前列腺特异性抗原细胞毒性T淋巴细胞表位多抗原肽的抗肿瘤免疫效应研究

目的:研究前列腺特异性抗原(PSA)来源的细胞毒性T淋巴细胞(CTL)表位多抗原肽对前列腺癌的抗肿瘤免疫效应。方法:体外分离培养来源于人白细胞抗原(HLA)-A2.1阳性的健康志愿者外周血单个核细胞的成熟树突状细胞(DC),按单抗原肽组(PSA146-154)、多抗原肽组(PSA146-154-MAP4)、阴性对照组(人类免疫缺陷病毒表位肽HIVpol476-484)培养制备相应的效应细胞,以前列腺癌细胞株LNCaP、DU-145和结肠癌SW480细胞为靶细胞,采用标准4 h51Cr释放试验检测不同效应细胞/靶细胞细胞个数比(效/靶比,10∶1、20∶1、40∶1、80∶1)的特异性杀伤效应(以特异性杀伤效率为指标),酶联免疫斑点(ELISPOT)法检测各组效应细胞分泌γ干扰素(IFN-γ)的CD8+效应细胞数量。结果:各组效应细胞对DU-145、SW480细胞均无特异性杀伤效应,单抗原肽组和多抗原肽组效应细胞对LNCaP细胞具有明显的特异性杀伤效应,且多抗原肽组强于单抗原肽组,与效/靶比呈正相关。与阴性对照组比较,单抗原肽组和多抗原肽组分泌IFN-γ的CD8+效应细胞数量明显增加;与单抗原肽组比较,多抗原肽组分泌CD8+细胞数量明显增加(P<0.05)。结论:PSA多抗原肽能诱导机体产生强于单抗原肽的PSA特异性抗肿瘤免疫效应,并可以在一定程度上增强非特异性的抗肿瘤效果。

Study on Anti-tumor Immune Responses of Epitopes Multiple Antigen Peptide of Cytotoxic T Lymphocytes from Prostate Specific Antigen

OBJECTIVE: To investigate anti-tumor immune response of epitopes multiple antigen peptide of cytotoxic T lymphocytes(CTL) from prostate specific antigen(PSA).METHODS: Dendritic cells(DC) were generated from the peripheral blood mononuclear cells of healthy volunteers with positive(HLA)-A2.1 in vitro.Response cells were cultured and prepared in accordance with single antigen peptide group(PSA146-154 group),multiple antigen peptide group(PSA146-154-MAP4 group) and negative control group(human HIV virus epitopes peptide HIVpol476-484).Using prostate cancer cell line LNCaP,DU-145 and colon cancer SW480 cells as target cells,and the specific killing effect of the number ratio of response cell to targe cells(10 ∶ 1,20 ∶ 1,40 ∶ 1,80 ∶ 1) were determined by a standard 4 h 51Cr release assay(using specific killing rate as index).ELISPOT was used to detect the number of CD8+ response cells of IFN-γ.RESULTS: There were no specific killing effects of response cells on DU-145 and SW480 cells,while significant specific killing effects of response cells on LNCaP cells were found in PSA146-154 group and PSA146-154-MAP4 group and that of PSA146-154-MAP4 group was superior to PSA146-154 group.It was positively correlated to the number ratio of response cell to targe cells.Compared with negative control group,the number of CD8+ response cells of IFN-γ in PSA146-154 group and PSA146-154-MAP4 group increased significantly;compared with PSA146-154 group,the number of CD8+ response cells in PSA146-154-MAP4 group increased significantly(P<0.05).CONCLUSION: PSA multiple antigen peptides not only elicit a more powerful specific anti-tumor immune response,but also elicit a more powerful non-specific anti-tumor immune response,compared with single antigen peptide.