Localization of il‐1β mrna and cell adhesion molecules in the maxillary sinus mucosa of patients with chronic sinusitis

Interleukin-1β (IL-1β) is a predominant cytokine in retained paranasal sinus fluid of chronic sinusitis where infiltration by polymorphonuclear neutrophils (PMNs) of nasal and paranasal mucosa is characteristic. The authors investigated the localization of IL-1β messenger RNA (mRNA) in the maxillary sinus mucosa of patients with chronic sinusitis, using digoxigenin-labeled oligonucleotide probes. IL-1β mRNA was detected in some extravascular PMNs and small numbers of mononuclear leukocytes but was not detected in other tissue cells or intravascular leukocytes. The expression and distribution of the cell adhesion molecules, intercellular adhesion molecule-1 (ICAM-1) and endothelial-leukocyte adhesion molecule-1 (ELAM-1), were also studied in cultured human mucosal microvascular endothelial cells and in the maxillary sinus mucosa in chronic sinusitis by immunohistochemistry using monoclonal antibodies against these cell adhesion molecules. Only ICAM-1 was expressed on cultured human mucosal microvascular endothelial cells without IL-1β stimulation. With IL-1β activation of these cells, ELAM-1 was expressed strongly and the expression of ICAM-1 was enhanced. In the maxillary sinus mucosa, ICAM-1 was strongly and universally expressed on endothelial cells of all small vessels, whereas ELAM-1 was expressed only in the subepithelial region. These findings suggest that IL-1β, one of mediators in chronic sinusitis, is produced by PMNs, induces the expression of ICAM-1 and ELAM-1 on endothelial cells, and, thereby, stimulates PMN infiltration in chronic sinusitis.