Expression and distribution of glucocorticoid receptor isoforms in eosinophilic chronic rhinosinusitis.

OBJECTIVE: Patients with eosinophilic chronic rhinosinusitis (ECRS) show a high percentage of eosinophilic infiltration in the paranasal sinus mucosa. It is well documented that topical steroids have a beneficial effect in ECRS with nasal polyposis. We investigated mucosal distribution and cellular localization of glucocorticoid receptor (GR) isoform expression in human paranasal sinuses in relation to the clinical characteristics of eosinophilic chronic rhinosinusitis (ECRS) patients. METHODS: Mucosal specimens were obtained from 20 sinusitis patients by endoscopic sinus surgery (ESS). Quantitative fluorescence immunohistochemical analysis was employed to examine the degree of glucocorticoid receptor (GR) isoform expression in sinus mucosa specimens. An RT-PCR procedure was performed to determine the relative quantities of mRNA for the human GRalpha and GRbeta genes. RESULTS: Patients in the ECRS group showed significant increases in peripheral blood eosinophils as compared to the non-ECRS group (16.98% vs. 2.31%). Positive immunoreactivity of GRbeta expression was predominantly found to be positive in inflammatory cells. The absolute number of GRbeta-positive cells in the ECRS group was increased in comparison with that in the non-ECRS group. The difference was statistically significant both in the maxillary (179.7 cells/mm(2) vs. 82.5 cells/mm(2)) and ethmoid sinus (302.0 cells/mm(2) vs. 61.5 cells/mm(2)) mucosa. The GRbeta/GRalpha cell ratio in the ECRS group was elevated when compared with that in the non-ECRS group both in the maxillary and the ethmoid sinus mucosa, with the latter difference being significant. CONCLUSIONS: The presence of high peripheral eosinophilia indicates a high likelihood of ECRS disease. Our results support the association of GRbeta expression with ECRS. The expression of GRbeta immunoreactivity, an endogenous inhibitor of steroid action previously associated with steroid insensitivity, may be one of major contributing factors in ECRS.

Efficient production of monoclonal antibodies recognizing specific structures in Caenorhabditis elegans embryos using an antigen subtraction method.

Monoclonal antibodies (mAbs) have been widely used to probe molecular components of specific cell types or cellular structures. We have developed a method to enrich antigens of low abundance in heterogeneous molecule mixtures by subtracting abundant antigens. The subtracted immunogen mixture is then used for immunization, which significantly increases the production of mAbs that exhibit specific staining patterns. By applying this "antigen subtraction" method to the embryonic extract of Caenorhabditis elegans, we have successfully isolated 35 mAbs that recognize specific structures, including P granules, muscles, the pharynx, and subsets of hypodermal cells; some of the mAbs revealed previously unreported cellular structures. This antigen subtraction approach can be used in various applications to produce mAbs against relatively scarce antigens in complex molecular mixtures. The mAbs will be useful tools for developmental and cell biological studies.