Cutting Edge: CD1a Tetramers and Dextramers Identify Human Lipopeptide-Specific T Cells Ex Vivo
Cutting Edge: CD1a Tetramers and Dextramers Identify Human Lipopeptide-Specific T Cells Ex Vivo
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DOI：
10.4049/jimmunol.1301660
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发表时间：
2013-11-01
影响因子：
4.4
通讯作者：
Moody, D. Branch
中科院分区：
文献类型：
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作者：
Kasmar, Anne G.;Van Rhijn, Ildiko;Moody, D. Branch
人CD1a通过T细胞克隆介导外源抗原识别，但TCR可能与CD1a/脂质相互作用的性质尚不清楚。将CD1a与分枝杆菌脂肽Ag，DDM孵育后，我们鉴定并测量了与重组TCR(TRAV3/TRBV3-1，K-D约为100µM)的结合。通过检测CD1a/脂质/TCR三元相互作用，可以开发出CD1a四聚体和带有碳水化合物骨架的CD1a多聚体(右旋糖体)，它们使用一种依赖于肽骨架的精确立体化学并被可溶性TCR阻断的机制特异性地染色T细胞。此外，对来自无关结核病患者的人类T细胞进行明亮的DDM-葡聚体染色，可以恢复由CD1a和DDM激活的T细胞。这些研究表明，脂肽激活T细胞的机制是通过CD1a/Ag/TCR三元相互作用实现的。此外，这些研究还证明了人类体内脂肽特异性T细胞的存在。
Human CD1a mediates foreign Ag recognition by a T cell clone, but the nature of possible TCR interactions with CD1a/lipid are unknown. After incubating CD1a with a mycobacterial lipopeptide Ag, dideoxymycobactin (DDM), we identified and measured binding to a recombinant TCR (TRAV3/TRBV3-1, K-D of approximate to 100 mu M). Detection of ternary CD1a/lipid/TCR interactions enabled development of CD1a tetramers and CD1a multimers with carbohydrate backbones (dextramers), which specifically stained T cells using a mechanism that was dependent on the precise stereochemistry of the peptide backbone and was blocked with a soluble TCR. Furthermore, sorting of human T cells from unrelated tuberculosis patients for bright DDM-dextramer staining allowed recovery of T cells that were activated by CD1a and DDM. These studies demonstrate that the mechanism of T cell activation by lipopeptides occurs via ternary interactions of CD1a/Ag/TCR. Furthermore, these studies demonstrate the existence of lipopeptide-specific T cells in humans ex vivo.