Construction of a replicative expression vector based on the porcine circovirus 2 replicon / 生物工程学报

The antigen gene expression level of a DNA vaccine is the key factor influencing the efficacy of the DNA vaccine. Accordingly, one of the ways to improve the antigen gene expression level of a DNA vaccine is to utilize a plasmid vector that is replicable in eukaryotic cells. A replicative DNA vaccine vector pCMVori was constructed based on the non-replicative pcDNA3.1 and the replicon of porcine circovirus 2 (PCV2) in this study. An EGFP gene was cloned into pCMVori and the control plasmid pcDNA3.1. The two recombinant vectors were transfected into PK-15 cell, and the plasmid DNA and RNA were extracted from the transfected cells. Real-time PCR was used to determine the plasmid replication efficiency of the two plasmids using plasmid before and after Bcl Ⅰ digestion as templates, and the transcription level of the Rep gene in PCV2 replicon was detected by RT-PCR. The average fluorescence intensity of cells transfected with the two plasmids was analyzed with software Image J, and the transcription level of EGFP was determined by means of real-time RT-PCR. The results showed that the replication efficiency of pCMVori in PK-15 cells incubated for 48 h was 136%, and the transcriptions of Rep and Rep' were verified by RT-PCR. The average fluorescence intensity of the cells transfected with pCMVori-EGFP was 39.14% higher than that of pcDNA3.1-EGFP, and the transcription level of EGFP in the former was also 40% higher than that in the latter. In conclusion, the DNA vaccine vector pCMVori constructed in this study can independently replicate in eukaryotic cells. As a result, the expression level of cloned target gene was elevated, providing a basis for developing the pCMVori-based DNA vaccine.

Construction of a fusion plasmid containing the PSCA gene and cytotoxic T-lymphocyte associated antigen-4 (CTLA-4) and its anti-tumor effect in an animal model of prostate cancer

Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is a negative regulator of T cell activation, which competes with CD28 for B7.1/B7.2 binding, and which has a greater affinity. Fusion of specific antigens to extracellular domain of CTLA4 represents a promising approach to increase the immunogenicity of DNA vaccines. In this study, we evaluated this interesting approach for CTLA4 enhancement on prostate stem cell antigen (PSCA)-specific immune responses and its anti-tumor effects in a prostate cancer mouse model. Consequently, we constructed a DNA vaccine containing the PSCA and the CTLA-4 gene. Vaccination with the CTLA4-fused DNA not only induced a much higher level of anti-PSCA antibody, but also increased PSCA-specific T cell response in mice. To evaluate the anti-tumor efficacy of the plasmids, murine models with PSCA-expressing tumors were generated. After injection of the tumor-bearing mouse model, the plasmid carrying the CTLA4 and PSCA fusion gene showed stronger inhibition of tumor growth than the plasmid expressing PSCA alone. These observations emphasize the potential of the CTLA4-fused DNA vaccine, which could represent a promising approach for tumor immunotherapy.

Improved immunogenicity of Newcastle disease virus inactivated vaccine following DNA vaccination using Newcastle disease virus hemagglutinin-neuraminidase and fusion protein genes

The present study describes the development of DNA vaccines using the hemagglutinin-neuraminidase (HN) and fusion (F) genes from AF2240 Newcastle disease virus strain, namely pIRES/HN, pIRES/F and pIRES-F/HN. Transient expression analysis of the constructs in Vero cells revealed the successful expression of gene inserts in vitro. Moreover, in vivo experiments showed that single vaccination with the constructed plasmid DNA (pDNA) followed by a boost with inactivated vaccine induced a significant difference in enzyme-linked immunosorbent assay antibody levels (p < 0.05) elicited by either pIRES/F, pIRES/F+ pIRES/HN or pIRES-F/HN at one week after the booster in specific pathogen free chickens when compared with the inactivated vaccine alone. Taken together, these results indicated that recombinant pDNA could be used to increase the efficacy of the inactivated vaccine immunization procedure.

