CD1d+CD5+调节性B细胞在自身免疫性葡萄膜炎中的作用及治疗意义

A subset of regulatory CD1d+CD5+ B cells (Bregs) has been defined functionally by their ability to express interleukin (IL)-10. Many studies have found that Bregs exhibit reduced frequency and impaired function in autoimmune and inflammatory diseases. But the role of Bregs in Autoimmune Uveitis (AU) is lack of intensive study. Our preliminary data showed that anti-B cell CD-20 antigen achieved good results in treating patients with AU. In addition, we observed faster Bregs recovery in patients of neuromyelitis optica with good response than those with poor response to anti-CD-20 antigen treatment. Thus we hypothesize that Bregs may play a role in the mechanism of AU and its treatment response. In current study, we will investigate the presence, function and dynamics of Bregs and its secretory function for IL-10 in AU patients compared with healthy subjects. We will pursue the correlation between clinical characteristics and the frequency of Bregs after using anti-CD20 antigen in patients with AU. We will also investigate the optimum condition for Bregs proliferation and repair, and culture the Bregs with peripheral blood mononuclear cells to to study the kinetics of repopulation of subsets of B cells and ILs. By adoptive transferring of Bregs to experimental AU mice to evaluate its therapeutic effects. The results will promote better understanding the mechanism of Bregs in AU and its therapeutic possibilities as well.

调节性B细胞(Regulatory B cell,Breg)为能分泌IL-10的CD1d+CD5+双阳性B细胞，能抑制多种自身免疫疾病炎症反应。其在自身免疫性葡萄膜炎(Autoimmune uveitis,AU)的作用缺乏深入研究。本课题组应用抗B细胞CD20单抗治疗AU患者取得较好临床效果；发现Breg在视神经脊髓炎患者细胞数减少，且以CD20单抗治疗后，疗效好者比疗效差者Breg恢复快。因此我们推测Breg也可能在AU发病及治疗中发挥作用。本研究拟检测AU患者和健康人Breg数量、频率及分泌IL-10功能。分析CD20单抗治疗后，AU患者Breg变化及其与临床之间的联系。探索体外增殖、修复Breg的最佳条件，将Breg与AU患者外周血单个核细胞共培养，观察其对不同细胞亚群分化及细胞因子分泌的影响。通过实验性AU小鼠回输Breg，评价其治疗作用，以明确Breg在AU发病中作用及治疗意义。

调节性B细胞为能分泌IL-10的CD1d+CD5+双阳性B细胞，能抑制多种自身免疫疾病炎症反应。本课题组应用抗B细胞CD20单抗治疗实验性自身免疫性葡萄膜炎（experimental autoimmune uveitis，EAU），通过建立EAU小鼠模型，并应用利妥昔单抗（抗B细胞抗体）进行干预，我们观察到干预后，小鼠眼内炎性明显减轻，抗B细胞抗体对EAU起到了一定的治疗作用，能够抑制炎症反应，保护眼部组织结构，并且此保护机制与多种细胞因子相关，通过适当的给药剂量、给药方式及给药时间点可以达到治疗葡萄膜炎的效果。 另外，本课题组对颗粒蛋白前体（progranulin，PGRN）在EAU模型中的作用及对CD4+/CD8+ T细胞表达的影响也进行了研究，结果观察到PGRN可减轻大鼠EAU的炎症反应，保护眼部组织结构，其作用机制可能是抑制CD4+ T细胞的增加和CD8+ T细胞的减少，降低CD4+/CD8+比值，从而调控机体的免疫功能，达到治疗葡萄膜炎的效果。本研究为临床应用抗B细胞抗体及PGRN治疗EAU的研究提供了实验基础与理论依据。