|Budget Amount *help
¥3,800,000 (Direct Cost : ¥3,800,000)
Fiscal Year 1998 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1997 : ¥3,200,000 (Direct Cost : ¥3,200,000)
In the present study, the secretion polarity of interferon (IFN)-beta exogenously expressed following transfection of mouse or human IFN-beta expression plasmid in four kinds of epithelial cells was studied using a bicameral culture system : human colorectal carcinoma Caco-2, mouse squamous cell carcinoma Pam-T, Mardin-Darby canine kidney MDCK, and porcine tubular epithelial cell LLC-PK1 I_n the former three kinds, transiently expressed IFN-beta was predominantly secreted from the cell membrane side to which the transfection was carried out ; if the plasmid was applied to the upper or lower compartment, IFN-beta was secreted from the apical or basolateral membrane, respectively. Interestingly, simultaneous transfection from both sides, apically with mouse IFN-beta gene and basally with human LFN-betag ene, resulted in mouse IFN-beta secretion into upper compartments and human IFN-beta secretion into lower compartments, and vice versa. LLC-PK_1 cells showed non-polarized transient secretion. Meanwhile, stable secretion from the transformants, which is established from either cell line transfected with IFN-beta expression plasmid was non-polarized. Taken together these results suggest that epithelial cells have various protein sorting-secretion pathways for the same protein. The sorting manner seems to be depended on how the protein is expressed, constitutive oremergent. These findings would be useful to construct the strategy for gene transfer into intestinal epithelial cells and other polarized cells.