title: Impact of antigen presentation on TCR modulation and cytokine release: implications for detection and sorting of antigen-specific CD8+ T cells using HLA-A2 wild-type or HLA-A2 mutant tetrameric complexes.
abstract: Soluble MHC class I molecules loaded with antigenic peptides are available either to detect and to enumerate or, alternatively, to sort and expand MHC class I-restricted and peptide-reactive T cells. A defined number of MHC class I/peptide complexes can now be implemented to measure T cell responses induced upon Ag-specific stimulation, including CD3/CD8/zeta-chain down-regulation, pattern, and quantity of cytokine secretion. As a paradigm, we analyzed the reactivity of a Melan-A/MART-1-specific and HLA-A2-restricted CD8(+) T cell clone to either soluble or solid-phase presented peptides, including the naturally processed and presented Melan-A/MART-1 peptide AAGIGILTV or the peptide analog ELAGIGILTV presented either by the HLA-A2 wild-type (wt) or mutant (alanineright arrowvaline aa 245) MHC class I molecule, which reduces engagement of the CD8 molecule with the HLA-A2 heavy chain. Soluble MHC class I complexes were used as either monomeric or tetrameric complexes. Soluble monomeric MHC class I complexes, loaded with the Melan-A/MART-1 peptide, resulted in CD3/CD8 and TCR zeta-chain down-regulation, but did not induce measurable cytokine release. In general, differences pertaining to CD3/CD8/zeta-chain regulation and cytokine release, including IL-2, IFN-gamma, and GM-CSF, were associated with 1) the format of Ag presentation (monomeric vs tetrameric MHC class I complexes), 2) wt vs mutant HLA-A2 molecules, and 3) the target Ag (wt vs analog peptide). These differences are to be considered if T cells are exposed to recombinant MHC class I Ags loaded with peptides implemented for detection, activation, or sorting of Ag-specific T cells.
authors.affiliation: Medizinische Klinik II, Hämatologie-Onkologie, Krankenhaus Nordwest, Frankfurt, Germany.
authors.forename: Elke
authors.initials: E
authors.lastname: Jäger
authors.forename: Russell
authors.initials: R
authors.lastname: Salter
authors.forename: Chiara
authors.initials: C
authors.lastname: Castelli
authors.forename: Hanni
authors.initials: H
authors.lastname: Höhn
authors.forename: Kirsten
authors.initials: K
authors.lastname: Freitag
authors.forename: Julia
authors.initials: J
authors.lastname: Karbach
authors.forename: Claudia
authors.initials: C
authors.lastname: Neukirch
authors.forename: Antje
authors.initials: A
authors.lastname: Necker
authors.forename: Alexander
authors.initials: A
authors.lastname: Knuth
authors.forename: Markus J
authors.initials: MJ
authors.lastname: Maeurer
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D017951:Antigen Presentation / Q000235:genetics; D016827:CD8 Antigens / Q000096:biosynthesis / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D016207:Cytokines / Q000096:biosynthesis / Q000378:metabolism*; D003602:Cytotoxicity, Immunologic / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D015789:HLA-A2 Antigen / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D017260:Receptor-CD3 Complex, Antigen, T-Cell / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000378:metabolism
chemical_list: D016827:CD8 Antigens; D016207:Cytokines; D018984:Epitopes, T-Lymphocyte; D015789:HLA-A2 Antigen; D008565:Membrane Proteins; D017260:Receptor-CD3 Complex, Antigen, T-Cell; D011948:Receptors, Antigen, T-Cell; C054979:antigen T cell receptor, zeta chain