CCR3 expression induced by IL-2 and IL-4 as a terminal receptor on germinal center B cells
Objective To study the expression and functions of chemokine receptor CCR3 induced by the action of IL-2 and IL-4 on human germinal center (GC) B cells. Methods Flow cytometry was used to detect the expression of CCR3 in GC B cells as well as the apoptosis of GC B cells. Realtime quantitative reverse transcription (RT)-PCR and Northern blot assay were utilized to analyze the CCR3 mRNA expressed in the GC B cells. Chemotaxis and adhesion assay were exploited to determine GC B cell chemotaxis and adhesion induced by CCR3 and its ligand. Results There was few CCR3 expressed in human GC B cells. Combination of IL-2 and IL-4 were able to up-regulated CCR3 molecule expression in GC B cells as well as CCR3 mRNA in the cells. Eotaxin,the ligand to CCR3,could not induce GC B cell chemotaxis and adhesion. However,it triggered apoptosis of GC B cells. Conclusion Combination of IL-2 and IL-4 can induce expression of CCR3,which acts as a death receptor on GC B cells.