Sebzda E, Wallace V A, Mayer J, Yeung R S, Mak T W, Ohashi P S
Ontario Cancer Institute, Department of Medical Biophysics, Toronto, Canada.
Science. 1994 Mar 18;263(5153):1615-8. doi: 10.1126/science.8128249.
T lymphocyte maturation is dependent on interactions between the T cell receptor (TCR) expressed on the developing thymocyte and intrathymic major histocompatibility complex (MHC)-peptide ligands. The relation between the peptide-MHC complex that results in negative or positive selection has not been identified. Here, the requirements for the maturation of thymocytes expressing a defined transgenic TCR specific for a viral peptide are studied in fetal thymic organ culture. Low concentrations of the viral peptide antigen recognized by this transgenic TCR can mediate positive selection, whereas high concentrations result in thymocyte tolerance. These findings support the affinity-avidity model of thymocyte selection.
T淋巴细胞的成熟依赖于发育中的胸腺细胞所表达的T细胞受体（TCR）与胸腺内主要组织相容性复合体（MHC）-肽配体之间的相互作用。导致阴性或阳性选择的肽-MHC复合体之间的关系尚未明确。在此，在胎儿胸腺器官培养中研究了表达针对病毒肽的特定转基因TCR的胸腺细胞成熟的要求。这种转基因TCR识别的低浓度病毒肽抗原可介导阳性选择，而高浓度则导致胸腺细胞耐受。这些发现支持胸腺细胞选择的亲和力-亲合力模型。
