Multhoff G, Botzler C, Wiesnet M, Müller E, Meier T, Wilmanns W, Issels R D
Forschungszentrum für Umwelt und Gesundheit, GSF-Institut für Klinische Hämatologie, Munich, Germany.
Int J Cancer. 1995 Apr 10;61(2):272-9. doi: 10.1002/ijc.2910610222.
It is suggested that members of the heat-shock protein (HSP) 70 and 90 families are involved in intracellular antigen processing and the presentation of cell-membrane-anchored antigens. We show that non-lethal heat shock (41.8 degrees C) causes comparable rates of HSP72 (about 20x) and HSP73 (about 3x) synthesis in both tumor (including human Ewing's sarcoma, ES and osteosarcoma cells, HOS58) and normal cells (including EBV-transformed B-LCL, PBL and fibroblasts derived from healthy human volunteers). However, following non-lethal heat stress and a recovery period at 37 degrees C, flow cytometric analysis with a specific MAb showed HSP72 to be expressed only on the cell surface of tumor cells. The cell-surface localization of HSP72 was confirmed by Western-blot analysis of separated membranes and by immunoprecipitation with the HSP72-specific MAb. In addition, co-incubation of untreated tumor cells with supernatants from lethally heat-shocked cells, which contain HSP72, did not lead to HSP72 cell-surface expression. Thus, non-specific association of HSP72 molecules with the outer plasma membrane is unlikely. In conclusion, despite comparable cytoplasmic HSP72 induction, human tumor cells differ from normal cells in their capacity to express HSP72 on their surface. This might imply clinical application as a means to target a stress-inducible, tumor-specific immune response.
有人提出，热休克蛋白（HSP）70和90家族的成员参与细胞内抗原加工以及细胞膜锚定抗原的呈递。我们发现，非致死性热休克（41.8摄氏度）在肿瘤细胞（包括人尤因肉瘤、ES和骨肉瘤细胞、HOS58）和正常细胞（包括EBV转化的B-LCL、PBL以及源自健康人类志愿者的成纤维细胞）中引起的HSP72（约20倍）和HSP73（约3倍）合成速率相当。然而，在非致死性热应激以及37摄氏度的恢复期后，用特异性单克隆抗体进行的流式细胞术分析显示，HSP72仅在肿瘤细胞的细胞表面表达。通过对分离膜的蛋白质印迹分析以及用HSP72特异性单克隆抗体进行免疫沉淀，证实了HSP72在细胞表面的定位。此外，将未处理的肿瘤细胞与含有HSP72的经致死性热休克细胞的上清液共同孵育，并未导致HSP72在细胞表面表达。因此，HSP72分子与质膜外表面的非特异性结合不太可能。总之，尽管细胞质中HSP72的诱导相当，但人类肿瘤细胞在表面表达HSP72的能力上与正常细胞不同。这可能意味着作为一种针对应激诱导的肿瘤特异性免疫反应的手段具有临床应用价值。
