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1.
Hum Gene Ther Clin Dev ; 29(4): 226-232, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30381976

RESUMO

The 2014 Ebola outbreak in West Africa brought great threat to public health worldwide. There was no approved antiviral therapy or vaccine available to control the disease at that time. Several kinds of Ebola vaccines were urgently under development across the world. Among these, the novel recombinant adenovirus type 5 vector-based Ebola vaccine (Ad5-EBOV)-the first Ebola vaccine based on the 2014 Zaire Guinea epidemic strain-was developed in China, and its safety and immunogenicity were demonstrated in China and Sierra Leone. The license to market the drug was approved on October 19, 2017, by the Chinese Food and Drug Administration. In order to standardize the test on the Ad5-EBOV virus titer, China's national standard substance for the virus titer of Ad5-EBOV was established according to the recommendations for the preparation, characterization, and establishment of international and other biological reference standards from the World Health Organization and Chinese Pharmacopoeia (third edition). The standard for the Ad5-EBOV virus titer was prepared with a volume of 0.5 mL per ampoule in lyophilized form. The samples of the standard, designated as A, B, C, D with different aims, were blinded and distributed to five laboratories to be collaboratively calibrated. The virus titer for this standard was determined with the antibody staining method according to the instructions in the Adeno-X™ Rapid Titer Kit. The homogeneity and stability of the standard substance were also satisfied. The virus titer standard value was 8.54 lg infectious units (IFU)/mL, and the 95% confidence interval was between 7.94 lg IFU/mL and 9.14 lg IFU/mL. This standard was approved by the Chinese national committee and is available on the National Institutes for Food and Drug Control Web site ( www.nifdc.org.cn ; lot no. 250019-201501).


Assuntos
Aprovação de Drogas , Vacinas contra Ebola/normas , Vacinas Sintéticas/normas , Carga Viral/normas , Adenoviridae/genética , China , Vacinas contra Ebola/imunologia , Ebolavirus/imunologia , Células HEK293 , Humanos , Vacinas Sintéticas/imunologia
2.
Exp Parasitol ; 185: 62-70, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29309783

RESUMO

The development of an effective and safe vaccine to prevent Toxoplasma gondii infection is an important aim due to the great clinical and economic impact of this parasitosis. We have previously demonstrated that immunization with the serine protease inhibitor-1 (TgPI-1) confers partial protection to C3H/HeN and C57BL/6 mice. In order to improve the level of protection, in this work, we combined this novel antigen with ROP2 and/or GRA4 recombinant proteins (rTgPI-1+rROP2, rTgPI-1+rGRA4, rTgPI-1+rROP2+rGRA4) to explore the best combination against chronic toxoplasmosis in C3H/HeN mice. All tested vaccine formulations, administered following a homologous prime-boost protocol that combines intradermal and intranasal routes, conferred partial protection as measured by the reduction of brain cyst burden following oral challenge with tissue cysts of Me49 T. gondii strain. The highest level of protection was achieved by the mixture of rTgPI-1 and rROP2 proteins with an average parasite burden reduction of 50% compared to the unvaccinated control group. The vaccine-induced protective effect was related to the elicitation of systemic cellular and humoral immune responses that included antigen-specific spleen cell proliferation, the release of Th1/Th2 cytokines, and the generation of antigen-specific antibodies in serum. Additionally, mucosal immune responses were also induced, characterized by secretion of antigen-specific IgA antibodies in intestinal lavages and specific mesenteric lymph node cell proliferation. Our results demonstrate that rTgPI-1+rROP2 antigens seem a promising mixture to be combined with other immunogenic proteins in a multiantigenic vaccine formulation against toxoplasmosis.


Assuntos
Antígenos de Protozoários/imunologia , Vacinas Protozoárias/normas , Toxoplasma/imunologia , Toxoplasmose Animal/prevenção & controle , Animais , Anticorpos Antiprotozoários/sangue , Linhagem Celular , Doença Crônica , Citocinas/metabolismo , Feminino , Fibroblastos/parasitologia , Prepúcio do Pênis/citologia , Humanos , Imunoglobulina A Secretora/análise , Imunoglobulina G/sangue , Mucosa Intestinal/imunologia , Masculino , Proteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos C3H , Proteínas de Protozoários/imunologia , Baço/citologia , Baço/imunologia , Vacinas Sintéticas/normas
3.
Vaccine ; 35(48 Pt B): 6700-6706, 2017 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-29079101

RESUMO

BACKGROUND: The risk of developing herpes zoster (HZ) increases with age and is thought to be associated with a decrease in cell-mediated immunity in older adults. The adjuvanted varicella-zoster virus (VZV) glycoprotein E (gE) recombinant subunit vaccine (HZ/su) showed >90% efficacy in the prevention of HZ when administered in adults ≥50 years of age. Here we aim to evaluate immunogenicity consistency of 3 different HZ/su vaccine lots and to assess safety of these lots. METHODS: This multicenter, phase III, double-blind, randomized study (NCT02075515), assessed lot-to-lot consistency in terms of immunogenicity of HZ/su and also assessed safety of these lots. Participants aged 50 years or older were randomized (1:1:1) to receive 2 doses of HZ/su, 2 months apart, from 1 out of 3 randomized HZ/su lots (Lots A, B and C). Humoral immunogenicity was assessed pre-vaccination and 1 month post-second vaccination by anti-gE antibody enzyme-linked immunosorbent assay. Lot-to-lot consistency was demonstrated if the 2-sided 95% confidence intervals of the anti-gE geometric mean concentration ratio between all lot pairs were within 0.67 and 1.5. Solicited symptoms were recorded within 7 days and unsolicited adverse events (AEs) within 30 days after each vaccination. Serious AEs (SAEs) and potential immune-mediated diseases (pIMDs) were reported until study end (12 months post-second vaccination). RESULTS: Of 651 participants enrolled in the study, 638 received both doses of the HZ/su vaccine and 634 completed the study. Humoral immune responses were robust and consistency between 3 manufacturing lots was demonstrated. The incidence of solicited symptoms, unsolicited AEs and SAEs was comparable between all lots. Three fatal SAEs, 1 in each lot, were reported, none of which were considered vaccine-related by investigator assessment. Two out of the 8 reported pIMDs were considered vaccine-related by the investigator. CONCLUSION: The three HZ/su manufacturing lots demonstrated consistent immunogenicity. No safety concerns were identified. Clinical trial registry number: NCT02075515 (ClinicalTrials.gov).


