Yang Hao, Lei Guanglin, Sun Fang, Cheng Jinxia, Yan Jin, Zhang Shaogeng, Yang Penghui
National Clinical Research Center for Infectious Diseases, Fifth Medical Center of Chinese PLA General Hospital, Beijing, China.
The Graduate Department, Hebei North University, Zhangjiakou, China.
Front Oncol. 2022 Apr 12;12:875525. doi: 10.3389/fonc.2022.875525. eCollection 2022.
Oncolytic virotherapy belongs to a kind of active immunotherapy, which could trigger a potent antitumor immune response, showing great potential in clinical application. OVs could induce immune responses through the dual mechanisms of selective tumor killing without destroying normal tissues and induction of systemic antitumor immunity. In this study, we successfully rescued a chimeric oncolytic influenza virus carrying a human CTLA4 antibody in the background of the A/PR/8/34 (PR8) virus. The chimeric virus, called rFlu-huCTLA4, contained the heavy and light chains of the human CTLA4 antibody in the PB1 and PA segments of the PR8 virus, respectively. The first-generation hemagglutination (HA) titers of the rFlu-huCTLA4 virus ranged from 2 to 2, which could be passaged stably in specific pathogen-free (SPF) chicken embryos from P1 to P5. The morphology and size distribution of the chimeric virus were consistent with those of the influenza virus. The rFlu-huCTLA4 virus could effectively replicate in various cells in time- and dose-dependent manners. ELISA assay revealed that the secreted huCTLA4 antibody levels in chicken embryos increased gradually over time. Furthermore, MTS and crystal violet analysis showed that the selective cytotoxicity of the virus was higher in hepatocellular carcinoma cells (HepG2 and Huh7) than in normal liver cells (MIHA). experiments displayed that intratumoral injection with rFlu-huCTLA4 reduced tumor growth and increased the survival of mice compared with the PR8 group. More importantly, in the rFlu-huCTLA4 group, we found that CD4+ and CD8 +T cells were significantly increased in tumor-bearing BALB/c mice. Taken together, these findings demonstrated that the chimeric oncolytic virus rFlu-huCTLA4 could selectively destroy hepatocellular carcinoma cells and and may provide a promising clinical strategy for targeted immunotherapy of HCC with the oncolytic flu virus.
溶瘤病毒疗法属于一种主动免疫疗法，可引发强大的抗肿瘤免疫反应，在临床应用中显示出巨大潜力。溶瘤病毒可通过选择性杀伤肿瘤而不破坏正常组织以及诱导全身抗肿瘤免疫的双重机制诱导免疫反应。在本研究中，我们成功拯救了一种嵌合溶瘤流感病毒，该病毒在A/PR/8/34（PR8）病毒背景下携带人CTLA4抗体。这种嵌合病毒称为rFlu-huCTLA4，在PR8病毒的PB1和PA片段中分别包含人CTLA4抗体的重链和轻链。rFlu-huCTLA4病毒的第一代血凝（HA）滴度范围为2至2，可在无特定病原体（SPF）鸡胚中从P1到P5稳定传代。嵌合病毒的形态和大小分布与流感病毒一致。rFlu-huCTLA4病毒可在各种细胞中以时间和剂量依赖性方式有效复制。ELISA分析显示，鸡胚中分泌的huCTLA4抗体水平随时间逐渐增加。此外，MTS和结晶紫分析表明，该病毒在肝癌细胞（HepG2和Huh7）中的选择性细胞毒性高于正常肝细胞（MIHA）。实验显示，与PR8组相比，瘤内注射rFlu-huCTLA4可减少肿瘤生长并提高小鼠存活率。更重要的是，在rFlu-huCTLA4组中，我们发现荷瘤BALB/c小鼠的CD4+和CD8 +T细胞显著增加。综上所述，这些发现表明嵌合溶瘤病毒rFlu-huCTLA4可选择性破坏肝癌细胞，并可能为溶瘤流感病毒靶向免疫治疗肝癌提供一种有前景的临床策略。
