期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2004
卷号：101
期号：33
页码：12254-12259
DOI：10.1073/pnas.0404632101
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Natural killer (NK) T cells with an invariant V{alpha}14 rearrangement (V{alpha}14i) are the largest population of lipid antigen-specific T lymphocytes identified in animals. They react to the glycolipid {alpha}-galactosyl ceramide ({alpha}-GalCer) presented by CD1d, and they may have important regulatory functions. It was previously shown that the V{alpha}14i T cell antigen receptor (TCR) has a high affinity for the {alpha}-GalCer/CD1d complex, driven by a long half-life (t1/2). Although this result could have reflected the unique attributes of {alpha}-GalCer, using several related glycolipid compounds, we show here that the threshold for full activation of V{alpha}14i NKT cells by these glycosphingolipids requires a relatively high-affinity TCR interaction with a long t1/2. Furthermore, our data are consistent with the view that the mechanism of recognition of these compounds presented by CD1d to the V{alpha}14i NKT cell TCR is likely to fit a lock-and-key model. Overall, these findings emphasize the distinct properties of glycosphingolipid antigen recognition by V{alpha}14i NKT cells.
