热休克蛋白65与βhCG多表位融合蛋白疫苗的抗黑色素瘤研究

Study on the Anti-Tumor Effects of Vaccines Against Ectopic Human Chorionic Gonadotrophin Beta(eβhCG)

选取HSP65-X10-βhCGCTP37融合蛋白作为免疫原,观察其对小鼠黑色素瘤B16-F10的体内抑制作用,以及对荷瘤小鼠生存期的影响,并对其抗肿瘤的作用机理进行初步探讨。以制备的HSP65-X10-βhCGCTP37蛋白免疫C57BL/6J小鼠,2 w免疫1次,共4次。第4次免疫后的第2 w,进行肿瘤攻击实验。HSP65-X10-βhCGCTP37激发的免疫应答对于小鼠黑色素瘤的攻击起到了有效的保护作用,与PBS阴性对照组比较,实验组小鼠的平均肿瘤重量显著降低(P<0.05);并有效延长了荷瘤鼠的生存期;小鼠的黑色素移植瘤的肿瘤病理切片结果显示,疫苗对肿瘤细胞的体内生长有明显的抑制作用,核分裂减少,淋巴细胞浸润增加,有灶性坏死。HSP65-X10-βhCGCTP37蛋白疫苗能有效地抑制小鼠黑色素瘤的生长。

β-hCG, as a highly promising tumor-associated antigen （TSA） , contains a number of B-cell epitopes which are located in 37 amino acid C-terminal peptide（CTP37） of β-subunit. It is reported that a 10-amino acid sequence（109-118） of β-hCG（ also in CTP37 ） was specifically recognized. Furthermore, HSP65 could act as another important part in enhancing immnnogenicity. It has been demonstrated that HSP65 possesses dual functions in eliciting an immune response and serving as an adjuvant in a vaccine. In the current experiment,mice were immunized with HSP65-X10-βhCGCTP37 fused protein by subcutaneous injection for 4 times at biweekly intervals. After the 4^th immunization, all mice were loaded subcutaneously by B16-F10 cells. The mice were sacrificed 2 weeks after tumor implantation,and tumor tissue sections were made from mice immunized with vaccines. The results showed that HSP65-X10-βhCGCTP37 administration effectively inhibited the growth of B16-F10 melanoma in mice and prolonged the survival of the tumor-bearing mice. Compared with PBS group, the average weight of tumors of the vaccined mice was much lower. And the pathological sections showed that the karyokinesis of tumor cells decreased, the lymphocytes invasion inceased, and nodules neorobiosis appeared. In summary,it has been verified that the administration of HSP65-X10-βhCGCTP37 could effectively inhibit the growth of melanoma in vivo.