LOCALIZATION OF IL-1-BETA MESSENGER-RNA AND CELL-ADHESION MOLECULES IN THE MAXILLARY SINUS MUCOSA OF PATIENTS WITH CHRONIC SINUSITIS

Interleukin-1 beta (IL-1 beta) is a predominant cytokine in retained p aranasal sinus fluid of chronic sinusitis where infiltration by polymo rphonuclear neutrophils (PMNs) of nasal and paranasal mucosa is charac teristic. The authors investigated the localization of IL-1 beta messe nger RNA (mRNA) in the maxillary sinus mucosa of patients with chronic sinusitis, using digoxigenin-labeled oligonucleotide probes. IL-1 bet a mRNA was detected in some extravascular PMNs and small numbers of mo nonuclear leukocytes but was not detected in other tissue cells or int ravascular leukocytes. The expression and distribution of the cell adh esion molecules, intercellular adhesion molecule-1 (ICAM-1) and endoth elial-leukocyte adhesion molecule-1 (ELAM-1), were also studied in cul tured human mucosal microvascular endothelial cells and in the maxilla ry sinus mucosa in chronic sinusitis by immunohistochemistry using mon oclonal antibodies against these cell adhesion molecules. Only ICAM-1 was expressed on cultured human mucosal microvascular endothelial cell s without IL-1 beta stimulation. With IL-1 beta activation of these ce lls, ELAM-1 was expressed strongly and the expression of ICAM-1 was en hanced. In the maxillary sinus mucosa, ICAM-1 was strongly and univers ally expressed on endothelial cells of all small vessels, whereas ELAM -1 was expressed only in the subepithelial region. These findings sugg est that IL-1 beta, one of mediators in chronic sinusitis, is produced by PMNs, induces the expression of ICAM-1 and ELAM-1 on endothelial c ells, and, thereby, stimulates PMN infiltration in chronic sinusitis.