Notícias do Levantamento de Recursos e Necessidades de Enfermagem na Revista Brasileira de Enfermagem (1955-1958) / News of the Inquiry about Nursing Needs and Resources in the Brazilian Journal of Nursing (1955-1958) / Noticias del Levantamiento de Necesidades y Recursos de Enfermería en la Revista Brasileña de Enfermería (1955-1958)

Estudo Histórico Social que tem como objeto notícias sobre o Levantamento de Recursos e Necessidades de Enfermagem no Brasil, publicadas na Revista Brasileira de Enfermagem entre 1955 e 1958. A fonte primária foi constituída pelos exemplares da Revista Brasileira de Enfermagem, publicados dentro do recorte temporal do estudo. As fontes secundárias foram constituídas por livros, artigos, dissertações e teses relativas à história da Enfermagem. A análise dos dados teve apoio das fontes secundárias e do pensamento do sociólogo Pierre Bourdieu. Os dados evidenciaram que a Revista Brasileira de Enfermagem, além de oportunizar a divulgação de notícias acerca do Levantamento, proporcionou visibilidade ao mesmo mediante a veiculação dessas notícias e, por fim, teve o efeito simbólico de conferir poder e prestígio à Enfermagem Brasileira.

Social historical study that has as object news related to the Assessment of the Resources and Needs of Nursing in Brazil published in the Revista Brasileira de Enfermagem between 1955 and 1958. The primary source is constituted of copies of Revista Brasileira de Enfermagem published within the selected period of the study. The secondary sources are constituted of books, papers, dissertations and thesis related to the Nursing history. The data analysis was supported by the secondary sources and the thought of the sociologist Pierre Bourdieu. The results evidenced that Revista Brasileira de Enfermagem, in addition to making possible the dissemination of news about the Assessment provided visibility to it and, at last, had the symbolic effect of giving power and prestige to the Brazilian Nursing.

Estudio Histórico Social que tiene como objeto noticias referentes al Levantamiento de Recursos y Necesidades de Enfermería en Brasil publicadas en la Revista Brasileira de Enfermagem entre 1955 y 1958. La fuente primaria se constituye de los ejemplares de la Revista Brasileira de Enfermagem publicados dentro del recorte temporal do estudio. Las fuentes secundarias están constituidas de libros, artículos disertaciones y tesis relativas a la historia de la Enfermería. El análisis de los datos tuvo apoyo de las fuentes secundarias y del pensamiento del Sociólogo Pierre Bourdieu. Los resultados evidencian que la Revista Brasileira de Enfermagem, además de posibilitar la divulgación de noticias acerca del Levantamiento proporcionó visibilidad al mismo mediante la divulgación de esas noticias y, por fin, tuve el efecto simbólico de conferir poder y prestigio a la Enfermería Brasileña.

In silico experiment with an-antigen-toll like receptor-5 agonist fusion construct for immunogenic application to Helicobacter pylori.

BACKGROUNDS: Helicobacter pylori colonize the gastric mucosa of half of the world's population. Although it is classified as a definitive type I carcinogen by World Health Organization, there is no effective vaccine against this bacterium. H. pylori evade the host immune response by avoiding toll-like detection, such as detection via toll-like receptor-5 (TLR-5). Thus, a chimeric construct consisting of selected epitopes from virulence factors that is incorporated into a TLR-5 ligand (Pseudomonas flagellin) could result in more potent innate and adaptive immune responses. MATERIALS AND METHODS: Based on the histocompatibility antigens of BALB/c mice, in silico techniques were used to select several fragments from H. pylori virulence factors with a high density of B- and T-cell epitopes. RESULTS: These segments consist of cytotoxin-associated geneA (residue 162-283), neutrophil activating protein (residue 30-135) and outer inflammatory protein A (residue 155-268). The secondary and tertiary structure of the chimeric constructs and other bioinformatics analyses such as stability, solubility, and antigenicity were performed. The chimeric construct containing antigenic segments of H. pylori proteins was fused with the D3 domain of Pseudomonas flagellin. This recombinant chimeric gene was optimized for expression in Escherichia coli. The in silico results showed that the conserved C- and N-terminal domains of flagellin and the antigenicity of selected fragments were retained. DISCUSSION: In silico analysis showed that Pseudomonas flagellin is a suitable platform for incorporation of an antigenic construct from H. pylori. This strategy may be an effective tool for the control of H. pylori and other persistent infections.

Construction of a recombinant plasmid harbouring the glyceraldenyde-3-phosphate dehydrogenase gene of periodic Brugia malayi and observation on DNA immunity.

