Meyer zum Bueschenfelde Christian O, Unternaehrer Julia, Mellman Ira, Bottomly Kim
Department of Immunobiology, Ludwig Institute for Cancer Research, Yale University School of Medicine, New Haven, CT 06520, USA.
J Immunol. 2004 Nov 15;173(10):6119-24. doi: 10.4049/jimmunol.173.10.6119.
T cell activation has long been associated with the partitioning of Ag receptors and associated molecules to lipid microdomains. We now show that dendritic cells (DCs) also accomplish the selective recruitment to lipid rafts of molecules critical for Ag presentation. Using mouse bone marrow-derived DCs, we demonstrate that MHC class II molecules become substantially localized to rafts upon DC maturation. Even more striking is the fact that CD86 is recruited to rafts upon T cell-DC interaction. Recruitment is Ag dependent and requires CD28 on T cells. Despite the regulated recruitment of MHC class II and CD86 to rafts, unlike the counter-receptors in T cells, DCs do not polarize these molecules to sites of DC-T cell contact. This difference may reflect the necessity for DCs to interact with multiple T cells simultaneously and emphasizes that the biochemical and morphological correlates of lipid rafts are not necessarily equivalent.
长期以来，T细胞活化一直与抗原受体及相关分子向脂质微区的分配有关。我们现在发现，树突状细胞（DC）也能将抗原呈递关键分子选择性招募至脂筏。利用小鼠骨髓来源的DC，我们证明，DC成熟时，MHC II类分子会大量定位于脂筏。更引人注目的是，T细胞与DC相互作用时，CD86会被招募至脂筏。这种招募依赖抗原，且需要T细胞上的CD28。尽管MHC II类分子和CD86被调控性招募至脂筏，但与T细胞中的对应受体不同，DC不会将这些分子极化至DC-T细胞接触位点。这种差异可能反映了DC同时与多个T细胞相互作用的必要性，并强调脂筏的生化和形态学关联不一定等同。
