title: Human infant respiratory syncytial virus (RSV)-specific type 1 and 2 cytokine responses ex vivo during primary RSV infection.
abstract: BACKGROUND
  Respiratory syncytial virus (RSV) infection is the most common respiratory viral infection resulting in hospitalizations in infants worldwide. Illness severity is likely multifactorial; however, unlike other viral infections, both type 1 and type 2 cytokine responses have been implicated in severe disease.
  
  
  METHODS
  We measured RSV-specific cytokine responses ex vivo during primary RSV infection in the blood of 18 infants with polymerase chain reaction-confirmed RSV infection. To focus on primary RSV infection, subjects were all<9 months old. RSV-specific cytokine responses were measured at 3 time points during acute primary RSV infection and at 1 memory time point 3-6 months later.
  
  
  RESULTS
  RSV-specific interferon (IFN)- gamma responses were detected in 10 of 18 of infants. Infants with mild disease had higher RSV-specific IFN- gamma memory responses than did those with moderate or severe disease. No consistent correlations between RSV-specific IFN- gamma responses and corticosteroid administration were observed. RSV-specific interleukin (IL)-4 or IL-5 responses to primary RSV infection were detectable in 5 of 18 and 8 of 15 infants, respectively.
  
  
  CONCLUSIONS
  During primary RSV infection, many infants demonstrated RSV-specific IFN- gamma responses. The strongest IL-4 and IL-5 responses were detected in 3 infants with severe disease, suggesting that type 2 responses may contribute to the pathogenesis of severe disease.
authors.affiliation: David H. Smith Center for Vaccine Biology and Immunology, Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA. eunhyung_lee@urmc.rochester.edu
authors.forename: F Eun-Hyung
authors.initials: FE
authors.lastname: Lee
authors.forename: Edward E
authors.initials: EE
authors.lastname: Walsh
authors.forename: Ann R
authors.initials: AR
authors.lastname: Falsey
authors.forename: Megan E
authors.initials: ME
authors.lastname: Lumb
authors.forename: Ngozi V
authors.initials: NV
authors.lastname: Okam
authors.forename: Nathaniel
authors.initials: N
authors.lastname: Liu
authors.forename: Anagha A
authors.initials: AA
authors.lastname: Divekar
authors.forename: Caroline B
authors.initials: CB
authors.lastname: Hall
authors.forename: Tim R
authors.initials: TR
authors.lastname: Mosmann
mesh_terms: D005260:Female; D006801:Humans; D007223:Infant; D007371:Interferon-gamma / Q000097:blood / Q000378:metabolism*; D015847:Interleukin-4 / Q000378:metabolism; D015848:Interleukin-5 / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000276:immunology* / Q000821:virology; D008297:Male; D010835:Phytohemagglutinins / Q000276:immunology; D016133:Polymerase Chain Reaction; D018357:Respiratory Syncytial Virus Infections / Q000175:diagnosis / Q000276:immunology*; D018113:Respiratory Syncytial Virus, Human / Q000276:immunology*; D012141:Respiratory Tract Infections / Q000175:diagnosis / Q000276:immunology* / Q000821:virology; D012720:Severity of Illness Index; D013997:Time Factors
chemical_list: D015848:Interleukin-5; D010835:Phytohemagglutinins; D015847:Interleukin-4; D007371:Interferon-gamma