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The demand of plasmid DNA (pDNA) as a key element for gene therapy products, as well as mRNA and DNA vaccines, is increasing together with the need for more efficient production processes. An engineered E. coli strain lacking the phosphotransferase system and the pyruvate kinase A gene has been shown to produce more pDNA than its parental strain. With the aim of improving pDNA production in the engineered strain, several strategies to increase the flux to the pentose phosphate pathway (PPP) were evaluated. The simultaneous consumption of glucose and glycerol was a simple way to increase the growth rate, pDNA production rate, and supercoiled fraction (SCF). The overexpression of key genes from the PPP also improved pDNA production in glucose, but not in mixtures of glucose and glycerol. Particularly, the gene coding for the glucose 6-phosphate dehydrogenase (G6PDH) strongly improved the SCF, growth rate, and pDNA production rate. A linear relationship between the G6PDH activity and pDNA yield was found. A higher flux through the PPP was confirmed by flux balance analysis, which also estimates relevant differences in fluxes of the tricarboxylic acid cycle. These results are useful for developing further cell engineering strategies to increase pDNA production and quality.
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To improve a DNA vaccine containing the truncated dengue virus serotype 2 (DENV-2) envelope (E) protein and evaluate the influence of precursor membrane (prM) glycoprotein polymorphism on E protein immunogenicity, two vaccine candidates have been constructed by upstream insertion of the DENV-2 and DENV-3 prM genes into the DENV-2 E gene, named pCID2EtD2prM and pCID2EtD3prM, respectively. Both constructs were able to induce antibody production, which were neutralizing against DENV-2 in a murine model. Splenocytes of immunized groups, when challenged with virus, demonstrated Th1 cytokine pattern and proliferation, in addition to the increase of specific T cells. Vaccine candidates pCID2EtD2prM and pCID2EtD3prM confer 70% and 90% protection against DENV-2, respectively. The pCID2EtD3prM plasmid conferred only 40% protection in the lethal challenge with DENV-2. The results demonstrate that DENV-3 prM has a greater influence on the immunogenicity of the E protein and, probably due to its role as a chaperone, these results may be related to the correct folding and, consequently, an increase in the presentation efficiency of produced transcripts.
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Vacinas contra Dengue , Vírus da Dengue , Dengue , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais , Modelos Animais de Doenças , Glicoproteínas de Membrana , Camundongos , Proteínas do Envelope ViralRESUMO
DNA vaccines have been used as a promising strategy for delivery of immunogenic and immunomodulatory molecules into the host cells. Although, there are some obstacles involving the capability of the plasmid vector to reach the cell nucleus in great number to promote the expected benefits. In order to improve the delivery and, consequently, increase the expression levels of the target proteins carried by DNA vaccines, alternative methodologies have been explored, including the use of non-pathogenic bacteria as delivery vectors to carry, deliver, and protect the DNA from degradation, enhancing plasmid expression.
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DNA/genética , Vetores Genéticos/genética , Lactobacillales/genética , Plasmídeos/genética , DNA/imunologia , DNA/isolamento & purificação , Escherichia coli/genética , Técnicas de Transferência de Genes , Vetores Genéticos/administração & dosagem , Vetores Genéticos/imunologia , Vetores Genéticos/isolamento & purificação , Humanos , Plasmídeos/administração & dosagem , Plasmídeos/imunologia , Plasmídeos/isolamento & purificação , Transfecção , Transformação Bacteriana , Vacinas de DNA/administração & dosagem , Vacinas de DNA/genética , Vacinas de DNA/imunologiaRESUMO
Dengue infections still have a tremendous impact on public health systems in most countries in tropical and subtropical regions. The disease is systemic and dynamic with broad range of manifestations, varying from mild symptoms to severe dengue (Dengue Hemorrhagic Fever and Dengue Shock Syndrome). The only licensed tetravalent dengue vaccine, Dengvaxia, is a chimeric yellow fever virus with prM and E genes from the different dengue serotypes. However, recent results indicated that seronegative individuals became more susceptible to develop severe dengue when infected after vaccination, and now WHO recommends vaccination only to dengue seropositive people. One possibility to explain these data is the lack of robust T-cell responses and antibody-dependent enhancement of virus replication in vaccinated people. On the other hand, DNA vaccines are excellent inducers of T-cell responses in experimental animals and it can also elicit antibody production. Clinical trials with DNA vaccines have improved and shown promising results regarding the use of this approach for human vaccination. Therefore, in this paper we review preclinical and clinical tests with DNA vaccines against the dengue virus. Most of the studies are based on the E protein since this antigen is the main target for neutralizing antibody production. Yet, there are other reports with DNA vaccines based on non-structural dengue proteins with protective results, as well. Combining structural and non-structural genes may be a solution for inducing immune responses aging in different infection moments. Furthermore, DNA immunizations are also a very good approach in combining strategies for vaccines against dengue, in heterologous prime/boost regimen or even administering different vaccines at the same time, in order to induce efficient humoral and cellular immune responses.
