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Localization of IL-1 beta mRNA and cell adhesion molecules in the maxillary sinus mucosa of patients with chronic
E Tokushige1, K Itoh, M Ushikai
1Department of Otolaryngology, Kagoshima University School of Medicine, Japan.
Abstract:
Interleukin-1 beta (IL-1 beta) 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-1 beta messenger RNA (mRNA) in the maxillary sinus mucosa of patients with chronic sinusitis, using digoxigenin-labeled oligonucleotide probes. IL-1 beta 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-1 beta stimulation. With IL-1 beta 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-1 beta, 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.
Insights
Interleukin-1 beta (IL-1 beta) is produced by immune cells in chronic sinusitis. This cytokine promotes the infiltration of neutrophils into the nasal mucosa by influencing adhesion molecules.
Area of Science:
- Immunology
- Rhinology
- Cell Biology
Background:
- Chronic sinusitis is characterized by inflammation and neutrophil infiltration in the nasal and paranasal mucosa.
- Interleukin-1 beta (IL-1 beta) is a key cytokine found in the sinus fluid of chronic sinusitis patients.
Purpose of the Study:
- To investigate the localization of IL-1 beta messenger RNA (mRNA) in chronic sinusitis mucosa.
- To examine the expression and distribution of ICAM-1 and ELAM-1 in chronic sinusitis.
Main Methods:
- Localization of IL-1 beta mRNA using digoxigenin-labeled oligonucleotide probes.
- Immunohistochemistry with monoclonal antibodies to study ICAM-1 and ELAM-1 expression.
- Cultured human mucosal microvascular endothelial cells and maxillary sinus mucosa from chronic sinusitis patients were used.
Main Results:
- IL-1 beta mRNA was detected in extravascular polymorphonuclear neutrophils (PMNs) and some mononuclear leukocytes.
- ICAM-1 was constitutively expressed on endothelial cells, while ELAM-1 expression was induced by IL-1 beta.
- In chronic sinusitis mucosa, ICAM-1 was widespread on small vessel endothelial cells, and ELAM-1 was localized to the subepithelial region.
Conclusions:
- IL-1 beta, a mediator in chronic sinusitis, is likely produced by PMNs.
- IL-1 beta induces ICAM-1 and ELAM-1 expression on endothelial cells.
- This process contributes to PMN infiltration in chronic sinusitis.