Serum interleukin 5

Interleukin (il-5) is also produced by antigen-activated cd4 + t cells; mast cells can also produce il-5. Natural il-5 has a molecular weight of 40-50 kd and is a dimeric glycoprotein linked by disulfide bonds, but the monomer il-5 also has il-5 activity. Il-5 was once called tcellreplacing factor (trf). Later, it was discovered that human IL-5 has no obvious stimulating effect on b cells; its main function is to stimulate the proliferation, differentiation and activation of eosinophils. Il-5 not only increases the number of eosinophils, but also enhances its function. Eosinophilia that occurs during worm infections and allergic diseases is mainly caused by il-5. Human il-5 can also promote the release of inflammatory mediators such as histamine and leukotriene by basophils, thereby increasing the activity of basophils.