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Dengue virus represents the main arbovirus affecting humans, but there are no effective drugs or available worldwide licensed vaccine formulations capable of conferring full protection against the infection. Experimental studies and results generated after the release of the licensed anti-DENV vaccine demonstrated that induction of high-titer neutralizing antibodies does not represent the sole protection correlate and that, indeed, T cell-based immune responses plays a relevant role in the establishment of an immune protective state. In this context, this study aimed to further demonstrate protective features of immune responses elicited in immunocompetent C57BL/6 mice immunized with three plasmids encoding DENV2 nonstructural proteins (NS1, NS3, and NS5), which were subsequently challenged with a DENV2 strain naturally capable of inducing lethal encephalitis in immunocompetent mouse strains. The animals were immunized intramuscularly with the DNA vaccine mix and complete protection was observed among vaccinated mice. Vaccine induced protection correlated with the cytokine profiles expressed by spleen cells and brain-infiltrating mononuclear cells. The results confirm the pivotal role of cellular immune responses targeting nonstructural DENV proteins and validate the experimental model based on a DENV2 strain capable of infecting and killing immunocompetent mice as a tool for the evaluation of protective immunity induced by anti-DENV vaccines.
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[This corrects the article DOI: 10.3389/fmedt.2020.558984.].
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Introducción. Cryptosporidium parvum es un parásito zoonótico altamente prevalente, asociado a enfermedad diarreica en población inmunocomprometida, niños y terneros menores de 30 días. Esta infección puede ocasionar deshidratación, alteración del estado de conciencia, retraso en el desarrollo global y, en algunos casos, la muerte del paciente. A pesar de la alta prevalencia de C. parvum, no existen medicamentos completamente efectivos ni una vacuna aprobada para prevenir dicha enfermedad. Objetivo. Realizar una revisión de la literatura sobre candidatos vacunales contra C. parvum. Método. Revisión documental mediante la búsqueda de la literatura de los últimos 20 años, disponible en las bases de datos PubMed central, WEB OF SCIENCE, Embase, REDALYC y LILACS. Resultados. Las vacunas atenuadas, recombinantes, basadas en ADN, expresadas en vectores bacterianos y sintéticas han mostrado resultados prometedores en la inducción de inmunogenicidad contra los antígenos de C. parvum, siendo el antígeno de superficie de 15 kilodaltons de Cryptosporidium parvum (cp15), el antígeno inductor de una mejor respuesta inmune celular y humoral en el modelo murino estudiado. Conclusión. Se espera que la incorporación de nuevas técnicas para la selección de antígenos promisorios y la ejecución de una gran cantidad de ensayos in vivo, favorezcan el desarrollo de una vacuna totalmente efectiva contra C. parvum. Aunque el camino para lograr este objetivo será largo y difícil, se convierte en la mejor alternativa para controlar una de las enfermedades de interés en salud pública, con mayor impacto en la población inmunocomprometida.
Introduction. Cryptosporidium parvum is a highly prevalent zoonotic parasite, associated with diarrheal disease in immunocompromised population, children and calves under 30 days. This infection is associa- ted to dehydration, delayed global development and, in some cases, the death of the patient. Despite the high prevalence of C. parvum, there are no fully effective medications and an approved vaccine to prevent such disease. Objective. To conduct a thorough review of the literature on vaccine candidates against C. parvum. Method Documentary review by searching the literature of the last 20 years, available in the central PubMed, WEB OF SCIENCE, Embase, REDALYC and LILACS databases. Results. Attenuated, recombinant, DNA-based, expressed in bacterial vectors and synthetic vaccines have shown promising results in inducing immunogenicity against C. parvum, being the Cryptospori- dium parvum 15 kiloDalton surface antigen (cp15), the antigen inducer of a better cellular and humoral immune response in the murine model studied. Conclusion. It is expected that the incorporation of new techniques for the selection of promising antigens and the execution of a large number of in vivo assays will favor the development of a fully effective vaccine against C. parvum. Although the way to achieve this goal will be long and difficult, it will become the best alternative to control one of the diseases with the greatest impact on the immu- nocompromised population.
