Plasmodiun vivax circumsporozoite protein genotypes associated to the Histocompatibility Major Complex

Abstract

Currently, more than 99% of the malaria cases in Brazil occur in the region of the Amazonian and species P. vivax has been responsible for about 80% of the registered cases. Diverse studies analyzing serologic response to different peptides of the parasite have gotten resulted variable in accordance with the used antigen and the analyzed population. Previous reports have described associations between the immune antibody response against to CSP repetitive regions and allelic differences in the HLA II genes. Knowledge of this variability of response immunity and the characteristic highly admixed of the Brazilian population, the present study aim to evaluate the relation between the antibody response against antigens peptides of the variants of P. vivax (VK210, VK247 and P. vivax-like) and the HLA II polymorphisms in Amazon endemic populations, for better agreement of the mechanisms that modulate the immune response against the malaria. Blood samples of 150 malaria patients, diagnosed for the blood thick film and the technique of Nested-PCR will be used as P. vivax, of three Brazilian Amazon regions. The variant types of this parasite will be identified by technique PCR-RFLP. Blood samples of 150 donors collected in blood banks at the respective endemic areas will be used as local control groups. The HLA II genotyping will be carried through by PCR-SSP for the HLA-DRB and HLA-DQB alleles. The serologic response will be analyzed by ELISA tests for a fragment of the amino region of the PvMSP1, for the PvDBP, two regions of the PvCSP and epitopes of the CSP repetitive region of the three variant types of P. vivax aiming to find modulation of the immune response by HLA II polymorphisms front of these variant types of the parasite.