Matthews N
Immunology. 1984 Nov;53(3):537-43.
Mononuclear phagocytes can synthesize a cytotoxin, similar to that in tumour necrosis serum, which is cytotoxic to certain tumour cell lines in vitro. This study has investigated whether susceptibility and resistance to the cytotoxin can be explained in terms of the amount of cytotoxin receptor expressed on the tumour cell surface. Binding of cytotoxin has been quantitated both by direct adsorption and competitive inhibition assays with cytotoxin-resistant or -susceptible tumour lines and with sublines of susceptible lines, selected for resistance to the cytotoxin. For both rabbit and human cytotoxin, there was no correlation between cytotoxin adsorption by tumour cell lines and their cytotoxin susceptibility, suggesting that resistance to the cytotoxin is expressed at a post-receptor stage. Preliminary studies on the cytotoxin receptor of K562 cells have shown that it is probably not the transferrin receptor, and that protein but not carbohydrate is essential for its function.
单核吞噬细胞能够合成一种细胞毒素，类似于肿瘤坏死血清中的细胞毒素，在体外对某些肿瘤细胞系具有细胞毒性。本研究调查了肿瘤细胞对该细胞毒素的易感性和抗性是否可以根据肿瘤细胞表面表达的细胞毒素受体数量来解释。通过直接吸附和竞争抑制试验，用抗细胞毒素或对细胞毒素敏感的肿瘤细胞系以及选择对细胞毒素具有抗性的敏感细胞系亚系，对细胞毒素的结合进行了定量。对于兔和人细胞毒素，肿瘤细胞系对细胞毒素的吸附与其对细胞毒素的敏感性之间均无相关性，这表明对细胞毒素的抗性在受体后阶段表达。对K562细胞的细胞毒素受体的初步研究表明，它可能不是转铁蛋白受体，并且蛋白质而非碳水化合物对其功能至关重要。
