1. T Cell Receptor Antagonist Peptides Induce Positive Selection.
- Author
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Hogquist, Kristin A., Jameson, Stephen C., Heath, William R., Howard, Jane L., Bevan, Michael J., and Carbone, Francis R.
- Subjects
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T cell receptors , *PEPTIDES , *ORGAN culture , *FETUS , *THYMUS , *TRANSGENIC mice , *LABORATORY mice - Abstract
We have used organ culture of fetal thymic lobes from T cell receptor (TCR) transgenic &brg;2M(-/-) mice to study the role of peptides in positive selection. The TCR used was from a CD8+ T cell specific for ovalbumin 257-264 in the context of Kb. Several peptides with the ability to induce positive selection were identified. These pep-tide-selected thymocytes have the same phenotype as mature CD8+ T cells and can respond to antigen. Those peptides with the ability to induce positive se-lection were all variants of the antigenic peptide and were identified as TCR antagonist peptides for this re-ceptor. One peptide tested, E1, induced positive selec-tion on the &brg;2M[-l-) background but negative selec-tion on the &brg;2M(+l-) background. These results show that the process of positive selection is exquisitely peptide specific and sensitive to extremely low ligand density and support the notion that low efficacy li-gands mediate positive selection. [ABSTRACT FROM AUTHOR]
- Published
- 2012