Huber S A, Lucas Z J
J Immunol. 1978 Dec;121(6):2485-9.
Sera from Fischer rats 3 to 13 days after i.p. injection of syngeneic 13762A mammary adenocarcinoma contain three factors specifically blocking cell-mediated cytotoxicity (CMC). The major blocking factor is a 160,000-dalton IgG that combines specifically to cytolytic lymphocytes but not to tumor cells or tumor antigen, and that is not dissociated after treatment with 8 M urea. The other factors have been putatively identified as tumor antigen (less than 70,000 daltons) and as soluble antigen-antibody complexes (greater than 200,000 daltons). Injecting the tumor antigen into tumor-free rats induced spleen cells specifically cytotoxic to the 13762A tumor and provided partial protection to challenge with live tumor cells. Treating soluble antigen-antibody complexes with 8 M urea decreased the size of the blocking activity from greater than 200,000 to less than 70,000 daltons. Although the IgG fraction dissociated from the complex did not block CMC, it did recombine with the tumor antigen fraction to transfer activity to the greater than 200,000-dalton fraction. In contrast, mixing tumor antigen with the IgG fraction that did block CMC did not alter the size of the blocking activities.
在腹腔注射同基因13762A乳腺腺癌3至13天后，Fischer大鼠的血清中含有三种特异性阻断细胞介导细胞毒性（CMC）的因子。主要的阻断因子是一种160,000道尔顿的IgG，它特异性结合溶细胞性淋巴细胞，但不结合肿瘤细胞或肿瘤抗原，并且在用8M尿素处理后不会解离。其他因子被推测为肿瘤抗原（小于70,000道尔顿）和可溶性抗原-抗体复合物（大于200,000道尔顿）。将肿瘤抗原注射到无肿瘤大鼠中可诱导对13762A肿瘤具有特异性细胞毒性的脾细胞，并为活肿瘤细胞攻击提供部分保护。用8M尿素处理可溶性抗原-抗体复合物可使阻断活性的大小从大于200,000道尔顿降至小于70,000道尔顿。虽然从复合物中解离出的IgG部分不阻断CMC，但它确实与肿瘤抗原部分重新结合，将活性转移到大于200,000道尔顿的部分。相反，将肿瘤抗原与确实阻断CMC的IgG部分混合不会改变阻断活性的大小。
