Abstract
We have previously reported that the retention fluid components of chronic sinusitis induced neutrophil adherence to microvascular endothelial cells, and this adherence was inhibited by anti-IL-lβ antibody.
In this study, we carried outin situhybridization experiments using the maxillary sinus mucosa to identify the cells responsible for the production of IL-1βin vivo.
IL-1β mRNA was noted in the part of PMNs which migrate extravascularly as well as in some macrophages in the maxillary sinus mucosa taken from the patients with chronic sinusitis. On the other hand, IL-1β mRNA was not noted in intravascular PMNs. The expressions of ICAM-1 and ELAM-1 were also investigated employing immunohistochemical techniques using anti-ICAM-1 and anti-ELAM-1 monoclonal antibody. ICAM-1 was strongly expressed upon the lumeninal surface of vascular endothelial cells. On the other hand, ELAM-1 was evident only in relatively shallow regions of the maxillary sinus mucosa.
These findings suggest that IL-1β produced by PMNs which migrate extravascularly and infiltrate into the maxillary sinus mucosa, and then stimulates the vascular endothelial cells to express the adhesion molecules such as ICAM-1 and ELAM-1. It is considered that this mechanism plays an important role in the repeated infiltration of PMNs which caused in a prolonged action of chronic sinus inflammation.
