ABSTRACT
This chapter presents subdivision of CD4+ T cells based on patterns of cytokine production and suggested that the Th2 subset made the right combination of cytokines to coordinately stimulate production of the effector cells and molecules most characteristic of allergic responses: immunoglobulin E (IgE), eosinophils and mucosal mast cells. The counterpart to the Th2 subset is the Thl subset, which regulates a very different set of effector functions centered around macrophage activation and T-cell-mediated immunity. A completely analogous body of evidence demonstrates the parallel role of Interferon-gamma in the differentiation of Thl responses in resistant mouse strains. Interferon-gamma can also act as an inhibitor of interleukin-5-stimulated eosinophilia in mice infected with helminth parasites and can increase the severity of the infection. Interestingly, interferon-alpha has similar activity in inhibiting IgE production and parasite-induced eosinophilia.