Introdução. O Cryptosporidium parvum é um parasita zoonótico de alta prevalência associado à doença diarreica em populações imunocomprometidas, crianças e bezerros com menos de 30 dias. Essa infecção pode causar desidratação, alteração do estado de consciência, atraso no desenvolvi- mento global e, em alguns casos, a morte do paciente. Apesar da alta prevalência de C. parvum, não existem medicamentos totalmente eficazes e uma vacina aprovada para prevenir a doença. Objetivo. Realizar uma revisão literária dos candidatos à vacina contra C. parvum. Método. Revisão documental, mediante pesquisa da literatura dos últimos 20 anos, disponível nas bases de dados PubMed central, WEB OF SCIENCE, Embase, REDALYC e LILACS. Resultados. Vacinas atenuadas, recombinantes e baseadas em DNA, expressas em vetores bacteria- nos e sintéticos, mostraram resultados promissores na indução de imunogenicidade contra antígenos de C. parvum, sendo o antígeno de superfície de 15 kilodaltons de Cryptosporidium parvum (cp15) o antígeno indutor de uma melhor resposta imune celular e humoral no modelo murino estudado. Conclusão. Se espera que a incorporação de novas técnicas para a seleção de antígenos promissores e a execução de um grande número de ensaios in vivo favoreçam o desenvolvimento de uma vacina totalmente eficaz contra C. parvum. Embora o caminho para alcançar este objetivo seja longo e difícil, torna-se a melhor alternativa para controlar uma das doenças de interesse na saúde pública com maior impacto na população imunocomprometida.
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Cryptosporidium parvum , Vacinas Sintéticas , Vacinas de DNA , Imunogenicidade da VacinaRESUMO
The importance of the cellular immune response against DENV has been increasingly highlighted in the past few years, in particular for vaccine development. We have previously constructed two plasmids, pE1D2, and pcTPANS1, encoding the envelope (E) ectodomain (domains I, II, and III) and the non-structural 1 (NS1) protein of dengue virus serotype 2 (DENV2), respectively. In the present work, we analyzed the induction of the cellular response in mice immunized with these DNA vaccines and identified the immunogenic peptides. Vaccinated BALB/c mice became protected against a lethal challenge of DENV2. Depletion of CD4+ cells in vaccinated animals almost completely abolished protection elicited by both vaccines. In contrast, a significant number of pE1D2- and pcTPANS1-immunized mice survived virus challenge after depletion of CD8+ cells, although some animals presented morbidity. To identify immunogenic peptides recognized by T cells, we stimulated splenocytes with overlapping peptide libraries covering the E and NS1 proteins and evaluated the production of IFN-γ by ELISPOT. We detected two and three immunodominant epitopes in the E and NS1 proteins, respectively, and four additional NS1-derived peptides after virus challenge. Characterization by intracellular cytokine staining (ICS) revealed that both CD4+ and CD8+ T cells were involved in IFN-γ and TNF-α production. The IFN-γ ICS confirmed reaction of almost all E-derived peptides before challenge and identified other epitopes after infection. All NS1-derived peptides were able to elicit IFN-γ production in CD4+ cells, while only a few peptides induced expression of this cytokine in CD8+ T lymphocytes. Interestingly, we observed an increase in the frequency of either CD4+ or CD8+ T cells producing TNF-α after immunization with the pE1D2 and challenge with DENV2, while lymphocytes from pcTPANS1-vaccinated animals maintained ordinary TNF-α production after virus infection. We also assessed the recognition of E and NS1 immunogenic peptides in C57BL/6 mice due to the difference in MHC haplotype expression. Two NS1-derived epitopes featured prominently in the IFN-γ response with cells from both animal strains. Overall, our results emphasize the importance of the T cell response involved in protection against dengue induced by E and NS1 based DNA vaccines.
