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.
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.
Jäger
Elke
E
Medizinische Klinik II, Hämatologie-Onkologie, Krankenhaus Nordwest, Frankfurt, Germany.
Salter
Russell
R
Castelli
Chiara
C
Höhn
Hanni
H
Freitag
Kirsten
K
Karbach
Julia
J
Neukirch
Claudia
C
Necker
Antje
A
Knuth
Alexander
A
Maeurer
Markus J
MJ
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
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