MULTIPLE RECEPTORS ON PORCINE INTESTINAL EPITHELIAL-CELLS FOR THE 3 VARIANTS OF ESCHERICHIA-COLI K88 FIMBRIAL ADHESIN

We evaluated intestinal epithelial membrane preparations from five phe notypes of pigs, distinguished by the variant of K88 fimbrial adhesin (K88ab, K88ac, K88ad) which bind to their intestinal epithelial cells (A-all three variants, B-K88ab and K88ac, C-K88ab and K88ad, D-K88ad, and E-none of the variants), for the presence of K88 adhesin receptors . Intestinal brush border membranes were prepared from 20 animals (fou r from each phenotype). Brush border proteins, that had been separated using SDS-PAGE and transferred to nitrocellulose membranes, were over laid with biotinylated K88 adhesin, S-35-labelled K88(+) Escherichia c oli, or biotinylated K88(+) E. coli. Biotinylated K88ab and K88ac fimb rial adhesins and labelled E. coli expressing K88ab or K88ac adhesin b ound to 210- and 240-kDa receptors in phenotype A and B, but not pheno type C, D, or E animals. In contrast, no phenotype-specific receptors were identified for the K88ad adhesin. Previously, purified K88ab and K88ac fimbriae were shown to block K88ad binding, but purified K88ad f imbriae were unable to block K88ab or K88ac binding in phenotype A ani mals. These results point to the existence of three K88 adhesin recept ors to account for the observed phenotypes: (1) Receptor bcd binds all three variants and is found in phenotype A pigs, (2) Receptor be (210 - and 240-kDa receptors) binds K88ab and K88ac and is found in phenoty pe A and B pigs, and (3) Receptor d binds K88ad and is found in phenot ype C and D pigs. (C) 1998 Elsevier Science B.V.