Pratt-Riccio, Lilian Rose3; Perce-da-Silva, Daiana de Souza3; Lima-Junior, Josué da Costa3; Theisen, Michael4; Santos, Fátima3; Daniel-Ribeiro, Cláudio Tadeu3; de Oliveira-Ferreira, Joseli3; Banic, Dalma Maria3
1 Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Københavns Universitet2 Graduate School of Health and Medical Sciences, Graduate School of Health and Medical Sciences, Faculty of Health and Medical Sciences, Københavns Universitet3 unknown4 Graduate School of Health and Medical Sciences, Graduate School of Health and Medical Sciences, Faculty of Health and Medical Sciences, Københavns Universitet
The genetic diversity displayed by Plasmodium falciparum, the most deadly Plasmodium species, is a significant obstacle for effective malaria vaccine development. In this study, we identified genetic polymorphisms in P. falciparum glutamate-rich protein (GLURP), which is currently being tested in clinical trials as a malaria vaccine candidate, from isolates found circulating in the Brazilian Amazon at variable transmission levels. The study was performed using samples collected in 1993 and 2008 from rural villages situated near Porto Velho, in the state of Rondônia. DNA was extracted from 126 P. falciparum-positive thick blood smears using the phenol-chloroform method and subjected to a nested polymerase chain reaction protocol with specific primers against two immunodominant regions of GLURP, R0 and R2. Only one R0 fragment and four variants of the R2 fragment were detected. No differences were observed between the two time points with regard to the frequencies of the fragment variants. Mixed infections were uncommon. Our results demonstrate conservation of GLURP-R0 and limited polymorphic variation of GLURP-R2 in P. falciparum isolates from individuals living in Porto Velho. This is an important finding, as genetic polymorphisms in B and T-cell epitopes could have implications for the immunological properties of the antigen.
Memórias Do Instituto Oswaldo Cruz, 2013, Vol 108, Issue 4, p. 523-8