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Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Vacinas contra Dengue/imunologia , Vírus da Dengue/imunologia , Dengue/prevenção & controle , Epitopos de Linfócito T/imunologia , Vacinas de DNA/imunologia , Proteínas do Envelope Viral/imunologia , Proteínas não Estruturais Virais/imunologia , Animais , Dengue/genética , Dengue/imunologia , Vacinas contra Dengue/genética , Vírus da Dengue/genética , Epitopos de Linfócito T/genética , Camundongos , Camundongos Endogâmicos BALB C , Vacinas de DNA/genética , Proteínas do Envelope Viral/genética , Proteínas não Estruturais Virais/genéticaRESUMO
Foot and mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals, which causes severe economic losses in the livestock industry. Currently available vaccines are based on inactivated FMD virus (FMDV). Although inactivated virus vaccines have proved to be effective in FMD control, they have a number of disadvantages, including the need for high bio-containment production facilities and the lack of induction of immunological memory. Novel FMD vaccines based on the use of recombinant empty capsids have shown promising results. These recombinant empty capsids are attractive candidates because they avoid the use of virus in the production facilities but conserve its complete repertoire of conformational epitopes. However, many of these recombinant empty capsids require time-consuming procedures that are difficult to scale up. Achieving production of a novel and efficient FMD vaccine requires not only immunogenic antigens, but also industrially relevant processes. This review intends to summarize and compare the different strategies already published for the production of FMDV recombinant empty capsids, focusing on large-scale production.
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Proteínas do Capsídeo/genética , Febre Aftosa/tratamento farmacológico , Proteínas Recombinantes/genética , Vacinas/genética , Animais , Capsídeo/química , Capsídeo/imunologia , Proteínas do Capsídeo/imunologia , Proteínas do Capsídeo/uso terapêutico , Febre Aftosa/imunologia , Febre Aftosa/virologia , Vírus da Febre Aftosa/efeitos dos fármacos , Vírus da Febre Aftosa/imunologia , Vírus da Febre Aftosa/patogenicidade , Humanos , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/uso terapêutico , Vacinas/uso terapêutico , Vacinas de Produtos Inativados/genética , Vacinas de Produtos Inativados/imunologiaRESUMO
Memory CD8+ T cell responses have the potential to mediate long-lasting protection against cancers. Resident memory CD8+ T (Trm) cells stably reside in non-lymphoid tissues and mediate superior innate and adaptive immunity against pathogens. Emerging evidence indicates that Trm cells develop in human solid cancers and play a key role in controlling tumor growth. However, the specific contribution of Trm cells to anti-tumor immunity is incompletely understood. Moreover, clinically applicable vaccination strategies that efficiently establish Trm cell responses remain largely unexplored and are expected to strongly protect against tumors. Here we demonstrated that a single intradermal administration of gene- or protein-based vaccines efficiently induces specific Trm cell responses against models of tumor-specific and self-antigens, which accumulated in vaccinated and distant non-vaccinated skin. Vaccination-induced Trm cells were largely resistant to in vivo intravascular staining and antibody-dependent depletion. Intradermal, but not intraperitoneal vaccination, generated memory precursors expressing skin-homing molecules in circulation and Trm cells in skin. Interestingly, vaccination-induced Trm cell responses strongly suppressed the growth of B16F10 melanoma, independently of circulating memory CD8+ T cells, and were able to infiltrate tumors. This work highlights the therapeutic potential of vaccination-induced Trm cell responses to achieve potent protection against skin malignancies.
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Actinobacillus pleuropneumoniae is the etiological agent of porcine pleuropneumonia, a respiratory disease leading to severe economic losses in the swine industry. The most widely used commercial vaccines are bacterins comprising inactivated whole cells of A. pleuropneumoniae but these have only been partially effective in preventing disease. Innovative immuno-prophylactic preparations of A. pleuropneumoniae based on ApxI, ApxII, ApxIII, ApxIV toxins and outer membrane proteins, among others (i.e. RnhB, GalU, GalT, HflX, ComL, LolB, LppC), have high protective efficacy in mice and pigs. Some vaccine preparations have efficacy against homologous and heterologous A. pleuropneumoniae serovars, which constitute an important advance to control porcine pleuropneumonia. In this arena, subunit vaccines based on toxins are one of the most advanced and promising developments. Many research groups have focussed on the development of live attenuated vaccines comprising strains with inactivated Apx toxins and/or other virulence factors, their protective efficacy being determined in mouse and/or swine models. Other innovative approaches such as bacteria, yeast and plants as production and oral delivery platforms have been explored in animal models and the definitive host with encouraging results. In addition, further research into A. pleuropneumoniae-based DNA and nano-vaccines, as well as bioencapsulation of antigens in plants, is envisaged. Here, the recent findings and future trends in innovative vaccine development against A. pleuropneumoniae are reviewed and placed in perspective.