Assuntos
Vacina contra Herpes Zoster/efeitos adversos , Vacina contra Herpes Zoster/imunologia , Herpes Zoster/prevenção & controle , Imunogenicidade da Vacina , Vacinação/efeitos adversos , Adjuvantes Imunológicos/administração & dosagem , Idoso , Anticorpos Antivirais/imunologia , Linfócitos T CD4-Positivos/imunologia , Método Duplo-Cego , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Ensaio de Imunoadsorção Enzimática , Feminino , Vacina contra Herpes Zoster/genética , Vacina contra Herpes Zoster/normas , Herpesvirus Humano 3/imunologia , Humanos , Imunidade Celular , Imunidade Humoral , Masculino , Pessoa de Meia-Idade , Vacinação/estatística & dados numéricos , Vacinas de Subunidades/efeitos adversos , Vacinas de Subunidades/genética , Vacinas de Subunidades/imunologia , Vacinas de Subunidades/normas , Vacinas Sintéticas/efeitos adversos , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/normas , Proteínas do Envelope Viral/administração & dosagem , Proteínas do Envelope Viral/imunologia
4.
PLoS Med ; 13(11): e1002181, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27898668

RESUMO

BACKGROUND: Large Phase III trials across Asia and Latin America have recently demonstrated the efficacy of a recombinant, live-attenuated dengue vaccine (Dengvaxia) over the first 25 mo following vaccination. Subsequent data collected in the longer-term follow-up phase, however, have raised concerns about a potential increase in hospitalization risk of subsequent dengue infections, in particular among young, dengue-naïve vaccinees. We here report predictions from eight independent modelling groups on the long-term safety, public health impact, and cost-effectiveness of routine vaccination with Dengvaxia in a range of transmission settings, as characterised by seroprevalence levels among 9-y-olds (SP9). These predictions were conducted for the World Health Organization to inform their recommendations on optimal use of this vaccine. METHODS AND FINDINGS: The models adopted, with small variations, a parsimonious vaccine mode of action that was able to reproduce quantitative features of the observed trial data. The adopted mode of action assumed that vaccination, similarly to natural infection, induces transient, heterologous protection and, further, establishes a long-lasting immunogenic memory, which determines disease severity of subsequent infections. The default vaccination policy considered was routine vaccination of 9-y-old children in a three-dose schedule at 80% coverage. The outcomes examined were the impact of vaccination on infections, symptomatic dengue, hospitalised dengue, deaths, and cost-effectiveness over a 30-y postvaccination period. Case definitions were chosen in accordance with the Phase III trials. All models predicted that in settings with moderate to high dengue endemicity (SP9 ≥ 50%), the default vaccination policy would reduce the burden of dengue disease for the population by 6%-25% (all simulations: -3%-34%) and in high-transmission settings (SP9 ≥ 70%) by 13%-25% (all simulations: 10%- 34%). These endemicity levels are representative of the participating sites in both Phase III trials. In contrast, in settings with low transmission intensity (SP9 ≤ 30%), the models predicted that vaccination could lead to a substantial increase in hospitalisation because of dengue. Modelling reduced vaccine coverage or the addition of catch-up campaigns showed that the impact of vaccination scaled approximately linearly with the number of people vaccinated. In assessing the optimal age of vaccination, we found that targeting older children could increase the net benefit of vaccination in settings with moderate transmission intensity (SP9 = 50%). Overall, vaccination was predicted to be potentially cost-effective in most endemic settings if priced competitively. The results are based on the assumption that the vaccine acts similarly to natural infection. This assumption is consistent with the available trial results but cannot be directly validated in the absence of additional data. Furthermore, uncertainties remain regarding the level of protection provided against disease versus infection and the rate at which vaccine-induced protection declines. CONCLUSIONS: Dengvaxia has the potential to reduce the burden of dengue disease in areas of moderate to high dengue endemicity. However, the potential risks of vaccination in areas with limited exposure to dengue as well as the local costs and benefits of routine vaccination are important considerations for the inclusion of Dengvaxia into existing immunisation programmes. These results were important inputs into WHO global policy for use of this licensed dengue vaccine.


Assuntos
Vacinas contra Dengue/economia , Vacinas contra Dengue/normas , Modelos Teóricos , Saúde Pública , Segurança , Vacinação/métodos , Criança , Análise Custo-Benefício , Vacinas contra Dengue/efeitos adversos , Humanos , Estudos Soroepidemiológicos , Vacinação/efeitos adversos , Vacinação/economia , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/economia , Vacinas Atenuadas/normas , Vacinas Sintéticas/efeitos adversos , Vacinas Sintéticas/economia , Vacinas Sintéticas/normas
5.
Avian Dis ; 60(3): 603-12, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27610719

