Measuring Ag-specific immune responses: understanding immunopathogenesis and improving diagnostics in infectious disease, autoimmunity and cancer.

Characterization of antigen-specific immune responses at the single-cell level has been made possible by recent advancements in reagent and technology development, combined with increasing knowledge of molecular mechanisms. Fluorescently labelled MHC-peptide multimers and antigens identify directly specific T and B cells, respectively, whereas dynamic assays exploit mediator production or secretion, or the changes in surface expression of other proteins, to identify specific lymphocytes--some techniques enabling the recovery of viable cells. Meanwhile, multiparameter flow cytometry has emerged as the most versatile platform for integrating most of these methods. As the complexity of experimental data increases, so does the level of technical sophistication required for analysis and interpretation, both in terms of basic research and modern medicine, with new applications for infectious diseases, autoimmunity and cancer.