Frederick M J, Yu T K, Krohn E G, Johnston D A, Grimm E A
Department of Tumor Biology, University of Texas 77030, USA.
Immunopharmacology. 1996 Nov;35(2):83-102. doi: 10.1016/s0162-3109(96)00115-4.
Short-term pretreatment of human lymphokine-activated killer cells (LAK) with the protein tyrosine kinase-specific inhibitor Herbimycin A (Herb A) blocked cytotoxic function against the NK-resistant (LAK-sensitive) tumor targets, SK-Mel-1 (human melanoma) and Daudi (human lymphoma). Greater than 50% inhibition of LAK activity was observed after a 2.5-h pretreatment with 0.125 microgram/ml (ca. 0.2 microM) Herb A. Inhibition of LAK occurred over a time interval in which LAK were not dependent upon IL-2 for maintenance of killing function, supporting the conclusion that the drug interfered with mobilization of cytotoxic function. Conjugate formation between LAK and tumor targets was unaffected by Herb A, indicating that inhibition was occurring at a post-binding step. Granule exocytosis as measured by BLT-esterase release was detected from LAK after coincubation with tumor targets, and was inhibited by Herb A pretreatment. The majority of LAK killing was dependent upon extracellular calcium, supporting the hypothesis that granule exocytosis rather than Fas ligand was the principal pathway leading to target cell death. The data suggest that protein tyrosine kinases play a pivotal role in LAK cytolytic function by regulating granule exocytosis.
用人淋巴细胞因子激活的杀伤细胞（LAK）进行短期预处理，使用蛋白酪氨酸激酶特异性抑制剂赫比霉素A（Herb A）可阻断其对NK抗性（LAK敏感）肿瘤靶标SK-Mel-1（人黑色素瘤）和Daudi（人淋巴瘤）的细胞毒性功能。用0.125微克/毫升（约0.2微摩尔）的Herb A预处理2.5小时后，观察到LAK活性受到超过50%的抑制。LAK抑制发生在一个时间间隔内，在此期间LAK维持杀伤功能不依赖于白细胞介素-2，这支持了该药物干扰细胞毒性功能动员的结论。LAK与肿瘤靶标之间的结合形成不受Herb A影响，表明抑制发生在结合后的步骤。与肿瘤靶标共同孵育后，通过BLT酯酶释放测量的颗粒胞吐作用在LAK中被检测到，并且被Herb A预处理所抑制。大多数LAK杀伤依赖于细胞外钙，支持颗粒胞吐作用而非Fas配体是导致靶细胞死亡的主要途径这一假设。数据表明蛋白酪氨酸激酶通过调节颗粒胞吐作用在LAK溶细胞功能中起关键作用。