RESUMO

The efficacy of commercially available recombinant herpesvirus of turkeys-infectious bursal disease (rHVT-IBD) virus vaccines was studied in broiler chickens derived from an IBDV-vaccinated breeder flock at 30 wk of age (Trial 1) and 60 wk of age (Trial 2). In parallel, specific-pathogen-free (SPF) white leghorn chickens were used to evaluate vaccine efficacy to control for the effects of maternally derived antibodies (MDA) associated with the broiler chickens. Broilers and SPF leghorns were vaccinated subcutaneously in the neck at 1 day of age with Vaxxitek® HVT+IBD or Vectormune® HVT-IBD vaccines and were placed in isolators. On 10, 14, 18, 22, and 26 days postvaccination (DPV), vaccinated and nonvaccinated broilers and SPF leghorns were bled prior to challenge via the oral-nasal route with infectious bursal disease (IBD) reference strains ST-C, Delaware variant E (Del E), or contemporary field isolates DMV/5038/07 or FF6. Microscopic lesion assessment of the bursa was useful for assessing IBDV challenge in both rHVT-IBD-vaccinated broiler and SPF leghorn chickens. In general, rHVT-IBD vaccines induced greater protection as the time between vaccination and challenge increased. Based on incidence of microscopic lesions (IML) of bursa tissue, Vaxxitek HVT+IBD vaccination of SPF leghorns induced protection by 18 DPV and continued to protect 22 DPV and 26 DPV in Trials 1 and 2. Vectormune HVT-IBD vaccine induced protection of SPF leghorns by 18 or 22 DPV in Trial 1, depending upon the IBDV challenge strain. However, the onset of protection was delayed until 22 or 26 DPV in Trial 2. With either commercial vaccine, rHVT-IBD vaccination of broiler chickens was not as effective as was observed in SPF leghorns, based on IML of bursa tissue. However, Vaxxitek HVT+IBD vaccination protected broilers following challenge with ST-C in both Trial 1 (30-wk-old breeder progeny) and Trial 2 (60-wk-old breeder progeny). Partial protection against FF6 (Trial 1) and DMV/5038/07 (Trial 2) challenges was observed. Vectormune HVT-IBD vaccination protected broilers vs. FF6 challenge in Trial 1. In Trial 2, the vaccine did not offer protection on the basis of IML of bursa tissue. The results indicate that 1) bursa/body weight ratios were not consistently useful as a tool for assessing IBDV challenge in broiler chickens with anti-IBDV MDA compared to assessment by IML of bursa tissue, though were useful for assessing protection in SPF leghorns; and 2) both vaccines may offer some protection to older broilers; however, a window of susceptibility exists between the waning of MDA and the development of vaccine-induced antibodies. The SPF studies showed that some vaccinated chickens were not protected from an IBDV challenge earlier than 14 DPV while broiler studies showed that MDA was not fully protective beyond 10 DPV. Because these vaccines did not protect chickens from an IBDV challenge during this window of susceptibility, our data show that breeder vaccination programs for IBDV must aim to maximize anti-IBDV MDA in progeny to protect against early IBDV challenge.


Assuntos
Infecções por Birnaviridae/veterinária , Herpesvirus Meleagrídeo 1/imunologia , Vírus da Doença Infecciosa da Bursa/imunologia , Doença de Marek/prevenção & controle , Doenças das Aves Domésticas/prevenção & controle , Vacinação/veterinária , Vacinas Virais/normas , Animais , Infecções por Birnaviridae/prevenção & controle , Galinhas , Vacinas contra Doença de Marek/administração & dosagem , Vacinas contra Doença de Marek/normas , Organismos Livres de Patógenos Específicos , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/normas , Vacinas Virais/administração & dosagem
6.
Vet Microbiol ; 191: 35-43, 2016 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-27374905

RESUMO

The increasing diversity of influenza strains circulating in swine herds escalates the potential for the emergence of novel pandemic viruses and highlights the need for swift development of new vaccines. Baculovirus has proven to be a flexible platform for the generation of recombinant forms of hemagglutinin (HA) including subunit, VLP-displayed, and baculovirus-displayed antigens. These presentations have been shown to be efficacious in mouse, chicken, and ferret models but little is known about their immunogenicity in pigs. To assess the utility of these HA presentations in swine, Baculovirus constructs expressing HA fused to swine IgG2a Fc, displayed in a FeLV gag VLP, or displayed in the baculoviral envelope were generated. Vaccines formulated with these antigens wer The e administered to groups of pigs who were subsequently challenged with H1α cluster H1N1 swine influenza virus (SIV) A/Swine/Indiana/1726/88. Our results demonstrate that vaccination with any of these three vaccines elicits robust hemagglutinin inhibition titers in the serum and decreased the severity of SIV-associated lung lesions after challenge when compared to placebo-vaccinated controls. In addition, the number of pigs with virus detected in the lungs and nasal passages was reduced. Taken together, the results demonstrate that these recombinant approaches expressed with the baculovirus expression vector system may be viable options for development of SIV vaccines for swine.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vírus da Influenza A Subtipo H1N1 , Vacinas contra Influenza/normas , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/prevenção & controle , Animais , Anticorpos Antivirais/sangue , Baculoviridae/genética , Baculoviridae/imunologia , Linhagem Celular , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/imunologia , Pulmão/virologia , Nariz/virologia , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/prevenção & controle , Distribuição Aleatória , Suínos , Doenças dos Suínos/patologia , Doenças dos Suínos/virologia , Vacinas de Subunidades/normas , Vacinas Sintéticas/normas
7.
Hum Vaccin Immunother ; 12(10): 2603-2610, 2016 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-27184971

RESUMO

Hepatitis E virus infections have been continuously reported in Indian subcontinent, Africa, southeast and central Asia, posing great health threats to the public, especially to pregnant women. Hecolin® is the only licensed HEV vaccine developed by Xiamen Innovax Biotech Co., Ltd. Extensive characterizations on antigenicity, physicochemical properties, efficacy in clinical trials, and manufacturing capability have made Hecolin® a promising vaccine for HEV control. However, there are many obstacles in large scale application of Hecolin®. Efforts are needed to further evaluate safety and efficacy in HEV risk populations, and to complement HEV standards for quality control. Passing World Health Organization prequalification and licensing outside China are priorities as these are also hindering Hecolin® promotion. Multilateral cooperation among Chinese vaccine manufacturers, Chinese National Regulatory Authorization (NRA) and WHO will expedite the entrance of Hecolin® into international market, so that Hecolin® could play its due role in global hepatitis E control.


Assuntos
Vírus da Hepatite E/imunologia , Hepatite E/epidemiologia , Hepatite E/prevenção & controle , Vacinas Sintéticas/efeitos adversos , Vacinas Sintéticas/imunologia , Vacinas contra Hepatite Viral/efeitos adversos , Vacinas contra Hepatite Viral/imunologia , África , Ásia , China , Aprovação de Drogas , Saúde Global , Humanos , Vacinas Sintéticas/normas , Vacinas contra Hepatite Viral/normas , Organização Mundial da Saúde
8.
Vet Parasitol ; 221: 30-8, 2016 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-27084468

