Th1/Th2 cells.

摘要: A large body of evidence indicates the existence functionally polarized CD4+ T-cell responses based on their profile cytokine secretion. Type 1 T helper (Th1) cells produce interferon-gamma, interleukin (IL)-2, and tumour necrosis factor (TNF)-beta, which activate macrophages are responsible for cell-mediated immunity phagocyte-dependent protective responses. By contrast, type 2 Th (Th2) IL-4, IL-5, IL-10, IL-13, strong antibody production, eosinophil activation, inhibition several macrophage functions, thus providing phagocyte-independent Th1 mainly develop following infections by intracellular bacteria some viruses, whereas Th2 predominate in response to infestations gastrointestinal nematodes. Polarized not only exhibit different functional properties, but also show preferential expression activation markers distinct transcription factors. Several mechanisms may influence cell differentiation, include "natural immunity" evoked offending agents, nature peptide ligand, as well activity costimulatory molecules microenvironmentally secreted hormones, context individual genetic background. In addition playing roles protection, Th1-type Th2-type types immunopathological reactions. involved pathogenesis organ-specific autoimmune disorders, Crohn's disease, Helicobacter pylori-induced peptic ulcer, acute kidney allograft rejection, unexplained recurrent abortions. allergen-specific atopic disorders genetically susceptible individuals. Moreover, against still unknown antigens Omenn's syndrome, idiopathic pulmonary fibrosis, progressive systemic sclerosis. Finally, prevalence play role a more rapid evolution human immunodeficiency virus infection full-blown disease. The Th1/Th2 paradigm provides rationale development new vaccines infectious agents novel strategies therapy allergic disorders.