imunopatologias das leishmanioses. Por este motivo, duas esp??cies de import??ncia epidemiol??gica foram examinadas, L. braziliensise L. infantum, agentes causadores das leishmanioses cut??nea e visceral, respectivamente. O LPG de L. braziliensisn??o possui cadeias laterais enquanto o LPG de L. infantumcarrega em sua estrutura olig??meros de at?? tr??s ??-glicoses como cadeias laterais. Por outro lado a estrutura dos GIPLs destas esp??cies era desconhecida e foi objeto de estudo deste trabalho. A an??lise estrutural dos GIPLs mostrou que L. infantumpossui GIPLs pequenos e ricos em manose, sugerindo predomin??ncia de GIPLs do tipoI e h??bridos enquanto L. braziliensis apresenta GIPLs grandes e ricos em galactose, sugestivo do tipo II. Para analisar o papel destas mol??culas na intera????o com o hospedeiro, macr??fagosperitoneais murinos foram tratados com LPG ou GIPLs e a produ????o de nitrito, citocinas, bem como a ativa????o de MAPKs foram avaliados. De forma geral, macr??fagos estimulados com LPG de L. braziliensis, demonstraram uma produ????o maior de TNF-??, IL-1??, IL-6 e NO do que os estimulados com LPG de L. infantum, adicionalmente, c??lulas tratadas com LPG de ambas as esp??cies mostraram uma resposta pro inflamat??ria mais proeminente. Al??m disto, os GIPLsmostraram a capacidade de inibir a produ????o de IL-12 e NO em macr??fagos estimulados com IFN-??e LPS. Finalmente, os glicoconjugados destas duas esp??cies resultaram em uma cin??tica diferencial na ativa????o de MAPKs. O LPG de L. braziliensis mostrou uma ativa????o transiente enquanto o de L. infantum uma ativa????o gradual. Os GIPLs de ambas esp??cies falharam em ativar MAPKsLeismania LPG has being extensively studied but little is known about in what extent interspecies variations contribute to the differentimmunopathologies of leishmaniases. Similarly, for GIPLs, a relatively neglected molecule, little is known about its polymorphisms among Leishmania species and its role during infection. To address this issue, two epidemiologically important South American species of Leishmania were examined, L. braziliensis and L. infantum, causative agents of cutaneous and visceral leishmaniasis, respectively. The LPG from these two species differ in structure, being L. braziliensis LPG devoid of side chains while L. infantum LPG carries one to three ??-glucoses on its side chains. In the other hand the structure of the GIPLs from these two species is still unknown and was addressed in this present work. A structural analysis of the GIPLs showed that L. infantum has small, mannose rich GIPLs, suggestive of type I and Hybrid GIPLs while L. braziliensis has larger and galactose rich GIPLs, suggestive of Type II GIPLs. To address the role of these molecules upon macrophage invasion, mouse peritoneal macrophages were treatedwith either LPG or GIPLs and Nitrite and cytokine production, as well as MAPKs activation were evaluated. Overall, macrophages stimulated with L. braziliensis LPG, had a higher TNF-??, IL-1??, IL-6 e NO production than those stimulated with that of L. infantum, also, IFN-??primed macrophages stimulated with LPG, had a higher production of NO and TNF-??than GIPLs stimulated cells. Additionally, GIPLs showed the capacity of inhibit IL-12 and NO production in IFN-??and LPS stimulated macrophages. Furthermore, the glycoconjugates from the two species resulted in differential kinetics of signaling via MAPK activation. L. infantum LPG exhibited a gradual activation profile, whereas L. braziliensisLPG showed a sharp but transient activation, while GIPLs failed to activate MAPK