Evaluation of the maturation profile of IgG antibodies anti-hapten polysaccharide and peptide in visceral leishmaniasis

• Grant number: 17/15381-0
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): September 01, 2017
• Effective date (End): June 30, 2018
• Field of knowledge: Biological Sciences - Parasitology - Protozoology of Parasites
• Principal Investigator: Heitor Franco de Andrade Junior
• Grantee: Flávia Regina Novais de Freitas
• Home Institution: Instituto de Medicina Tropical de São Paulo (IMT). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

In visceral leishmaniasis occurs a high production of polyclonal antibodies and B cells, unrelated to the parasite burden or disease control by the host. Glycoconjugates are widely distributed in the membrane of leishmanias, such as lipofosfoglican (LPG), glycoinositolphopholipids (GIPLs), phosphoglycans (GPI), and glycoprotein GP63. Its presence is related to resistance and survival of the parasite in the host. The objective of this study is to determine if the antibodies produced in this disease react to the different haptens or antigens commonly used in serological tests for diagnosis. Two strategies will be used for specific antibody assays, one utilizing the solid phase capture of antibody by ligands as protein A and using biotinylated antigens or haptens to determine their specificity; And another involving the construction of hybrid antigens that allow adsorption to the solid support in a Conventional ELISA. In this second assay, we intend to evaluate the maturation of the avidity of IgG antibodies, from sera from experimental infected hamster. In conclusion, we aimed to determine the presence of antibodies anti parasite hapten during the experimental infection, evaluating the origin of these antibodies by the maturation of the IgG antibodies avidity. (AU)