Related Experiment Video
Updated: Jun 8, 2026

Peptide:MHC Tetramer-based Enrichment of Epitope-specific T cells
Published on: October 22, 2012
Negative selection and peptide chemistry determine the size of naive foreign peptide-MHC class II-specific CD4+ T
H Hamlet Chu1, James J Moon, Andrew C Kruse
1Department of Microbiology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
Naive CD4(+) T cell populations that express TCRs specific for different foreign peptide-MHC class II complex (pMHCII) ligands can vary in size over several orders of magnitude. This variation may explain why immune responses to some peptides are stronger than others. In this study, we used a sensitive pMHCII-tetramer-based cell enrichment method to study the derivation of two naive foreign pMHCII-specific naive CD4(+) T cell populations that differed in size by 8-fold in normal mice. Analysis of mice in which thymic negative selection was impaired revealed that the smaller population underwent more clonal deletion than the larger population. In addition, large naive cell populations tended to recognize peptides with tryptophan residues as TCR contacts. Thus, the foreign pMHCII that tend to be recognized by large naive populations induce minimal clonal deletion and contain certain amino acids with the capacity to interact favorably with TCRs.
Naive CD4(+) T cell populations that express TCRs specific for different foreign peptide-MHC class II complex (pMHCII) ligands can vary in size over several orders of magnitude. This variation may explain why immune responses to some peptides are stronger than others. In this study, we used a sensitive pMHCII-tetramer-based cell enrichment method to study the derivation of two naive foreign pMHCII-specific naive CD4(+) T cell populations that differed in size by 8-fold in normal mice. Analysis of mice in which thymic negative selection was impaired revealed that the smaller population underwent more clonal deletion than the larger population. In addition, large naive cell populations tended to recognize peptides with tryptophan residues as TCR contacts. Thus, the foreign pMHCII that tend to be recognized by large naive populations induce minimal clonal deletion and contain certain amino acids with the capacity to interact favorably with TCRs.
Related Concept Videos
T Cell Activation and Clonal Selection
Naive T cells that have not yet encountered an antigen express two primary CD...
Antigens Involved in Adaptive Immunity
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.
Diversity of Antigen Receptors
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
B Cell Activation and Differentiation
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...
Cytotoxic T Cells-mediated Immune Response
Immunological surveillance is the ability of immune cells to monitor and eliminate infected cells with intracellular pathogens, neoplastically transformed cells, and cells with non-self antigens. Cytotoxic T cells and NK...
Antigen Processing Pathways
MHC Class I: Presenting Endogenous...