RESUMO

Tick infestation may cause several problems including affecting domestic animal health and reducing the production of meat and milk, among others. Resistance to several classes of acaricides have been reported, forcing researchers to search for alternative measures, such as vaccines against ticks, to ensure tick control while having no or at least low negative impacts on the environment and public health. However, the current commercially available vaccines in different strains of Rhipicephalus microplus are reported to be of low efficacy. Fortunately, reverse vaccinology approaches have shown positive results in the new generation of vaccines. On this basis, a synthetic peptide from the ATAQ protein, which is present in the gut and Malpighi tubes of R. microplus, was synthesized. The ATAQ proteins were isolated, characterized and sequenced from several species of the genus Rhipicephalus. The alignment showed 93.3% identity among DNA sequences of ATAQs from these species. Because of this, immunization trials with this peptide were conducted on mice, rabbits and cattle to evaluate the humoral immune response and the efficacy against Rhipicephalus sanguineus in addition to R. microplus. Based on recent results, we conclude that reverse vaccinology is a promising approach because it is more accurate and faster than conventional methods in the detection of potential antigens to use in anti-tick vaccines. It is not only applicable against R. microplus but also against tick species that play important roles in spreading other diseases. ATAQ proteins should be considered as the antigen in new trials to develop a multi-antigenic vaccine. Although these peptides behave as hapten and are not able to be recognized by the immune system on its own, using carriers and adjuvants helps its presentation and induces strong immune responses. Furthermore, an efficiency of 35% reduction in overall life cycle parameters was reported for R. microplus (98% for ELISA responder animals) and 47% for R. sanguineus. Although not yet enough to prevent the environment to infestation of ticks, this still constitutes a promising strategy that could be applied to integrated measures on tick control and in new research that develops anti-tick vaccines.


Assuntos
Proteínas de Artrópodes/imunologia , Doenças dos Bovinos/prevenção & controle , Peptídeos/imunologia , Rhipicephalus/imunologia , Infestações por Carrapato/veterinária , Vacinas/imunologia , Sequência de Aminoácidos , Animais , Anticorpos/sangue , Proteínas de Artrópodes/química , Bovinos , Feminino , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Coelhos , Distribuição Aleatória , Alinhamento de Sequência , Infestações por Carrapato/prevenção & controle , Vacinas/normas , Vacinas Sintéticas/genética , Vacinas Sintéticas/normas
9.
Exp Parasitol ; 162: 7-17, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26743188

RESUMO

There have been only a few antigen genes of Eimeria brunetti reported up to now. In this study, the gene encoding the microneme protein 2 (EbMIC2) was isolated from oocysts of E. brunetti by RT-PCR and the immunogenicity of recombinant EbMIC2 was observed. The EbMIC2 was cloned into vector pMD19-T for sequencing. The sequence was compared with the published EbMIC2 gene from GenBank revealed homology of the nucleotide sequence and amino acids sequence were 99.43 and 98.63%, respectively. The correct recombinant pMD-EbMIC2 plasmid was inserted into the pET-28a (+) expressing vector and transformed into competent Escherichia coli BL21 cells for expression. The expressed product was analyzed using SDS-PAGE and Western-blot. The results indicated that the recombinant EbMIC2 protein was recognized strongly by serum from naturally infected chicken with E. brunetti. Rat rcEbMIC2 antisera bound to bands of about 36 kDa in the somatic extract of E. brunetti sporozoites. The recombinant plasmid pVAX1-EbMIC2 was constructed and then the efficacies of recombinant plasmid and recombinant protein were evaluated. The results of IgG antibody level and cytokines concentration suggested that recombinant EbMIC2 could increase the IgG antibody level and induce the expressions of cytokines. Animal challenge experiments demonstrated that the recombinant EbMIC2 protein and recombinant plasmid pVAX1-EbMIC2 could significantly increase the average body weight gains, decrease the mean lesion scores and the oocyst outputs of the immunized chickens and presented high anti-coccidial index. All results suggested that EbMIC2 could become an effective candidate for the development of new vaccine against E. brunetti infection.


Assuntos
Galinhas/parasitologia , Coccidiose/veterinária , Surtos de Doenças/veterinária , Eimeria/isolamento & purificação , Doenças das Aves Domésticas/parasitologia , Proteínas de Protozoários/isolamento & purificação , Animais , Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , China/epidemiologia , Clonagem Molecular , Coccidiose/epidemiologia , Coccidiose/parasitologia , DNA Complementar/química , DNA Complementar/metabolismo , Eimeria/imunologia , Regulação da Expressão Gênica , Soros Imunes/imunologia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/prevenção & controle , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Vacinas Protozoárias/normas , RNA de Protozoário/isolamento & purificação , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Transcrição Reversa , Alinhamento de Sequência/veterinária , Vacinação/veterinária , Vacinas Sintéticas/normas
10.
Exp Parasitol ; 160: 1-10, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26551412

RESUMO

Profilins are actin-binding proteins that regulate the polymerization of actin filaments. In apicomplexan parasites, they are essential for invasion. Profilins also trigger the immune response of the host by activating TLRs on dendritic cells (DCs), inducing the production of pro-inflammatory cytokines. In this study we characterized for the first time the immune response and protection elicited by a vaccine based on Neospora caninum profilin in mice. Groups of eight BALB/c mice received either two doses of a recombinant N. caninum profilin expressed in Escherichia coli. (rNcPRO) or PBS, both formulated with an aqueous soy-based adjuvant enriched in TLR-agonists. Specific anti-profilin antibodies were detected in rNcPRO-vaccinated animals, mainly IgM and IgG3, which were consumed after infection. Splenocytes from rNcPRO-immunized animals proliferated after an in vitro stimulation with rNcPRO before and after challenge. An impairment of the cellular response was observed in NcPRO vaccinated and infected mice following an in vitro stimulation with native antigens of N. caninum, related to an increase in the percentage of CD4+CD25+FoxP3+. Two out of five rNcPRO-vaccinated challenged mice were protected; they were negative for parasite DNA in the brain and showed no histopathological lesions, which were found in all PBS-vaccinated animals. As a whole, our results provide evidence of a regulatory response elicited by immunization with rNcPRO, and suggest a role of profilin in the modulation and/or evasion of immune responses against N. caninum.


