Philochem AG, Libernstrasse 3, Otelfingen 8112, Switzerland.
Institut des Maladies Métaboliques et Cardiovasculaires, INSERM U1048, Université de Toulouse, UPS, Cedex 4, Toulouse 31432, France.
Exp Biol Med (Maywood). 2021 Apr;246(8):940-951. doi: 10.1177/1535370220981578. Epub 2021 Jan 21.
Interleukin-9 is a cytokine with multiple functions, including the ability to activate group 2 innate lymphoid cells, which has been postulated to be therapeutically active in mouse models of arthritis. Similarly, interleukin-9 has been suggested to play an important role in tumor immunity. Here, we describe the cloning, expression, and characterization of three fusion proteins based on murine interleukin-9 and the F8 antibody, specific to the alternatively spliced EDA domain of fibronectin. EDA is strongly expressed in cancer and in various arthritic conditions, while being undetectable in the majority of healthy organs. Interleukin-9-based fusion proteins with an irrelevant antibody specific to hen egg lysozyme served as negative control in our study. The fusion proteins were characterized by quantitative biodistribution analysis in tumor-bearing mice using radioiodinated protein preparations. The highest tumor uptake and best tumor:organ ratios were observed for a format, in which the interleukin-9 moiety was flanked by two units of the F8 antibody in single-chain Fv format. Biological activity of interleukin-9 was retained when the payload was fused to antibodies. However, the targeted delivery of interleukin-9 to the disease site resulted in a modest anti-tumor activity in three different murine models of cancer (K1735M2, CT26, and F9), while no therapeutic benefit was observed in a collagen induced model of arthritis. Collectively, these results confirm the possibility to deliver interleukin-9 to the site of disease but cast doubts about the alleged therapeutic activity of this cytokine in cancer and arthritis, which has been postulated in previous publications.
白细胞介素 9 是一种具有多种功能的细胞因子，包括激活 2 型固有淋巴细胞的能力，据推测在关节炎的小鼠模型中具有治疗活性。同样，白细胞介素 9 被认为在肿瘤免疫中发挥重要作用。在这里，我们描述了三种基于鼠白细胞介素 9 和 F8 抗体的融合蛋白的克隆、表达和特性，该抗体特异性针对纤连蛋白的剪接 EDA 结构域。EDA 在癌症和各种关节炎中强烈表达，而在大多数健康器官中无法检测到。在我们的研究中，与无关的针对鸡卵溶菌酶的抗体结合的白细胞介素 9 融合蛋白作为阴性对照。使用放射性碘标记的蛋白质制剂在荷瘤小鼠中进行定量生物分布分析来表征融合蛋白。观察到一种格式的最高肿瘤摄取和最佳肿瘤：器官比值，其中白细胞介素 9 部分被单链 Fv 格式的两个 F8 抗体单位包围。当有效载荷融合到抗体上时，白细胞介素 9 的生物学活性得以保留。然而，将白细胞介素 9 靶向递送到疾病部位导致三种不同的癌症小鼠模型（K1735M2、CT26 和 F9）中产生适度的抗肿瘤活性，而在胶原诱导的关节炎模型中未观察到治疗益处。总的来说，这些结果证实了将白细胞介素 9 递送到疾病部位的可能性，但对先前出版物中提出的白细胞介素 9 在癌症和关节炎中的治疗活性提出了质疑。
