Dendritic cell number is related to IL-4 expression in the airways of atopic asthmatic subjects.
BACKGROUND
Airway dendritic cells are essential for stimulating naive T cells in response to inhaled antigen and for the development of allergic sensitization. IL-4 in vitro can distinguish dendritic cell lines from peripheral blood mononuclear cells. Our study had the following aims: 1) to compare the distribution of CD1a+ dendritic cells and IL-4+ cells, in the bronchial mucosa of asthmatics and controls 2) to determine the relationship between the numbers of CD1a+ dendritic cells and IL-4+ cells in the bronchial mucosa of asthmatics 3) to determine whether CD1a+ cells express the IL-4 receptor.


METHODS
Twenty atopic asthmatic and eight normal subjects were studied. In each subject, bronchoscopy with bronchial biopsies was performed. CD1a, IL-4, and IL-4 receptor expressions were evaluated by immunohistochemistry.


RESULTS
The number of CD1a+ and IL-4+ cells was significantly higher in asthmatics than controls. The number of CD1a+ cells was positively correlated to the number of IL-4 + cells. Bronchial biopsy serial section studies showed that CD1a+ cells express the receptor for IL-4.


CONCLUSIONS
These results suggest that an increased amount of IL-4 may play a physiopathologic role in maintaining the dendritic cell pool in vivo. Therefore, because of possible IL-4 activity on antigen-presenting cells in T-cell immune responses to allergens, an important new role of IL-4 in asthma inflammation can be envisaged.
Bertorelli
G
G
Department of Respiratory Disease, University of Parma, Italy.
Bocchino
V
V
Zhou
X
X
Zanini
A
A
Bernini
M V
MV
Damia
R
R
Di Comite
V
V
Grima
P
P
Olivieri
D
D
D000293:Adolescent; D000328:Adult; D018949:Antigens, CD1 / Q000032:analysis; D001249:Asthma / Q000276:immunology* / Q000473:pathology; D001706:Biopsy; D001980:Bronchi / Q000473:pathology; D002452:Cell Count; D003713:Dendritic Cells / Q000276:immunology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015847:Interleukin-4 / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D019948:Receptors, Interleukin-4 / Q000032:analysis; D020545:Respiratory Mucosa / Q000473:pathology
D018949:Antigens, CD1; D019948:Receptors, Interleukin-4; D015847:Interleukin-4