The name Interleukin was originally coined to describe soluble mediators of communication between leucocytes. A number of the cytokines important in natural immunity also play a major role in acquired immunity. IL-6 is produced by activated T cells as are some chemokines. May be an important B cell growth factor. Required for IgE synthesis.
Principal role is in eosinophil activation and maturation.
Important in response to helminths. Acts on macrophages in an inhibitory fashion, antagonistic to IFNgamma. A potent activator of macrophages, stimulating secondary release of TNFa, IL-1 etc. and critical in inducing secondary killing mechanisms vital to eliminating intracellular pathogens. Added Value Other cytokines made by T cells TGFbeta . Inhibitory role, an important anti-inflammatory cytokine little understood at present.