| Abstract
| - Immunopathology and Immune responses to Schistosoma mansoni were examined in IL-4 -/- mice. IL-5 and IL-10 production by lymphoid cells stimulated with soluble egg antigen (SEA), peripheral eosinophilla and serum levels of soluble IL-4 receptor but not IgE were all significantly elevated over background normal levels in IL-4 -/- mice as a result of infection. Additionally, IL-10 and IL-5 in addition to IL-2 and IFN-γ transcripts were equally evident in diseased liver tissue from infected IL-4 -/- and wild-type mice. Nevertheless, analysis of antigen-stimulated IL-2, IL-4, IL-5, IL-10 and IFN-γ production by lymphoid organ cells from infected or egg-injected IL-4 / mice revealed a more Th1 -like pattern of cytokine production (IFN-γ > IL-5) than In (wild-type) mice in which a stronger type 2 response to SEA was detectable (IL-4, IL-5 > IFN-γ). Despite this, at 8 and 16 weeks after infection, liver pathology, as indicated by the size, ceilularity, cellular composition and collagen content of granulomas, was similar in IL-4 / and wild-type animals. As in wild-type animals, granuloma size at week 16 was smaller than at week 8, Indicating that modulation had occurred in the absence of IL-4. Differences in pathology were seen only when eggs were experimentally embolized to the lungs, in which case IL-4 / mice made smaller granulomatous responses than did wild-type animals. These data clearly show that IL-4 Is not necessary for the hepatic granuloma formation which occurs during experimental schistosomiasis.
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