Secretion polarity of interferon-β in epithelial cell lines

Effects of Methyl-.BETA.-cyclodextrin Treatment on Secretion Profile of Interferon-.BETA. and Zonula Occuludin-1 Architecture in Madin-Darby Canine Kidney Cell Monolayers

“…10) We have investigated the secretion polarity of IFN-b exogenously expressed in several epithelial cell monolayers and found that IFN-b transiently expressed by gene transfection was predominantly secreted from the cell membrane side on which the transfection has been carried out, whereas the secretion of constitutive IFN-b from stable transformants was apparently unpolarized in Pam-T and Madin-Darby canine kidney (MDCK) type I cells. 11,12) Similar phenomena have been observed in IFN production by type I IFN inducer, polyriboinosinic acid : polyribocytidylic acid (poly I : poly C), in various epithelial cell monolayers. 13) Furthermore, subcellular localization analysis using enhanced green fluorescent protein (EGFP)-tagged IFN-b had shown that identical IFNb was conveyed to the apical and/or basolateral membrane side, depending on the gene expression strategy, presumably by post-TGN additional sorting events.…”

“…11,28) In our bioassay, contamination by a small amount of mouse IFN-b (lower than ca. 1000 U/ml) did not adversely affect the determination of the target human IFN-b activity.…”

Secretion Mode and Subcellular Localization of Human Interferon-.BETA. Exogenously Expressed in Porcine Renal Epithelial LLC-PK1 Cells

“…14) The expression plasmids for HuIFN-b and HuIFNb-EGFP, dubbed pCMV-HuIFNb and pCMV-HuIFNb-EGFP, respectively, have been previously described. 12,13,16) LLC-PK 1 cells, seeded at 5ϫ10 4 cells/cm 2 in 6 well plates and cultured for 24 h, were transfected with pCMV-HuIFN-b or pCMVHuIFNb-EGFP (3 mg/ml) complexed with a cationic liposome, Lipofectamine 2000 (GIBCO-Invitrogen) (10 mg/ml). Stable transformants were picked up as sigle cell colonies in the presence of 1 mg/ml Geneticin (G418) (Sigma-Aldrich, St Louis, MO, U.S.A.).…”

“…Furthermore, we have shown that stably and transiently expressed IFN-b is transported presumably through separate post-TGN routes in experiments involving confocal imaging of the subcellular localization of IFN-b by tagging with enhanced green fluorescent protein (EGFP). 13) In this report, we investigated the secretion polarity of human IFN-b (HuIFN-b) and the subcellular localization of EGFP-tagged HuIFN-b (HuIFNb-EGFP) in another type of epithelial cell line, LLC-PK 1 , comparing with the previous results of Pam-T 12) and MDCK (type I) cells.…”

“…12,13) In stable expression, IFN-b is apparently secreted in a non-polarized manner 12,13) while, in transient expression, IFN-b is predominantly secreted from the cell side to which gene transfection was carried out. A similar phenomenon was observed in IFN production by the treatment with polyriboinosinic acid: polyribocytidylic acid (poly I: poly C) in several types of epithelial cells including Pam-T and MDCK (type I).…”