title: Ex vivo monitoring of antigen-specific CD4+ T cells after recall immunization with tetanus toxoid.
abstract: To monitor antigen-specific CD4+ T cells during a recall immune response to tetanus toxoid (TT), a sequential analysis including ex vivo phenotyping and cytokine flow cytometry, followed by cloning and T-cell-receptor (TCR) spectratyping of cytokine-positive CD4+ T cells, was performed. Grossly, twice as many TT-specific CD4+ T-cell clones, ex vivo derived from the CCR7+/- CD69+ interleukin-2-positive (IL-2+) CD4+ subsets, belonged to the central memory (T(CM); CD62L+ CD27+ CCR7+) compared to the effector memory population (T(EM); CD62L- CD27- CCR7-). After the boost, a predominant expansion of the T(CM) population was observed with more limited variations of the T(EM) population. TCR beta-chain-variable region (BV) spectratyping and sequencing confirmed a large concordance between most frequently expressed BV TCR-CDR3 from ex vivo-sorted CCR7+/- CD69+ IL-2+ CD4+ subsets and BV usage of in vitro-derived TT-specific CD4+ T-cell clones, further demonstrating the highly polyclonal but stable character of the specific recall response to TT. Taken together, ex vivo flow cytometry analysis focused on the CCR7+/- CD69+ IL-2+ CD4+ subsets appears to target the bulk of antigen-specific T cells and to reach an analytical power sufficient to adequately delineate in field trials the profile of the antigen-specific response to vaccine.
authors.affiliation: Division of Immunology and Allergy, Centre Hospitalier Universitaire Vaudois, Rue du Bugnon, 1011 Lausanne, Switzerland.
authors.forename: Catherine
authors.initials: C
authors.lastname: Barbey
authors.forename: Estelle
authors.initials: E
authors.lastname: Pradervand
authors.forename: Nathalie
authors.initials: N
authors.lastname: Barbier
authors.forename: François
authors.initials: F
authors.lastname: Spertini
mesh_terms: D015703:Antigens, CD / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007117:Immunization, Secondary; D007376:Interleukin-2 / Q000276:immunology; D037181:Lectins, C-Type; D008137:Longitudinal Studies; D008213:Lymphocyte Activation; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D054400:Receptors, CCR7 / Q000276:immunology; D013745:Tetanus Toxoid / Q000008:administration & dosage / Q000276:immunology*; D000099192:CD69 Antigens
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D018984:Epitopes, T-Lymphocyte; D007376:Interleukin-2; D037181:Lectins, C-Type; D011948:Receptors, Antigen, T-Cell; D054400:Receptors, CCR7; D013745:Tetanus Toxoid; D000099192:CD69 Antigens; C515370:CCR7 protein, human; C508594:IL2 protein, human