Omoto Masahiro, Katikireddy Kishore R, Rezazadeh Alexandra, Dohlman Thomas H, Chauhan Sunil K
Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary and Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States.
Invest Ophthalmol Vis Sci. 2014 Sep 16;55(10):6631-8. doi: 10.1167/iovs.14-15413.
To investigate whether systemically injected syngeneic mesenchymal stem cells (MSCs) can home to the transplanted cornea, suppress induction of alloimmunity, and promote allograft survival.
Mesenchymal stem cells were generated from bone marrow of wild-type BALB/c or GFP (green fluorescent protein)+ C57BL/6 mice, and 1×10(6) cells were intravenously injected to allografted recipients 3 hours after surgery. Mesenchymal stem cells homing to the cornea were examined at day 3 post transplantation by immunohistochemistry. MHC (major histocompatibility complex) II+CD11c+ cells were detected in the cornea and lymph nodes (LNs) 14 days post transplantation using flow cytometry. Cytokine expression of bone marrow-derived dendritic cells (BMDCs) was determined using real-time PCR. ELISPOT assay was used to assess indirect and direct host T cell allosensitization, and graft survival was evaluated by slit-lamp biomicroscopy weekly up to 8 weeks.
Intravenously injected GFP+ MSCs were found in abundance in the transplanted cornea, conjunctiva, and LNs, but not in the ungrafted (contralateral) tissue. The frequencies of mature MHC II+CD11c+ antigen-presenting cells (APCs) were substantially decreased in the corneas and draining LNs of MSC-injected allograft recipients compared to control recipients. Maturation and function of in vitro cultured BMDCs were decreased when cocultured with MSCs. Draining LNs of MSC-injected allograft recipients showed lower frequencies of IFNγ-secreting Th1 cells compared to the control group. Allograft survival rate was significantly higher in MSC-injected recipients compared to non-MSC-injected recipients.
Our data demonstrate that systemically administered MSCs specifically home to the inflamed ocular surface and promote allograft survival by inhibiting APC maturation and induction of alloreactive T cells.
研究全身注射同基因间充质干细胞（MSCs）是否能归巢至移植角膜，抑制同种免疫诱导，并促进同种异体移植存活。
从野生型BALB/c或绿色荧光蛋白（GFP）+ C57BL/6小鼠的骨髓中生成间充质干细胞，并在手术后3小时将1×10⁶个细胞静脉注射给同种异体移植受体。移植后第3天通过免疫组织化学检查归巢至角膜的间充质干细胞。移植后14天使用流式细胞术检测角膜和淋巴结（LNs）中的主要组织相容性复合体（MHC）II+CD11c+细胞。使用实时PCR测定骨髓来源的树突状细胞（BMDCs）的细胞因子表达。ELISPOT测定用于评估间接和直接宿主T细胞同种致敏，并通过裂隙灯显微镜每周评估移植物存活情况，直至8周。
静脉注射的GFP+ MSCs大量存在于移植的角膜、结膜和LNs中，但未在未移植（对侧）组织中发现。与对照受体相比，注射MSCs的同种异体移植受体的角膜和引流LNs中成熟MHC II+CD11c+抗原呈递细胞（APC）的频率显著降低。与MSCs共培养时，体外培养的BMDCs的成熟和功能降低。与对照组相比，注射MSCs的同种异体移植受体的引流LNs中分泌IFNγ的Th1细胞频率较低。与未注射MSCs的受体相比，注射MSCs的受体的同种异体移植存活率显著更高。
我们的数据表明，全身给药的MSCs特异性归巢至炎症性眼表，并通过抑制APC成熟和同种反应性T细胞诱导来促进同种异体移植存活。
