Inhibition of blood clearance and hepatic tissue binding of Escherichia coli by liver lectin-specific sugars and glycoproteins

Abstract

The effects of sugars and glycoproteins that are known to bind to lectins of liver tissue on the clearance of cells of Escherichia coli from mouse blood was investigated. The administration of 100 mg per mouse of methyl-alpha-D-mannoside, methyl-alpha-D-glucoside, or methyl-alpha-D-fucoside, but not of methyl-alpha-D-galactoside or L-rhamnose, markedly inhibited the blood clearance of cells of E. coli 346. Clearance was similarly inhibited by 0.1 and 1.0 mg per mouse of asialofetuin or ovalbumin, respectively, whereas fetuin had no effect. The inhibitory effects of the sugars on blood clearance was abolished by pretreating the E. coli cells with antibodies against whole organisms. All of these effects were equal for fimbriated and nonfimbriated phenotypes of E. coli 346. Homogenates of mouse liver tissue coaggregated with nonfimbriated cells of E. coli. The aggregation was blocked by 100 mM solutions of methyl-alpha-D-mannoside, or methyl-alpha-D-glucoside, 1 mg of bacterial lipopolysaccharide per ml, or 10 mM EDTA but not by L-rhamnose. These results suggest that the mannose-N-acetylglucosamine hepatic lectin recognizes specific sugars on the surface of E. coli and may be centrally involved in the nonimmune clearance of nonfimbriated E. coli from the blood of the infected host.