J Asthma Allergy Clin Immunol.
1998 Jun;18(2):280-289.
Infiltration of eosinophils and expression of intercellular adhesion molecule-1
in in vivo allergen-challenged nasal mucosa of allergic rhinitics
Abstract
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We aimed to investigate the effect of in vitro allergen challenge on activation of eosinophils
and expression of intercellular adhesion molecule-1(ICAM-1) in the epithelial and endothelial
cells of the nasal mucosa of allergic rhinitics.
MATERIALS AND METHODS
Inferior turbinate mucosal specimens which were obtained from 16
perennial allergic rhinitics and sensitized to D. farinae during conchotomy operations
were used. Each mucosal specimen was divided into six pieces. The first two pieces were
used as basic control group without culture, the second two pieces as culture-control
group which was cultured with diluent only, and the last two pieces as antigen-challenge
group cultured with D. farinae solution for 24 hours. Specimens were immunohistochemically
stained using monoclonal antibody against eosinophil cationic protein(EG1 for all eosinophils
and EG2 for activated forms) and ICAM-1.
RESULTS
Average counts of EG1 cells and EG2+ cells within 1 mm of lamina propria of nasal
mucosa were 14 and 11 respectively in the basic control group, 17 and 19 in culture control
group, and 16 and 16 in the antigen-challenge group. ICAM-1 expression on vessels was
observed more than half of t,he vessels in the nasal mucosa and there was no significant
difference between groups, however, its expression on the epithelial cells was most
prominent in the antigen-challenge group (2.1 in basic control group, 3.3 in culture
control group, and 6.2 in antigen-challenge group).
CONCLUSION
Most of the eosinophils infiltrating into the nasal mucosae out of vessels
in allergic rhinitics are activated forms. Significant up-regulation of epithelial ICAM-1
expression by antigen-challenge suggests that ICAM-1 contributes to the transmigration of
eosinophils from the subepithelial tissue into the epithelial cell layer and then finally
into the nasal secretion.