Notch信号途径在Bregs发育及口服耐受中的作用

Notch Signal Pathway in Bregs Development and Oral Tolerance

目的:调节性B细胞(Bregs)是近年来确认的一类具有负向免疫调节功能的B细胞亚群,在免疫反应中通过IL-10发挥调节功能,又称为B10细胞,其表型为CD19+CD5+CD1dhigh,在多种疾病中发挥重要的调节作用,但关于Bregs的发育及发挥调节功能的具体机制尚不明确。Notch信号途径是调控细胞双向亚群和双向功能分化的重要信号途径,在T/B细胞分化、CD4/CD8细胞等细胞发育中发挥重要的作用,但其在B10细胞发育及其免疫应答中调控作用尚不明确。本研究利用特异性在B细胞剔除Notch信号分子RBP-J基因的小鼠,分析Notch信号对Bregs发育及口服耐受的影响。方法:将CD19-Cre小鼠与RBP-Jflox小鼠交配,获得CD19-Cre/RBP-Jf/f基因型小鼠,流式细胞仪分析该小鼠CD19+CD5+CD1dhighB10细胞及体外刺激后产生IL-10的B10细胞数量;制备口服免疫耐受模型,分析Notch信号缺失对B10细胞发育和功能的影响。结果:B细胞特异性敲除RBP-J基因的小鼠的CD19+CD5+CD1dhighBregs数量及体外刺激后产生IL-10的B10细胞数量比杂合子小鼠显著降低;且在口服免疫耐受模型中血清IgE水平显著升高。结论:Notch信号敲除后,脾脏Bregs及其产生IL-10减少,在口服耐受中不能产生耐受,Notch信号可能促进Bregs发育,并通过IL-10参与调控口服耐受。

Objective： Regualtory B cell （Bregs） is a specific B cell population potently inhibits immune responses through the se- cretion oflL-10 recent years, termed B10 cells also. Its phenotype is CD5＋CDIdhighCD19＋. Bregs play an important role in several dis- eases. However, the precise mechanisms of Bregs development has not been elucidated so far. Notch signaling pathway participated in regulating cell subsets and bi functional differentiation. It involved in T/B cell and CD4/CD8 T cell differentiation It is not clear that Notch signaling pathway regulates B10 development and immune response. We will focus on analysis of the role of Notch signal path- way on Bregs cell development and the regulation on Breg in oral immune tolerance in a class of transgenic mice, in which the RBP-J gene were inactiveed in B ceils. Methods： We acquired the CD19-cre/RBP-Jflox/flox genotype mice by mating the CD19-cre mice and RBP-Jflox mice, analysis of the frequencies of CD 19＋Cd5＋CD1 dhigh Bregs and IL-10-producing B 10 cell after stimu by Flow cytometric. Preparation of oral immune tolerance model to analyse of Notch signaling pathway effect on Bregs function. Results： The frequencies of CD19＋CD5＋CDldhigh Bregs were significantly reduced in CD19-cre-RBP-Jf/f mice compared with the heteroaygous mice, the level of IgE increased in the mice which B cell specific knockout RBP-J. Conclusions： The numbers of Bregs and IL-10-producing decreased, which B cell specific knockout RBP-J can not tolerance in oral immune tolerance. Noch signaling pathway promotes Bregs development and controls oral tolerance by mediating IL-10.