title: The effect of oral tolerance on the allergic airway response in younger and aged mice.
abstract: BACKGROUND
  The effect of increased age on the induction of oral tolerance by low-dose antigen feeding and its effect on the response to antigen airway challenge in aged mice have not been well characterized.
  
  
  OBJECTIVE
  To determine whether oral tolerance can be induced in aged mice and its impact on the development of allergic airway inflammation.
  
  
  METHODS
  Younger (6 weeks old) and aged (18 months old) mice were fed ovalbumin (OVA) prior to sensitization to induce antigen tolerance. Serum antigen-specific immunoglobulins (Igs), bronchoalveolar lavage fluid (BALF), lung histology, enumeration of CD4 + Foxp3+ Treg cells, and airway hyperresponsiveness (AHR) were determined after the final antigen challenge.
  
  
  RESULTS
  Feeding antigen to aged mice prior to sensitization induced oral tolerance as determined by a decrease in antigen-specific IgE and IgG(1); however, the effect was greater in younger mice. Induction of oral tolerance was associated with a greater increase in airway Treg cells in the younger mice. Despite these differences, oral tolerance significantly suppressed features of asthma in aged mice, including BALF total cell and eosinophil numbers, cytokine production, and AHR.
  
  
  CONCLUSIONS
  Aged mice developed oral tolerance to antigen, which suppressed several features of allergic airway inflammation.
authors.affiliation: Division of Clinical Immunology, Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA.
authors.forename: Janette M
authors.initials: JM
authors.lastname: Birmingham
authors.forename: Sangita
authors.initials: S
authors.lastname: Patil
authors.forename: Xiu-Min
authors.initials: XM
authors.lastname: Li
authors.forename: Paula J
authors.initials: PJ
authors.lastname: Busse
mesh_terms: D000284:Administration, Oral; D000367:Age Factors; D000818:Animals; D001249:Asthma / Q000276:immunology*; D016535:Bronchial Hyperreactivity / Q000276:immunology*; D001985:Bronchial Provocation Tests; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000276:immunology; D016207:Cytokines / Q000032:analysis; D005260:Female; D006651:Histocytochemistry; D007108:Immune Tolerance / Q000276:immunology*; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000008:administration & dosage / Q000276:immunology*; D018709:Statistics, Nonparametric; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D016207:Cytokines; D007074:Immunoglobulin G; D007073:Immunoglobulin E; D010047:Ovalbumin