title: Involvement of type I immune responses in swine-origin H1N1 influenza virus infection.
abstract: Swine-origin H1N1 influenza virus (S-OIV) appeared in 2009 with a higher incidence rate among children. Although fever was the most common symptom, some complicated cases occurred. We evaluated the percentages of effector T cells, B cells, and regulatory T cells in peripheral blood from 5 children infected by S-OIV (1 with acute necrotizing encephalitis, 2 with pneumonia, and 2 without complications), 5 children with seasonal influenza, and 5 healthy children. We found higher percentages of T-bet(+) CD4(+)CD8(+) T cells, monocytes, and B cells, granzyme B(+) and perforin(+) CD4(+), and CD8(+) T cells in affected children with both seasonal and H1N1 influenza than in controls, whereas both groups demonstrated similar percentages of CD4(+)CD25(+)Foxp3(+) regulatory T cells. In infected children with complications we observed high percentages of perforin(+) and interferon-γ(+) CD4(+) and CD8(+) T cells associated with low percentages of T regulatory cells. Our data suggest a dysregulation of antipathogen type I immune responses in complicated S-OIV infections.
authors.affiliation: Institute of Neurology, Department of Neurosciences, Catholic University, Rome, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Frisullo
authors.forename: Raffaele
authors.initials: R
authors.lastname: Iorio
authors.forename: Domenico
authors.initials: D
authors.lastname: Plantone
authors.forename: Viviana
authors.initials: V
authors.lastname: Nociti
authors.forename: Agata Katia
authors.initials: AK
authors.lastname: Patanella
authors.forename: Alessandro
authors.initials: A
authors.lastname: Marti
authors.forename: Concetta
authors.initials: C
authors.lastname: Palermo
authors.forename: Piero
authors.initials: P
authors.lastname: Valentini
authors.forename: Paolo
authors.initials: P
authors.lastname: Mariotti
authors.forename: Anna Paola
authors.initials: AP
authors.lastname: Batocchi
mesh_terms: D000293:Adolescent; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000821:virology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000821:virology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D053804:Granzymes / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D053118:Influenza A Virus, H1N1 Subtype / Q000254:growth & development / Q000276:immunology*; D009981:Influenza B virus / Q000254:growth & development / Q000276:immunology*; D007251:Influenza, Human / Q000276:immunology / Q000821:virology; D018655:Lymphocyte Count; D008297:Male; D009000:Monocytes / Q000276:immunology* / Q000821:virology; D054353:Perforin / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D034421:Sus scrofa / Q000821:virology; D058408:Th1-Th2 Balance
chemical_list: D015703:Antigens, CD; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D054353:Perforin; D053804:Granzymes