Ke Nengwen, Su Anping, Huang Wei, Szatmary Peter, Zhang Zhaoda
Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China.
NIHR Liverpool Pancreas Biomedical Research Unit, Royal Liverpool University Hospital, University of Liverpool, Liverpool, United Kingdom.
Immunobiology. 2016 Jul;221(7):803-12. doi: 10.1016/j.imbio.2016.02.002. Epub 2016 Feb 3.
Antigen present cells (APCs) have been demonstrated to play dual roles in immune tolerance. Recently, compelling evidence indicates that APCs that express CD80, but not CD86 can protect allograft. We investigated whether modulation of CD80 in dendritic cells (DCs) offer protection for xeno-islets.
In vitro, isolated mature murine DCs received untransfection, transfection with CD86 siRNA or negative control siRNA. The DCs were used in mixed lymphocyte reaction in which rat islets and murine splenocytes were further added. On day 3 of co-culturing, the proliferation of lymphocytes was measured and interleukin (IL)-2, IL-4, IL-10, transforming growth factor β (TGF-β), interferon γ (INF-γ) and indoleamine 2,3-dioxygenase (IDO) from the supernatants were determined. Islets viability and function were also assessed. In vivo, streptozotocin-induced diabetic mice underwent rat islets transplantation were pre-treated with above DCs. At designated time, xeno-islets were subjected to histopathology, immunohistochemistry, survival time and functional tests. Peripheral blood T lymphocyte profiles were also examined.
CD86-silenced-DCs had unchanged expression of CD80 and significantly suppressed the proliferation of lymphocytes. CD86-silenced-DCs simultaneously reduced IL-2 and INF-γ and increased IL-10, TGF-β and IDO, while had minimal effect on IL-4. The CD86-silenced-DCs also improved cell viability and function of xeno-islets when compared to untransfection and transfection control groups. In xeno-islets transplanted diabetic mice, transfer of CD86-silenced-DCs resulted in improved histopathology and dramatically prolonged survival time of the islets. These effects were also mirrored by the functional tests. Further analysis revealed that CD86-silenced-DCs had up-regulated levels of CD4(+)CD25(+)T cells in the peripheral blood compared to the other groups.
CD86-silenced-DCs induced immune tolerance of rat xeno-islets in recipient diabetic mice with up-regulated peripheral blood CD4(+)CD25(+)T cells.
抗原呈递细胞（APCs）已被证明在免疫耐受中发挥双重作用。最近，有力证据表明，表达CD80而非CD86的抗原呈递细胞可保护同种异体移植物。我们研究了树突状细胞（DCs）中CD80的调节是否能为异种胰岛提供保护。
在体外，分离出的成熟小鼠树突状细胞分别进行未转染、用CD86小干扰RNA（siRNA）转染或阴性对照siRNA转染。将这些树突状细胞用于混合淋巴细胞反应，其中进一步加入大鼠胰岛和小鼠脾细胞。共培养第3天，检测淋巴细胞增殖情况，并测定上清液中的白细胞介素（IL）-2、IL-4、IL-10、转化生长因子β（TGF-β）、干扰素γ（INF-γ）和吲哚胺2,3-双加氧酶（IDO）。还评估了胰岛的活力和功能。在体内，用上述树突状细胞对链脲佐菌素诱导的糖尿病小鼠进行大鼠胰岛移植预处理。在指定时间，对异种胰岛进行组织病理学、免疫组织化学、存活时间和功能测试。还检测了外周血T淋巴细胞谱。
沉默CD86的树突状细胞CD80表达未变，显著抑制了淋巴细胞增殖。沉默CD86的树突状细胞同时降低了IL-2和INF-γ水平，增加了IL-10、TGF-β和IDO水平，而对IL-4影响最小。与未转染和转染对照组相比，沉默CD86的树突状细胞还改善了异种胰岛的细胞活力和功能。在移植了异种胰岛的糖尿病小鼠中，转移沉默CD86的树突状细胞导致组织病理学改善，胰岛存活时间显著延长。这些作用在功能测试中也得到体现。进一步分析显示，与其他组相比，沉默CD86的树突状细胞外周血中CD4(+)CD25(+)T细胞水平上调。
沉默CD86的树突状细胞通过上调外周血CD4(+)CD25(+)T细胞，诱导受体糖尿病小鼠对大鼠异种胰岛产生免疫耐受。