Assuntos
Coccidiose/prevenção & controle , Imunização/métodos , Neospora/imunologia , Profilinas/imunologia , Linfócitos T Reguladores/imunologia , Animais , Anticorpos Antiprotozoários/biossíntese , Anticorpos Antiprotozoários/sangue , Sequência de Bases , Linfócitos T CD4-Positivos/citologia , Proliferação de Células , Coccidiose/imunologia , Células Dendríticas/imunologia , Feminino , Fatores de Transcrição Forkhead/análise , Imunidade Celular , Subunidade alfa de Receptor de Interleucina-2/análise , Linfócitos/imunologia , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Profilinas/administração & dosagem , Vacinas Protozoárias/normas , Distribuição Aleatória , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/imunologia , Alinhamento de Sequência , Baço/citologia , Baço/imunologia , Vacinas Sintéticas/normas
11.
Berl Munch Tierarztl Wochenschr ; 128(11-12): 464-72, 2015.
Artigo em Alemão | MEDLINE | ID: mdl-26697713

RESUMO

Poxviruses as expression vectors are widely used in medical research for the development of recombinant vaccines and molecular therapies. Here we review recent accomplishments in vaccine research using recombinant modified vaccinia virus ankara (MVA). MVA is a highly attenuated vaccinia virus strain that originated from serial tissue culture passage in chicken embryo fibroblasts more than 40 years ago. Growth adaptation to avian host cells caused deletions and mutations in the viral genome affecting about 15% of the original genetic information. In consequence, MVA is replication-deficient in cells of mammalian origin and fails to produce many of the virulence factors encoded by conventional vaccinia virus. Because of its safety for the general environment MVA can be handled under conditions of biosafety level one. Non-replicating MVA can enter any target cell and activate its molecular life cycle to express all classes of viral and recombinant genes. Therefore, recombinant MVA have been established as an extremely safe and efficient vector system for vaccine development in medical research. By now, various recombinant MVA vaccines have been found safe and immunogenic when used for phase I/II clinical testing in humans, and suitable for industrial scale production following good practice of manufacturing. Thus, there is an obvious usefulness of recombinant MVA vaccines for novel prophylactic and therapeutic approaches also in veterinary medicine. Results from first studies in companion and farm animals are highly promising.


Assuntos
Animais Domésticos , Vetores Genéticos , Vírus Vaccinia/imunologia , Medicina Veterinária/métodos , Vacinas Virais , Animais , Regulação Viral da Expressão Gênica , Vacinas Atenuadas/genética , Vacinas Atenuadas/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/normas , Vírus Vaccinia/genética , Vacinas Virais/genética , Vacinas Virais/imunologia
12.
Exp Parasitol ; 156: 19-25, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26008611

RESUMO

Chimeric DNA vaccines encoding Eimeria tenella (E. tenella) surface antigen 5401 were constructed and their efficacies against E. tenella challenge were studied. The open reading frame (ORF) of 5401 was cloned into the prokaryotic expression vector pGEX-4T2 to express the recombinant protein and the expressed recombinant protein was identified by Western blot. The ORF of 5401 and chicken cytokine gene IFN-γ or IL-2 were cloned into the eukaryotic expression vector pVAX1 consecutively to construct DNA vaccines pVAX-5401-IFN-γ, pVAX-5401-IL-2 and pVAX-5401. The expression of aim genes in vivo was detected by reverse transcription-polymerase chain reaction and Western blot. Fourteen-day-old chickens were inoculated twice at an interval of 7 days with 100 µg of plasmids pVAX-5401, pVAX-5401-IFN-γ and pVAX-5401-IL-2 or 200 µg of recombinant 5401 protein by leg intramuscular injection, respectively. Seven days after the second inoculation, all chickens except the unchallenged control group were challenged orally with 5 × 10(4) sporulated oocysts of E. tenella. Seven days after challenge, all chickens were weighted and slaughtered to determine the effects of immunization. The results showed the recombinant protein was about 90 kDa and reacted with antiserum against soluble sporozoites. The animal experiment showed that all the DNA vaccines pVAX-5401, pVAX-5401-IFN-γ or pVAX-5401-IL-2 and the recombinant 5401 protein could obviously alleviate body weight loss and cecal lesions as compared with non-vaccinated challenged control and empty vector pVAX1control. Furthermore, pVAX-5401-IFN-γ or pVAX-5401-IL-2 induced anti-coccidial index (ACI) of 180.01 or 177.24 which were significantly higher than that of pVAX-5401. The results suggested that 5401 was an effective candidate antigen for vaccine. This finding also suggested that chicken IFN-γ or IL-2 could effectively improve the efficacies of DNA vaccines against avian coccidiosis.


Assuntos
Galinhas/parasitologia , Coccidiose/veterinária , Citocinas/imunologia , Eimeria tenella/imunologia , Doenças das Aves Domésticas/prevenção & controle , Vacinas de DNA/normas , Sequência de Aminoácidos , Animais , Sequência de Bases , Galinhas/genética , Clonagem Molecular , Coccidiose/prevenção & controle , Citocinas/genética , Eimeria tenella/genética , Interferon gama/genética , Interferon gama/imunologia , Interleucina-2/genética , Interleucina-2/imunologia , Dados de Sequência Molecular , Fases de Leitura Aberta , Distribuição Aleatória , Ratos , Proteínas Recombinantes de Fusão/imunologia , Vacinas Sintéticas/normas
13.
Vet Immunol Immunopathol ; 162(3-4): 142-53, 2014 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-25467890

RESUMO

The aim of the present study was to evaluate the immunogenicity and protective efficacy of rNcSAG1, rNcHSP20 and rNcGRA7 recombinant proteins formulated with immune stimulating complexes (ISCOMs) in pregnant heifers against vertical transmission of Neospora caninum. Twelve pregnant heifers were divided into 3 groups of 4 heifers each, receiving different formulations before mating. Immunogens were administered twice subcutaneously: group A animals were inoculated with three recombinant proteins (rNcSAG1, rNcHSP20, rNcGRA7) formulated with ISCOMs; group B animals received ISCOM-MATRIX (without antigen) and group C received sterile phosphate-buffered saline (PBS) only. The recombinant proteins were expressed in Escherichia coli and purified nickel resin. All groups were intravenously challenged with the NC-1 strain of N. caninum at Day 70 of gestation and dams slaughtered at week 17 of the experiment. Heifers from group A developed specific antibodies against rNcSAG1, rNcHSP20 and rNcGRA7 prior to the challenge. Following immunization, an statistically significant increase of antibodies against rNcSAG1 and rNcHSP20 in all animals of group A was detected compared to animals in groups B and C at weeks 5, 13 and 16 (P<0.001). Levels of antibodies against rNcGRA7 were statistical higher in group A animals when compared with groups B and C at weeks 5 and 16 (P>0.001). There were no differences in IFN-γ production among the experimental groups at any time point (P>0.05). Transplacental transmission was determined in all foetuses of groups A, B and C by Western blot, immunohistochemistry and nested PCR. This work showed that rNcSAG1, rNcHSP20 and rNcGRA7 proteins while immunogenic in cattle failed to prevent the foetal infection in pregnant cattle challenged at Day 70 of gestation.


