AI үүсгэсэн The T helper cell is a major target for the genetic factors that control the expression of the IgE responder phenotype. Two types of T lymphocyte helper cells have been identified. T helper 1 (TH1) cells produce interferon gamma (INF γ) and other cytokines that are necessary to mount an effective immune response against infection. T helper 2 (TH2) cells that produce interleukin (IL)-4 and IL-5 play a dominant role in IgE production (2,3) and eosinophil activation. IL-4which is produced by TH2 cellsis critical in initiating a switch in production by plasma cells to IgE. IL-5 increases eosinophil activation. INF γwhich is produced by TH1 helper lymphocytesis important in cell-mediated responsesbut can also ‘down-modulate’ TH2 cells andconsequentlythe production of IL-4. ReciprocallyIL-4 can also decrease the production of INF γ by TH1 cells. Both types of T helper cells are reactive to allergensbut at the clonal levelthe atopic response is predominantly TH2 as opposed to TH1 cells in healthy individuals. Текст эффект