Interaction of latex-insolubilized endotoxins with murine macrophages: phagocytic responses of endotoxin-responsive (C3HeB/FeJ) and -unresponsive (C3H/HeJ) macrophages in vitro.

Insolubilized lipopolysaccharides (LPS) were prepared by covalently coupling LPS from polysaccharide-deficient S. minnesota R595 and polysaccharide-rich E. coli 055:B5 to carboxylated latex particles. The stability of these LPS-latex complexes was determined using several assays to detect soluble LPS following incubation at ambient and elevated temperatures. Resident and thioglycollate-elicited macrophages from both LPS-responder C3HeB/FeJ and LPS nonresponder C3H/HeJ mice were examined for their capacity to phagocytose the LPS particles following in vitro culture for various time periods. Uptake was demonstrated by an increase in the number of particles within the macrophages with increasing time of incubation. Rough polysaccharide-deficient LPS-latex particles were found to be more readily phagocytosed than control particles, whereas smooth polysaccharide-rich LPS particles were phagocytosed less readily than the controls. Qualitatively similar results were found in the relative rate of uptake of particles by the macrophages from the endotoxin-responsive and -unresponsive mouse strains used in this study.