Evaluation of transcutaneous immunization as a delivery route for an enterotoxigenic E. coli adhesin-based vaccine with CfaE, the colonization factor antigen 1 (CFA/I) tip adhesin

Vaccine. 2019 Sep 30;37(42):6134-6138. doi: 10.1016/j.vaccine.2019.08.057. Epub 2019 Sep 3.

Abstract

dscCfaE is a recombinant form of the CFA/I tip adhesin CfaE, expressed by a large proportion of enterotoxigenic E. coli (ETEC). It is highly immunogenic by the intranasal route in mice and Aotus nancymaae, protective against challenge with CFA/I+ ETEC in an A. nancymaae challenge model, and antibodies to dscCfaE passively protect against CFA/I+ ETEC challenge in human volunteers. Here, we show that transcutaneous immunization (TCI) with dscCfaE in mice resulted in strong anti-CfaE IgG serum responses, with a clear dose-response effect. Co-administration with heat-labile enterotoxin (LT) resulted in enhanced immune responses over those elicited by dscCfaE alone and strong anti-LT antibody responses. The highest dose of dscCfaE administered transcutaneously with LT elicited strong HAI titers, a surrogate for the neutralization of intestinal adhesion. Fecal anti-adhesin IgG and IgA antibody responses were also induced. These findings support the feasibility of TCI for the application of an adhesin-toxin based ETEC vaccine.

Keywords: Adhesin; CFA/I; CfaE; ETEC; TCI; Transcutaneous.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adhesins, Escherichia coli / immunology
  • Administration, Cutaneous
  • Animals
  • Bacterial Toxins / immunology*
  • Enterotoxigenic Escherichia coli / immunology*
  • Enterotoxins / immunology*
  • Escherichia coli Proteins / immunology*
  • Escherichia coli Vaccines / immunology*
  • Female
  • Fimbriae Proteins / immunology*
  • Immunoglobulin A / blood
  • Immunoglobulin A / immunology
  • Immunoglobulin G / blood
  • Immunoglobulin G / immunology
  • Mice
  • Mice, Inbred BALB C
  • Recombinant Proteins / immunology
  • Vaccination / methods*

Substances

  • Adhesins, Escherichia coli
  • Bacterial Toxins
  • CfaE protein, E coli
  • Enterotoxins
  • Escherichia coli Proteins
  • Escherichia coli Vaccines
  • Immunoglobulin A
  • Immunoglobulin G
  • Recombinant Proteins
  • Fimbriae Proteins
  • heat-labile enterotoxin, E coli