The protective immune response against Toxoplasma gondii is widely recognised as being type-1 mediated. Nevertheless, the overproduction of type-1 cytokines can induce severe pathology. The extent to which Th2 cytokines can modulate the disease protective versus disease exacerbating effects of type-1 cytokines remains to be resolved. We have therefore, compared the disease induced by T. gondii cysts in IL-4)/), IL-4Ra)/), and wild-type BALB/c mice, a mouse strain normally resistant to this disease. Increased mortality and increased lung pathology were observed in the absence of IL-4 and signalling via IL-4Ra and splenocyte type 1 cytokine and NO production was increased during early infection (day 12). IL-4 can modulate type-1 inflammatory responses by counter-regulating the effects of IFN-c on CD4+ T cells and/or macrophages.
- IL-4R alpha signalling
- toxoplasma gondii infection