title: Both CD4⁺ and CD8⁺ lymphocytes participate in the IFN-γ response to filamentous hemagglutinin from Bordetella pertussis in infants, children, and adults.
abstract: Infant CD4⁺ T-cell responses to bacterial infections or vaccines have been extensively studied, whereas studies on CD8⁺ T-cell responses focused mainly on viral and intracellular parasite infections. Here we investigated CD8⁺ T-cell responses upon Bordetella pertussis infection in infants, children, and adults and pertussis vaccination in infants. Filamentous hemagglutinin-specific IFN-γ secretion by circulating lymphocytes was blocked by anti-MHC-I or -MHC-II antibodies, suggesting that CD4⁺ and CD8⁺ T lymphocytes are involved in IFN-γ production. Flow cytometry analyses confirmed that both cell types synthesized antigen-specific IFN-γ, although CD4⁺ lymphocytes were the major source of this cytokine. IFN-γ synthesis by CD8⁺ cells was CD4⁺ T cell dependent, as evidenced by selective depletion experiments. Furthermore, IFN-γ synthesis by CD4⁺ cells was sometimes inhibited by CD8⁺ lymphocytes, suggesting the presence of CD8⁺ regulatory T cells. The role of this dual IFN-γ secretion by CD4⁺ and CD8⁺ T lymphocytes in pertussis remains to be investigated.
authors.affiliation: Laboratory of Vaccinology and Mucosal Immunity, Université Libre de Bruxelles (ULB), 1070 Brussels, Belgium.
authors.forename: Violette
authors.initials: V
authors.lastname: Dirix
authors.forename: Virginie
authors.initials: V
authors.lastname: Verscheure
authors.forename: Françoise
authors.initials: F
authors.lastname: Vermeulen
authors.forename: Iris
authors.initials: I
authors.lastname: De Schutter
authors.forename: Tessa
authors.initials: T
authors.lastname: Goetghebuer
authors.forename: Camille
authors.initials: C
authors.lastname: Locht
authors.forename: Françoise
authors.initials: F
authors.lastname: Mascart
mesh_terms: D000293:Adolescent; D000328:Adult; D057134:Antibodies, Neutralizing / Q000276:immunology / Q000494:pharmacology; D000942:Antigens, Bacterial / Q000276:immunology / Q000494:pharmacology; D001886:Bordetella pertussis / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D002478:Cells, Cultured; D002648:Child; D005434:Flow Cytometry; D005805:Genes, MHC Class I / Q000276:immunology; D005802:Genes, MHC Class II / Q000276:immunology; D006388:Hemagglutinins / Q000276:immunology / Q000494:pharmacology; D006801:Humans; D007223:Infant; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology*; D008212:Lymphocyte Depletion; D010567:Pertussis Vaccine / Q000008:administration & dosage; D014917:Whooping Cough / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control
chemical_list: D057134:Antibodies, Neutralizing; D000942:Antigens, Bacterial; D006388:Hemagglutinins; D010567:Pertussis Vaccine; D007371:Interferon-gamma