IN-VIVO DETECTION OF A NOVEL MACROPHAGE-DERIVED PROTEIN INVOLVED IN THE REGULATION OF NASAL MUCUS-LIKE GLYCOCONJUGATE SECRETION

Background: We recently described a novel 68 kd mucus secretagogue (MM S-68) derived from human monocytes, pulmonary macrophages, and a macro phage hybridoma, clone 63. We detected MMS-68 in monocyte culture supe rnatants from patients with steroid-dependent asthma and in bronchoalv eolar lavage fluid from patients with chronic bronchitis by antigen ca pture ELISA and in normal lung tissue by immunohistochemistry. Methods : To determine a role for MMS-68 in the regulation of nasal mucus, we labeled human nasal turbinates with tritiated glucosamine and assayed for the ability of the previously purified MMS-68 (stock solution) to induce mucus-like glycoconjugate release (MLGC). We also performed imm unohistochemistry stains with an anti-MMS-68 antibody (1-D-10) on froz en sections (n = 5) of nasal turbinates from patients with allergic an d nonallergic rhinitis who were undergoing rhinoplasty and measured MM S-68 levels in nasal lavages from patients who were undergoing topical nasal histamine or methacholine challenge. Results: MMS-68 is a poten t nasal MLGC secretagogue causing a dose-dependent increase in MLGC re lease in vitro. Staining revealed a subepithelial distribution for MMS -68. Antigen capture ELISA of nasal lavages demonstrated mean MMS-68 l evels from saline control challenge of 0.9 +/- 0.5 mug MMS-68 per mill igram of protein (n = 5), 8.6 +/- 1.4 mug MMS-68 per milligram of prot ein from histamine challenge and 20.7 +/- 2.3 mug MMS-68 per milligram of protein (n = 5) after methacholine challenge. Conclusion: Taken to gether these data suggest that MMS-68 may play a role in the normal re gulation of mucus secretion.