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：2010
卷号：107
期号：6
页码：2550-2555
DOI：10.1073/pnas.0914508107
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：To determine the role that competition plays in a molecular mimic's capacity to induce autoimmunity, we studied the ability of naive encephalitogenic T cells to expand in response to agonist altered peptide ligands (APLs), some capable of stimulating both self-directed and exclusively APL-specific T cells. Our results show that although the APLs capable of stimulating exclusively APL-specific T cells are able to expand encephalitogenic T cells in vitro, the encephalitogenic repertoire is effectively outcompeted in vivo when the APL is used as the priming immunogen. Competition as a mechanism was supported by: (i) the demonstration of a population of exclusively APL-specific T cells, (ii) an experiment in which an encephalitogenic T cell population was successfully outcompeted by adoptively transferred naive T cells, and (iii) demonstrating that the elimination of competing T cells bestowed an APL with the ability to expand naive encephalitogenic T cells in vivo. In total, these experiments support the existence of a reasonably broad T cell repertoire responsive to a molecular mimic (e.g., a microbial agent), of which the exclusively mimic-specific component tends to focus the immune response on the invading pathogen, whereas the rare cross-reactive, potentially autoreactive T cells are often preempted from becoming involved.
