Department of Internal Medicine, Section Nephrology and Transplantation, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
Clin Exp Immunol. 2013 Dec;174(3):449-58. doi: 10.1111/cei.12199.
CD28/B7 co-stimulation blockade with belatacept prevents alloreactivity in kidney transplant patients. However, cells lacking CD28 are not susceptible to belatacept treatment. As CD8(+) CD28(-) T-cells have cytotoxic and pathogenic properties, we investigated whether mesenchymal stem cells (MSC) are effective in controlling these cells. In mixed lymphocyte reactions (MLR), MSC and belatacept inhibited peripheral blood mononuclear cell (PBMC) proliferation in a dose-dependent manner. MSC at MSC/effector cell ratios of 1:160 and 1:2·5 reduced proliferation by 38·8 and 92·2%, respectively. Belatacept concentrations of 0·1 μg/ml and 10 μg/ml suppressed proliferation by 20·7 and 80·6%, respectively. Both treatments in combination did not inhibit each other's function. Allostimulated CD8(+) CD28(-) T cells were able to proliferate and expressed the cytolytic and cytotoxic effector molecules granzyme B, interferon (IFN)-γ and tumour necrosis factor (TNF)-α. While belatacept did not affect the proliferation of CD8(+) CD28(-) T cells, MSC reduced the percentage of CD28(-) T cells in the proliferating CD8(+) T cell fraction by 45·9% (P = 0·009). CD8(+) CD28(-) T cells as effector cells in MLR in the presence of CD4(+) T cell help gained CD28 expression, an effect independent of MSC. In contrast, allostimulated CD28(+) T cells did not lose CD28 expression in MLR-MSC co-culture, suggesting that MSC control pre-existing CD28(-) T cells and not newly induced CD28(-) T cells. In conclusion, alloreactive CD8(+) CD28(-) T cells that remain unaffected by belatacept treatment are inhibited by MSC. This study indicates the potential of an MSC-belatacept combination therapy to control alloreactivity.
CD28/B7 共刺激阻断剂贝利尤单抗可预防肾移植患者的同种异体反应。然而，缺乏 CD28 的细胞对贝利尤单抗治疗不敏感。由于 CD8+CD28-T 细胞具有细胞毒性和致病性，我们研究了间充质干细胞（MSC）是否能有效控制这些细胞。在混合淋巴细胞反应（MLR）中，MSC 和贝利尤单抗以剂量依赖的方式抑制外周血单核细胞（PBMC）的增殖。MSC 与效应细胞的比例为 1:160 和 1:2.5 时，增殖分别减少 38.8%和 92.2%。贝利尤单抗浓度为 0.1μg/ml 和 10μg/ml 时，增殖分别抑制 20.7%和 80.6%。两种治疗方法联合使用不会相互抑制其功能。刺激后的 CD8+CD28-T 细胞能够增殖，并表达细胞毒性和细胞毒性效应分子颗粒酶 B、干扰素（IFN）-γ 和肿瘤坏死因子（TNF）-α。虽然贝利尤单抗不影响 CD8+CD28-T 细胞的增殖，但 MSC 将增殖的 CD8+T 细胞亚群中 CD28-的比例降低了 45.9%（P=0.009）。在 CD4+T 细胞辅助下，MLR 中的 CD8+CD28-T 细胞作为效应细胞获得 CD28 表达，这一效应与 MSC 无关。相反，在 MSC 共培养的 MLR 中，同种刺激的 CD28+T 细胞不会丢失 CD28 表达，这表明 MSC 控制的是预先存在的 CD28-T 细胞，而不是新诱导的 CD28-T 细胞。总之，贝利尤单抗治疗未受影响的同种异体反应性 CD8+CD28-T 细胞被 MSC 抑制。本研究表明 MSC-贝利尤单抗联合治疗控制同种异体反应的潜力。