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Infecções por Actinobacillus/veterinária , Actinobacillus pleuropneumoniae/imunologia , Pleuropneumonia/veterinária , Doenças dos Suínos/prevenção & controle , Infecções por Actinobacillus/epidemiologia , Infecções por Actinobacillus/imunologia , Infecções por Actinobacillus/prevenção & controle , Actinobacillus pleuropneumoniae/genética , Animais , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Vacinas Bacterianas , Sistemas de Liberação de Medicamentos , Camundongos , Mutação , Pleuropneumonia/epidemiologia , Pleuropneumonia/microbiologia , Pleuropneumonia/prevenção & controle , Suínos , Doenças dos Suínos/microbiologia , Vacinas Atenuadas/imunologia , Vacinas de Subunidades Antigênicas/imunologia , VirulênciaRESUMO
INTRODUCTION: Cervical cancer and cervical intraepithelial neoplasia (CIN) are well-known outcomes of a human papillomavirus (HPV) infection. Viral oncogenes expressions like E6, E7, and, recently recognized E5, lead to HPV-related malignant progression. Although HPV prevention by powerful vaccines against most frequent and oncogenic genotypes is feasible, current treatment against cervical neoplasia is distant from an ideal one. In addition, late diagnosis is commonly associated with a poor prognosis. On top of that, radiotherapy, chemotherapy, or surgery are less effective in high-grade lesions. Areas covered: Due to their peculiarities, HPV oncogenes represent an excellent target for cancer immunotherapy. Safety, efficacy, and potential immunogenicity are features achieved by DNA vaccines targeting HPV. The literature search has indicated that genetic immunotherapy is becoming a pharmacological tool and therapeutic option against cervical disease, as more and more DNA vaccines are reaching clinical trial phases. Expert commentary: Among some of the promising results, a phase II randomized trial showed a clinical activity of a nucleic acid-based vaccine in HPV16 or HPV18 positive CIN patients. The concept of a synergic combination of anti-HPV DNA vaccines with radiotherapy, chemotherapy, sophisticated delivery methods, immunomodulators or immune adjuvants opens a new and interesting perspective in cervical malignancy treatment.
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Vacinas Anticâncer/administração & dosagem , Displasia do Colo do Útero/prevenção & controle , Neoplasias do Colo do Útero/prevenção & controle , Adjuvantes Imunológicos/administração & dosagem , Animais , Vacinas Anticâncer/imunologia , Feminino , Humanos , Imunoterapia/métodos , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/administração & dosagem , Vacinas contra Papillomavirus/imunologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Neoplasias do Colo do Útero/imunologia , Neoplasias do Colo do Útero/virologia , Vacinas de DNA/administração & dosagem , Vacinas de DNA/imunologia , Displasia do Colo do Útero/imunologia , Displasia do Colo do Útero/virologiaRESUMO
Immunogenicity induced by recombinant plasmids based on the BAB1_0267 and BAB1_0270 open reading frames (ORFs) of Brucella abortus 2308 was evaluated. Bioinformatics analyses indicate that the BAB1_0267 and BAB1_0270 ORFs encode a protein with a SH3 domain and a Zn-dependent metalloproteinase, respectively. Both ORFs have important effects on intracellular survival and replication of B. abortus 2308, mediated via professional and non-professional phagocytic cells. Our results show that immunization with the recombinant plasmid based on the BAB1_0267 ORF significantly increases the production of IgG1, levels of IFN-γ and the lymphoproliferative response of splenocytes. However, BAB1_0267 did not provide significant levels of protection. The plasmid based on the BAB1_0270 significantly increased IgG2a production, levels of IFN-γ and TNF-α, and the lymphoproliferative response of splenocytes. These results demonstrate that immunization with the BAB1_0270 derived recombinant plasmid induce a Th1-type immune response, correlated with a heightened resistance to B. abortus 2308 infection in mice. It is concluded that the Th1-type immune response against bacterial Zn-dependent metalloproteinase induces a protective response in mice, and that pV270 recombinant plasmid is an effective candidate microbicide against brucellosis.
