编码IL-7的溶瘤疱疹病毒通过激活CD8^(+)T细胞增强对肝癌的杀伤活性

Oncolytic spore eruption virus encoding IL-7 enhances killing activity of liver cancer by activating CD8^(+)T cells

目的:探究分泌IL-7的溶瘤疱疹病毒(HSV)是否可以通过激活CD8^(+)T细胞抑制肝癌生长。方法:Western blot检测IL-7表达情况;结晶紫染色法检测溶瘤病毒HSV以及HSV-IL-7对肿瘤细胞的体外裂解情况;皮下移植瘤模型检测HSV以及HSV-IL-7对肿瘤的抑制能力;ELISA法检测血清以及肿瘤组织中IL-7、IFN-γ、TNF-α含量;免疫组化法检测肿瘤组织中CD8^(+)T细胞的浸润情况;流式细胞术检测肿瘤浸润CD8^(+)T细胞Granzyme B的分泌水平。结果:HSV-IL-7感染的肿瘤细胞均高表达IL-7;HSV以及HSV-IL-7在体外均可以有效裂解B16-F10、CT-26以及H22肿瘤细胞系,且具有剂量依赖性;HSV-IL-7可以显著抑制H22肝癌细胞的体内生长(P<0.01),延长荷瘤小鼠的生存期(P<0.001);HSV-IL-7可以显著提高肿瘤部位IL-7的含量(P<0.0001),同时有效增加肿瘤浸润CD8^(+)T细胞的数目(P<0.001);HSV-IL-7可以显著增强肿瘤浸润CD8^(+)T细胞分泌Gran-zyme B的能力以及增加肿瘤组织中IFN-γ和TNF-α含量(P<0.0001)。结论:HSV-IL-7在体内外均具有良好的肿瘤抑制活性,同时其可以通过分泌IL-7,激活体内CD8^(+)T细胞的抗肿瘤性,从而进一步抑制肿瘤生长并延长荷瘤小鼠的生存期。

Objective:To investigate whether IL-7-secreting oncolytic herpes simplex virus(HSV)could activate CD8^(+)T cells and inhibit the growth of hepatocellular carcinoma.Methods:The expression of IL-7 was detected by Western blot.The in vitro cleavage of tumor cells by tumor oncolytic virus HSV and HSV-IL-7 were detected by crystal violet staining.The tumor inhibition ability of HSV-IL-7 and HSV were detected in subcutaneous transplanted tumor model.Levels of IL-7,IFN-γand TNF-αin serum and tumor tissues were determined by ELISA.The infiltration of CD8^(+)T cells in tumor tissues was detected by immunohistochemistry.Flow cytometry was used to detect Granzyme B secretion in CD8^(+)T cells infiltrated by tumor.Results:Tumor cells infected with HSV-IL-7 expressed high level of IL-7.Both HSV and HSV-IL-7 can effectively lyse B16-F10,CT-26 and H22 tumor cell lines in a dose-dependent manner in vitro.HSV-IL-7 could significantly inhibit the growth of H22 hepatoma cells in vivo(P<0.01)and prolong the survival time of tumorbearing mice(P<0.001).HSV-IL-7 could significantly increase the IL-7 content in tumor sites(P<0.0001),and effectively increase the number of tumor infiltrating CD8^(+)T cells(P<0.001).HSV-IL-7 significantly enhanced Granzyme B secretion of tumor-infiltrating CD8^(+)T cells and IFN-γand TNF-αin tumor tissues(P<0.0001).Conclusion:HSV-IL-7 has well tumor inhibition activity in vivo and in vitro.It also can activate the anti-tumor activity of CD8^(+)T cells in vivo by secreting IL-7,inhibit tumor growth and prolong the survival time of tumor-bearing mice.