title: Epithelial cell-conditioned media inhibits degranulation of the RBL-2H3 rat mast cell line.
abstract: The effect of epithelial cells on mast cell responses was investigated by examination of degranulation of the rat mast cell line RBL-2H3 after overnight culture in media conditioned by the BEAS-2B human bronchial epithelial cell line [epithelial cell-conditioned media (ECM)]. These studies indicate that BEAS-2B cells secrete an inhibitor(s) of immunoglobulin E and A-23187-mediated degranulation of the RBL-2H3 cell line. The inhibitory activities of ECM are recovered after filtration through a 3-kDa cutoff filter. Pharmacological inhibition of cyclooxygenase in the BEAS-2B cells before preparation of ECM has no effect on subsequent inhibition of mast cell degranulation by ECM. However, cycloheximide treatment of the BEAS-2B cells before the conditioning process does preclude development of mast cell inhibitor activity in ECM, suggesting that this activity depends on protein synthesis. The effects of ECM on mast cell function are reversible, demonstrating that these effects do not result from overt cytotoxicity. Finally, media conditioned by primary cultures of human respiratory epithelial cells, but not fibroblasts, influence RBL-2H3 degranulation in a manner similar to ECM, suggesting that secretion of mast cell inhibitors may be somewhat unique to epithelial cells.
authors.affiliation: Department of Pediatrics, University of North Carolina School of Medicine, Chapel Hill 27599, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: Peden
authors.forename: L
authors.initials: L
authors.lastname: Dailey
authors.forename: I
authors.initials: I
authors.lastname: Wortman
authors.forename: M
authors.initials: M
authors.lastname: Madden
authors.forename: P A
authors.initials: PA
authors.lastname: Bromberg
mesh_terms: D000818:Animals; D001094:Arachidonate 5-Lipoxygenase / Q000378:metabolism; D001980:Bronchi / Q000166:cytology / Q000502:physiology*; D000001:Calcimycin / Q000494:pharmacology; D002460:Cell Line; D002470:Cell Survival; D017077:Culture Media, Conditioned; D016861:Cyclooxygenase Inhibitors; D003594:Cytoplasmic Granules / Q000187:drug effects / Q000502:physiology*; D004847:Epithelial Cells; D004848:Epithelium / Q000502:physiology; D006801:Humans; D007073:Immunoglobulin E / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D007700:Kinetics; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology; D008407:Mast Cells / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D051381:Rats; D002722:Chlorobenzenes
chemical_list: D001094:Arachidonate 5-Lipoxygenase; D000001:Calcimycin; D017077:Culture Media, Conditioned; D016861:Cyclooxygenase Inhibitors; D007073:Immunoglobulin E; D007211:Indoles; D007476:Ionophores; D016859:Lipoxygenase Inhibitors; D011451:Prostaglandin-Endoperoxide Synthases; C060893:MK-886; D002722:Chlorobenzenes