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Brucella abortus/genética , Brucella abortus/imunologia , Brucelose/imunologia , Brucelose/prevenção & controle , DNA Recombinante , Fases de Leitura Aberta/genética , Plasmídeos/genética , Vacinas de DNA , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Contagem de Colônia Microbiana , Citocinas/análise , DNA Bacteriano , Modelos Animais de Doenças , Feminino , Genes Bacterianos/genética , Imunoglobulina G/biossíntese , Interferon gama/análise , Metaloendopeptidases , Camundongos , Camundongos Endogâmicos BALB C , Fagócitos/imunologia , Sobrevida , VacinaçãoRESUMO
Salmonella Enteritidis is the main cause of foodborne salmonellosis worldwide. The limited effectiveness of current interventions against this pathogen has been the main incentive to develop new methods for the efficient control of this infection. To investigate the use of DNA vaccines against S. Enteritidis in humans, immune responses stimulated by two plasmids containing the genes designated SEN1002, located in the pathogenicity island SPI-19 and encoding a Hcp protein involved in transport mechanisms, and SEN1395, located in the genomic island ΦSE14 and encoding a protein of a new superfamily of lysozymes, were evaluated. Humoral and cellular responses following intranasal immunization of two groups of BALB/c mice with the plasmids pV1002 and pV1395 plus adjuvant were evaluated and it was observed that the IgG2a/IgG1 ratios were sixfold higher than control groups. Both plasmids stimulated specific secretory IgA production. Increased proliferation of lymphocytes and IFN-γ production were detected in both experimental groups. DNA-vaccinated mice developed protective immunity against a virulent strain of S. Enteritidis, with nearly 2 logs of protection level compared to the negative control values in the spleen. Therefore, DNA vaccines are efficient at stimulating cellular and humoral immune responses at systemic and mucosal levels.
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Imunidade nas Mucosas/imunologia , Salmonelose Animal/imunologia , Vacinas contra Salmonella/imunologia , Vacinação , Adjuvantes Imunológicos/farmacologia , Adjuvantes Imunológicos/uso terapêutico , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/metabolismo , Feminino , Imunidade nas Mucosas/efeitos dos fármacos , Imunoglobulina G/sangue , Camundongos , Camundongos Endogâmicos BALB C , Fases de Leitura Aberta , Salmonelose Animal/microbiologia , Salmonella enteritidis , Vacinas de DNA/imunologiaRESUMO
Expression of HPV E5, E6 and E7 oncogenes are likely to overcome the regulation of cell proliferation and to escape immunological control, allowing uncontrolled growth and providing the potential for malignant transformation. Thus, their three oncogenic products may represent ideal target antigens for immunotherapeutic strategies. In previous attempts, we demonstrated that genetic vaccines against recombinant HPV16 E7 antigen were able to affect the tumor growth in a pre-clinical mouse model. To improve this anti-HPV strategy we developed a novel approach in which we explored the effects of E5-based genetic immunization. We designed novel HPV16 E5 genetic vaccines based on two different gene versions: whole E5 gene and E5Multi. The last one is a long multi epitope gene designed as a harmless E5 version. Both E5 genes were codon optimized for mammalian expression. In addition, we demonstrated that HPV 16 E5 oncogene is expressed in C3 mouse cell line making it an elective model for the study of E5 based vaccine. In this mouse model the immunological and biological activity of the E5 vaccines were assessed in parallel with the activity of anti-E7 and anti-E6 vaccines already reported to be effective in an immunotherapeutic setting. These E7 and E6 vaccines were made with mutated oncogenes, the E7GGG mutant that does not bind pRb and the E6F47R mutant that is less effective in inhibiting p53, respectively. Results confirmed the immunological activity of genetic formulations based on attenuated HPV16 oncogenes and showed that E5-based genetic immunization provided notable anti-tumor effects.
