Immune Mechanism of Tumor Cell Lysate Combined with IL-2 Preventing Melanoma and Inhibiting Tumor Growth / 肿瘤防治研究

ABSTRACT

Objective To investigate the preventive and inhibitory effects of tumor cell lysate(TCL) combined with IL-2 on melanoma and the potential immune mechanism. Methods The B16F10 melanoma TCL cell were prepared using an ultrasonic disruptor. Twenty-four C57BL/6 mice were randomly divided into four groups which were immunized with PBS, IL-2, TCL and TCL+IL-2 for three weeks, and contra lateral tumors were implanted in the fourth week. We observed onset time of tumor and tumor size, collected peripheral blood continuously and monitored the expression of CD4+T and CD8+T cell subsets dynamically by flow cytometry. Spleen and tumor tissues of mice were also tested for CD4+T and CD8+T cell subsets by flow cytometry and immunohistochemistry, respectively. Results The preventive immunization of the TCL+IL-2 group significantly delayed the onset time of tumor (P=0.034); moreover, the tumor volume (P=0.023) and tumor weight (P=0.0015) were also significantly smaller than those in the control group. The expression of CD8+T cell subsets in the TCL+IL-2 group and the TCL-only group were significantly higher than that in the control group (P=0.0016, P=0.012). However, the CD4+T cell subsets of the TCL+IL-2 group decreased after tumor implantation, compared with the control group (P=0.0089). The expression of CD4+T and CD8+T cell subsets in spleen and tumor tissues were as same as those in peripheral blood. Conclusion The tumor vaccine of TCL combined with IL-2 could prevent the occurrence of melanoma in mouse and effectively inhibit tumor growth by activating CD8+T cells.