Plasmodium falciparum: sequence analysis of the gene encoding the C-terminus region of the merozoite surface protein-1, a potential malaria vaccine antigen, in Iranian clinical isolates

摘要

C-terminal region of merozoite surface protein-1 of Plasmodium falciparum (PfMSP-1) isolated from different parts of the world revealed sequence variability, however no data exist on sequence heterogeneity of this region from Iran. To address this question, DNA encoding the carboxyl (C)-terminal region of PfMSP-1 was amplified in 144 Iranian P. falciparum clinical isolates, using allele type-specific primers. In this study both MAD20 (88.2%) and K1 (7.6%) types were detected. Sequence analysis of 33 and 92 fragments corresponding to pfmsp-1(42) and pfmsp-1(19) revealed eight (15MAD1-15MAD7 and 15KCH) and five [A1 (E/TSR/L), A2 (Q/KNG/F), A3 (E/KNG/F), A4 (E/TSG/L), and A5 (Q/KNG/L)] distinct haplotypes, respectively. E/TSG/L variant type was the predominant haplotype, and reported only from Thailand and India, but E/KNG/L is widespread in Africa, Asia, and Latin America; but not found among Iranian isolates. In summary, result of this study indicates limited antigenic diversity, and thus support the potential utility of the C-terminal region of PfMSP-1 in designing polyvalent vaccine constructs.