Department of Microbiology, University of Pennsylvania, Philadelphia, PA 19104, USA.
Cancer Immunol Immunother. 2011 Jul;60(7):931-42. doi: 10.1007/s00262-011-1002-x. Epub 2011 Mar 23.
The FDA approval of bevacizumab (Avastin®, Genentech/Roche), a monoclonal antibody raised against human VEGF-A, as second-line therapy for colon and lung carcinoma validated the approach of targeting human tumors with angiogenesis inhibitors. While the VEGF/VEGFR pathway is a viable target for anti-angiogenesis tumor therapy, additional targets involved in tumor neovascularization have been identified. One promising target present specifically on tumor vasculature is endoglin (CD105), a member of the TGF-β receptor complex expressed on vascular endothelium and believed to play a role in angiogenesis. Monoclonal antibody therapy and preventive vaccination against CD105 has met with some success in controlling tumor growth. This report describes the in vivo proof-of-concept studies for two novel therapeutic vaccines, Lm-LLO-CD105A and Lm-LLO-CD105B, directed against CD105 as a strategy to target neovascularization of established tumors. Listeria-based vaccines directed against CD105 lead to therapeutic responses against primary and metastatic tumors in the 4T1-Luc and NT-2 mouse models of breast cancer. In a mouse model for autochthonous Her-2/neu-driven breast cancer, Lm-LLO-CD105A vaccination prevented tumor incidence in 20% of mice by week 58 after birth while all control mice developed tumors by week 40. In comparison with previous Listeria-based vaccines targeting tumor vasculature, Lm-LLO-CD105A and Lm-LLO-CD105B demonstrated equivalent or superior efficacy against two transplantable mouse models of breast cancer. Support is provided for epitope spreading to endogenous tumor antigens and reduction in tumor vascularity after vaccination with Listeria-based CD105 vaccines. Reported here, these CD105 therapeutic vaccines are highly effective in stimulating anti-angiogenesis and anti-tumor immune responses leading to therapeutic efficacy against primary and metastatic breast cancer.
贝伐单抗(Avastin ® ,基因泰克/罗氏)的 FDA 批准,一种针对人 VEGF-A 的单克隆抗体,作为结肠癌和肺癌的二线治疗药物,验证了用血管生成抑制剂靶向人肿瘤的方法。虽然 VEGF/VEGFR 途径是抗血管生成肿瘤治疗的可行靶点,但已经确定了肿瘤新生血管形成中涉及的其他靶点。一种存在于肿瘤血管中的有前途的特定靶点是内皮糖蛋白(CD105),它是血管内皮细胞表达的 TGF-β 受体复合物的成员,被认为在血管生成中发挥作用。针对 CD105 的单克隆抗体治疗和预防性疫苗接种在控制肿瘤生长方面取得了一些成功。本报告描述了两种针对 CD105 的新型治疗性疫苗(Lm-LLO-CD105A 和 Lm-LLO-CD105B)的体内概念验证研究,作为靶向已建立肿瘤新生血管的策略。针对 CD105 的李斯特菌疫苗可导致乳腺癌 4T1-Luc 和 NT-2 小鼠模型中原发性和转移性肿瘤的治疗反应。在同源 Her-2/neu 驱动的乳腺癌小鼠模型中,Lm-LLO-CD105A 疫苗在出生后第 58 周时使 20%的小鼠预防肿瘤发生,而所有对照小鼠在第 40 周时均发生肿瘤。与以前针对肿瘤血管的李斯特菌疫苗相比,Lm-LLO-CD105A 和 Lm-LLO-CD105B 对两种可移植的乳腺癌小鼠模型显示出等效或更高的疗效。据报道,李斯特菌 CD105 疫苗接种后可引起针对内源性肿瘤抗原的表位扩展,并减少肿瘤血管生成。本文报道,这些 CD105 治疗性疫苗在刺激抗血管生成和抗肿瘤免疫反应方面非常有效,可导致原发性和转移性乳腺癌的治疗疗效。