B7-1/B7-H1相对比例变化对Hsp70-肽复合物抗肿瘤免疫效应的影响

目的：探讨Hsp7肽复合物对B7-1／B7-H1相对比例的影响及真核表达可溶性PD-1(sPD-1)对Hsp70-肽复合物抗肿瘤作用的影响。方法：通过RT-PCR和半定量PCR技术检测Hsp70-肽复合物体外刺激和体内免疫对小鼠脾细胞正调控共刺激分子B7-1和抑制性共刺激分子B7-H1及其受体PD-1表达的影响；体内转染表达sPD-1后，观察Hsp70-肽复合物免疫小鼠的肿瘤生长以及脾淋巴细胞毒性的变化。结果：基因表达检测表明．Hsp70-肽复合物体外刺激的小鼠脾细胞B7-1 mRNA和B7-H1 mRNA的水平随时问而变化，B7-1／B7-H1比值随刺激时间而增高；Hsp70-肽复合物体内免疫小鼠后期脾细胞B7-1表达下降，B7-H1及其受体PD-1表达上调，B7-1／B7-H1比值逆转；体内表达sPD-1可显著增强和延长Hsp70-肽复合物的抑瘤效果；体内表达sPD-1可提高Hsp70-肽复合物免疫的荷瘤小鼠脾细胞的杀伤率。结论：Hsp70-肽复合物的刺激引起共刺激分子B7-1和B7-H1表达的变化，B7-1／B7-H1的比例与激活效应相关，sPD-1通过阻抑B7-H1／PD-1途径、上调B7-1／B7-H1比例，可增强免疫应答，提高Hsp70-肽复合物特异性免疫治疗肿瘤的效应。

The effect of Hsp70-peptides on B7-1/B7-H1 ratio and the anti-tumor efficiency

Objective:To investigate the effect of Hsp70-peptides complex on B7-1/B7-H1 ratio and the effect of the soluble PD-1(sPD-1)on the anti-tumor immune efficacy of Hsp70-peptides complex.Methods:The splenocytes were treated with Hsp70-peptides complex in vitro and in vivo, and then the levels of B7-1 mRNA and B7-H1 mRNA in splenocytes were determined by RT-PCR technique. The mice vaccinated with Hsp70-peptides complex were applied for sPD-1 effect.Results:The levels of B7-1 mRNA and B7-H1 mRNA in splenocytes increased after the stimulation with Hsp70-peptides complex in vitro, and B7-1/B7-H1 ratio increased too. In in vivo experiment, the B7-1 level of immunized mice increased within the first two weeks and then decreased dramatically,but the B7-H1 level increased stably, and so the B7-1/ B7-H1 ratio increased firstly and then reversed in the late immune phase. sPD-1 administration enhanced the anti-tumor efficacy of Hsp70-peptides,which immunized the mice. sPD-1 transfection in mice enhanced the cytotoxic activity of splenocytes in the inmmunized mice.Conclusion:Hsp70-peptides complex has the effect on the expression of B7-1 and B7-H1 in splenocytes. sPD-1 has the synergistic anti-tumor effect with Hsp70-peptides complex by blocking the specific ligand B7-H1 and raising the B7-1/B7-H1 ratio.