Assuntos
Doenças dos Bovinos/parasitologia , Coccidiose/veterinária , Transmissão Vertical de Doença Infecciosa/veterinária , Neospora/imunologia , Vacinas Protozoárias/imunologia , Vacinas Sintéticas/imunologia , Animais , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , Western Blotting/veterinária , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/transmissão , Coccidiose/imunologia , Coccidiose/parasitologia , Coccidiose/transmissão , DNA de Protozoário/química , DNA de Protozoário/genética , Feminino , Feto , Proteínas de Choque Térmico HSP20/genética , Proteínas de Choque Térmico HSP20/imunologia , ISCOMs/farmacologia , Imuno-Histoquímica/veterinária , Transmissão Vertical de Doença Infecciosa/prevenção & controle , Reação em Cadeia da Polimerase/veterinária , Gravidez , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Distribuição Aleatória , Estatísticas não Paramétricas , Vacinas Sintéticas/normas
14.
Vet Immunol Immunopathol ; 162(3-4): 96-107, 2014 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-25454469

RESUMO

Staphylococcus aureus is the most frequently isolated pathogen from bovine intramammary infections worldwide. Commercially available vaccines for mastitis control are composed either of S. aureus lysates or inactivated whole-cells formulated with traditional adjuvants. We recently showed the ability of a S. aureus CP5 lysate vaccine adjuvanted with Iscom Matrix to generate a longer lasting specific antibody response in blood and milk, with improved opsonic capacity, compared with a S. aureus CP5 whole-cell formulation. The aim of the present study was to obtain an experimental immunogen composed of lysed cells of a CP5 S. aureus strain supplemented with recombinant clumping factor A, fibronectin binding protein A and ß-toxin formulated with Iscom Matrix, characterize the immune response generated when immunizing pregnant heifers and assess the functional role of antibodies raised against this immunogen in experimental models. Both a lysate vaccine and a lysate+recombinant antigens vaccine elicited antibodies that promoted neutrophil phagocytosis and inhibited internalization into mammary epithelial cells, in vitro. Incorporation of defined antigenic molecules to the lysate formulation elicited a strong specific humoral immune response against both lysate and recombinant antigens and was associated with higher expression of regulatory and pro-inflammatory cytokines. In addition, antibodies were efficient for blocking S. aureus binding to bovine fibrinogen and fibronectin, and neutralizing ß-toxin effect in vitro, placing these antigens as candidates to be included in a formulation directed to prevent staphylococcal bovine mastitis.


Assuntos
Imunização/veterinária , Mastite Bovina/microbiologia , Infecções Estafilocócicas/veterinária , Vacinas Antiestafilocócicas/imunologia , Staphylococcus aureus/imunologia , Vacinas Sintéticas/imunologia , Adesinas Bacterianas/genética , Adesinas Bacterianas/imunologia , Animais , Anticorpos Antibacterianos/sangue , Toxinas Bacterianas/genética , Toxinas Bacterianas/imunologia , Bovinos , Linhagem Celular , Coagulase/genética , Coagulase/imunologia , Citocinas/sangue , Feminino , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/imunologia , ISCOMs/farmacologia , Imunização/métodos , Mastite Bovina/imunologia , Mastite Bovina/prevenção & controle , Leite/microbiologia , Gravidez , Distribuição Aleatória , Esfingomielina Fosfodiesterase/genética , Esfingomielina Fosfodiesterase/imunologia , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/prevenção & controle , Vacinas Antiestafilocócicas/administração & dosagem , Estatísticas não Paramétricas , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/normas
15.
Vaccine ; 32(48): 6556-62, 2014 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-25077418

RESUMO

BACKGROUND: For regulatory approval, consistency in manufacturing of vaccine lots is expected to be demonstrated in confirmatory immunogenicity studies using two-sided equivalence trials. This randomized, double-blind study (NCT01323972) assessed consistency of three RTS,S/AS01 malaria vaccine batches formulated from commercial-scale purified antigen bulk lots in terms of anti-CS-responses induced. METHODS: Healthy children aged 5-17 months were randomized (1:1:1:1) to receive RTS,S/AS01 at 0-1-2 months from one of three commercial-scale purified antigen bulk lots (1600 litres-fermentation scale; commercial-scale lots), or a comparator vaccine batch made from pilot-scale purified antigen bulk lot (20 litres-fermentation scale; pilot-scale lot). The co-primary objectives were to first demonstrate consistency of antibody responses against circumsporozoite (CS) protein at one month post-dose 3 for the three commercial-scale lots and second demonstrate non-inferiority of anti-CS antibody responses at one month post-dose 3 for the commercial-scale lots compared to the pilot-scale lot. Safety and reactogenicity were evaluated as secondary endpoints. RESULTS: One month post-dose-3, anti-CS antibody geometric mean titres (GMT) for the 3 commercial scale lots were 319.6 EU/ml (95% confidence interval (CI): 268.9-379.8), 241.4 EU/ml (207.6-280.7), and 302.3 EU/ml (259.4-352.3). Consistency for the RTS,S/AS01 commercial-scale lots was demonstrated as the two-sided 95% CI of the anti-CS antibody GMT ratio between each pair of lots was within the range of 0.5-2.0. GMT of the pooled commercial-scale lots (285.8 EU/ml (260.7-313.3)) was non-inferior to the pilot-scale lot (271.7 EU/ml (228.5-323.1)). Each RTS,S/AS01 lot had an acceptable tolerability profile, with infrequent reports of grade 3 solicited symptoms. No safety signals were identified and no serious adverse events were considered related to vaccination. CONCLUSIONS: RTS,S/AS01 lots formulated from commercial-scale purified antigen bulk batches induced a consistent anti-CS antibody response, and the anti-CS GMT of pooled commercial-scale lots was non-inferior to that of a lot formulated from a pilot-scale antigen bulk batch.


