title: Purification and characterization of Haemophilus influenzae pili, and their structural and serological relatedness to Escherichia coli P and mannose-sensitive pili.
abstract: Haemophilus influenzae pili were purified, and their physical and serological properties were examined. The solution properties of the pili were determined, and then a purification scheme involving repeated cycles of precipitation and solubilization was developed. The purified pili from one type b isolate (A02) were found to consist of multiple copies of a 25,000 mol wt subunit. Amino-terminal sequence analysis of A02 pili was carried out to 40 amino acid residues, and a remarkable degree of sequence homology was found with E. coli P and mannose-sensitive (MS) pili (27.5 and 25% homology, respectively). Purified A02 pili were found to be highly immunogenic, and serological analysis by enzyme-linked immunosorbent assay and whole piliated cell agglutination revealed significant cross-reactivity between A02 pilus antiserum and the pili of seven other H. influenzae strains tested (heterologous titers = 2-100% of the homologous titer). Cross-reactivity was also observed between the H. influenzae pili (five of eight strains tested) and the P pili from E. coli strains HU849 and 3669; no cross-reactivity was detected with MS pili from E. coli strain H10407 and C94. The structural similarities between H. influenzae and E. coli P and MS pili suggest a common gene ancestry.
authors.forename: N G
authors.initials: NG
authors.lastname: Guerina
authors.forename: S
authors.initials: S
authors.lastname: Langermann
authors.forename: G K
authors.initials: GK
authors.lastname: Schoolnik
authors.forename: T W
authors.initials: TW
authors.lastname: Kessler
authors.forename: D A
authors.initials: DA
authors.lastname: Goldmann
mesh_terms: D000328:Adult; D000372:Agglutination Tests; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D011232:Chemical Precipitation; D003429:Cross Reactions; D004926:Escherichia coli / Q000276:immunology*; D005260:Female; D010861:Fimbriae, Bacterial / Q000032:analysis* / Q000187:drug effects / Q000648:ultrastructure; D006193:Haemophilus influenzae / Q000032:analysis* / Q000276:immunology / Q000648:ultrastructure; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007106:Immune Sera / Q000494:pharmacology; D007231:Infant, Newborn; D008358:Mannose / Q000494:pharmacology*; D008970:Molecular Weight; D011817:Rabbits; D012995:Solubility
chemical_list: D000596:Amino Acids; D007106:Immune Sera; D008358:Mannose