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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Maternal Vaccination with a Fimbrial Tip Adhesin and Passive Protection of Neonatal Mice against Lethal Human Enterotoxigenic Escherichia coli Challenge

Texto completo
Autor(es):
Luiz, Wilson B. [1, 2] ; Rodrigues, Juliana F. [1] ; Crabb, Joseph H. [3] ; Savarino, Stephen J. [4, 5] ; Ferreira, Luis C. S. [1]
Número total de Autores: 5
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Inst Biomed Sci, Dept Microbiol, Lab Vaccine Dev, Sao Paulo - Brazil
[2] Univ Estadual Santa Cruz, Dept Biol Sci, Ilheus - Brazil
[3] ImmuCell Corp, Portland, ME - USA
[4] Naval Med Res Ctr, Enter Dis Dept, Infect Dis Directorate, Silver Spring, MD 20910 - USA
[5] Uniformed Serv Univ Hlth Sci, Dept Pediat, Bethesda, MD 20814 - USA
Número total de Afiliações: 5
Tipo de documento: Artigo Científico
Fonte: Infection and Immunity; v. 83, n. 12, p. 4555-4564, DEC 2015.
Citações Web of Science: 15
Resumo

Globally, enterotoxigenic Escherichia coli (ETEC) is a leading cause of childhood and travelers' diarrhea, for which an effective vaccine is needed. Prevalent intestinal colonization factors (CFs) such as CFA/I fimbriae and heat-labile enterotoxin (LT) are important virulence factors and protective antigens. We tested the hypothesis that donor strand-complemented CfaE (dscCfaE), a stabilized form of the CFA/I fimbrial tip adhesin, is a protective antigen, using a lethal neonatal mouse ETEC challenge model and passive dam vaccination. For CFA/I-ETEC strain H10407, which has been extensively studied in volunteers, an inoculum of 2 x 10(7) bacteria resulted in 50% lethal doses (LD50) in neonatal DBA/2 mice. Vaccination of female DBA/2 mice with CFA/I fimbriae or dscCfaE, each given with a genetically attenuated LT adjuvant (LTK63) by intranasal or orogastric delivery, induced high antigen-specific serum IgG and fecal IgA titers and detectable milk IgA responses. Neonates born to and suckled by dams antenatally vaccinated with each of these four regimens showed 78 to 93% survival after a 20 x LD50 challenge with H10407, compared to 100% mortality in pups from dams vaccinated with sham vaccine or LTK63 only. Crossover experiments showed that high pup survival rates after ETEC challenge were associated with suckling but not birthing from vaccinated dams, suggesting that vaccine-specific milk antibodies are protective. In corroboration, preincubation of the ETEC inoculum with antiadhesin and antifimbrial bovine colostral antibodies conferred a dose-dependent increase in pup survival after challenge. These findings indicate that the dscCfaE fimbrial tip adhesin serves as a protective passive vaccine antigen in this small animal model and merits further evaluation. (AU)

Processo FAPESP: 10/52167-8 - Controle de diarréias associadas a linhagens de Escherichia coli enterotoxigênica (ETEC): formulações baseadas na fímbria CFA/I, adesina CfaE toxina termo-lábil (LT) e validação de um novo modelo experimental
Beneficiário:Luis Carlos de Souza Ferreira
Linha de fomento: Auxílio à Pesquisa - Regular