Comparative assessment of the immune response of the family of recombinant Plasmodium vivax erythrocyte binding proteins (PvRBPs) in mice and individuals from malaria endemic areas

Malaria, an infectious disease transmitted by the bite of female Anopheles mosquitoes infected with parasites of the genus Plasmodium spp. It is estimated that in 2021 there were around 247 million cases and 619,000 deaths from malaria. In Brazil, the disease is endemic in the Amazon basin, with P. vivax (Pv) being the most prevalent species followed by P. falciparum (Pf) and P. malariae (Pm). The most affected populations are indigenous people, miners, loggers and rubber tappers due to the geographical location and limited access to healthcare. Treatment can be carried out using combined therapies based on artemisinin (Pf) or chloroquine + primaquine (Pv). However, with the emergence of strains resistant to antimalarial drugs and mosquitoes resistant to insecticides, more research into prevention through vaccination is needed. Vaccination strategies against malaria currently focus on searching for antigens against the pre-erythrocytic stage. On the other hand, few blood stage antigens are explored in clinical tests, especially those derived from P. vivax. Even neglected, some studies point to promising vaccine candidates for P. vivax. The immunity conferred by PvDBP proteins, responsible for the invasion of young erythrocytes, is strongly associated with long-lasting humoral and cellular responses. However, more recent studies indicate that antibodies against PvDBP do not completely prevent invasion of erythrocytes, indicating alternative forms of infection. Recently, PvRBP proteins are receiving greater attention, as they are responsible for contributing to the invasion of reticulocytes and normocytes through the interaction of their N-terminal region with CD71 (TfR1) and CD98 (heteromeric amino acid transporter, SLCA2) receptors. There are 5 known genes that fully encode PvRBP proteins in the P. vivax genome (PvRBP1a, PvRBP1b, PvRBP2a, PvRBP2b, PvRBP2c). Some information regarding the antigenicity and longevity of antibodies in different populations is scarce.

Project details

Genetics and Genomics
P. vivax

Dec 2023

Brazil

Towards a vaccine for Plasmodium vivax