异种胸腺修饰对淋巴细胞功能的影响

Influence of intrathymic inoculation with xenogeneic antigen on the function of lymphocytes

目的探讨猪-猴异种胸腺修饰对受体淋巴细胞功能可能产生的影响。方法将猪淋巴细胞注入猴胸腺内,在胸腺修饰前后,分别分组行猪猴单向混合淋巴细胞反应。A组：猪淋巴细胞+猴NK细胞+猴T细胞；B组：猪淋巴细胞+猴T细胞；C组：猪淋巴细胞+猴NK细胞。检测细胞增殖及NK细胞活性变化和干扰素(IFN)-γ及肿瘤坏死因子(TNF)-α水平变化。结果胸腺修饰后,A组及B组细胞增殖明显抑制(P＜0．05),IFN-γ及TNF-α分泌明显下降(P＜0．05)；C组细胞增殖及IFN-γ及TNF-α分泌均无明显差异(P＞0．05)。单独胸腺修饰前后比较,A组NK细胞杀伤活性均较C组有明显提高(P＜0．05)。结论胸腺修饰对T细胞可产生一定程度功能抑制,并减少相关细胞因子分泌,对NK细胞分泌细胞因子无影响。T细胞可通过细胞因子在一定程度上提高NK细胞杀伤活性,但抑制T细胞功能对NK细胞活性无明显影响。

Objective To investigate the influence of intrathymic inoculation with xenogeneic antigen on the function of recipient lymphoeytes, especially natural killer （NK） cells. Methods Three mixed cell euhures were performed using different lymphoeytes. The T cells and NK cells from recipients （Rhesus monkey） were, respectively, mixed and euhured with lymphoeytes from donors （meishan pig） before intrathymie pretreatment. The same mixed euhures were performed using lymphoeytes from recipients after the intrathymie inoculation of donor xenogeneie antigen. After incubation, cells were washed and a 3H-TdR releasing assay was performed to assess the eytotoxieity of NK cells and T cells. The levels of IFN-γ and TNF-α in the supernatant were assayed by ELISA. Results Compared with the result before inoculation, the secretion of IFN-γ and TNF-α of NK cells remained stable after the intrathymie treatment （ P 〉 0.05 ）. But the eytotoxieity of T cells was signifieantly suppressed （ P 〈 0.05 ）. The levels of IFN-γ secreted by T cells were dropped from （93.9 ± 7.2） ng/L to （79.9± 5.8 ） ng/L （P 〈 0.05 ） and the level of TNF-α was obviously dropped from （19.6 ± 1.9） U/mL to （13.2 ± 2.6） U/mL （P 〈 0.05 ）. The suppression of T cell function could not reduce the cytotoxieity of NK cells （ P 〉 0.05 ）. Conclusion Intrathymie inoculation of xenogeneie antigen can specially suppress the eytotoxieity of T cells and decrease the level of eytokines secreted by T cells in recipients, but not influence the eytokine secretion of NK cells,suggesting T cells can enhance the eytotoxieity of NK cells through eytokines, but can not decrease the eytotoxieity of NK cells if the function of T cells is suppressed.