Tang Bo, Li Xue, Liu Yuanlin, Chen Xiuhui, Li Ximei, Chu Yanan, Zhu Heng, Liu Weijiang, Xu Fenfen, Zhou Fan, Zhang Yi
Department of Cell Biology, Institute of Military Cognitive and Brain Sciences, Academy of Military Medical Sciences, Academy of Military Sciences, Beijing, China.
Department of Hematology, Peking University First Hospital, Beijing, China.
Cell Physiol Biochem. 2018;46(6):2624-2635. doi: 10.1159/000489689. Epub 2018 May 7.
BACKGROUND/AIMS: Mesenchymal stem cells (MSCs) do not readily migrate to appropriate sites, and this creates a major obstacle for their use in the treatment of graft-versus-host disease (GVHD). Intercellular adhesion molecule-1 (ICAM-1) can guide the homing of various immune cells to the proper anatomical location within secondary lymphoid organs (SLOs), which are the major niches for generating immune responses or tolerance. MSCs rarely migrate to SLOs after intravenous infusion, and are constitutively low expression of ICAM-1. So in our previous work, ICAM-1 was engineered into a murine MSC line C3H10T1/2 by retrovirus transfection system (ICAM-1MSCs). Here, we hypothesized that ICAM-1highMSCs may significantly improve their immunomodulatory effect.
We used different co-culture methods combined with real-time PCR and flow cytometry to evaluate ICAM-1highMSCs immunomodulatory effect on dendritic cells (DCs) and T cells in vitro and in vivo. MSCs were labeled with carboxyfluorescein diacetate succinimidylester (CFSE) to detect its distribution in mouse model.
Our in vitro analyses revealed ICAM-1 MSCs could suppress DCs maturation according to co-culture methods and suppress the T cell immune response according to the mixed lymphocyte response (MLR) and lymphoblast transformation test (LTT) tests. We found that infusion of ICAM-1highMSCs potently prolonged the survival of GVHD mouse model. The infused ICAM-1highMSCs migrate to SLOs in vivo, and suppressed DCs maturation, suppressed CD4+ T cell differentiation to Th1 cells, and increased the ratios of Treg cells.
Taken together, these data demonstrate that ICAM-1highMSCs had an enhanced immunosuppressive effect on DCs and T cells, which may help explain the protective effect in a GVHD model. This exciting therapeutic strategy may improve the clinical efficacy of MSC-based therapy for GVHD.
背景/目的：间充质干细胞（MSCs）不易迁移至合适的部位，这为其用于治疗移植物抗宿主病（GVHD）带来了重大障碍。细胞间黏附分子-1（ICAM-1）可引导各种免疫细胞归巢至次级淋巴器官（SLOs）内的适当解剖位置，而SLOs是产生免疫反应或免疫耐受的主要微环境。静脉输注后，MSCs很少迁移至SLOs，且其ICAM-1呈组成型低表达。因此，在我们之前的研究中，通过逆转录病毒转染系统将ICAM-1导入小鼠MSC系C3H10T1/2（ICAM-1 MSCs）。在此，我们假设ICAM-1高表达的MSCs（ICAM-1highMSCs）可能会显著增强其免疫调节作用。
我们采用不同的共培养方法，并结合实时聚合酶链反应（PCR）和流式细胞术，在体外和体内评估ICAM-1highMSCs对树突状细胞（DCs）和T细胞的免疫调节作用。用羧基荧光素二乙酸琥珀酰亚胺酯（CFSE）标记MSCs，以检测其在小鼠模型中的分布。
我们的体外分析显示，根据共培养方法，ICAM-1 MSCs可抑制DCs成熟，并根据混合淋巴细胞反应（MLR）和淋巴细胞转化试验（LTT）抑制T细胞免疫反应。我们发现，输注ICAM-1highMSCs可显著延长GVHD小鼠模型的生存期。输注的ICAM-1highMSCs在体内迁移至SLOs，抑制DCs成熟，抑制CD4+T细胞向Th1细胞分化，并增加调节性T细胞（Treg细胞）的比例。
综上所述，这些数据表明ICAM-1highMSCs对DCs和T细胞具有增强的免疫抑制作用，这可能有助于解释其在GVHD模型中的保护作用。这种令人兴奋的治疗策略可能会提高基于MSCs的GVHD治疗的临床疗效。
