Stolfi R L, Fugmann R A, Stolfi L M, Martin D S
J Immunol. 1975 Jun;114(6):1824-30.
Increased cytolytic activity of mouse complement as a result of modified reaction conditions described permitted the detection of tumor-specific cytotoxic antibody in high dilutions of sera (1:100--1:000) from mice carrying spontaneously occuring autochthonous breast tumors, or primary syngeneic transplants of such tumors. However, these same sera failed to demonstrate cytotoxic antibody activity at low dilution (i.e., 1:10). Such a pattern of reactivity suggested the presence of an inhibitor of cytotoxic antibody in high concentrations of serum from tumor-bearing mice. Sequential measurements subsequent to primary tumor implantation revealed that, although the time of appearance of this inhibitor varied from tumor to tumor, it always became detectable simultaneously with significant levels of lymphocyte-blocking activity. Also like lymphocyte-blocking activity, the inhibitor of cytotoxic antibody disappeared following surgical tumor removal. In addition, the inhibitor of cytotoxic antibody activity was shown to operate through a competitive antigen-binding and blocking mechanism. This data suggests the possibility that a single serum moiety may be responsible for the efferent blocking of both the cellular and the humoral components of the immune tumor rejection response.
由于所述反应条件的改变，小鼠补体的溶细胞活性增强，这使得能够在携带自发性原位乳腺肿瘤的小鼠血清（1:100 - 1:1000）高稀释度中，或此类肿瘤的原发性同基因移植小鼠血清高稀释度中检测到肿瘤特异性细胞毒性抗体。然而，这些相同的血清在低稀释度（即1:10）时未能显示出细胞毒性抗体活性。这种反应模式表明，荷瘤小鼠高浓度血清中存在细胞毒性抗体抑制剂。原发性肿瘤植入后的连续测量显示，虽然这种抑制剂出现的时间因肿瘤而异，但它总是在淋巴细胞阻断活性达到显著水平时同时变得可检测到。同样与淋巴细胞阻断活性一样，细胞毒性抗体抑制剂在手术切除肿瘤后消失。此外，细胞毒性抗体活性抑制剂被证明是通过竞争性抗原结合和阻断机制起作用的。这些数据表明，单一血清成分可能负责免疫肿瘤排斥反应的细胞和体液成分的传出阻断。
