Human lymphatic filiariasis: intensity of exposure changes the immune response

Abstract

New research by Kazura and colleagues has indicated that the intensity of exposure to the infective helminths of filiariasis has a major impact on the nature of immune responses in humans [King, C. (2001) J. Immunol. 166, 7427–7436]. These conclusions were drawn from a study of T cell and cytokine responses in 97 residents from two villages in Papua New Guinea. During the study period, the transmission intensity of the helminth Wuchereria bancrofti differed by 63 fold between the two villages. Lymphocyte proliferative responses and Th1 cytokine production were markedly poor in the high-transmission village compared with those in the low transmission village, even when corrected for infective load. Furthermore, filarial antigen-driven IL-5 production and plasma Th2 cytokine levels were highest in the high-transmission village. The authors believe that the mechanism used by infective filarial parasites to influence immune responses is mediated via the host antigen-presenting cells. SHK