Pecht Israel, Gakamsky Dmitry M
Department of Immunology, The Weizmann Institute of Science, 76100 Rehovot, Israel.
FEBS Lett. 2005 Jun 13;579(15):3336-41. doi: 10.1016/j.febslet.2005.04.025. Epub 2005 Apr 26.
The interactions between the TCR and peptides bound to class I MHC encoded molecules (pMHC) and a mechanism for CD8 cooperation in this process are reviewed. Observation of two TCR/CD8 populations with different lateral diffusion rate constants as well as two distinct association phases of class I MHC tetramers ((pMHC)4) with T-cells suggest that the most efficient pMHC-T-cell association route corresponds to a fast tetramer binding to a colocalized CD8/TCR population, which apparently resides within membrane rafts. Thus, ligand-cell association starts by pMHC binding to the CD8. This rather fast step promotes pMHC association with CD8-proximal TCRs and thereby enhances the overall association process. The model suggests that this raft-associated CD8-TCR subpopulation is responsible for evoking T-cell activation.
本文综述了T细胞受体（TCR）与与I类主要组织相容性复合体（MHC）编码分子结合的肽（pMHC）之间的相互作用，以及CD8在此过程中的协同机制。观察到两个具有不同横向扩散速率常数的TCR/CD8群体，以及I类MHC四聚体（(pMHC)4）与T细胞的两个不同结合阶段，这表明最有效的pMHC-T细胞结合途径对应于快速四聚体与共定位的CD8/TCR群体结合，该群体显然位于膜筏内。因此，配体与细胞的结合始于pMHC与CD8的结合。这一相当快速的步骤促进了pMHC与CD8近端TCR的结合，从而增强了整体结合过程。该模型表明，这种与筏相关的CD8-TCR亚群负责引发T细胞活化。
