Fahmy T M, Bieler J G, Edidin M, Schneck J P
Department of Pathology and Medicine, Division of Immunopathology, Johns Hopkins University, Baltimore, MD 21218, USA.
Immunity. 2001 Feb;14(2):135-43.
While activated T cells are known to have enhanced biological responses to antigen stimulation, the biophysical basis of this increased sensitivity remains unknown. Here, we show that, on activated T cells, the TCR avidity for peptide-MHC complexes is 20- to 50-fold higher than the TCR avidity of naive T cells. This increased avidity for peptide-MHC depends on TCR reorganization and is sensitive to the cholesterol content of the T cell membrane. Analysis of the binding data indicates the enhanced avidity is due to increases in cross-linking of TCR on activated T cells. Activation-induced membrane (AIM) changes in TCR avidity represent a previously unrecognized means of increasing the sensitivity of activated T cells to small amounts of antigen in the periphery.
虽然已知活化的T细胞对抗原刺激具有增强的生物学反应，但这种敏感性增加的生物物理基础仍然未知。在这里，我们表明，在活化的T细胞上，TCR对肽-MHC复合物的亲和力比未活化的T细胞的TCR亲和力高20至50倍。这种对肽-MHC亲和力的增加取决于TCR的重组，并且对T细胞膜的胆固醇含量敏感。结合数据分析表明，亲和力增强是由于活化T细胞上TCR交联增加所致。TCR亲和力的活化诱导膜（AIM）变化代表了一种以前未被认识的增加活化T细胞对外周少量抗原敏感性的方式。