Assuntos
Formação de Anticorpos , Vacinas Antimaláricas/normas , Vacinas Antimaláricas/uso terapêutico , Malária Falciparum/prevenção & controle , Vacinas Sintéticas/normas , Vacinas Sintéticas/uso terapêutico , Anticorpos Antiprotozoários/sangue , Método Duplo-Cego , Feminino , Humanos , Lactente , Vacinas Antimaláricas/imunologia , Masculino , Nigéria , Vacinas Sintéticas/imunologia
16.
Vaccine ; 32(32): 4039-50, 2014 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-24892250

RESUMO

The hepatitis E virus (HEV) vaccine, Hecolin(®), was licensed in China for the prevention of HEV infection and HEV-related diseases with demonstrated safety and efficacy [1,2]. The vaccine is composed of a truncated HEV capsid protein, p239, as the sole antigen encoded by open reading frame 2 and produced using Escherichia coli platform. The production of this virus-like particle (VLP) form of the antigen was successfully scaled up 50-fold from a bench scale to a manufacturing scale. Product consistency was demonstrated using a combination of biophysical, biochemical and immunochemical methods, which revealed comparable antigen characteristics among different batches. Particle size of the nanometer scale particulate antigen and presence of key epitopes on the particle surface are two prerequisites for an efficacious VLP-based vaccine. The particle size was monitored by several different methods, which showed diameters between 20 and 30nm for the p239 particles. The thermal stability and aggregation propensity of the antigen were assessed using differential scanning calorimetry and cloud point assay under heat stress conditions. Key epitopes on the particulate antigen were analyzed using a panel of murine anti-HEV monoclonal antibodies (mAbs). The immuno reactivity to the mAbs among the different antigen lots was highly consistent when analyzed quantitatively using a surface plasmon resonance technique. Using a sandwich ELISA to probe the integrity of two different epitopes in the antigen, the specific antigenicity of multiple batches was assessed to demonstrate consistency in these critical product attributes. Overall, our findings showed that the antigen production process is robust and scalable during the manufacturing of Hecolin(®).


Assuntos
Proteínas do Capsídeo/imunologia , Vírus da Hepatite E , Vacinas Sintéticas/biossíntese , Vacinas de Partículas Semelhantes a Vírus/biossíntese , Vacinas contra Hepatite Viral/biossíntese , Animais , Anticorpos Monoclonais Murinos/imunologia , Antígenos Virais/imunologia , Epitopos/imunologia , Feminino , Camundongos Endogâmicos BALB C , Peso Molecular , Tamanho da Partícula , Vacinas Sintéticas/normas , Vacinas de Partículas Semelhantes a Vírus/normas , Vacinas contra Hepatite Viral/normas
17.
Exp Parasitol ; 139: 24-32, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24560833

RESUMO

Schistosoma mansoni tegument is involved in essential functions for parasite survival and represents a target for screening candidates for vaccine and diagnosis. Our group using reverse vaccinology selected six candidates, previously demonstrated by proteomics studies to be expressed in the parasite tegument, among them was Sm200. In this work we have cloned and expressed a recombinant form of Sm200 C-terminal (1069-1520) region. The efficacy of rSm200 (1069-1520) in the diagnosis of schistosomiasis and in the formulation of a vaccine against S. mansoni was assessed respectively in an ELISA based diagnostic assay and immunization protocols in mice. Significant differences between non-infected and acutely infected or chronically infected animals were observed and no cross-recognition was observed with sera from Ascaris suum or Ancylostoma ceylanicum infected mice. rSm200-ELISA test could also discriminate infected individuals from healthy donors not living in endemic area for schistosomiasis but failed to discriminate between individuals from a low endemic area for schistosomiasis known to have positive or negative stools after examination. Recombinant Sm200 also failed to induce protection against schistosomiasis, demonstrating that the C-terminal part of Sm200 is unable to induce protective immune response in mice. Therefore rSm200 (1069-1520)-ELISA represents an important tool to be used in the diagnosis of schistosomiasis.


Assuntos
Proteínas de Helminto/química , Proteínas de Helminto/imunologia , Schistosoma mansoni/química , Esquistossomose mansoni/diagnóstico , Esquistossomose mansoni/prevenção & controle , Vacinas Sintéticas/normas , Sequência de Aminoácidos , Animais , Anticorpos Anti-Helmínticos/biossíntese , Anticorpos Anti-Helmínticos/imunologia , Antígenos de Helmintos/química , Antígenos de Helmintos/genética , Antígenos de Helmintos/imunologia , Linfócitos B/imunologia , Cricetinae , Ensaio de Imunoadsorção Enzimática , Epitopos/química , Epitopos/imunologia , Fezes/parasitologia , Feminino , Glicoproteínas/química , Glicoproteínas/genética , Glicoproteínas/imunologia , Proteínas de Helminto/genética , Humanos , Soros Imunes/imunologia , Masculino , Proteínas de Membrana/química , Proteínas de Membrana/genética , Proteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Schistosoma mansoni/genética , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia
18.
Can J Vet Res ; 77(3): 161-9, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24101791

RESUMO

We evaluated the immunogenic and protective potential of a recombinant VapA/CpG oligodeoxynucleotide (ODN) 2395 vaccine in neonatal foals undergoing experimental Rhodococcus equi challenge. Foals (n = 8) were vaccinated by intramuscular injection on days 1 and 15 of the study; control foals (n = 7) received a phosphate-buffered saline (PBS) solution. All foals were challenged by intrabronchial administration of 5 × 106 R. equi 103⁺ on day 29. Bronchoalveolar lavages were done on days 15, 29, and 36 and total cell count, differential cell count, rVapA-stimulated cell proliferation and interferon (IFN)-γ mRNA expression determined. Clinical examination, complete blood (cell) counts, serology for VapA-specific antibodies, and culture of nasal and fecal swabs were done on days 1, 15, 29, 36, 43, and 50. Foals were humanely euthanized on day 50 and severity of pneumonia scored on a 4-point scale. Vaccination resulted in a significant increase in VapA-specific immunoglobulin (Ig) production, with total IgG and IgG(T) being increased by day 15. Expression of VapA-specific IFN-γ mRNA by BAL cells was increased in the vaccinated foals following challenge. Postmortem lung severity scores did not differ between groups. Two foals shed virulent R. equi in feces; however, real-time polymerase chain reaction (PCR) revealed the isolates to be different from the challenge strain.


