title: Unbiased identification of target antigens of CD8+ T cells with combinatorial libraries coding for short peptides.
abstract: Cytotoxic CD8(+) T cells recognize the antigenic peptides presented by class I major histocompatibility complex (MHC) molecules. These T cells have key roles in infectious diseases, autoimmunity and tumor immunology, but there is currently no unbiased method for the reliable identification of their target antigens. This is because of the low affinities of antigen-specific T cell receptors (TCR) to their target MHC-peptide complexes, the polyspecificity of these TCRs and the requirement that these TCRs recognize protein antigens that have been processed by antigen-presenting cells (APCs). Here we describe a technology for the unbiased identification of the antigenic peptides presented by MHC class I molecules. The technology uses plasmid-encoded combinatorial peptide libraries and a single-cell detection system. We validated this approach using a well-characterized influenza-virus–specific TCR, MHC and peptide combination. Single APCs carrying antigenic peptides can be detected among several million APCs that carry irrelevant peptides. The identified peptide sequences showed a converging pattern of mimotopes that revealed the parent influenza antigen. This technique should be generally applicable to the identification of disease-relevant T cell antigens.
authors.affiliation: Institute of Clinical Neuroimmunology, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Katherina
authors.initials: K
authors.lastname: Siewert
authors.forename: Joachim
authors.initials: J
authors.lastname: Malotka
authors.forename: Naoto
authors.initials: N
authors.lastname: Kawakami
authors.forename: Hartmut
authors.initials: H
authors.lastname: Wekerle
authors.forename: Reinhard
authors.initials: R
authors.lastname: Hohlfeld
authors.forename: Klaus
authors.initials: K
authors.lastname: Dornmair
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D019556:COS Cells; D002522:Chlorocebus aethiops; D020650:Combinatorial Chemistry Techniques; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D019151:Peptide Library; D011948:Receptors, Antigen, T-Cell / Q000276:immunology
chemical_list: D015395:Histocompatibility Antigens Class I; D019151:Peptide Library; D011948:Receptors, Antigen, T-Cell