Nasal immunization with E. coli verotoxin 1 (VT1)-B subunit and a nontoxic mutant of cholera toxin elicits serum neutralizing antibodies

Academic Article


  • Escherichia coli O157:H7 produces two forms of verotoxin (VT), VT1 and VT2, which cause hemorrhagic colitis with development, in some cases, of hemolytic uremic syndrome. These toxins consist of an enzymatically active A subunit and pentamers of B subunit responsible for their binding to host cells. We used the secretion-expression system of Bacillus brevis to produce recombinant VT1B and VT2B. The secreted B subunits were purified and sequenced to verify their structure. Receptor-binding showed that rVT1B but not rVT2B bound to Gb3-receptor. When mice were nasally immunized with rVT1B or rVT2B together with a nontoxic mutant of cholera toxin (mCT) or native cholera toxin (nCT) as adjuvants, serum IgG and mucosal IgA antibody responses to VT1B were induced. The VT1B-specific antibodies prevented VT1B binding to its Gb3 receptor. In contrast, poor serum and no mucosal VT2B-specific antibodies but brisk CTB-specific antibody responses were induced by nasal immunization with rVT2B in the presence of mCT or nCT. These results show that nasal immunization with rVTB and mCT as a nontoxic mucosal adjuvant is an effective regimen for the induction of VT1B but not VT2B antibody responses which inhibit VT1B binding to Gb3 receptor. © 2001 Elsevier Science Ltd.
  • Published In

  • Vaccine  Journal
  • Digital Object Identifier (doi)

    Author List

  • Byun Y; Ohmura M; Fujihashi K; Yamamoto S; McGhee JR; Udaka S; Kiyono H; Takeda Y; Kohsaka T; Yuki Y
  • Start Page

  • 2061
  • End Page

  • 2070
  • Volume

  • 19
  • Issue

  • 15-16