IMMUNOLOGY

Detailed explanation-1: -Interleukin-4 (IL-4), IL-5 and IL-13, the signature cytokines that are produced during type 2 immune responses, are critical for protective immunity against infections of extracellular parasites and are responsible for asthma and many other allergic inflammatory diseases.

Detailed explanation-2: -In addition to driving the differentiation of TH0 lymphocytes into the TH2 phenotype, IL-4 is important in allergic immune responses owing to its ability to prevent apoptosis of T lymphocytes. Activation of these cells results in rapid proliferation and secretion of cytokines.

Detailed explanation-3: -The Th2-type cytokines include interleukins 4, 5, and 13, which are associated with the promotion of IgE and eosinophilic responses in atopy, and also interleukin-10, which has more of an anti-inflammatory response. In excess, Th2 responses will counteract the Th1 mediated microbicidal action.

Detailed explanation-4: -IL-4 has been called the “prototypic immunoregulatory cytokine.” Like many cytokines, it can affect a variety of target cells in multiple ways. IL-4 has an important role in regulating antibody production, hematopoiesis and inflammation, and the development of effector T-cell responses.