Genetic diversity of T-helper cell epitopic regions of circumsporozoite protein of Plasmodium falciparum isolates from India

SummaryGenetic variation in the T-helper cell epitopic regions (Th2R and Th3R) of circumsporozoite protein of 135 Plasmodium falciparum isolates collected from different epidemic and endemic regions of India was studied. Variation in the Th2R and Th3R regions was found to exhibit restricted polymorphism and can be grouped. The variations were not regionally biased, as different isolates collected from different regions were found to belong to the same group. The Th2R and Th3R sequences were found to be linked in each isolate. Since the variations are regionally unbiased and restricted, the prototype variant from the groups could be included in a subunit polyvalent vaccine against sporozoites.