Purpose: Controlling and eliminating lymphatic filariasis will require further research of preventative measures and implementation. Parasite is dependent on glycolysis for ATP production. The glycolytic enzyme glyceraldenyde-3-phosphate dehydrogenase (GAPDH) plays an important role in glycolysis and therefore is either a potential target for anti-parasite drug development or a vaccine candidate. Therefore, we tried to investigate the DNA vaccine-elicited immune responses in BALB/c mice. Materials and Methods: We cloned a gene encoding the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from periodic Brugia malayi into vector pcDNA3.1. Mice were injected at a dosage of 100 μg recombinant plasmid DNA with CpG intramuscular injection and immunized three times at 2-week intervals. pcDNA3.1 and normal saline were used as control. The tissue of muscles at the 4 weeks after the third injection was collected and target genes were detected using RT-PCR. The humoral responses elicited in mice by inoculation with the recombinant plasmid pcDNA3.1-BmGAPDH were detected using a standard ELISA. Two weeks after the third immunization, stimulation index (SI) was measured using the MTT method and the level of secreted IL-4 and INF-g were detected using ELISA. Results: Specific gene fragment coding GAPDH was amplified and the recombinant plasmid pcDNA3.1-BmGAPDH was constructed. Post-challenge sera from the mice immunized with the DNA vaccine had specific antibody titres of 1:1600 to 1:6400, and the highest titre was observed in the mice that were inoculated by pcDNA3.1-BmGAPDH/CpG at 6 weeks. At 4 weeks after immunization, the spleens of the mice were obviously enlarged. The proliferation of spleen T lymphocytes seen on the MTT assay was higher in the pcDNA3.1-BmGAPDH group than in the control group (P value <0.05). The levels of IL-4 and INF-g in serums from the immunized mice were significantly higher than that of the control (P value <0.05). Conclusions: We conclude that the recombinant eukaryotic plasmid pcDNA3.1-BmGAPDH could elicit humoral and cellular immune responses in mice.

Enhanced anti-tumor effect of a gene gun-delivered DNA vaccine encoding the human papillomavirus type 16 oncoproteins genetically fused to the herpes simplex virus glycoprotein D

Anti-cancer DNA vaccines have attracted growing interest as a simple and non-invasive method for both the treatment and prevention of tumors induced by human papillomaviruses. Nonetheless, the low immunogenicity of parenterally administered vaccines, particularly regarding the activation of cytotoxic CD8+ T cell responses, suggests that further improvements in both vaccine composition and administration routes are still required. In the present study, we report the immune responses and anti-tumor effects of a DNA vaccine (pgD-E7E6E5) expressing three proteins (E7, E6, and E5) of the human papillomavirus type 16 genetically fused to the glycoprotein D of the human herpes simplex virus type 1, which was administered to mice by the intradermal (id) route using a gene gun. A single id dose of pgD-E7E6E5 (2 µg/dose) induced a strong activation of E7-specific interferon-γ (INF-γ)-producing CD8+ T cells and full prophylactic anti-tumor effects in the vaccinated mice. Three vaccine doses inhibited tumor growth in 70 percent of the mice with established tumors. In addition, a single vaccine dose consisting of the co-administration of pgD-E7E6E5 and the vector encoding interleukin-12 or granulocyte-macrophage colony-stimulating factor further enhanced the therapeutic anti-tumor effects and conferred protection to 60 and 50 percent of the vaccinated mice, respectively. In conclusion, id administration of pgD-E7E6E5 significantly enhanced the immunogenicity and anti-tumor effects of the DNA vaccine, representing a promising administration route for future clinical trials.

Co-Immunization of Plasmid DNA Encoding IL-12 and IL-18 with Bacillus Calmette-Guerin Vaccine against Progressive Tuberculosis

