title: Age-related alterations in blood and colonic dendritic cell properties.
abstract: BACKGROUND
  Dendritic cells (DC) determine initiation, type and location of immune responses and, in adults, show decreased Toll-like receptors and some increased cytokine levels on ageing. Few studies in children have characterised DC or explored DC-related mechanisms producing age-related immune changes.
  
  
  RESULTS
  The pDC marker BDCA2 (but not CD123) was absent in pre-pubertal children and numbers of pDC decreased with age. Blood and colonic DC were more mature and activated in adults. Decrease in pDC numbers correlated with reduced GM-CSF levels with aging, but increasing IL-4 and IL-8 levels correlated with a more activated DC profile in blood. CXCL16 levels decreased with age.
  
  
  METHODS
  Blood and colonic DC phenotypes were determined in healthy adults and children by flow cytometry and correlated with aging. Blood DC were divided into plasmacytoid (pDC) and myeloid (mDC) while only mDC were identified in colon. Serum cytokine levels were determined by multiplex cytokine assays and correlated with DC properties.
  
  
  CONCLUSIONS
  In children, lack of BDCA2, a receptor mediating antigen capture and inhibiting interferon induction, may be immunologically beneficial during immune development. Conversely, reduced pDC numbers, probably secondary to decreasing GM-CSF and increasing cytokine-induced maturation of DC are likely to determine deteriorating immunity with ageing.
authors.affiliation: Antigen Presentation Research Group, Imperial College London, Northwick Park and St. Mark's Campus, Harrow, UK.|London North West Healthcare NHS Trust, St. Mark's Campus, Harrow, UK.|Chelsea and Westminster Hospital NHS Foundation Trust, London, UK.
authors.forename: Rakesh
authors.initials: R
authors.lastname: Vora
authors.affiliation: Antigen Presentation Research Group, Imperial College London, Northwick Park and St. Mark's Campus, Harrow, UK.|Gastroenterology Unit, Hospital Universitario de La Princesa and Instituto de Investigación Sanitaria Princesa (IIS-IP), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Madrid, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Bernardo
authors.affiliation: Antigen Presentation Research Group, Imperial College London, Northwick Park and St. Mark's Campus, Harrow, UK.
authors.forename: Lydia
authors.initials: L
authors.lastname: Durant
authors.affiliation: Antigen Presentation Research Group, Imperial College London, Northwick Park and St. Mark's Campus, Harrow, UK.
authors.forename: Durga
authors.initials: D
authors.lastname: Reddi
authors.affiliation: Antigen Presentation Research Group, Imperial College London, Northwick Park and St. Mark's Campus, Harrow, UK.|London North West Healthcare NHS Trust, St. Mark's Campus, Harrow, UK.
authors.forename: Ailsa L
authors.initials: AL
authors.lastname: Hart
authors.affiliation: Antigen Presentation Research Group, Imperial College London, Northwick Park and St. Mark's Campus, Harrow, UK.|Chelsea and Westminster Hospital NHS Foundation Trust, London, UK.
authors.forename: John M E
authors.initials: JM
authors.lastname: Fell
authors.affiliation: Antigen Presentation Research Group, Imperial College London, Northwick Park and St. Mark's Campus, Harrow, UK.
authors.forename: Hafid O
authors.initials: HO
authors.lastname: Al-Hassi
authors.affiliation: Antigen Presentation Research Group, Imperial College London, Northwick Park and St. Mark's Campus, Harrow, UK.
authors.forename: Stella C
authors.initials: SC
authors.lastname: Knight
mesh_terms: D000328:Adult; D000367:Age Factors; D015415:Biomarkers / Q000378:metabolism*; D002454:Cell Differentiation; D002478:Cells, Cultured; D002648:Child; D003106:Colon / Q000166:cytology / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism*; D003713:Dendritic Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D022423:Myeloid Cells / Q000166:cytology / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D016207:Cytokines
keywords: BDCA-2; Gerotarget; aging; children; cytokines; mDC; pDC