Department of Thoracic Surgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, People's Republic of China.
J Surg Res. 2013 Aug;183(2):894-9. doi: 10.1016/j.jss.2013.01.066. Epub 2013 Feb 22.
Dendritic cells (DCs) are the principal antigen-presenting cells involved in primary immune response and immunoregulation. The function of DCs is believed to depend on their degree of maturation. Mature DCs activate immune responses, whereas immature DCs (imDCs) tend to induce immune tolerance. CD1 is involved in regulating the development of imDCs, which have important roles in initiating or suppressing the immune response after transplantation.
We used male BALB/c mice and C57BL/6 mice (aged 8-10 wk, 18-22 g). We isolated and purified T lymphocytes from mouse spleen. Immature DCs modified by viral delivery of interleukin-10 (IL-10) were stimulated with granulocyte macrophage colony-stimulating factor and lipopolysaccharide (LPS) and treated with anti-CD1d in vitro. We used mixed lymphocyte cultures to evaluate the heterogeneity of T lymphocyte response. We also examined the proliferation of T lymphocytes and the expression of cytokines.
CD1d blockade did not impair granulocyte macrophage colony-stimulating factor and LPS-stimulated DC maturation. We observed a dramatic increase in allogeneic T lymphocyte proliferation (stimulation index) at all tested responder-stimulator ratios in response to imDCs cultured in the presence of LPS (P < 0.05). CD1d has an important role in imDC-primed T cell response (P < 0.05). CD1d blockade reduced the capacity of imDCs to prime allogeneic T cells. T cells pre-sensitized by LPS-stimulated imDCs showed remarkably elevated proliferation in response to T cells from either BALB/c or C57BL/6 mice (P < 0.01). We observed a significant decrease in the proliferation of T cells pre-sensitized by stimulated imDCs after CD1d blockade. Lipopolysaccharide stimulation caused elevated the production of IL-12 and tumor necrosis factor-α (TNF-α) (P < 0.01) and decreased the secretion of IL-10 (P < 0.05). The addition of CD1d neutralization antibody did not significantly change the concentrations of IL-12, TNF-α, or IL-10 produced by imDCs cultured in the presence of LPS (P > 0.05).
Blockade of CD1d impaired the ability of imDCs to stimulate allogeneic T cell response. By reduced T cell proliferation, the secretion of IL-12 and TNF-α decreased and production of a T-helper type 2 cytokine IL-10 increased, which indicates the potential of CD1d blockade as a method to induce immune tolerance to allograft antigens in transplantation.
树突状细胞（DCs）是参与初次免疫应答和免疫调节的主要抗原呈递细胞。DCs 的功能被认为取决于其成熟程度。成熟的 DCs 激活免疫反应，而未成熟的 DCs（imDCs）则倾向于诱导免疫耐受。CD1 参与调节 imDCs 的发育，imDCs 在移植后启动或抑制免疫反应方面具有重要作用。
我们使用雄性 BALB/c 小鼠和 C57BL/6 小鼠（8-10 周龄，18-22g）。我们从鼠脾中分离和纯化 T 淋巴细胞。通过病毒传递白细胞介素-10（IL-10）修饰的未成熟 DCs，并用粒细胞巨噬细胞集落刺激因子和脂多糖（LPS）刺激，并在体外用抗-CD1d 处理。我们使用混合淋巴细胞培养来评估 T 淋巴细胞反应的异质性。我们还检查了 T 淋巴细胞的增殖和细胞因子的表达。
CD1d 阻断并不损害 LPS 刺激的 DC 成熟。我们观察到，在用 LPS 培养的 imDCs 刺激下，所有检测到的反应者-刺激者比例下，同种异体 T 淋巴细胞增殖（刺激指数）均显著增加（P<0.05）。CD1d 在 imDC 诱导的 T 细胞反应中具有重要作用（P<0.05）。CD1d 阻断降低了 imDC 诱导同种异体 T 细胞的能力。由 LPS 刺激的 imDCs 预先致敏的 T 细胞对来自 BALB/c 或 C57BL/6 小鼠的 T 细胞的反应明显增强（P<0.01）。我们观察到，在用 CD1d 中和抗体阻断后，由刺激的 imDC 预先致敏的 T 细胞的增殖显著降低。LPS 刺激导致 IL-12 和肿瘤坏死因子-α（TNF-α）的产生显著增加（P<0.01），IL-10 的分泌减少（P<0.05）。添加 CD1d 中和抗体不会显著改变 LPS 培养的 imDCs 产生的 IL-12、TNF-α 或 IL-10 的浓度（P>0.05）。
CD1d 阻断削弱了 imDC 刺激同种异体 T 细胞反应的能力。通过减少 T 细胞增殖，IL-12 和 TNF-α 的分泌减少，辅助性 T 细胞 2 型细胞因子 IL-10 的产生增加，这表明 CD1d 阻断作为一种诱导移植中同种异体抗原免疫耐受的方法具有潜力。
