Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents

This Article Full Text Full Text (PDF, 324K) PPT slides of all figures Alert me when this article is cited Citation Map Services Email this article Similar articles in this journal Similar articles in PubMed Alert me to new content in the JEM Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Williams, C. B. Articles by Allen, P. M. Search for Related Content PubMed PubMed Citation Articles by Williams, C. B. Articles by Allen, P. M. Social Bookmarking                            What's this?

Articles

Calvin B. Williams^*, Deborah L. Engle, Gilbert J. Kersh, J. Michael White, and Paul M. Allen

From the ^* Department of Pediatrics and the Department of Pathology, Center for Immunology, Washington University School of Medicine, St. Louis, Missouri 63110

We have developed a unique in vivo system to determine the relationship between endogenous altered peptide ligands and the development of major histocompatibility complex class II– restricted T cells. Our studies use the 3.L2 T cell receptor (TCR) transgenic mouse, in which T cells are specific for Hb(64–76)/I-E^k and positively selected on I-E^k plus self-peptides. To this endogenous peptide repertoire, we have individually added one of six well-characterized 3.L2 ligands. This transgenic approach expands rather than constrains the repertoire of self-peptides. We find that a broad range of ligands produce negative selection of thymocytes in vivo. When compared with the in vitro TCR–ligand binding kinetics, we find that these negatively selecting ligands all have a half-life of 2 s or greater. Additionally, one of two ligands examined with no detectable binding to the 3.L2 TCR and no activity on mature 3.L2 T cells (Q72) enhances the positive selection of transgenic thymocytes in vivo. Together, these data establish a kinetic threshold between negative and positive selection based on the longevity of TCR–ligand complexes.

Key Words: T cell receptor • thymocyte • transgenic • selection • altered peptide ligand

Many colleagues have provided reagents and helpful discussions. In particular, we wish to thank Dr. Emil Unanue, Dr. Chris Nelson, and Daniel Peterson for the 3A9 clonotypic antibody, the mHEL construct, and the mHEL transgenic mouse; Dr. Mark Davis for the 3A9 TCR transgenic mice; Drs. Diane Mathis and Christophe Benoist for the E promoter construct; Kathy Frederick, Darren Kreamalmeyer, and Donna Thompson for help breeding the mice; David Donermeyer and Stephen Horvath for help screening the mice; Dr. Peiqing Qian and Dr. Karine Vidal for assistance with the immunofluorescence; and Jerri Smith for her assistance in preparation of the manuscript.

Abbreviations used: APL, altered peptide ligand; APLtg, transgenic mouse expressing mHEL/APL in all class II–positive cells; CAB, 3.L2 clonotypic antibody; DN, double-negative (CD4^–CD8^–); DP, double-positive (CD4⁺CD8⁺); Hb, hemoglobin; HEL, hen egg-white lysozyme; 3.L2tg, 3.L2 TCR transgenic mouse; mHEL/APL, chimeric membrane protein containing HEL and one of the APLs listed below; N72(wt), the native Hb(64–76) peptide with asparagine at position 72; RT, room temperature; SP, single positive; T72, I72, A72, Q72, and E72, APLs of Hb(64–76) with position 72 substitutions as indicated.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Facebook    Reddit    Technorati    Twitter    What's this?

Home | Help | Feedback | Subscriptions | Archive | Search

TABLE OF CONTENTS