Oral and Maxillofacial Surgery, Guangdong Provincial Stomatological Hospital Affiliated to Southern Medical University, Guangzhou, PR China.
Oncol Rep. 2012 Mar;27(3):798-806. doi: 10.3892/or.2011.1556. Epub 2011 Nov 15.
Attenuated Salmonella can invade tumor cells and acts as a eukaryotic expression vector for gene propagation. We constructed a bi-gene, eukaryotic co-expression DNA vaccine of Mycobacterium tuberculosis heat shock protein 70 (mtHSP70) and Herpes simplex virus-thymidine kinase (HSV-tk) and used attenuated Salmonella as a vector to treat murine melanoma. In vitro, recombinant Salmonella can carry plasmid stably and can invade into the cytoplasm of B16 tumor cells expressing the protein of the mtHSP70/HSV-tk gene by Western blot assay. In vivo, after the recombinant Salmonella was injected into tumors, the HSV-tk precursor drug ganciclovir (GCV) was administered to start the HSV-tk killing of tumor cells. We found that the mtHSP70/HSV-tk recombinant bacteria can raise CD8+ T lymphocytes in peripheral blood by flow cytometry and in tumor tissues by immunofluorescence detection, increase IFN‑γ contents in tumor tissue by ELISA and significantly suppress tumor growth.
减毒沙门氏菌可以侵袭肿瘤细胞，并作为真核表达载体进行基因扩增。我们构建了分枝杆菌热休克蛋白 70（mtHSP70）和单纯疱疹病毒胸苷激酶（HSV-tk）的双基因、真核共表达 DNA 疫苗，并使用减毒沙门氏菌作为载体来治疗鼠黑色素瘤。在体外，重组沙门氏菌可以稳定携带质粒，并通过 Western blot 分析侵袭表达 mtHSP70/HSV-tk 基因蛋白的 B16 肿瘤细胞的细胞质。在体内，将重组沙门氏菌注入肿瘤后，给予 HSV-tk 前体药物更昔洛韦（GCV）以启动 HSV-tk 杀伤肿瘤细胞。我们发现 mtHSP70/HSV-tk 重组菌可以通过流式细胞术在外周血中、通过免疫荧光检测在肿瘤组织中诱导 CD8+T 淋巴细胞，通过 ELISA 检测增加肿瘤组织中 IFN-γ 的含量，并显著抑制肿瘤生长。