PURPOSE: Bacillus Calmette-Guerin (BCG) vaccine has widely been used to immunize against tuberculosis, but its protective efficacy is variable in adult pulmonary tuberculosis, while it is not efficiently protective against progressive infection of virulent Mycobacterium tuberculosis strains. In this study, the protective effects of plasmid DNA vaccine constructs encoding IL-12 or IL-18 with the BCG vaccine were evaluated against progressive infection of M. tuberculosis, using mouse aerosol challenge model. MATERIALS AND METHODS: Plasmid DNA vaccine constructs encoding IL-12 or IL-18 were constructed and mice were immunized with the BCG vaccine or with IL-12 DNA or IL-18 DNA vaccine constructs together with the BCG vaccine. RESULTS: The BCG vaccine induced high level of interferon gamma (IFN-gamma) but co-immunization of IL-12 or IL-18 DNA vaccine constructs with the BCG vaccine induced significantly higher level of IFN-gamma than a single BCG vaccine. The BCG vaccine was highly protective at early stage of M. tuberculosis infection, but its protective efficacy was reduced at later stage of infection. The co-immunization of IL-12 DNA vaccine constructs with the BCG vaccine was slightly more protective at early stage of infection and was significantly more protective at later stage infection than a single BCG vaccine. CONCLUSION: Co-immunization of IL-12 DNA vaccine with the BCG vaccine induced more protective immunity and was more effective for protection against progressive infection of M. tuberculosis.

Caracterização da resposta imune induzida por protocolos de vacinação dose e reforço usando diferentes vetores virais (adenovirus e MVA) expressando o gene A2 de Leishmania donovani

As Leishmanioses são consideradas pela Organização Mundial de Saúde comouma das seis doenças tropicais mais importantes. A ausência de uma forma eficaz decontrole e contenção da doença justifica o desenvolvimento de uma vacina mais eficaz.Por sua vez, o antígeno A2, exclusivamente expresso nas formas amastigotas deLeishmania tem sido considerado um excelente alvo no desenvolvimento deformulações vacinais em fase experimental. Esse trabalho visou à caracterização daresposta imune induzida por diferentes protocolos de vacinação dose e reforço usando,além do MVA-A2, o Adenovírus-A2, AdA2. O MVA é um vírus atenuado, derivado doVírus Vaccínia Ankara, não replicativo em células de mamíferos. Assim, foramavaliadas as respostas celular, por ensaios de ELISPOT e citotoxicidade in vivo,mediante estimulação dos esplenócitos com peptídeos correspondentes aos epítopospara células TCD4+ e TCD8+ na proteína A2 e a resposta humoral, por ELISA. Apenasos animais vacinados com AdA2 + MVAA2 apresentaram níveis elevados de célulasprodutoras de IFNg e níveis de baixos IL-10 e IL-4, sob estimulação com ambos ospeptídeos, nos ensaios de ELISPOT. Da mesma forma, alta porcentagem de lise foiobservada apenas nesse grupo de animais, indicando que esse esquema vacinal foicapaz de induzir a resposta de células T CD8+ e TCD4+. A resposta imune induzidanesse grupo, considerada do tipo Th1, tem sido relacionada à proteção contra ainfecção desafio por diferentes espécies de Leishmania. Nos testes de ELISA, não foiidentificada produção de anticorpos contra o Antígeno Solúvel de Leishmania, SLA, daforma promastigota, em quaisquer grupos vacinais, o que os diferenciou dos animaisinfectados, nos quais a produção foi observada. Isso é importante no diagnóstico doscães domésticos, uma vez que a vacina atual não possibilita essa diferenciação. Nosoutros grupos vacinados, a resposta imune celular será investigada contra a formaíntegra da proteína A2 e SLA da forma amastigota

Caracterização da resposta imune induzida por protocolos de vacinação dose e reforço usando diferentes vetores virais (adenovirus e MVA) expressando o gene A2 de Leishmania donovani / Characterization of the immune response induced by vaccination protocols dose and reinforcement using different viral vectors (adenovirus and MVA) expressing the Leishmania donovani A2 gene

