| Vaccination of mice with radiation-attenuated cercariae of Schistosoma mansoni induces a high level of protection against challenge with normal larvae. The immune effector mechanism, which operates in the lungs, is a cell-mediated delayed-type hypersensitivity response and involves the formation of a tight focus of mononuclear cells around embolised larvae. CD4+ T cells with Th1 characteristics are a major component of the infiltrate. They secrete abundant interferon gamma (IFN<FONT FACE="Symbol">g</font>) upon antigen stimulation in vitro, whilst in vivo neutralisation of the cytokine results in 90% abrogation of immunity. IFN<FONT FACE="Symbol">g</font> can induce a large number of genes and an attempt has been made to identify... |