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Papillomavirus Humano 16/imunologia , Proteínas Oncogênicas Virais/imunologia , Vacinas contra Papillomavirus/imunologia , Neoplasias do Colo do Útero/prevenção & controle , Vacinas de DNA/imunologia , Animais , Linhagem Celular Tumoral , Feminino , Papillomavirus Humano 16/genética , Camundongos Endogâmicos C57BL , Proteínas Oncogênicas Virais/genética , Vacinas contra Papillomavirus/administração & dosagem , Vacinas contra Papillomavirus/genética , Vacinas de DNA/administração & dosagem , Vacinas de DNA/genéticaRESUMO
Mycoplasma hyopneumoniae is the etiological agent of porcine enzootic pneumonia (PEP) and causes major economic losses to the pig industry worldwide. Commercially available vaccines provide only partial protection and are relatively expensive. In this study, we assessed the humoral and cellular immune responses to three recombinant antigens of M. hyopneumoniae. Immune responses to selected domains of the P46, HSP70 and MnuA antigens (P46102-253, HSP70212-601 and MnuA182-378), delivered as recombinant subunit or DNA vaccines, were evaluated in BALB/c mice. All purified recombinant antigens and two DNA vaccines, pcDNA3.1(+)/HSP70212-601 and pcDNA3.1(+)/MnuA182-378, elicited a strong humoral immune response, indicated by high IgG levels in the serum. The cellular immune response was assessed by detection of IFN-γ, IL-10 and IL-4 in splenocyte culture supernatants. The recombinant subunit and DNA vaccines induced Th1-polarized immune responses, as evidenced by increased levels of IFN-γ. All recombinant subunit vaccines and the pcDNA3.1(+)/MnuA182-378 vaccine also induced the secretion of IL-10, a Th2-type cytokine, in large quantities. The mixed Th1/Th2-type response may elicit an effective immune response against M. hyopneumoniae, suggesting that P46102-253, HSP70212-601 and MnuA182-378 are potential novel and promising targets for the development of vaccines against PEP.
Assuntos
Antígenos de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Pneumonia Suína Micoplasmática/prevenção & controle , Animais , Anticorpos Antibacterianos/sangue , Proteínas de Bactérias/imunologia , Células Cultivadas , Feminino , Proteínas de Choque Térmico HSP70/imunologia , Imunidade Celular , Imunoglobulina G/sangue , Interferon gama/imunologia , Interleucina-10/imunologia , Interleucina-4/imunologia , Camundongos Endogâmicos BALB C , Mycoplasma hyopneumoniae/imunologia , Estrutura Terciária de Proteína , Proteínas Recombinantes/imunologia , Baço/citologia , Baço/imunologia , Suínos , Células Th1/imunologia , Vacinas de DNA/imunologia , Vacinas de Subunidades Antigênicas/imunologiaRESUMO
A tuberculose (TB) é responsável por dois milhões de mortes a cada ano, apesar daampla utilização da vacina BCG (Bacilo Calmette-Guérin). Embora essa vacina nãoproteja contra a TB pulmonar no adulto, protege contra as formas graves da TB nainfância. Para muitos autores, a imunização heteróloga (prime-boost) talvezseja uma das estratégias mais importantes e realistas para o controle da TB,principalmente nos países endêmicos. Muitos estudos têm demonstrado que aimunização com BCG seguido de reforço com vacina gênica (genes de M.tuberculosis) induz melhor proteção contra TB do que somente a vacina BCG. Alémdisso, a estratégia prime-boost utilizando microesferas biodegradáveis pareceser uma imunização promissora para estimular a resposta imune de longa duração.A glicoproteína APA foi identificada como importante antígeno imunodominante,induzindo níveis significativos de proteção contra M. tuberculosis. Assim, esteestudo teve como objetivo avaliar a eficácia protetora da imunização heteróloga emmodelo experimental de TB. Para isso, camundongos BALB/c foram imunizados porvia subcutânea com BCG seguido de um reforço por via intramuscular com aformulação vacinal contendo apa e DMT co-encapsuladosem microesferas (BCG/APA). Essa estratégia prime-boost foi eficiente na indução daresposta imune protetora à infecção por M. tuberculosis, caracterizada pela reduçãosignificativa do número de bacilos no pulmão destes animais na fase mais tardia dainfecção (70 dias após desafio). Além de ser significativamente mais imunogênciaque a vacina BCG, permitiu uma melhor preservação do parênquima pulmonar, comredução do número e tamanho dos granulomas, limitando a extensão da injúriatecidual induzida pela infecção e restringindo a inflamação no tecido alveolar. Apotencialização do efeito protetor da vacina BCG induzida pelo reforço com a vacinapVAXapa+DMT-Me sugere que a estratégia utilizada pode ser importante para aprevenção da TB...
