靶向抑制Myc对小鼠LLC全细胞疫苗免疫原性的影响

EFFECT OF TARGETED INHIBITION OF Myc ON IMMUNOGENICITY OF LEWIS LUNG CARCINOMA WHOLE-CELL VACCINE IN MICE

目的制备小鼠Lewis肺癌(Lewis lung carcinoma,LLC)全细胞疫苗,并探讨该疫苗在提高C57BL/6N小鼠免疫系统对抗LLC方面的作用。方法利用TCGA数据库分析MYC扩增背景下人类肺腺癌(lung adenocarcinoma,LUAD)组织内免疫细胞浸润丰度的变化特点,探讨确定制备LLC全细胞疫苗时紫外线照射的最佳时长。利用小鼠模型,评估靶向抑制Myc的LLC全细胞疫苗在抵抗LLC方面的效果。结果在人LUAD组织样本中,相较于N-MYC低表达组,N-MYC高表达组的激活CD4^(+)记忆T细胞与激活NK细胞浸润丰度显著降低(W=28233、27990,P<0.05),Tregs细胞浸润丰度显著升高(W=36074,P<0.05)。抑制剂处理过的小鼠LLC细胞在经过15 min的紫外线照射后完全失去活性,并且LLC细胞内的c-Myc、N-Myc和PD-L1表达量显著降低(t=6.26~13.51,P<0.05)。在小鼠模型实验中,与Irra组相比,Irra处理组中的小鼠表现出肿瘤生长速度减缓和生存期延长的现象。此外,Irra处理组小鼠的脾脏和肿瘤内CD3^(+)CD8^(+)/CD3^(+)T细胞比值以及血清中的细胞因子TNF-α和IFN-γ表达水平也显著增加(F=54.83~381.10,P<0.05)。结论本研究成功制备了LLC全细胞疫苗。在小鼠实验中,接种靶向抑制Myc的LLC全细胞疫苗能够提高免疫系统对LLC的攻击能力,抑制肿瘤细胞的生长速度,延长小鼠生存期。

Objective To prepare a whole-cell vaccine for murine Lewis lung carcinoma(LLC),and to investigate the role of this vaccine in enhancing the anti-LLC ability of immune system in C57BL/6N mice.Methods TCGA database was used to analyze the changes in the infiltration level of immune cells within human lung adenocarcinoma(LUAD)tissue in the context of MYC amplification,and the optimal duration of ultraviolet irradiation was explored for the preparation of LLC whole-cell vaccine.A mouse model was used to assess the effect of LLC whole-cell vaccine with targeted inhibition of Myc on resistance to LLC.Results In human LUAD tissue samples,compared with the low N-MYC expression group,the high N-MYC expression group had a significant reduction in the infiltration abundance of activated CD4^(+)memory T cells and activated NK cells(W=28233,27990,P<0.05)and a significant increase in the infiltration abundance of Tregs cells(W=36074,P<0.05).The mouse LLC cells treated by an inhibitor completely lost their activity after 15 minutes of ultraviolet irradiation,and there were significant reductions in the expression levels of c-Myc,N-Myc,and PD-L 1 within LLC cells(t=6.26-13.51,P<0.05).In the mouse model experiment,compared with the Irra group,the Irra treatment group showed a reduction in tumor growth rate and an increase in survival time.In addition,the Irra treatment group had significant increases in CD3^(+)CD8^(+)/CD3^(+)ratio in the spleen and tumor and the serum levels of the cytokines tumor necrosis factor-α and interferon gamma(F=54.83-381.10,P<0.05).Conclusion The LLC whole-cell vaccine is successfully prepared in this study.In the mouse experiment,vaccination of the LLC whole-cell vaccine with targeted inhibition of Myc can enhance the ability of the immune system to attack LLC,thereby reducing tumor growth rate and prolonging survival time.