IL-4 RECEPTORS ON MURINE SOLID TUMORS AND TUMOR INFILTRATING LYMPHOCYTES

我们已经检测了白细胞介素-4受体（IL-4 R）的存在， 甲基胆蒽（MCA-106、MCA-102和MC-38）和病毒DNA（G-2 TS和 14- 2 TS）诱导的鼠肉瘤细胞。 我们第一次展示了 小鼠实体瘤细胞表达单一类型的高亲和力IL-1， 4R.约800个IL-4结合位点/细胞，解离常数（KD）为 观察到115 pM。 这些受体的特征与 我们在TIL细胞上观察到，其他人在T和B淋巴细胞上观察到， 肥大细胞和巨噬细胞。 通过肿瘤细胞的北方印迹分析， 观察到3.9Kb的单个mRNA种类。通过免疫过氧化物酶染色， 来自新鲜MCA-106肿瘤的81-92%为IL-4受体阳性，而 只有7-10%的肿瘤浸润细胞是Thy 1.2和少于1%的Mac。 1. 肿瘤表面的受体在结合到 一种IL-4与假单胞菌外毒素的嵌合蛋白（IL-4-PE 40）。 使用IL-4-PE 40，我们观察到IL-4-PE 40是细胞毒性的（通过免疫组织化学测定）。 通过氚化亮氨酸摄取抑制蛋白质合成 以剂量依赖性方式抑制肿瘤细胞。 PE 40是一种非嵌合蛋白， 不能与IL-4 R结合，不抑制肿瘤蛋白质合成 细胞 IL-4-PE 40 M，一种可与IL-4结合的嵌合突变蛋白 受体但不具有抑制蛋白质合成的能力， 对肿瘤细胞无细胞毒性。 这些研究强烈表明，IL- 小鼠MCA-106肉瘤细胞上的4 R在被IL-4占据时被内化。 PE 40，并且可以是功能性的。 此外，中和抗体（11B 11） 对IL-4，完全消除蛋白质合成抑制活性， IL-4-PE 40。 综上所述，这些数据表明IL-4受体可能 成为IL-4毒素治疗的靶点。 我们目前正在调查 IL-4 R对肿瘤细胞和TIL细胞的可能调节。 这 该项目目前正在进行中。

We have examined the presence of the Interleukin-4 receptor (IL-4R) on methylcholanthrene (MCA-106, MCA-102 and MC-38) and viral DNA (G-2TS and 14-2TS) induced murine sarcoma cells. We demonstrated for the first time that murine solid tumor cells express a single class of high affinity IL- 4R. About 800 IL-4 binding sites/cell with a dissociation constant (KD) of 115 pM was observed. These receptors are similar in characteristics to that observed by us on TIL cells and by others on T and B lymphocytes, mast cells and macrophages. By Northern blot analysis of tumor cells, a single mRNA species of 3.9 Kb was observed. By immunoperoxidase staining, 81-92% from fresh MCA-106 tumors were positive for IL-4 receptors, while only 7-10% of tumor infiltrating cells were Thy 1.2 and less than 1% Mac- 1. The receptors on the tumor surface are internalized after binding to a chimeric protein between IL-4 and pseudomonas exotoxin (IL-4-PE40). Using IL-4-PE40, we observed that IL-4-PE40 was cytotoxic (determined by inhibition of protein synthesis by tritiated-Leucine uptake) to MCA-106 tumor cells in a dose-dependent manner. PE40, a nonchimeric protein which cannot bind to the IL-4R, did not inhibit protein synthesis in tumor cells. IL-4-PE40M, a chimeric mutant protein which can bind to IL-4 receptors but does not have the capability to inhibit protein synthesis, was not cytotoxic to tumor cells. These studies strongly suggest that IL- 4R on murine MCA-106 sarcoma cells is internalized when occupied by IL-4- PE40 and may be functional. Furthermore, a neutralizing antibody (11B11) to IL-4, completely abolished the protein synthesis inhibitory activity of IL-4-PE40. Taken together, these data suggest that the IL-4 receptor may be a target for IL-4-Toxin therapy. We are currently investigating possible regulation of IL-4R on tumor cells and on TIL cells. This project is currently active.