Tuberculosis (TB) is responsible for two millions of deaths each year despite thewidespread use of BCG vaccine (Bacillus Calmette-Guérin). Although this vaccinedoes not protect against adult pulmonary TB, it is protective against severe forms ofchildhood TB. For many authors, heterologous prime-boost regimen is perhaps themost realistic strategy for future TB control, especially in endemic countries. Manystudies have demonstrated that BCG-prime DNA-(M. tuberculosis genes)-boosterinduce greater protection against TB than BCG alone. APA glycoprotein has beenidentified as major immunodominant antigen and induces significant levels ofprotection against M. tuberculosis. Moreover, prime-boost strategy by usingbiodegradable microspheres seems to be a promising immunization to stimulate longlasting immune response. Thus, this study had as aim to investigate the immuneprotection against M. tuberculosis challenge in mice based on BCG priming and DNAvaccine boosting. For that, BALB/c mice were inoculated subcutaneously with aheterologous BCG priming-DNA boosting immunization using pVAXapa and TDM coencapsulatedin microspheres (BCG/APA), intramuscularly. This prime-boost strategywas effective in inducing protective immune response against M. tuberculosisinfection, characterized by significant lower numbers of bacilli in the lungs of theseanimals, in the late phase of infection (70 days after infection). In addition to beingsignificantly more immunogenic than BCG, it allowed better preservation of the lungparenchyma and reduction in the number and size of granulomas, limiting the extentof lung injury induced by infection and inflammation in the alveolar tissue. Theimprovement of the protective effect of BCG vaccine mediated by pVAXapa boostersuggests that our strategy can be important in the treatment for prevention of TB...
Assuntos
Camundongos , Vacina BCG , Microesferas , Vacinas contra a Tuberculose , Tuberculose/epidemiologia , Tuberculose/imunologia , Vacinas de DNA/biossínteseRESUMO
Vaccination is the most practical and cost-effective strategy to prevent the majority of the flavivirus infection to which there is an available vaccine. However, vaccines based on attenuated virus can potentially promote collateral side effects and even rare fatal reactions. Given this scenario, the developent of alternative vaccination strategies such as DNA-based vaccines encoding specific flavivirus sequences are being considered. Endogenous cytoplasmic antigens, characteristically plasmid DNA-vaccine encoded, are mainly presented to the immune system through Major Histocompatibility Complex class I - MHC I molecules. The MHC I presentation via is mostly associated with a cellular cytotoxic response and often do not elicit a satisfactory humoral response. One of the main strategies to target DNA-encoded antigens to the MHC II compartment is expressing the antigen within the Lysosome-Associated Membrane Protein (LAMP). The flavivirus envelope protein is recognized as the major virus surface protein and the main target for neutralizing antibodies. Different groups have demonstrated that co-expression of flavivirus membrane and envelope proteins in mammalian cells, fused with the carboxyl-terminal of LAMP, is able to induce satisfactory levels of neutralizing antibodies. Here we reviewed the use of the envelope flavivirus protein co-expression strategy as LAMP chimeras with the aim of developing DNA vaccines for dengue, West Nile and yellow fever viruses.
A vacinação é a estratégia mais prática e o melhor custo-benefício para prevenir a maioria das infecções dos flavivirus, para os quais existe vacina disponível. Entretanto, as vacinas baseadas em vírus atenuados podem potencialmente promover efeitos colaterais e, mais raramente, reações fatais. Diante deste cenário, o desenvolvimento de estratégias alternativas de vacinação, como vacinas baseadas em DNA codificando seqüências específicas dos flavivirus, está sendo considerado. Antí-genos citoplasmáticos endógenos, caracteristicamente codificados por vacinas de DNA plasmidial, são majoritariamente apresentados ao sistema imune através de moléculas do Complexo Maior de Histocompatibilidade de classe I - MHC I. A via de apresentação MHC I é mais associada à resposta celular citotóxica e, frequentemente, não elicita uma resposta humoral satisfatória. Uma das principais estratégias para direcionar antígenos codificados pelas vacinas de DNA para o compartimento MHC II é expressar estes antígenos dentro da Proteína de Associação à Membrana Lisossomal (LAMP). A proteína do envelope dos flavivirus é reconhecidamente a principal proteína de superfície viral e o principal alvo para anticorpos neutralizantes. Diferentes grupos têm demonstrado que a co-expressão das proteínas de membrana e do envelope dos flavivirus em células de mamíferos, fusionada com a porção carboxi-terminal de LAMP, é capaz de induzir níveis satisfatórios de anticorpos neutralizantes. Neste trabalho revisamos a estratégia de co-expressão da proteína do envelope dos flavivírus, como quimeras de LAMP, com o objetivo de desenvolver vacinas de DNA contra a febre do Oeste do Nilo, dengue e febre amarela.