Cellular responses to Plasmodium falciparum major surface antigens and their relationship to human activities associated with malaria transmission

Ln Brazil, two types of activities have led to the worsening of malarial tr ansmission in the Amazon region: prospecting/mining and agricultural settle ments. In the present study, we analyze the cellular response of 52 of thes e individuals (14 gold-miners and 38 farmers) living within the same endemi c area, Two Plasmodium falciparum major surface antigens (recombinant prote ins) were used for cellular proliferative assays: circumsporozoite protein and merozoite surface protein-1. The frequency of these cellular responses were significantly higher among the miners (57-64%) than the farmers (10-20 %) when either recombinant protein was used. Our data suggest that a higher exposure to malaria of the gold-miners contributed to their higher in vitr o cellular response compared with the farmers. These findings point the way to further studies evaluating the influence of risk factors associated wit h the life styles of different social groups and the immune responses to th ese antigens.