TNF and malaria: To identify the predominant cellular source of P. falciparum-inducible IL-10 and to investigate longitudinally the functionality and kinetics of IL-10-producing cells in children exposed to intense seasonal malaria, we analyzed PBMCs by FACS with intracellular staining for IL-10, IFN-γ and TNF after in vitro iRBC stimulation at the healthy baseline before the malaria season, 7 days after malaria treatment (when symptoms had resolved), and after the 6-month dry season.