title: Cytometry by time-of-flight shows combinatorial cytokine expression and virus-specific cell niches within a continuum of CD8+ T cell phenotypes.
abstract: Cytotoxic CD8(+) T lymphocytes directly kill infected or aberrant cells and secrete proinflammatory cytokines. By using metal-labeled probes and mass spectrometric analysis (cytometry by time-of-flight, or CyTOF) of human CD8(+) T cells, we analyzed the expression of many more proteins than previously possible with fluorescent labels, including surface markers, cytokines, and antigen specificity with modified peptide-MHC tetramers. With 3-dimensional principal component analysis (3D-PCA) to display phenotypic diversity, we observed a relatively uniform pattern of variation in all subjects tested, highlighting the interrelatedness of previously described subsets and the continuous nature of CD8(+) T cell differentiation. These data also showed much greater complexity in the CD8(+) T cell compartment than previously appreciated, including a nearly combinatorial pattern of cytokine expression, with distinct niches occupied by virus-specific cells. This large degree of functional diversity even between cells with the same specificity gives CD8(+) T cells a remarkable degree of flexibility in responding to pathogens.
authors.affiliation: Department of Microbiology and Immunology, Stanford University, CA 94305, USA.
authors.forename: Evan W
authors.initials: EW
authors.lastname: Newell
authors.forename: Natalia
authors.initials: N
authors.lastname: Sigal
authors.forename: Sean C
authors.initials: SC
authors.lastname: Bendall
authors.forename: Garry P
authors.initials: GP
authors.lastname: Nolan
authors.forename: Mark M
authors.initials: MM
authors.lastname: Davis
mesh_terms: D000957:Antigens, Viral, Tumor / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000821:virology*; D016207:Cytokines / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D013058:Mass Spectrometry; D010641:Phenotype; D025341:Principal Component Analysis
chemical_list: D000957:Antigens, Viral, Tumor; D016207:Cytokines