The toxin-coregulated pilus (TCP) of Vibrio cholerae: molecular cloning of genes involved in pilus biosynthesis and evaluation of TCP as a protective antigen in the infant mouse model.
A serum containing antibodies to non-lipopolysaccharide (non-LPS) protective antigens of Vibrio cholerae has been used, after extensive absorption, to facilitate the cloning of genes involved in the synthesis of toxin-coregulated pili (TCP). A gene bank was constructed from V. cholerae Z17561 DNA using a mobilizable cosmid vector in Escherichia coli, and subsequently transferred by conjugation into V. cholerae O17. This strain does not produce TCP in vitro and lacks non-LPS protective antigens. Eight positive clones were isolated, and of these, four produced TCP as determined by electron microscopic and immunoblotting analyses. TCP-positive O17 clones were 70-fold more virulent than TCP-negative clones or O17 in the infant mouse cholera model. Only the former could remove protective antibodies from the clone-probing serum by absorption. As a corollary, serum containing antibodies to TCP protected mice from challenge with TCP-positive clones, but not with TCP-negative clones or O17. Our data indicate that TCP can function as both a virulence determinant and a protective antigen in the infant mouse model.
Sharma
D P
DP
Department of Microbiology and Immunology, University of Adelaide, South Australia.
Stroeher
U H
UH
Thomas
C J
CJ
Manning
P A
PA
Attridge
S R
SR
D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics*; D002771:Cholera / Q000276:immunology*; D002772:Cholera Toxin; D003001:Cloning, Molecular; D004195:Disease Models, Animal; D010861:Fimbriae, Bacterial / Q000276:immunology*; D051379:Mice; D014734:Vibrio cholerae / Q000235:genetics* / Q000276:immunology; D014774:Virulence / Q000235:genetics
D000942:Antigens, Bacterial; D002772:Cholera Toxin