Chidgey A P, Pircher H, MacDonald H R, Boyd R L
Department of Pathology and Immunology, Monash Medical School, Prahran, Australia.
Dev Immunol. 1998;6(3-4):157-70. doi: 10.1155/1998/10534.
Presented here is a cell-suspension model for positive selection using thymocytes from alphabeta-TCR (H-2Db-restricted) transgenic mice specific to the lymphocytic choriomeningitis virus (LCMV) on a nonselecting MHC background (H-2d or TAP-1 -/-), cocultured with freshly isolated adult thymus stromal cells of the selecting MHC type. The thymic stromal cells alone induced positive selection of functional CD4- CD8+ cells whose kinetics and efficiency were enhanced by nominal peptide. Fibroblasts expressing the selecting MHC alone did not induce positive selection; however, together with nonselecting stroma and nominal peptide, there was inefficient positive. These results suggest multiple signaling in positive selection with selection events able to occur on multiple-cell types. The ease with which this model can be manipulated should greatly facilitate the resolution of the mechanisms of positive selection in normal and pathological states.
本文展示了一种细胞悬浮模型，用于阳性选择。该模型使用来自αβ-TCR（H-2Db限制性）转基因小鼠的胸腺细胞，这些小鼠对淋巴细胞性脉络丛脑膜炎病毒（LCMV）具有特异性，其处于非选择的MHC背景（H-2d或TAP-1 -/-），并与新分离的选择的MHC类型的成年胸腺基质细胞共培养。单独的胸腺基质细胞可诱导功能性CD4-CD8+细胞的阳性选择，其动力学和效率可通过标称肽增强。仅表达选择的MHC的成纤维细胞不会诱导阳性选择；然而，与非选择的基质和标称肽一起时，阳性选择效率较低。这些结果表明阳性选择中存在多种信号传导，且选择事件能够在多种细胞类型上发生。该模型易于操作，这应极大地有助于解析正常和病理状态下阳性选择的机制。