Assuntos
Infecções por Actinomycetales/veterinária , Vacinas Bacterianas/imunologia , Doenças dos Cavalos/microbiologia , Pneumonia/veterinária , Rhodococcus equi/imunologia , Vacinação/veterinária , Infecções por Actinomycetales/imunologia , Infecções por Actinomycetales/microbiologia , Infecções por Actinomycetales/prevenção & controle , Animais , Animais Recém-Nascidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Vacinas Bacterianas/genética , Vacinas Bacterianas/normas , Líquido da Lavagem Broncoalveolar/citologia , Líquido da Lavagem Broncoalveolar/imunologia , Doenças dos Cavalos/imunologia , Doenças dos Cavalos/prevenção & controle , Cavalos , Interferon gama/genética , Interferon gama/imunologia , Modelos Lineares , Masculino , Oligodesoxirribonucleotídeos/genética , Oligodesoxirribonucleotídeos/imunologia , Pneumonia/imunologia , Pneumonia/microbiologia , Pneumonia/prevenção & controle , RNA Mensageiro/química , RNA Mensageiro/genética , Distribuição Aleatória , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Rhodococcus equi/genética , Vacinação/normas , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/normas
19.
PLoS One ; 8(7): e69692, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23936080

RESUMO

Bovine botulism is a fatal disease that is caused by botulinum neurotoxins (BoNTs) produced by Clostridium botulinum serotypes C and D and that causes great economic losses, with nearly 100% lethality during outbreaks. It has also been considered a potential source of human food-borne illness in many countries. Vaccination has been reported to be the most effective way to control bovine botulism. However, the commercially available toxoid-based vaccines are difficult and hazardous to produce. Neutralizing antibodies targeted against the C-terminal fragment of the BoNT heavy chain (HC) are known to confer efficient protection against lethal doses of BoNTs. In this study, a novel recombinant chimera, consisting of Escherichia coli heat-labile enterotoxin B subunit (LTB), a strong adjuvant of the humoral immune response, fused to the HC of BoNT serotypes C and D, was produced in E. coli. Mice vaccinated with the chimera containing LTB and an equivalent molar ratio of the chimera without LTB plus aluminum hydroxide (Al(OH)3) developed 2 IU/mL of antitoxins for both serotypes. Guinea pigs immunized with the recombinant chimera with LTB plus Al(OH)3 developed a protective immune response against both BoNT/C (5 IU/mL) and BoNT/D (10 IU/mL), as determined by a mouse neutralization bioassay with pooled sera. The results achieved with guinea pig sera fulfilled the requirements of commercial vaccines for prevention of botulism, as determined by the Brazilian Ministry of Agriculture, Livestock and Food, Supply. The presence of LTB was essential for the development of a strong humoral immune response, as it acted in synergism with Al(OH)3. Thus, the vaccine described in this study is a strong candidate for the control of botulism in cattle.


Assuntos
Botulismo/imunologia , Clostridium botulinum tipo C/imunologia , Clostridium botulinum tipo D/imunologia , Vacinas Sintéticas/imunologia , Hidróxido de Alumínio/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Antibacterianos/imunologia , Antitoxinas/imunologia , Toxinas Bacterianas/genética , Toxinas Bacterianas/imunologia , Toxinas Bacterianas/metabolismo , Sequência de Bases , Western Blotting , Toxinas Botulínicas/genética , Toxinas Botulínicas/imunologia , Toxinas Botulínicas/metabolismo , Botulismo/prevenção & controle , Botulismo/veterinária , Bovinos , Avaliação de Medicamentos , Enterotoxinas/genética , Enterotoxinas/imunologia , Enterotoxinas/metabolismo , Ensaio de Imunoadsorção Enzimática , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/imunologia , Proteínas de Escherichia coli/metabolismo , Feminino , Cobaias , Camundongos , Dados de Sequência Molecular , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/metabolismo , Vacinação/métodos , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/normas
20.
Exp Parasitol ; 135(1): 102-9, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23811052

RESUMO

In Fasciola gigantica, cathepsin Bs, especially cathepsin B2 and B3 are expressed in early juvenile stages, and are proposed to mediate the invasion of host tissues. Thus they are thought to be the target vaccine candidates that can block the invasion and migration of the juvenile parasite. To evaluate their vaccine potential, the recombinant cathepsin B2 (rFgCatB2) and cathepsin B3 (rFgCatB3) were expressed in yeast, Pichia pastoris, and used to immunize mice in combination with Freund's adjuvant to evaluate the protection against the infection by F. gigantica metacercariae, and the induction of immune responses. Mice immunized with both recombinant proteins exhibited high percent of parasite reduction at 60% for rFgCatB2 and 66% for rFgCatB3. Immunization by both antigens induced continuously increasing levels of IgG1 and IgG2a with a higher level of IgG1 isotype, indicating the mixed Th1/Th2 responses with Th2 predominating. When examined individually, the higher levels of IgG1 and IgG2a were correlated with the lower numbers of worm recoveries. Thus, both cathepsin B2 and cathepsin B3 are plausible vaccine candidates whose potential should be further tested in large economic animals.


Assuntos
Anticorpos Anti-Helmínticos/sangue , Catepsina B/imunologia , Fasciola/imunologia , Fasciolíase/prevenção & controle , Vacinas Sintéticas/normas , Animais , Especificidade de Anticorpos , Catepsina B/administração & dosagem , Catepsina B/genética , Modelos Animais de Doenças , Fasciola/isolamento & purificação , Adjuvante de Freund/administração & dosagem , Adjuvante de Freund/imunologia , Imunoglobulina G/sangue , Injeções Subcutâneas , Camundongos , Camundongos Endogâmicos ICR , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Vacinas Sintéticas/administração & dosagem
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