Denies Sofie, Leyman Bregje, Huysmans Hanne, Combes Francis, Mc Cafferty Séan, Cicchelero Laetitia, Steppe Marjan, De Temmerman Joyca, Sanders Niek N
Laboratory of Gene Therapy, Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Heidestraat 19, 9820, Merelbeke, Belgium.
iTeos Therapeutics, Rue Clément Ader 16, 6041, Gosselies, Belgium.
Cancer Immunol Immunother. 2017 Dec;66(12):1545-1555. doi: 10.1007/s00262-017-2046-3. Epub 2017 Aug 3.
In this study, a xenogeneic DNA vaccine encoding for human vascular endothelial growth factor receptor-2 (hVEGFR-2) was evaluated in two murine tumor models, the B16-F10 melanoma and the EO771 breast carcinoma model. The vaccine was administered by intradermal injection followed by electroporation. The immunogenicity and the biological efficacy of the vaccine were tested in (1) a prophylactic setting, (2) a therapeutic setting, and (3) a therapeutic setting combined with surgical removal of the primary tumor. The tumor growth, survival, and development of an immune response were followed. The cellular immune response was measured by a bioluminescence-based cytotoxicity assay with vascular endothelial growth factor-2 (VEGFR-2)-expressing target cells. Humoral immune responses were quantified by enzyme-linked immunosorbent assay (ELISA). Ex vivo bioluminescence imaging and immunohistological observation of organs were used to detect (micro)metastases. A cellular and humoral immune response was present in prophylactically and therapeutically vaccinated mice, in both tumor models. Nevertheless, survival in prophylactically vaccinated mice was only moderately increased, and no beneficial effect on survival in therapeutically vaccinated mice could be demonstrated. An influx of CD3+ cells and a slight decrease in VEGFR-2 were noticed in the tumors of vaccinated mice. Unexpectedly, the vaccine caused an increased quantity of early micrometastases in the liver. Lung metastases were not increased by the vaccine. These early liver micrometastases did however not grow into macroscopic metastases in either control or vaccinated mice when allowed to develop further after surgical removal of the primary tumor.
在本研究中,对一种编码人血管内皮生长因子受体2(hVEGFR-2)的异种DNA疫苗在两种小鼠肿瘤模型(B16-F10黑色素瘤模型和EO771乳腺癌模型)中进行了评估。该疫苗通过皮内注射并随后进行电穿孔给药。在以下三种情况下测试了疫苗的免疫原性和生物学功效:(1)预防性给药;(2)治疗性给药;(3)治疗性给药并联合手术切除原发性肿瘤。观察了肿瘤生长、生存情况以及免疫反应的发生。通过基于生物发光的细胞毒性试验,使用表达血管内皮生长因子-2(VEGFR-2)的靶细胞来检测细胞免疫反应。通过酶联免疫吸附测定(ELISA)对体液免疫反应进行定量。采用离体生物发光成像和器官的免疫组织学观察来检测(微)转移灶。在两种肿瘤模型中,预防性和治疗性接种疫苗的小鼠均出现了细胞和体液免疫反应。然而,预防性接种疫苗的小鼠生存率仅适度提高,且未证明对治疗性接种疫苗的小鼠生存率有有益影响。在接种疫苗小鼠的肿瘤中观察到CD3+细胞流入以及VEGFR-2略有下降。出乎意料的是,该疫苗导致肝脏中早期微转移灶数量增加。疫苗并未增加肺转移灶。然而,在手术切除原发性肿瘤后,让这些早期肝脏微转移灶进一步发展,无论是对照小鼠还是接种疫苗的小鼠,它们都未发展为肉眼可见的转移灶。