RATIONALE: We have previously demonstrated that intranasal Aspergillus fumigatus (Af) antigens-induces experimental asthma associated EE. We are now interested in uncovering the mechanism associating experimental asthma with EE. METHODS: Alexafluor conjugated Af was delivered intranasally to detect antigen translocation in mice. We used FACS, RNA protection assay (RPA) and ELISA to characterize lymphocyte populations in vivo and following in vitro stimulation. RESULTS: FACS analysis detected Alexafluor-labeled Af antigen in the lung, esophagus and mediastinal lymph nodes. Further analysis indicated 4-6 folds increase of B and T (CD4+ and CD8+) lymphocyte in mediastinal lymph nodes (MLN) and 2-5 folds in the esophagus of Af antigen challenged mice in comparison to saline mice. We also found >7 fold increase in the number of activated lymphocytes (CD4/CD25 and CD4/CD69) in MLN of Af antigen challenged mice. Furthermore, supernatant of culture MLN cells from Af antigen challenged mice showed >1000 fold increase of IL-5 in response to antigen. Additionally, RPA analysis identified Th2 cytokine (IL-5) mRNA expression in the esophagus of EE mice. CONCLUSIONS: Our data suggest that mediastinal lymph nodes play an important role in antigen and antigen-specific lymphocytes translocation from the lung to the esophagus. These activated antigen-specific lymphocytes are the source of Th2 cytokine (IL-5) that has an important role in the induction of asthma associated EE.
Full conference title:
2006 American Academy of Allergy, Asthma, and Immunology Annual Meeting
- AAAAI 2006 (62nd)