接种CEA重组痘苗病毒对小鼠CEA^+肿瘤抑制作用的机制探讨

A Study of the inhibitory effect of a recombinant CEA vaccinia virus inocnlation on mouse CE^A positive tumor

目的探讨CEA重组痘苗病毒(rV-CEA)治疗CEA＋肿瘤的机制。方法以我室构建的rV-CEA, 腹腔接种供体C57/BL小鼠，取其脾细胞及腹腔巨噬细胞(MΦ)，分别过继转移给荷CEA＋-HePa肝癌细胞的C57/BL小鼠，检测该供体小鼠脾细胞、腹腔MΦ及相应受体的脾细胞体外杀瘤细胞的效应。结果接种rV-CEA的供体小鼠的脾细胞及腹腔MΦ过继免疫给受体小鼠，具有明显抑制受体CEA阳性肿瘤生长的作用。体外实验表明，该供体脾细胞及接种了供体MΦ的受体脾细胞对同一靶细胞的杀伤活性明显增强，但供体MΦ体外的细胞毒活性无明显增加。结论rV-CEA对CEA＋肿瘤的抑制作用，可能主要通过CEA特异性免疫反应激活T细胞而实现。MΦ作为抗原提呈细胞可通过激活T细胞而杀伤肿瘤细胞，具体机制值得进一步研究。

：Aim To explore antitumor mechanism of a recombinant vaccinia virus containing the human CEA-cDNA (rV-CEA). Methods C57/BL mice were immunized three times with rV-CEA. Six weeks later, the macrophages(MΦs)and splenocytes from rV-CEA-immunized donors were transferred to CEA＋-HePa tnmor-bearing recipients,Meanwhile, the antitumor effects of these donor's MΦs and splenocytes and that of the recipient's splenocytes were detected in vitro. Results The MΦs and splenocytes from rV-CEA-immunized donors possessed strong antitumor activity in CEA-positive tumor-bearing recipients. The in vitro antitumor effect of splenocytes from mice inoculated with MΦs from rV-CEA-immunized donors were markedly stronger than those from W-VV-immunized donors. However,the in vitro antitumor effect of the MΦs from rV-CEA-immunized donors was the same as those from W-VV-immunized donors. Conclusion It is demonstrated that antitumor activity induced with rV-CEA may be mediated mainly by antigen present cells (the MΦs), which activated tumor-specific T cells to kill tumor cells.