Interleukin 4 or IL-4 is a cytokine that induces Th2 cell differentiation by naive T cells and naive helper cells. IL-4 activates Th2 cells, which then produce more IL-4 through a positive feedback loop. IL-4 is produced primarily in mast cells, Th2 and Th2 cells. Interleukin 4 plays many biological functions, including stimulation of activated T-cell proliferation and differentiation of B cells to plasma cells.
It plays a crucial role in adaptive and humoral immunity. IL-4 causes B-cell class switching from IgE and up-regulates MHC Class II production. IL-4 reduces Th1 cells, macrophages and IFN-gamma production, as well as dendritic cell IL-12. You can use the Interleukin-4 ELISA Kit to measure IL-4 in humans.
Allergies are associated with an overproduction of IL-4. Tissue macrophages are important in wound healing and chronic inflammation. Extravascular tissues containing IL-4 promote alternative activation of macrophages to M2 cells, while inhibiting classical activation by macrophages to M1 cells.
A decrease in pathological inflammation can be caused by an increase in repair macrophages in M2. This is combined with the secretion of IL-10, and TGF-b. The activation of the M2 cell results in wound repair and fibrosis. IL-4 is a 129-amino acids long secreted protein. IL-4 is a cytokine that is produced mainly by activated lymphocytes, mast cell and basophils.
It can modulate immune responses in many ways by acting on a variety of cell types. IL-4 is involved in many B-cell activation processes. It acts as a co-stimulator for DNA-synthesis. It stimulates the expression class II MHC molecules in resting B-cells. It increases both the secretion and surface expression of IgE/IgG1.