CD8+CD103+iTreg细胞诱导系统性红斑狼疮免疫耐受及其治疗作用的研究

We have proved that naive T cells in normal mice in vitro can be induced to produce a novel CD8+regulatory T cell subsets, namely CD8+Foxp3-CD103+iTreg cells, which have significant suppressive activity in vitro and in vivo.Further evidence show that CD103 has played a key role in the immunosuppressive function of these CD8+ iTreg cells. Our preliminary experiments showed that a similar phenotype and function of CD8+CD103+iTreg cells in healthy adult volunteers, lupus patients and lupus mice can be induced.But it is not clear whether CD8+CD103+ iTreg cells can induce immune tolerance and has therapeutic effects in lupus mice. We had demonstrated that iTreg cells directly suppress autoreactive B cells in vitro and in vivo in lupus mice. Thus, we propose that CD8+CD103+iTreg cells may induce immune tolerance, and has therapeutic effects in lupus mice through autologous cell induction and amplification. The project intends to use lupus mice model, adopt cell culture, flow cytometry and other methods, aiming to prove the hypothesis and obtain the reliable evidence that CD8+CD103+ iTreg cells induce immune tolerance and has therapeutic effects in lupus mice. This project will provide scientific evidence for exploring new treatment of systemic lupus erythematosus and lupus nephritis.

我们已证明体外诱导正常小鼠幼稚T细胞产生的新型CD8+Foxp3-CD103+iTreg细胞具有显著体内外免疫抑制作用，进一步证明CD103在CD8+iTreg细胞免疫抑制功能中发挥了关键性作用。我们预实验在健康成人、狼疮患者、狼疮小鼠中均诱导产生类似表型及功能的CD8+CD103+iTreg细胞。那么，CD8+CD103+iTreg细胞能否诱导免疫耐受，并对狼疮小鼠具有治疗作用？我们前期研究显示iTreg细胞在体内外能直接抑制狼疮小鼠自身反应性B细胞的反应。据此，我们提出假设：CD8+CD103+iTreg细胞诱导免疫耐受，并通过自体细胞诱导、扩增起治疗作用。本项目拟应用狼疮小鼠模型，采用细胞培养、流式细胞术等方法，旨在证明这一假设并获得自体CD8+CD103+iTreg细胞诱导免疫耐受并对狼疮小鼠具有治疗作用的可靠证据，为探索系统性红斑狼疮及狼疮肾炎新的治疗方法提供科学依据。

系统性红斑狼疮（systemic lupus erythematosus, SLE）是难以完全治愈的累及全身系统的自身免疫性疾病。前期我们已证明体外诱导正常小鼠幼稚T细胞产生的CD8+CD103+诱导型调节性T细胞（induced regulatory T cell，iTreg）具有显著体内外免疫抑制作用，而其能否诱导SLE免疫耐受尚不清楚。本研究我们主要探索在体外实验中CD8+CD103+ iTreg是否抑制自体B细胞的反应，体内实验中输注的CD8+CD103+ iTreg通过何种机制抑制B细胞的反应，且能否治疗狼疮性肾炎。结果显示CD8+CD103+ iTreg体内外实验中均可抑制B细胞的反应，其机制与其细胞接触、分泌TGF-β和IL-10有关。输注CD8+CD103+ iTreg可缓解模型小鼠狼疮性肾炎。因此，本研究初步取得自体CD8+CD103+iTreg细胞诱导免疫耐受并对狼疮小鼠具有治疗作用的可靠证据，为探索系统性红斑狼疮及狼疮肾炎新的治疗方法提供科学依据。