ABSTRACT

Antibody-based delivery of bioactive molecules represents a promising strategy for the improvement of cancer immunotherapy. Here, we describe the generation and characterization of R6N, a novel fully human antibody specific to the alternatively spliced domain D of Tenascin C, which is highly expressed in the stroma of primary tumors and metastasis. The R6N antibody recognized its cognate tumor-associated antigen with identical specificity in mouse and human specimens. Moreover, the antibody was able to selectively localize to solid tumors in vivo as evidenced by immunofluorescence-based biodistribution analysis. Encouraged by these results, we developed a novel fusion protein (termed mIL12-R6N) consisting of the murine interleukin 12 fused to the R6N antibody in homodimeric tandem single-chain variable fragment arrangement. mIL12-R6N exhibited potent antitumor activity in immunodeficient mice bearing SKRC52 renal cell carcinoma, as well as in immunocompetent mice bearing SMA-497 glioma. The experiments presented in this work provide a rationale for possible future applications for the R6N antibody for the treatment of cancer patients.

摘要

基于抗体的生物活性分子递送代表了改进癌症免疫疗法的有前景的策略。在这里，我们描述了 R6N 的生成和表征，R6N 是一种新型全人抗体，特异于 Tenascin C 的选择性剪接域 D，在原发性肿瘤和转移的基质中高度表达。R6N 抗体在小鼠和人类标本中以相同的特异性识别其同源肿瘤相关抗原。此外，该抗体能够在体内选择性定位于实体瘤基于免疫荧光的生物分布分析证明了这一点。受这些结果的鼓舞，我们开发了一种新型融合蛋白（称为 mIL12-R6N），该蛋白由以同源二聚体串联单链可变片段排列与 R6N 抗体融合的鼠白介素 12 组成。mIL12-R6N 在携带 SKRC52 肾细胞癌的免疫缺陷小鼠以及携带 SMA-497 神经胶质瘤的免疫活性小鼠中表现出有效的抗肿瘤活性。这项工作中提出的实验为 R6N 抗体在未来可能用于治疗癌症患者的应用提供了理论依据。