ehCGβ肿瘤基因疫苗诱生抗体的抗肿瘤作用

Anti-Tumor Effects of Anti-hCGβ Antibody Induced by Gene Immunization

目的:探讨ehCGβ肿瘤基因疫苗诱生抗hCGβ抗体的抗肿瘤作用。方法:以TR421-ehCGβ质粒实施基因免疫、空载质粒为对照,ELISA法检测免疫小鼠血清中特异性抗hCGβ-IgG抗体;以~3H-TdR掺入法检测灭活补体前后免疫血清对eh-CG^+肿瘤细胞增殖活性的抑制作用;倒置显微镜和FACS分别观察Hela细胞的形态变化及细胞凋亡情况。结果:TR421-ehCGβ质粒诱导小鼠产生高水平抗hCGβ-IgG抗体;抗hCGβ免疫血清对Hela细胞的抑制增殖作用明显强于对照血清,灭活补体后抑制率无明显变化;免疫血清的抑制作用与肿瘤细胞的hCGβ表达水平有一定的相关性;Hela细胞与免疫血清孵育后细胞死亡明显增多,但其中凋亡细胞为3.42％,与对照血清孵育细胞的凋亡(1.88％)比较无明显差异。结论:ehCGβ肿瘤基因疫苗诱生的抗hCGβ抗体以不依赖补作方式抑制ehCGβ^+肿瘤细胞的增殖。

Objective: To investigate the anti-tumor effects of anti-hCGβ antibody induced by gene immunization with ectopic human chorionic gonadotropin β-subunit. Methods: Sera were collected at the indicated times from the mice im- munized with plasmid TR421-ehCGβ-coding for hCGβ and mock DNA respectively and were determined the levels of anti- hCGβ antibody by ELISA. The tumor cells expressing ehCGβ were treated with different doses of sera, in which comple- ment were or not inactivated. The proliferation and morphological change as well as apoptosis of tumor cells were detected by [~3H]-Thymidine incorporation assay, converse-microscope and FACS. respectively. Results: All mice immunized with plasmid TR421-ehCGβ developed high levels of anti-hCGβ antibody, which could inhibit obviously the proliferation of He- la cells compared with the serum from animals immunized with mock DNA (P<0. 05), everi if complement was inactiva- ted. However, the inhibition of normal serum decreased significantly after complement was inactivated. The inhibition ac- tivity of the anti-hCGβ serum correlated with the expression level of ehCGβ in the tumor cells. The number of dead Hela cells increased obviously upon being incubated with the anti-hCGβ serum, while the percentage of the apoptotic cells was only 3. 42%, which had no significant difference with the cells incubated with the normal serum (1. 88%). Conclusion: The anti-hCGβ antibody induced by gene immunization had significant inhibitory influence on the proliferation of tumor cells expression ehCGβ in complement-independent manner.