title: Respiratory Syncytial Virus (RSV) Infects CD4+ T Cells: Frequency of Circulating CD4+ RSV+ T Cells as a Marker of Disease Severity in Young Children.
abstract: BACKGROUND
  Although human airway epithelial cells are the main target of respiratory syncytial virus (RSV), it also infects immune cells, such as macrophages and B cells. Whether T cells are permissive to RSV infection is unknown. We sought to analyze the permissiveness of CD4+ T cells to RSV infection.
  
  
  METHODS
  CD4+ and CD8+ T cells from cord blood, healthy young children, and adults were challenged by RSV or cocultured with infected HEp-2 cells. Infection, phenotype, and cytokine production by T cells were analyzed by flow cytometry or enzyme-linked immunosorbent assay. Expression of RSV antigens by circulating CD4+ T cells from infected children was analyzed by flow cytometry, and disease severity was defined by standard criteria.
  
  
  RESULTS
  CD4+ and CD8+ T cells were productively infected by RSV. Infection decreased interleukin 2 and interferon γ production as well as the expression of CD25 and Ki-67 by activated CD4+ T cells. Respiratory syncytial virus antigens were detected in circulating CD4+ and CD8+ T cells during severe RSV infection of young children. Interestingly, the frequency of CD4+ RSV+ T cells positively correlated with disease severity.
  
  
  CONCLUSIONS
  Respiratory syncytial virus infects CD4+ and CD8+ T cells and compromises T-cell function. The frequency of circulating CD4+ RSV+ T cells might represent a novel marker of severe infection.
authors.affiliation: Hospital General de Niños "Pedro de Elizalde".
authors.forename: Silvina
authors.initials: S
authors.lastname: Raiden
authors.affiliation: Hospital de Clínicas "José de San Martín", Universidad de Buenos Aires.|Instituto de Inmunología, Genética y Metabolismo, CONICET, Universidad de Buenos Aires.
authors.forename: Inés
authors.initials: I
authors.lastname: Sananez
authors.affiliation: Departamento de Microbiología, Facultad de Medicina, Universidad de Buenos Aires, and.|Instituto de Investigaciones Biomédicas en Retrovirus y SIDA, CONICET, Universidad de Buenos Aires, Argentina.
authors.forename: Federico
authors.initials: F
authors.lastname: Remes-Lenicov
authors.affiliation: Hospital de Clínicas "José de San Martín", Universidad de Buenos Aires.|Instituto de Inmunología, Genética y Metabolismo, CONICET, Universidad de Buenos Aires.
authors.forename: Julieta
authors.initials: J
authors.lastname: Pandolfi
authors.affiliation: Hospital General de Niños "Pedro de Elizalde".
authors.forename: Cecilia
authors.initials: C
authors.lastname: Romero
authors.affiliation: Hospital General de Niños "Pedro de Elizalde".
authors.forename: Leonardo
authors.initials: L
authors.lastname: De Lillo
authors.affiliation: Departamento de Microbiología, Facultad de Medicina, Universidad de Buenos Aires, and.|Instituto de Investigaciones Biomédicas en Retrovirus y SIDA, CONICET, Universidad de Buenos Aires, Argentina.
authors.forename: Ana
authors.initials: A
authors.lastname: Ceballos
authors.affiliation: Departamento de Microbiología, Facultad de Medicina, Universidad de Buenos Aires, and.|Instituto de Investigaciones Biomédicas en Retrovirus y SIDA, CONICET, Universidad de Buenos Aires, Argentina.
authors.forename: Jorge
authors.initials: J
authors.lastname: Geffner
authors.affiliation: Hospital de Clínicas "José de San Martín", Universidad de Buenos Aires.|Instituto de Inmunología, Genética y Metabolismo, CONICET, Universidad de Buenos Aires.
authors.forename: Lourdes
authors.initials: L
authors.lastname: Arruvito
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000821:virology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000821:virology; D002460:Cell Line; D005260:Female; D005312:Fetal Blood / Q000166:cytology; D005434:Flow Cytometry; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007371:Interferon-gamma / Q000276:immunology; D007376:Interleukin-2 / Q000276:immunology; D008297:Male; D018357:Respiratory Syncytial Virus Infections / Q000276:immunology*; D018113:Respiratory Syncytial Virus, Human
chemical_list: D015415:Biomarkers; C573415:IFNG protein, human; C508594:IL2 protein, human; D007376:Interleukin-2; D007371:Interferon-gamma
keywords: CD4+ T cells; bronchiolitis; infants; interferon γ; interleukin 2; markers of disease severity.; respiratory syncytial virus; viral infection