EFFECT OF ENDOTOXIN ON CYTOKINE PRODUCTION AND CELL-DYNAMICS IN MICE

Previous studies have shown that endotoxin potentiates immune response s by direct stimulation of B cells and macrophages. In the present stu dy, we assessed the ability of endotoxin to stimulate cells from diffe rent lymphoid tissue compartments to release cytokines. The in vitro s timulation of macrophages with endotoxin resulted in the production of IL-1 and TNF-alpha in a dose and time-dependent manner. Endotoxin als o induced the production of IL-2, IFN-gamma and IL-4 secretion in a do se dependent manner in cultured spleen, mesenteric lymph nodes and Pey er's patches cells. The intraperitoneal administration of endotoxin in mice resulted in the accumulation of leucocytes in the peritoneal cav ity and in the increase of IL-1, IL-6, TNF-alpha and IFN-gamma concent ration in serum. In conclusion, this study confirmed that endotoxin po ssesses immunomodulatory activities capable of stimulating immune func tions both in vitro and in vivo.