Secretions. Basophils arise and mature in bone marrow. When activated, basophils degranulate to release histamine, proteoglycans (e.g. heparin and chondroitin), and proteolytic enzymes (e.g. elastase and lysophospholipase). They also secrete lipid mediators like leukotrienes (LTD-4), and several cytokines.

What stimulates the production of basophils?

Like mast cells, basophils become activated by antigen crosslinking of FceRI receptor-bound IgE to undergo rapid degranulation and release their cellular contents. In addition, basophils can be activated without IgE crosslinking by inflammatory mediators such as complement factors C5a and C3a, MBP, PAF and chemokines.

When are basophils activated?

Basophils are activated by antigen and IgE stimulation (IgE-dependent) and degranulate and secrete histamine and several cytokines. Recently, several reports have demonstrated that basophil heterogeneity can be divided into two populations, IL-3-elicited and TSLP-elicited basophils.