Cytokine regulation of granuloma formation in schistosomiasis.

Granuloma induced by the schistosome egg is an inflammatory reaction that is tightly controlled by the interaction of T-helper cell type 1 (Th1) and Th2 cytokines produced locally. Studies focussing on the immunoregulation of the response have yielded numerous insights into the cytokine cascade that controls the formation of the lesions. It is clear from current data that the Th2 cytokines play a primary role in granuloma formation, whereas the Th1-associated lymphokine interferon-gamma acts as an endogenous downregulator of the response. Through recent advances, it may now be possible to design effective cytokine-based vaccination strategies that will suppress the tissue pathology associated with this helminth infection.