130 INHIBITION OF ADHESION OF S-FIHBRIATED E.COLI TO BUCCAL EPITAECIAL CELLS ST HUMAN MILK FAT GLOBULE MEMBRANE MUCINS: A NEW ASPECT OF PROTECTIVE FUNCTION Of THE NON-IMHUNOGLOSULIN FRACTION

Abstract

In search of factors of human milk that inhibit invasion of pathogenic bacteria we have analyzed the effect of human milk fat globule membrane (HMFGM) components on adhesion of cloned S-fimbriated E.Coli to human buccal epithelial cells. S-fimbriae are a common feature of E.Coli strains causing sepsis and meningitis in the newborn period and are bound to epthelia via sialyl-(α 2-3) or sialyl-(α 2-6) galactoside structures. Whole milk fat globules (MFG) could be agglutinated by the above mentioned bacteria. Agglutination could be inhibited by fetuin, human glycophorin and α1acid glykoprotein. In addition, pretreatment of MFG with Vibrio cholerae neuraminidase markedly reduced bacteria - induced agglutinations indicating the involvement of neuraminic acid containing glykoproteins. Lipid droplets of infant formula or arteficial lipid emulsions (IntralipidR), in contrast, could not be agglutinated. MFG were present in stools of breast fed newborn babies as shown by staining with a FITC-labelled monoclonal antibody directed against HMFGM and could be agglutinated by bacteria. To further characterize relevant HMFGM components they were separated by get chromatography. Of the fractions obtained mucins whose quality was confirmed by Western blot and monosaccharide analysis showed the most pronounced inhibitory effect on adhesion of S-fimbriated E.Coli to human buccal epithelial cells. Our data suggest that MFG besides their nutritive function provide protection against bacterial infections by inhibition of bacterial adhesion over the length of the entire intestine. Supported by Deutsche Forschungsgemeinschaft Schr 381/3-1