Production of interferon-β by fibroblast cells on membranes prepared with RGD-containing peptides

The production of interferon-β by NB1-RGB fibroblast cells cultured on protein and peptide membranes prepared from silk fibroin, motif peptides of silk fibroin [(AG)_n] containing arginine-glycine-aspartic acid (RGD) peptide, and Pronectin™ was investigated. The cell density on various protein and peptide membranes was approximately the same, although the production of interferon-β depended significantly on the membranes where the cells were cultured. The highest production of interferon-β was observed when the cells were cultured on (AG)₆RGD(AG)₇ membranes prepared with hexafluoroacetone (HFA) as the casting solvent. On RGD-containing peptide membranes more centrally located in the peptides, the cells produced more interferon-β when the peptide membranes were prepared with HFA as the casting solvent. However, there was no enhanced production of interferon-βb by cells on (AG)₆RGD(AG)₇ membranes prepared with 9 mol/L LiBr or 4.5 mol/L LiClO₄ solution as the casting solvent. Therefore, both the chemical composition and the secondary and higher order structure of the peptide membranes are important for enhanced production of interferon-β. The blocking of integrin β₁ on the cells by anti-integrin β₁ antibody prevented the enhanced production of interferon-β on (AG)₆RGD(AG)₇ membranes prepared with HFA. We suggest that the cells must bind to the RGD sequence having the appropriate conformation through their integrin β ₁ for enhanced production of interferon-β.