title: A single peptide-major histocompatibility complex ligand triggers digital cytokine secretion in CD4(+) T cells.
abstract: We have developed a single-molecule imaging technique that uses quantum-dot-labeled peptide-major histocompatibility complex (pMHC) ligands to study CD4(+) T cell functional sensitivity. We found that naive T cells, T cell blasts, and memory T cells could all be triggered by a single pMHC to secrete tumor necrosis factor-α (TNF-α) and interleukin-2 (IL-2) cytokines with a rate of ∼1,000, ∼10,000, and ∼10,000 molecules/min, respectively, and that additional pMHCs did not augment secretion, indicating a digital response pattern. We also found that a single pMHC localized to the immunological synapse induced the slow formation of a long-lasting T cell receptor (TCR) cluster, consistent with a serial engagement mechanism. These data show that scaling up CD4(+) T cell cytokine responses involves increasingly efficient T cell recruitment rather than greater cytokine production per cell.
authors.affiliation: Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Huang
authors.forename: Mario
authors.initials: M
authors.lastname: Brameshuber
authors.forename: Xun
authors.initials: X
authors.lastname: Zeng
authors.forename: Jianming
authors.initials: J
authors.lastname: Xie
authors.forename: Qi-jing
authors.initials: QJ
authors.lastname: Li
authors.forename: Yueh-hsiu
authors.initials: YH
authors.lastname: Chien
authors.forename: Salvatore
authors.initials: S
authors.lastname: Valitutti
authors.forename: Mark M
authors.initials: MM
authors.lastname: Davis
mesh_terms: D056704:Adaptive Immunity; D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation; D019921:Biotinylation; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D002454:Cell Differentiation; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D018796:Immunoconjugates; D007156:Immunologic Memory; D054992:Immunological Synapses; D007376:Interleukin-2 / Q000378:metabolism; D008213:Lymphocyte Activation; D008969:Molecular Sequence Data; D009036:Moths; D010446:Peptide Fragments / Q000276:immunology; D045663:Quantum Dots; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology; D012636:Secretory Rate; D059010:Single-Cell Analysis; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000949:Histocompatibility Antigens Class II; C024138:I-E-antigen; D018796:Immunoconjugates; D007376:Interleukin-2; D010446:Peptide Fragments; D016693:Receptors, Antigen, T-Cell, alpha-beta; D014409:Tumor Necrosis Factor-alpha