The Evolution of Human Basophil Biology from Neglect towards Understanding of Their Immune Functions

Figure 4

Scheme of basophil activation via FcεRI cross-linking and the involved signaling pathways leading to mediator release. Basophil-derived IL-4 and IL-13 trigger Th2 responses and enhance immunoglobulin production from B cells. DAG, diacylglycerol; ERK, extracellular signal-regulated kinase; FcεRI, high affinity IgE receptor 1; Fyn, src-related proto-oncogene; IgE, immunoglobulin E; IL, interleukin; IP3, inositol trisphosphate; LTC4, leukotriene C₄; Lyn, Lck/Yes novel tyrosine kinase; PI3K, phosphoinositide 3-kinase; PIP2, phosphatidylinositol 4,5-bisphosphate; PKC, protein kinase C; PLC, phospholipase C; MEK, MAPK/ERK Kinase; Raf, rapidly accelerated fibrosarcoma; Ras, rat sarcoma; S1P, sphingosine-1-phosphate; SK, sphingosine kinase 1; Syk, spleen associated tyrosine kinase.