Subcutaneous late phase responses are augmented during local inhalational tolerance in a murine asthma model.
Acute exposure of sensitized mice to antigen elicits allergic airway disease (AAD) characterized by Th2 cytokine-dependent pulmonary eosinophilia, methacholine hyperresponsiveness and antigen-specific IgE elevation. However, chronic exposure induces a local inhalational tolerance (LIT), with resolution of the airway responses but persistent systemic IgE production. To further determine if systemic immunologic responses were maintained during LIT, we assessed subcutaneous late phase responses to ovalbumin in this model. Sensitized and AAD mice developed small subcutaneous responses to ovalbumin, with footpad thickness increasing to 113.7 and 113.6% of baseline, respectively. In comparison, LIT mice developed marked foot swelling (141.6%). Histologic examination confirmed increased inflammation in the chronic animals, with a significant contribution by eosinophils. Thus, the resolution of airway inflammatory responses with chronic antigen inhalation is a localized response, not associated with loss of systemic responses to antigen.
Singh
Anurag
A
1Department of Immunology, University of Connecticut Health Center, Farmington, CT, USA.
Thrall
Roger S
RS
Guernsey
Linda A
LA
Carson
William F
WF
Secor
Eric R
ER
Cone
Robert E
RE
Rajan
Thiruchandurai V
TV
Schramm
Craig M
CM
D000280:Administration, Inhalation; D000818:Animals; D001249:Asthma / Q000139:chemically induced / Q000276:immunology* / Q000473:pathology; D016535:Bronchial Hyperreactivity / Q000276:immunology*; D004195:Disease Models, Animal; D004487:Edema / Q000209:etiology*; D004804:Eosinophils / Q000276:immunology* / Q000473:pathology; D005260:Female; D005528:Foot / Q000473:pathology; D007108:Immune Tolerance / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000008:administration & dosage / Q000494:pharmacology
D010047:Ovalbumin