Hemagglutination by purified type I Escherichia coli pili.

Abstract

Many enterobacteria can cause agglutination of erythrocytes, but previous investigations have not proven which components of the bacteria are responsible. We used a strain of Escherichia coli K12 which causes mannose-sensitive hemagglutination (HA) of guinea pig cells. Common pili were purified from these bacteria by shearing them from the bacteria followed by selective precipitation in acid and ammonium sulfate. Isopycnic centrifugation in cesium chloride removed the remaining outer membrane protein contaminants. These pili are pure by electron microscopy and gel electrophoresis. By amino acid analysis, they have a mol wt of 17,099 and consist of 45% nonpolar residues. These purified pili agglutinate guinea pig erythrocytes, a reaction that is inhibited by anti-pili antibodies and by saccharides related in structure to D-mannose. Proteolytic treatment of erythrocytes does not diminish HA but rather increases the pili-induced HA of human cells. Neuraminidase enhances HA and mannosidase slightly diminishes it. It is concluded that purified pili alone cause HA of erythrocytes by binding to mannose-like molecules on the erythrocyte surface. Thus HA by bacterial pili serves as a useful model system for the mechanism of bacterial pili attachment ot cell membranes.

The Distinct Binding Specificities Exhibited by Enterobacterial Type 1 Fimbriae Are Determined by Their Fimbrial Shafts

“…However, for this to be true, FimH presented at the fimbrial tip as well as FimH intercalated along the shaft would both have to be able to mediate adhesion. Much previous work has indicated that only FimH present at the tips of fimbriae is functional in mediating adhesion (35,(45)(46)(47)(48). For example, type 1 fimbriae have been observed to bind to erythrocyte membranes as well as the uroepithelium by the tips of the fimbriae (46,49).…”

“…For example, type 1 fimbriae have been observed to bind to erythrocyte membranes as well as the uroepithelium by the tips of the fimbriae (46,49). In addition, non-aggregated cell-free type 1 fimbriae do not agglutinate erythrocytes, whereas aggregated type 1 fimbriae and whole bacteria both cause hemagglutination (45,46,48), strongly indicating that, with respect to adhesion, type 1 fimbriae are monovalent. The work of Ponniah et al (47) supports this idea by showing that fragmentation of type 1 fimbriae greatly increases their mannose-binding activity by exposing FimH that was previously intercalated into the fimbrial shaft, indicating that shaft-located FimH is not functional in adhesion.…”

Type 1 Pili Enhance the Invasion of Salmonella braenderup and Salmonella typhimurium to HeLa Cells

“…Isolation and purification of type 1 pili. This was performed essentially according to the procedure described by Salit and Gotschlich (17). The strains 301 or 501, which expressed only type 1 pili were used.…”

Membrane cofactor protein (MCP or CD46) is a cellular pilus receptor for pathogenic Neisseria

“…A number of bacterial pili have been established as having lectin-like properties, including type IV pili of P. aeruginosa, which bind to ␤GalNAc(1-4)␤Gal of glycosphingolipids Sheth et al, 1994), the type 1 fimbriae of Escherichia coli, which bind to mannose residues (Salit and Gotschlich, 1977;Rivier and Darekar, 1975), and the E. coli pap-pili with binding specificity to ␣Gal(1-4)␤ disaccharides (Bock et al, 1985). We have previously investigated the nature of the gonococcal host cell receptor and found that the pilus-mediated attachment of the bacteria to human tissue is mediated by a eukaryotic receptor with protein characteristics (Jonsson et al, 1994).…”