Activity of Gelatins to Induce Secretion of a Variety of Cytokines from Murine Peritoneal Exudate Macrophages

Previously, we observed that liquid form bovine bone (BB) gelatin stimulates murine spleen cells to proliferate in vitro. In this study, activity of BB gelatin to stimulate murine-adherent peritoneal exudate cells(PEC) to secrete cytokines has been examined. Quantitatively, BB gelatin stimulated adherent PEC of C₃H/HeN mice to secrete interleukin (IL)-12 (+p40), TNF-α, and IL-6 but not IL-1β, IL-2, IL-10, and IFN-γ. Qualitatively, BB gelatin-induced secretion of KC, MIP-2, MCP-1, RANTES, and MIP-1a as well as IL-6 but not 6Ckine, CTACK, Eotaxin, G-CSF, GM-CSF, IL-2,-3,-4,-5,-9,-10,-12,-13,-17, Leptin, IFN-γ, SCF, sTNFri, TARC, TNF-α, TIMP-1, Tpo, and VEGF. BB gelatin acted on adherent PEC of C₃H/HeN mice but not C₃H/HeJ mice, which lack Toll-like receptor 4. Polymyxin B, a LPS antagonist, did not inhibit the activity of BB gelatin. Lipopolysaccharide (LPS) but not BB gelatin induced secretion of an appreciable amount of mIL-1β. These results suggest that the activity of BB gelatin is not attributed to contamination of LPS but BB gelatin itself. It was also suggested that BB gelatin stimulated adherent PEC to newly produce and secrete cytokines.