Pharmacological Analysis of Mast Cell Mediator and Neurotransmitter Receptors Coupled to Adenylate Cyclase and Phospholipase C on Immunocytochemically-Defined Human Conjunctival Epithelial Cells

Abstract

We sought to establish and immunocytochemically characterize primary cultures of human conjunctival epithelial (HCE) cells, and to determine the types of receptors coupled to adenylate cyclase (AC) and phospholipase C (PLC) present on them which may be stimulated following allergic or inflammatory provocation of the tissue. HCE cells possessed the key epithelial cell surface cytokeratins AE1, AE3 and AE5. Signal transduction studies (n > or = 3), using agonists and antagonists, revealed the presence of beta 2-adrenergic (isoproterenol EC50 = 5.2 nM), prostaglandin E2 (EC50 = 168 nM) and vasoactive intestinal peptide (EC50 = 0.69 nM) receptors positively coupled to AC in HCE cells. Bradykinin (EC50 = 0.83 nM), platelet activating factor (EC50 = 4.5 nM), leukotriene C4 (EC50 = 300 nM) and histamine1 (EC50 = 3.1 microM) receptors were coupled to PLC (n = 3 for each). These data suggest that HCE cells in vivo may represent target cells for mast cell mediators and certain neurotransmitters which are released into the tear-film upon allergic provocation of the conjunctiva.

Characterization of a Spontaneously Immortalized Cell Line (IOBA-NHC) from Normal Human Conjunctiva

“…43,44 Several other investigators have analyzed the expression of inflammation-related mediators and receptors in early cell passages. 41,42 A few continuous cell lines derived from human conjunctival epithelium have been reported. The most frequently used is the Wong-Kilbourne derivative of Chang conjunctival cells.…”

Pharmacology of [3H]‐pyrilamine binding and of the histamine‐induced inositol phosphates generation, intracellular Ca2+‐mobilization and cytokine release from human corneal epithelial cells

“…PI turnover studies were performed as previously described (Wiernas et al , 1997; Sharif et al , 1997a,b). In brief, CEPI cells (approximately 2 × 10 5 cells/well) cultured in 24‐well plates were incubated with [ 3 H]‐myo‐inositol (2 μCi ml −1 ) in DMEM for 24 h at 37°C in order to label the cell membrane lipids.…”

Prostaglandin DP receptors positively coupled to adenylyl cyclase in embryonic bovine tracheal (EBTr) cells: pharmacological characterization using agonists and antagonists

“…Cyclic AMP RIA techniques have been described previously Sharif et al, 1997; I]-cyclic AMP (100 ml) to the samples followed by addition of primary antibody (100 ml). The contents were thoroughly mixed by repeated pipetting.…”