Siliciano R F, Zacharchuk C M, Shin H S
Proc Natl Acad Sci U S A. 1980 Apr;77(4):2192-6. doi: 10.1073/pnas.77.4.2192.
We describe two situations in which the recognition of hapten can compensate for the lack of recognition of appropriate H-2 gene products in hapten-specific, H-2 restricted, T lymphocyte-mediated cytolysis. First, we show that although recognition of appropriate H-2 gene products is essential for the lysis of target cells bearing a low hapten density, significant hapten-specific lysis of H-2 inappropriate target cells is observed at high levels of target cell derivatization. Secondly, we show that hapten-conjugated anti-H-2 antibody inhibits cytolysis poorly even though its binding to target cell H-2 antigens is equivalent to that of underivatized antibody. These results suggest that hapten and H-2 are recognized independently and are therefore inconsistent with the altered-self model. Although our data do not exclude the dual-recognition model, we prefer to interpret them within the framework of a single-receptor model in which hapten and H-2 are recognized independently by receptors of identical idiotype on the T cell. We postulate that the affinity of these receptors for the relevant H-2 gene product is low enough so that the T cell is not activated by encounters with normal-self cells expressing that H-2 gene product. However, when self cells express in addition a foreign antigen that can also be recognized by the same receptor, then the force of T cell-target cell interaction may be increased sufficiently to activate T cell effector function.
我们描述了两种情况，在半抗原特异性、H-2限制性、T淋巴细胞介导的细胞溶解过程中，对半抗原的识别可以弥补对合适H-2基因产物识别的不足。首先，我们发现，虽然识别合适的H-2基因产物对于裂解低半抗原密度的靶细胞至关重要，但在高水平的靶细胞衍生化情况下，可观察到对H-2不匹配的靶细胞有显著的半抗原特异性裂解。其次，我们发现半抗原偶联的抗H-2抗体抑制细胞溶解的能力很差，尽管其与靶细胞H-2抗原的结合与未衍生化抗体相当。这些结果表明，半抗原和H-2是被独立识别的，因此与改变自身模型不一致。虽然我们的数据不排除双重识别模型，但我们更倾向于在单受体模型的框架内解释它们，在该模型中，半抗原和H-2由T细胞上具有相同独特型的受体独立识别。我们推测，这些受体对相关H-2基因产物的亲和力足够低，以至于T细胞不会因与表达该H-2基因产物的正常自身细胞相遇而被激活。然而，当自身细胞另外表达一种也能被同一受体识别的外来抗原时，那么T细胞与靶细胞相互作用的强度可能会增加到足以激活T细胞效应功能的程度。
