New vaccine strategies against enterotoxigenic Escherichia coli: I: DNA vaccines against the CFA/I fimbrial adhesin

Alves, Ada M. B.; Lásaro, Marcio O.; Almeida, Darcy Fontoura de; Ferreira, L. C. S.

doi:10.1590/s0100-879x1999000200011

Cited by 16 publications

(14 citation statements)

References 25 publications

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“…Other reports with different genes, including those from our group, also used the t-PA signal peptide in DNA vaccines, in order to mediate the secretion of recombinant antigens. In these cases, protein secretion seemed to be essential for the induction of a robust immune response, particularly regarding the production of antibodies [38], [56]–[58]. Nevertheless, in the present work, after immunization with plasmids encoding the t-PA signal sequence, we observed only a weak antibody response against the NS3, detected in 1/5, 2/5 and 3/5 animals inoculated with pcTPANS3H, pcTPANS3P and pcTPANS3 DNA vaccines, respectively, with titers ranging from 200 to 1500 (data not shown).…”

Section: Discussionmentioning

confidence: 99%

Induction of a Protective Response in Mice by the Dengue Virus NS3 Protein Using DNA Vaccines

et al. 2011

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The dengue non-structural 3 (NS3) is a multifunctional protein, containing a serino-protease domain, located at the N-terminal portion, and helicase, NTPase and RTPase domains present in the C-terminal region. This protein is considered the main target for CD4+ and CD8+ T cell responses during dengue infection, which may be involved in protection. However, few studies have been undertaken evaluating the use of this protein as a protective antigen against dengue, as well as other flavivirus. In the present work, we investigate the protective efficacy of DNA vaccines based on the NS3 protein from DENV2. Different recombinant plasmids were constructed, encoding either the full-length NS3 protein or only its functional domains (protease and helicase), fused or not to a signal peptide (t-PA). The recombinant proteins were successfully expressed in transfected BHK-21 cells, and only plasmids encoding the t-PA signal sequence mediated protein secretion. Balb/c mice were immunized with the different DNA vaccines and challenged with a lethal dose of DENV2. Most animals immunized with plasmids encoding the full-length NS3 or the helicase domain survived challenge, regardless of the presence of the t-PA. However, some mice presented clinical signs of infection with high morbidity (hind leg paralysis and hunched posture), mainly in animal groups immunized with the DNA vaccines based on the helicase domain. On the other hand, inoculation with plasmids encoding the protease domain did not induce any protection, since mortality and morbidity rates in these mouse groups were similar to those detected in the control animals. The cellular immune response was analyzed by ELISPOT with a specific-CD8+ T cell NS3 peptide. Results revealed that the DNA vaccines based on the full-length protein induced the production of INF-γ, thus suggesting the involvement of this branch of the immune system in the protection.

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Section: Discussionmentioning

confidence: 99%

Induction of a Protective Response in Mice by the Dengue Virus NS3 Protein Using DNA Vaccines

et al. 2011

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“…The construction of pRECFA and its induced immune response following administration in mice have been reported (11,12).…”

Section: Dna Vaccinementioning

confidence: 99%

“…Using a similar immunization strategy we evaluated the priming of the mucosal immune system by a parenteral DNA vaccine encoding the colonization factor I antigen (CFA/I) fimbrial adhesin subunit of enterotoxigenic Escherichia coli (11,12) followed by oral immunization with a live recombinant Salmonella vaccine strain expressing the same enterotoxigenic Escherichia coli (ETEC) antigen (13). We show that the combined immunization regime results in enhanced production of the CFA/I-specific systemic and secreted antibody response.…”

Section: Introductionmentioning

confidence: 99%

New vaccine strategies against enterotoxigenic Escherichia coli: II: Enhanced systemic and secreted antibody responses against the CFA/I fimbriae by priming with DNA and boosting with a live recombinant Salmonella vaccine

Lásaro

Alves

Guillobel

et al. 1999

Braz J Med Biol Res

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The induction of systemic (IgG) and mucosal (IgA) antibody responses against the colonization factor I antigen (CFA/I) of enterotoxigenic Escherichia coli (ETEC) was evaluated in mice primed with an intramuscularly delivered CFA/I-encoding DNA vaccine followed by two oral immunizations with a live recombinant Salmonella typhimurium vaccine strain expressing the ETEC antigen. The booster effect induced by the oral immunization was detected two weeks and one year after the administration of the DNA vaccine. The DNAprimed/Salmonella-boosted vaccination regime showed a synergistic effect on the induced CFA/I-specific systemic and secreted antibody levels which could not be attained by either immunization strategy alone. These results suggest that the combined use of DNA vaccines and recombinant Salmonella vaccine strains can be a useful immunization strategy against enteric pathogens.

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“…DNA immunization, a novel approach to vaccination, is regarded as a new era in vaccination against infectious diseases (Alves et al 1999). However, DNA vaccines appear to be inferior in generating immunogenic responses, especially in inducing effective cellular immunity in animals (Benvenisti et al 2001).…”

Section: Introductionmentioning

confidence: 99%

Multi-epitope recombinant vaccine induces immunoprotection against mixed infection of Eimeria spp.

Ding

Qian

et al. 2011

Parasitol Res

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Immunity to Eimeria is species-specific, and chickens with immunity to one species of Eimeria remain susceptible to other Eimeria species. This presents a major challenge in the development of effective vaccines against multiple Eimeria species. In this study, we cloned the antigenic epitope of a tachyzoite surface protein gene of Eimeria tenella, a tachyzoite surface protein gene of Eimeria acervulina and the gametocyte protein gene of Eimeria maxima, and constructed prokaryotic and eukaryotic plasmids carrying the multi-epitope antigenic gene. Immunization of chickens with the multivalent DNA and protein conferred partial protection against infection by the three Eimeria species, as shown by increased CD4+ T lymphocytes in the intestinal mucosa, decreased oocyst excretion and intestinal lesions, and increased body weight gain compared with non-immunized controls. The DNA prime-protein boost immunization schedule induced greater cellular immunity and protection from Eimeria infection than immunization with DNA or protein alone. Our findings demonstrated that DNA prime-protein boost immunization with a multivalent vaccine could stimulate protective immunity against challenge infection of multiple Eimeria species. This work provides a promising step towards DNA-protein vaccination against multiple species of pathogens.

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New vaccine strategies against enterotoxigenic Escherichia coli: I: DNA vaccines against the CFA/I fimbrial adhesin

Cited by 16 publications

References 25 publications

Induction of a Protective Response in Mice by the Dengue Virus NS3 Protein Using DNA Vaccines

Induction of a Protective Response in Mice by the Dengue Virus NS3 Protein Using DNA Vaccines

New vaccine strategies against enterotoxigenic Escherichia coli: II: Enhanced systemic and secreted antibody responses against the CFA/I fimbriae by priming with DNA and boosting with a live recombinant Salmonella vaccine

Multi-epitope recombinant vaccine induces immunoprotection against mixed infection of Eimeria spp.

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