Cytometry by Time-of-Flight Shows Combinatorial Cytokine Expression and Virus-Specific Cell Niches within a Continuum of CD8 + T Cell Phenotypes

• Published in: Immunity (Cambridge, Mass.) Vol. 36; no. 1; pp. 142 - 152
• Main Authors: Newell, Evan W., Sigal, Natalia, Bendall, Sean C., Nolan, Garry P., Davis, Mark M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 27.01.2012; Elsevier Limited
• Subjects: Antigens; Antigens, Viral, Tumor - immunology; CD8-Positive T-Lymphocytes - immunology; CD8-Positive T-Lymphocytes - virology; Cytokines; Cytokines - metabolism; Cytotoxicity; Flow Cytometry; Humans; Mass Spectrometry; Peptides; Phenotype; Principal Component Analysis; Principal components analysis; Software; Viral infections
• ISSN: 1074-7613; 1097-4180; 1097-4180
• DOI: 10.1016/j.immuni.2012.01.002

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. ► T cell specificity, phenotype, and function can be assessed by mass spectrometry ► Principal component analysis revealed a common pattern of phenotypic progression ► Expression of cytokines by CD8 + T cells showed large combinatorial diversity ► Viral-specific cells occupied distinct niches of phenotypic and functional diversity