As Leishmanioses são consideradas pela Organização Mundial de Saúde comouma das seis doenças tropicais mais importantes. A ausência de uma forma eficaz decontrole e contenção da doença justifica o desenvolvimento de uma vacina mais eficaz.Por sua vez, o antígeno A2, exclusivamente expresso nas formas amastigotas deLeishmania tem sido considerado um excelente alvo no desenvolvimento deformulações vacinais em fase experimental. Esse trabalho visou à caracterização daresposta imune induzida por diferentes protocolos de vacinação dose e reforço usando,além do MVA-A2, o Adenovírus-A2, AdA2. O MVA é um vírus atenuado, derivado doVírus Vaccínia Ankara, não replicativo em células de mamíferos. Assim, foramavaliadas as respostas celular, por ensaios de ELISPOT e citotoxicidade in vivo,mediante estimulação dos esplenócitos com peptídeos correspondentes aos epítopospara células TCD4+ e TCD8+ na proteína A2 e a resposta humoral, por ELISA. Apenasos animais vacinados com AdA2 + MVAA2 apresentaram níveis elevados de célulasprodutoras de IFNg e níveis de baixos IL-10 e IL-4, sob estimulação com ambos ospeptídeos, nos ensaios de ELISPOT. Da mesma forma, alta porcentagem de lise foiobservada apenas nesse grupo de animais, indicando que esse esquema vacinal foicapaz de induzir a resposta de células T CD8+ e TCD4+. A resposta imune induzidanesse grupo, considerada do tipo Th1, tem sido relacionada à proteção contra ainfecção desafio por diferentes espécies de Leishmania. Nos testes de ELISA, não foiidentificada produção de anticorpos contra o Antígeno Solúvel de Leishmania, SLA, daforma promastigota, em quaisquer grupos vacinais, o que os diferenciou dos animaisinfectados, nos quais a produção foi observada. Isso é importante no diagnóstico doscães domésticos, uma vez que a vacina atual não possibilita essa diferenciação. Nosoutros grupos vacinados, a resposta imune celular será investigada contra a formaíntegra da proteína A2 e SLA da forma amastigota

Cloning, protein expression and immunogenicity of HBs-murine IL-18 fusion DNA vaccine.

Hepatitis B is a global serious disease caused by hepatitis B virus (HBV). There is no known cure for hepatitis B. The best way to deal with the disease is by preventing with hepatitis B vaccine. However, the current protein-based vaccines made up of recombinant hepatitis B surface antigen (HBsAg) are ineffective in chronic HBV carriers and a significant number of the vaccinees do not mount the protective immune response. Novel DNA-based immunization may overcome the deficits of the protein-based immunization and may provide more effective prophylactic and therapeutic outcomes. In this study, we constructed a recombinant plasmid carrying gene encoding the HBV surface antigen (HBs) linked to DNA segment encoding full-length murine interleukin-18, i.e. pcDNA-HBs-IL-18. Immunogenicity of the DNA construct was carried out in BALB/c mice in comparison with mock, i.e. pcDNA3.1+ and vaccines comprised of pRc/CMV-HBs and pRc/CMV-HBs plus pcDNA-IL-18. All vaccinated mice revealed significant serum anti-HBs IgG response after two intramuscular injections of the vaccines at 28 day interval as compared to the level of mock. Co-administration of pRc/CMV-HBs and pcDNA-IL-18 elicited arbitrarily higher levels of anti-HBs IgG than the levels in mice immunized with pRc/CMV-HBs alone and mice that received pcDNA-HBs-IL-18 although not statistically different. Further experiments are needed to investigate the subisotypes of the IgG antibody, the kinetics of cytokine and the cell-mediated immune response. For this communication, the prototype HBs-IL-18 DNA vaccine was successfully constructed and the gene encoding murine IL-18 was successfully cloned. The latter can be co-injected with the antigen coding DNA or used as a fusion partner to the DNA for priming the immune response. The recombinant HBs and full-length IL-18 proteins have potential for other research purposes. They may be used also as standard proteins in the protein quantification assay.

Estudo da imunidade à saliva de Lutzomyia longipalpis em hamsters: vacinas de DNA baseadas na saliva de L. longipalpis são capazes de proteger contra leishmaniose visceral / Study of immunity to the saliva of Lutzomyia longipalpis in hamsters: DNA-based vaccines in the saliva of L. longipalpis are able to protect against visceral leishmaniasis

