微囊化CEA转基因细胞疫苗对小鼠免疫功能的影响

目的：探讨微囊化癌胚抗原(CEA)转基因细胞疫苗免疫小鼠后，对小鼠免疫功能的影响。方法：采用³H-TdR掺入法，测定ConA诱导荷瘤小鼠脾淋巴细胞的增殖作用；采用³H-TdR后标记法，测定荷瘤小鼠脾淋巴细胞NK细胞毒；以ELISA法测定小鼠脾淋巴细胞IL-2和IFNγ细胞因子水平；利用流式细胞术检测CEA疫苗免疫对小鼠脾T淋巴细胞亚群CD3、CD4、CD8百分率，CD4/CD8比值和NK细胞的影响；采用RT-PCR方法检测IL-2、IFNγ mRNA的表达水平。 结果：微囊化CEA疫苗免疫可以有效增强ConA诱导的小鼠淋巴细胞增殖能力，促进IL-2、IFNγ的产生以及增强NK细胞的细胞毒活性（P<0.05，P<0.01，P<0.05）；微囊化CEA疫苗能提高荷瘤小鼠CD4/CD8比值及NK细胞数（P<0.05，P<0.05）；促进脾细胞中细胞因子IL-2、INFγ mRNA的表达。 结论：微囊化CEA转基因细胞疫苗具有增强荷瘤小鼠免疫功能的作用，提示该疫苗可作为有效的抗CEA阳性肿瘤的治疗性疫苗。

Influence of microencapsulated tumor cell vaccine transfected with CEA on mouse cellular immunity

Objective To study the effect of microencapsulated tumor cell vaccine against CEA on immune function in tumor-bearing mice. Methods BALB/c mice were inoculated with 1×106 hepatocarcinoma cell line H-22 cells transfected with human CEA encoding sequence. Spleens were removed to prepare single cell suspensions. ConA-induced lymphocyte proliferation and NK cytotoxicity were detected by 3H-TdR incorporation assays. The levels of IL-2 and IFNγ were determined by ELISA and the mRNA expressions of the cytokines were analyzed by RT-PCR. The proportion of T lymphocyte subsets and NK cells were detected by FCM. Results Microencapsulated CEA tumor cell vaccine enhanced mitogen-induced proliferation and NK cytotoxicity of the splenocytes from tumor-bearing mice and promoted the expressions of IL-2 and IFNγ induced with ConA(P<0.05,P<0.01,P<0.05). Microencapsulated CEA vaccine increased the proportion of CD4 and decreased the proportion of CD8, leading to the increase of CD4/CD8 ratio(P<0.05). Conclusion Microencapsulated tumor cell vaccine against CEA can promote the immune function in tumor-inoculated mice, indicating that it may be an effective therapeutic vaccine to inhibit CEA positive tumors.