Department of Regenerative Medicine and Tissue Engineering, National Cerebral and Cardiovascular Center, Osaka, Japan.
J Mol Cell Cardiol. 2012 Sep;53(3):420-8. doi: 10.1016/j.yjmcc.2012.06.020. Epub 2012 Jul 13.
We have reported that systemic administration of autologous bone marrow or allogenic fetal membrane (FM)-derived mesenchymal stem cells (MSCs) similarly attenuated myocardial injury in rats with experimental autoimmune myocarditis (EAM). Since rat EAM is a T-helper (Th) cell-mediated autoimmune disease, and recent evidence has indicated that both autologous and allogenic MSCs exert an immunosuppressive effect on Th cell activity, we focused on Th cell differentiation in allogenic FM-MSC administered EAM rats. EAM was induced in Lewis rats by injecting porcine cardiac myosin (day 0). Allogenic FM-MSCs, obtained from major histocompatibility complex mismatched ACI rats, were intravenously injected (5 × 10(5)cells/rat) on days 7, 10, or 14 (MSCd7, MSCd10, or MSCd14 groups, respectively). At day 21, echocardiography confirmed that reduced ejection fraction in the untreated EAM group (63 ± 2%) was significantly improved in the MSCd10 and MSCd14 groups (74 ± 1 and 75 ± 2%, respectively, P<0.01). CD68 immunostaining revealed that prominent macrophage infiltration in the myocardium of the EAM group (1466 ± 93 cells/mm(2)) was significantly decreased in the MSCd10 group (958 ± 139 cells/mm(2), P<0.05). To evaluate Th cell differentiation, we used flow cytometry to determine the percentage of interferon (IFN)-γ positive Th1 and interleukin (IL)-17 positive Th17 cells in peripheral CD4-positive Th cells. The percentage of Th1 cells at day 16 was significantly lower in the MSCd10 (1.3 ± 0.2%) and MSCd14 (1.6 ± 0.3%) groups compared to the EAM group (2.4 ± 0.3%, P<0.05), as was the percentage of Th17 cells in the MSCd10 group (1.9 ± 0.5%) compared to the EAM group (2.2 ± 0.9%, P<0.05). At day 21, infiltrating Th17 cells in myocardium were significantly decreased in the MSCd10 group (501 ± 132 cells/mm(2), P<0.05) compared to EAM (921 ± 109 cells/mm(2)). In addition, human CD4+ Th cells co-cultured with human FM-MSCs exhibited reduced Th1 and Th17 cell-differentiation and proliferation, with increased expression of immunosuppressive molecules including indoleamine 2,3-dioxygenase 2 and IL-6 in co-cultured FM-MSCs. These results suggest that intravenous administration of allogenic FM-MSCs ameliorates EAM via the suppression of Th1/Th17 immunity.
我们曾报道，自体骨髓或异体胎盘中衍生的间充质干细胞（MSCs）的全身给药，同样能减轻实验性自身免疫性心肌炎（EAM）大鼠的心肌损伤。由于大鼠 EAM 是 T 辅助（Th）细胞介导的自身免疫性疾病，并且最近的证据表明，自体和异体 MSCs 对 Th 细胞活性均具有免疫抑制作用，因此我们将重点放在接受异体胎盘中衍生的 MSCs（FM-MSCs）治疗的 EAM 大鼠的 Th 细胞分化上。通过向 Lewis 大鼠注射猪心肌肌球蛋白（第 0 天）来诱导 EAM。在第 7、10 或 14 天（MSCd7、MSCd10 或 MSCd14 组）静脉内注射（5×10（5）个细胞/大鼠）源自主要组织相容性复合物不匹配的 ACI 大鼠的异体 FM-MSCs。在第 21 天，超声心动图证实未经治疗的 EAM 组（63±2%）的射血分数明显改善，MSCd10 和 MSCd14 组分别为（74±1%和 75±2%，P<0.01）。CD68 免疫染色显示，EAM 组心肌中明显的巨噬细胞浸润（1466±93 个细胞/mm（2））在 MSCd10 组中显著减少（958±139 个细胞/mm（2），P<0.05）。为了评估 Th 细胞分化，我们使用流式细胞术来确定外周血 CD4 阳性 Th 细胞中干扰素（IFN）-γ阳性 Th1 和白细胞介素（IL）-17 阳性 Th17 细胞的百分比。在 MSCd10（1.3±0.2%）和 MSCd14（1.6±0.3%）组中，第 16 天 Th1 细胞的百分比明显低于 EAM 组（2.4±0.3%，P<0.05），而 MSCd10 组的 Th17 细胞百分比（1.9±0.5%）也低于 EAM 组（2.2±0.9%，P<0.05）。在第 21 天，MSCd10 组心肌中的浸润性 Th17 细胞（501±132 个细胞/mm（2））明显减少，与 EAM 组（921±109 个细胞/mm（2））相比，P<0.05）。此外，与人 FM-MSCs 共培养的人 CD4+Th 细胞表现出 Th1 和 Th17 细胞分化和增殖减少，同时共培养的 FM-MSCs 中表达了抑制性免疫分子，包括吲哚胺 2,3-双加氧酶 2 和白细胞介素 6。这些结果表明，静脉内给予异体胎盘中衍生的 MSCs 通过抑制 Th1/Th17 免疫来改善 EAM。