O hamster (Mesocricetus auratus) tem sido bastante utilizado como modelo para o estudo da leishmaniose visceral (LV) causada pela Leishmania (L) donovani, Leishmania (L) infantum e Leishmania (L) chagasi. Entretanto, algumas características que reproduzem a biologia da transmissão natural das leishmanioses, como baixas doses de parasitas, a via de inoculação e, mais recentemente, a presença da saliva do vetor, não têm sido consideradas neste modelo. No presente trabalho, foram utilizados hamsters machos (3-4 meses de idade) inoculados por via intradérmica com 105 promastigotas de L. (L) chagasi na presença ou ausência de sonicado de glândula salivar (SOS) de L. longipalpis, estabelecendo-se a infecção parasitária com sintomas semelhantes aos observados na LV humana: hepatoesplenomegalia, hipergamaglobulinemia, caquexia e morte dos animais com 5 a 6 meses pós-infecção. Os parasitas foram detectados no sangue, baço e figado com 15 dias, 2 e 5 meses pós-infecção. A presença do SOS não altera a carga parasitária no baço e figado dos hamsters. Entretanto, foi observada uma expressão preferencial de TGF-β e IFN-y nos hamsters inoculados com parasita mais SOS durante o curso da infecção. Utilizando este modelo de infecção intradérmica em hamsters, quatro candidatos a vacinas de DNA que codificam proteínas salivares do vetor Lutzomyia longipalpis, selecionados a partir de dezesseis candidatos, foram avaliados quanto à sua capacidade de proteger os animais após um desafio com L. (L) chagasi mais SOS. Os plasmídios avaliados induziram a produção de anticorpos, hipersensibilidade tardia (DTH) ou ambas as respostas, contra a saliva total do vetor. O plasmídio que codifica uma proteína salivar de 61 kDa (LJLll) induz uma intensa resposta humoral anti-saliva, mas não foi capaz de proteger contra a infecção. Entretanto, a imunização com o plasmídeo que codifica uma proteína de 11 kDa (LJMI9) resultou exclusivamente em resposta de hipersensibilidade tardia e foi capaz...

Enhanced immune response with foot and mouth disease virus VP1 and interleukin-1 fusion genes

The capsid of the foot and mouth disease (FMD) virus carries the epitopes that are critical for inducing the immune response. In an attempt to enhance the specific immune response, plasmid DNA was constructed to express VP1/interleukin-1alpha (IL-1alpha) and precursor capsid (P1) in combination with 2A (P1-2A)/IL-1alpha under the control of the human cytomegalovirus (HCMV) immediateearly promoter and intron. After DNA transfection into MA104 (monkey kidney) cells, Western blotting and an immunofluorescence assay were used to confirm the expression of VP1 or P1-2A and IL-1alpha. Mice were inoculated with the encoding plasmids via the intradermal route, and the IgG1 and IgG2a levels were used to determine the immune responses. These results show that although the immunized groups did not carry a high level of neutralizing antibodies, the plasmids encoding the VP1/ IL-1alpha, and P1-2A /IL-1alpha fused genes were effective in inducing an enhanced immune response.

Immunization with HIV-1 subtype B gp160-DNA induces specific as well as cross reactive immune responses in mice.

BACKGROUND & OBJECTIVES: HIV-1 gp160 is an important structural protein for the virus cell interaction and virus entry. Therefore, it is regarded as the most important target for HIV-1 vaccine development. In this study we investigated the use of HIV-1 gp160-DNA construct in eliciting specific and cross reactive cell mediated immune response in mice. METHODS: DNA segment encoding env, tat and rev genes of HIV-1 subtype B (strain BRU-2) was amplified and cloned into mammalian expression vector pCI to generate plasmid pCIBRU-TRE. Mice were injected intramuscularly four times at biweekly intervals with 100 micrograms/dose of pCIBRU-TRE in normal saline, and subsequently analysed for anti HIV-envelope (env) immune responses. RESULTS: A low antibody level was detected as determined by ELISA after 4 doses. Subsequent inoculations failed to increase the antibody titres significantly. Spleen cells from the immunized mice were used for the detection of cellular immune response by lymphocyte proliferation assays (LPA), in vitro production of cytokines and cytotoxic T lymphocyte (CTL) assays. T cell response which was seen from the second week onwards, persisted even at the end of 24 wk following the last dose. Similar levels of T cell proliferation were observed on stimulation with either homologous or heterologous peptides. Cytokine studies showed a Th1 type of response. A cross clade MHC class I restricted CTL response was observed against target cells stimulated with either homologous or heterologous HIV antigens. INTERPRETATION & CONCLUSION: This study demonstrated that DNA encoding full length HIV-1 env glycoprotein gp160 induces specific as well as cross reactive cell mediated immune responses in mice. However, the induction of antibody response was poor.