[Cytokines in bronchial asthma]

Integracions among T cells, B cells and macrophages is central to the immune response. These cells produce a number of biologically active proteins, which form complex network of cell-to-cell interaction, and regulate proliferation and function of the immune systems. Cytokines act on variety of cells type in a non-antigen specific manner. Only helper cells receive antigen specific signal and convert them via lymphokines secretion into antigen-nonspecific mediators of immune response. The followings cytokines have been found in asthamic airways: IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, TNF-alfa, GM-CSH. CD+4 cells are major source of cytokines in astmatic airway. It has been identified that two subsets of helper cells (TH-1 and TH-2) exist, which secret different cytokines profils. Both produce IL-1, IL-3, GM-CSF and TNF-alfa. TH-1 produce IL-2, IFN-gamma and TNF-beta (LT). TH-2 cells produce IL-4, IL-5 and IL-10. IL-4 produced by activited TH-2 subset, mast cells, and basophils is enhanced in asthma and responsible for IgE synthesis and expresion of IgE Fc-R-II. TH-1 specific IFN-gamma inhibits IL-4 induced IgE synthesis whereas TH-2 specific IL-10 supresses IFN-gamma secretion. IL-3, IL-4 and IL-5 stimulate the growth of mucosal mast cells and eosinophils. The presence of activated T cells and eosinophils in BAL-fluid as well as increased amount of IFN-gamma and slL-2R in circulation correlate with severity of disease. Interplay between T cells and inflammatory cells through the cytokines is crucial in regulating of inflammatory processes in allergic asthma.