Rabinowich H, Banks M, Reichert T E, Logan T F, Kirkwood J M, Whiteside T L
Departments of Pathology and Medicine, University of Pittsburgh School of Medicine, and University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15213, USA.
Clin Cancer Res. 1996 Aug;2(8):1263-74.
Recent studies have demonstrated altered expression and function of signaling molecules in T and natural killer cells in patients with cancer. The impairment of immune cell functions in advanced cancer may result from defects in signal transduction. We studied purified T cells obtained from peripheral blood or tumor-involved lymph nodes (LNs) of 45 patients with advanced metastatic melanoma for the presence of abnormalities in expression or activity of various signaling molecules. Western blot analyses demonstrated reduced expression of CD3-zeta in 10 of 11 preparations of T cells obtained from tumor-involved LNs. Similar reduction in expression of CD3-zeta was demonstrated by immunostaining performed in situ on frozen sections of melanoma tissues. Expression of p56(lck) and Zap-70, but not phospholipase C-gamma1, was reduced in these patients' T cells relative to those obtained from normal individuals. In 50% of the patients, reduced expression of CD3-zeta and p56(lck) was observed in T lymphocytes obtained both from tumor-involved LNs and from peripheral blood. To determine whether deficient expression of these signaling molecules is reversible, T cells from melanoma-involved LNs were incubated in the presence of interleukin 2 (IL-2) for 48 h, and lysates from fresh or cultured lymphocytes were compared for changes in expression of signaling molecules. Cells cultured in the presence of IL-2 demonstrated increased expression of CD3-zeta and p56(lck), which approached the levels detected in normal T cells. However, the level of p56(lck) kinase activity did not normalize in any of the LN-derived lymphocytes cultured in the presence of IL-2. Decreased expression of CD3-zeta or p56(lck) observed in the patients' T cells was not reversed by immunotherapy with IL-2 at low or high dose in those patients with metastatic melanoma who failed to respond to therapy. However, in three patients who achieved clinical responses, the initially reduced expression of zeta in peripheral blood T cells normalized following IL-2 therapy.
最近的研究表明，癌症患者的T细胞和自然杀伤细胞中信号分子的表达和功能发生了改变。晚期癌症中免疫细胞功能的损害可能源于信号转导缺陷。我们研究了从45例晚期转移性黑色素瘤患者的外周血或肿瘤累及的淋巴结（LN）中获取的纯化T细胞，以检测各种信号分子的表达或活性是否存在异常。蛋白质印迹分析显示，从肿瘤累及的LN中获取的11份T细胞制剂中有10份CD3-ζ表达降低。通过对黑色素瘤组织冰冻切片进行原位免疫染色，也证实了CD3-ζ表达有类似降低。与正常个体的T细胞相比，这些患者的T细胞中p56(lck)和Zap-70的表达降低，但磷脂酶C-γ1的表达未降低。在50%的患者中，从肿瘤累及的LN和外周血中获取的T淋巴细胞均观察到CD3-ζ和p56(lck)表达降低。为了确定这些信号分子的表达缺陷是否可逆，将来自黑色素瘤累及LN的T细胞在白细胞介素2（IL-2）存在下孵育48小时，并比较新鲜或培养淋巴细胞的裂解物中信号分子表达的变化。在IL-2存在下培养的细胞显示CD3-ζ和p56(lck)表达增加，接近正常T细胞中检测到的水平。然而，在IL-2存在下培养的任何LN来源的淋巴细胞中，p56(lck)激酶活性水平均未恢复正常。在对治疗无反应的转移性黑色素瘤患者中，低剂量或高剂量IL-2免疫治疗均未逆转患者T细胞中观察到的CD3-ζ或p56(lck)表达降低。然而，在三名获得临床反应的患者中，IL-2治疗后外周血T细胞中最初降低的ζ表达恢复正常。
