Young David C, Moody D Branch
Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital and Harvard Medical School, Smith Building Room 514, 1 Jimmy Fund Way, Boston, MA 02115, USA.
Glycobiology. 2006 Jul;16(7):103R-112R. doi: 10.1093/glycob/cwj111. Epub 2006 Apr 5.
The most well-known molecular paradigm of antigen recognition by T cells involves partial digestion of proteins to generate small peptides, which bind to major histocompatibility complex (MHC) proteins. Recent studies of CD1, an MHC class I homolog encoded outside the MHC, have revealed that it presents diverse glycolipids to T cells. The molecular mechanism for lipid antigen recognition involves insertion of the lipid portion of antigens into a hydrophobic groove to form CD1-lipid complexes, which contact T-cell receptors (TCRs). Here, we examine the known antigen structures presented by CD1, the majority of which have sugar moieties that are capable of interacting with TCRs. Recognition of carbohydrate epitopes is precise, and lipid-reactive T cells alter systemic immune responses in models of infectious and autoimmune disease. These findings provide a previously unrecognized mechanism by which the cellular immune system can recognize alterations in many types of carbohydrate structures.
T细胞识别抗原最著名的分子模式涉及蛋白质的部分消化以产生小肽，这些小肽与主要组织相容性复合体（MHC）蛋白结合。对CD1（一种在MHC之外编码的MHC I类同源物）的最新研究表明，它将多种糖脂呈递给T细胞。脂质抗原识别的分子机制涉及抗原的脂质部分插入疏水凹槽以形成CD1-脂质复合物，该复合物与T细胞受体（TCR）接触。在这里，我们研究了CD1呈递的已知抗原结构，其中大多数具有能够与TCR相互作用的糖部分。对碳水化合物表位的识别是精确的，并且脂质反应性T细胞在感染性和自身免疫性疾病模型中改变全身免疫反应。这些发现提供了一种以前未被认识的机制，通过该机制细胞免疫系统可以识别多种碳水化合物结构的改变。
