Genetic polymorphisms in the glutamate-rich protein of Plasmodium falciparum field isolates from a malaria-endemic area of Brazil

• Published in: Memórias do Instituto Oswaldo Cruz Vol. 108; no. 4; pp. 523 - 528
• Main Authors: Pratt-Riccio, Lilian Rose, Perce-da-Silva, Daiana de Souza, Lima-Junior, Josué da Costa, Theisen, Michael, Santos, Fátima, Daniel-Ribeiro, Cláudio Tadeu, de Oliveira-Ferreira, Joseli, Banic, Dalma Maria
• Format: Journal Article
• Language: English
• Published: Instituto Oswaldo Cruz, Ministério da Saúde 01-06-2013
• Subjects: Short Communications
• ISSN: 0074-0276; 1678-8060
• DOI: 10.1590/0074-0276108042013022

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.