T helper 1 and T helper 2 cells exhibit functionally distinct characteristics

T helper 1 and T helper 2 cells exhibit functionally distinct characteristics. For example, Th1 cells primarily are involved in cell-mediated inflammatory reactions and thus the cytokines they produce activate cytotoxic and inflammatory reactions. IFN-g, a Th1 cytokine, is often found at sites of delayed-type hypersensitivity reactions. Th1 cells mediate these reactions; likewise, Th2 cytokines augment antibody production, particularly IgE responses, and enhance eosinophil production. Therefore, the Th2 cytokines are often found in association with allergic and antibody-driven immune responses.