Interleukin-10 responses to liver-stage antigen 1 predict human resistance to Plasmodium falciparum.

The design of an effective vaccine against Plasmodium falciparum, the most deadly malaria parasite of humans, requires a careful definition of the epitopes and the immune responses involved in protection. Liver-stage antigen 1 (LSA-1) is specifically expressed during the hepatic stage of P. falciparum and elicits cellular and humoral immune responses in naturally exposed individuals. We report here that interleukin-10 (IL-10) production in response to LSA-1 predicts resistance to P. falciparum after eradication therapy. Resistance was not related to gamma interferon or tumor necrosis factor alpha production. This is the first report that human IL-10 responses are associated with resistance after eradication therapy, and our findings support the inclusion of LSA-1 in a vaccine against malaria.