INTERLEUKIN-4 AND THEIR RECEPTORS IN TUMOR BIOLOGY AND AIDS

我们发现多种人类实体肿瘤细胞表达 白介素4受体(IL-4R)进行了研究，以表征 IL-4R对人体固形物的功能意义及结构 血液肿瘤，IL-4R靶向一株假单胞菌外毒素 (PE)，以及IL-4R与其他细胞因子的调节和相互作用。 A.肿瘤细胞上IL-4受体的结构和功能。IL-4引起 组织培养中对肿瘤细胞生长的抑制及其抑制作用 在不同的人类肿瘤中有不同程度的改变。交联剂研究 证实了IL-4R在肾癌中的作用 肾细胞癌(RCC)肿瘤细胞由一种约140 kDa的优势蛋白组成 与H-9 T细胞淋巴瘤和Raji B细胞Burkitt~S淋巴瘤细胞的比较 除了140 kDa的条带外，它还表达了一个较小的70 kDa 蛋白。我们还发现IL-2R g链可能与 IL-4R在肾癌细胞上的表达。然而，北方的分析表明， G链基因在肾癌细胞中缺失，而在B细胞中强表达 和T淋巴瘤细胞。正在进行的实验旨在确定 新的IL-4R相关蛋白在肾癌细胞上的鉴定 定向瞄准一种假单胞菌外毒素。IL-4R在细胞上的表达 以人肿瘤细胞为靶点的IL-4嵌合蛋白 和体育课。还产生了新一代的IL4-PE毒素，这些毒素与 IL-4R优于旧的IL-4毒素。此外，这种嵌合蛋白是 对IL-4R阳性肿瘤细胞有更强的细胞毒作用；但正常外周血 血淋巴细胞对细胞毒作用有一定的抵抗力。安妮特- 肿瘤研究是在裸鼠身上使用较老的毒素进行的 人表皮样癌异种移植模型的建立。我们的数据显示 IL4-PE4E和IL4-PE38QQR这两种嵌合毒素导致了这种退化 已经建立的人类肿瘤在小鼠体内的异种移植。完全的回归是 虽然是暂时的，但观察到了。目前正在进行研究，以探索最佳 治疗的路线和时间表以及最常见的人类肿瘤类型 对IL4毒素的抗肿瘤作用敏感。C.IL-1的作用机制 4R受HIV-Tat基因的调控。IL-2的内化和再循环 4R复合体在Tat转染组和未转染组Raji中相似 细胞。放线菌酮处理后IL-4R蛋白的半衰期 似乎不会因为TAT的转导而改变。同样，放线菌素追逐 实验证明，IL-4R mRNA的半衰期与 两种类型的细胞。相比之下，初步的核径流实验 提示TAT基因可提高IL-2的转录水平 4R在Raji细胞中。这些结果表明，白介素4受体上调。 TAT基因是通过增加IL-4R的转录速率而介导的。

We have discovered that a variety of human solid tumor cells express Interleukin-4 Receptors (IL-4R). Studies were carried out to characterize the functional significance and structure of IL-4R on human solid and hematologic tumors, IL-4R directed targeting of a Pseudomonas exotoxin (PE), and regulation and interaction of IL- 4R with other cytokines. A. Structure and Function of IL-4 receptors on tumor cells. IL-4 caused the inhibition of tumor cell growth in tissue culture and this inhibition was of different degrees in different human tumors. Crosslinking studies were carried out which demonstrated that IL-4R on renal cell carcinoma (RCC) tumor cells is composed of one predominant protein of about 140 kDa compared to H-9 T cell lymphoma and Raji B cell Burkitt~s lymphoma cells which in addition to the140 kDa band also expressed a smaller 70 kDa protein. We also discovered that IL-2R g chain may be possibly associated with IL-4R on RCC cells. Northern analysis, however, demonstrated that g chain mRNA is absent in RCC cells while it is strongly expressed in B and T lyphoma cells. Experiments in progress aim to determine the identity of this novel IL-4R associated protein on RCC cells.B. IL-4R directed targeting of a Pseudomonas exotoxin. The IL-4R expressed on human tumor cells were targeted with a chimeric protein comprised of IL-4 and PE. Newer generations of IL4-PE toxins were also produced which bound IL-4R better than old IL4-toxin. In addition, this chimeric protein was more cytotoxic to IL-4R positive tumor cells; however, normal peripheral blood lymphocytes were somewhat resistant to the cytotoxic effect. Anit- tumor studies were carried out in nude mice using older toxin in a xenograft model bearing human epidermoid carcinoma. Our data demonstrat that IL4-PE4E and IL4-PE38QQR, two chimeric toxins, caused the regression of established human tumor xenografts in mice. Complete regressions were observed although transient. Studies are underway to explore optimal route and schedule of therapy and type of human tumor which will be most susceptible to the antitumor effect of IL4-toxins. C. Mechanism of IL- 4R regulation by HIV-tat gene. The internalization and recycling of IL- 4R complex was similar in both tat transfected and untransfected Raji cells. The half life of IL-4R protein after cycloheximide treatment does not appear to alter due to tat transfection. Similarly, actinomycin chase experiments demonstrated that the half life of IL-4R mRNA is similar in both types of cells. In contrast, preliminary nuclear run-off experiments demonstrated that the tat gene may increase the transcription rate of IL- 4R in Raji cells. These results suggest that IL-4R upregulation by the tat gene is mediated through an increase in transcription rate of IL-4R.