Administration of a single chain variable fragments chimeric protein (SD) of ovalbumin epitopes internalizing receptor DEC-205 antibody inhibits food allergy in mice / 细胞与分子免疫学杂志

Objective To investigate the preventive therapeutic effect and possible mechanism of single chain variable fragments chimeric protein (SD) of ovalbumin epitopes internalizing receptor DEC-205 antibody on food allergy in mice. Methods Mice were randomly divided to five groups (control, PBS, scFv DEC 100 μg, SD 50 μg, SD 100 μg) and treated for 24 hours before OVA administration. After challenge, the serum level of OVA-specific IgE, IgG1, IgG2a and IL-4 were detected by ELISA. Infiltration of eosinophils and mast cells in the jejunum was observed by HE staining and toluidine blue staining respectively. The bone marrow of tibia and femur was isolated and cultured to obtain immature dendritic cells(BMDCs), which were further treated with LPS (10 ng/mL), TSLP (50 ng/mL), scFv DEC protein (1000 ng/mL) and SD protein (10,100,1000)ng/mL for 24 hours, and the IL-10 level of supernatant was assayed by ELISA. Results Compared with PBS group, the number of SD-treated mice with diarrhea was markedly reduced. The difference in rectal temperature and the levels of serum OVA-specific IgE, IgG1, IgG2a and IL-4 decreased significantly after prophylactic administration of SD; The number of eosinophils and mast cells in jejunum also decreased significantly while the IL-10 level in the supernatant of BMDCs increased significantly after SD intervention. Conclusion SD mitigates experimental FA response by fosters the immune tolerance property of dendritic cells.

Production of antimicrobial peptide (Oxysterlin 1) in Escherichia coli with ELP self-cleavage tag / 生物工程学报

Antimicrobial peptides are the most promising alternatives to antibiotics. However, the strategy of producing antimicrobial peptides by recombinant technology is complicated and expensive, which is not conducive to the large-scale production. Oxysterlin 1 is a novel type of cecropin antimicrobial peptide mainly targeting on Gram-negative bacteria and is of low cytotoxicity. In this study, a simple and cost-effective method was developed to produce Oxysterlin 1 in Escherichia coli. The Oxysterlin 1 gene was cloned into a plasmid containing elastin-like polypeptide (ELP) and protein splicing elements (intein) to construct the recombinant expression plasmid (pET-ELP-I-Oxysterlin 1). The recombinant protein was mainly expressed in soluble form in E. coli, and then the target peptide can be purified with a simple salting out method followed by pH changing. The final yield of Oxysterlin 1 was about 1.2 mg/L, and the subsequent antimicrobial experiment showed the expected antimicrobial activity. This study holds promise for large-scale production of antimicrobial peptides and the in-depth study of its antimicrobial mechanism.

Characterization of the affinity-tags-regulated (S)-carbonyl reductase 2 towards 2-hydroxyacetophenone reduction / 生物工程学报

The influence of different affinity tags on enzyme characteristics varies. The (S)-carbonyl reductase 2 (SCR2) from Candida parapsilosis can reduce 2-hydroxyacetophenone, which is a valuable prochiral ketones. Different affinity tags, i.e. his-tag, strep-tag and MBP-tag, were attached to the N terminus of SCR2. These tagged SCR2 enzymes, i.e. his6-SCR2, strep-SCR2 and MBP-SCR2, were heterologously expressed in Escherichia coli and purified to study their characteristics towards 2-hydroxyacetophenone reduction. Affinity tags did affect the characteristics of the recombinant SCR2 enzymes. Specifically, affinity tags affect the stability of recombinant SCR2 enzymes: 1) At pH 6.0, the remaining enzyme activities of his6-SCR2 and strep-SCR2 were only 95.2% and 90.0% of the untagged SCR2, while that of MBP-SCR2 was 1.2 times of the untagged SCR2 after incubating for 13 h at 30 °C. 2) The half-life of MBP-SCR2 at 50 °C was 26.6%-48.8% longer than those of strep-SCR2, his6-SCR2 and untagged SCR2. 3) The kcat of MBP-SCR2 was about 1.25-1.45 times of that of small affinity-tagged and untagged SCR2 after storing at -80 °C for 60 d. Structural informatics indicated that the α-helices at the C terminus of MBP-SCR2 contributed to the stability of the N terminus of fusion protein of SCR2. Data from circular dichroism showed that the MBP-tag has some influence on the secondary structure of SCR2, while melting temperature analysis demonstrated that the Tm of the recombinant MBP-SCR2 was about 5 °C higher than that of the untagged SCR2. This study obtained an efficient and stable recombinant SCR2, i.e. the MBP-SCR2. Moreover, this study could serve as a reference for other researchers to evaluate and select appropriate affinity tags for their research.

Prokaryotic expression, purification and characterization of tissue inhibitor of metalloproteinase-2 / 生物工程学报

Tissue inhibitor of metalloproteinases-2 (TIMP-2) inhibits tumor migration and invasion. Obtaining TIMP-2 protein is conducive to a comprehensive and in-depth study of its function and mechanism in tumorigenesis and development. We collected human TIMP-2 protein through prokaryotic expression in vitro. We expressed, purified and characterized human TIMP-2 protein. First, the human TIMP-2 gene was cloned from the cDNA obtained by reverse transcription of total RNA of human lung cancer A549 cells, and constructed to pET28a vector. The recombinant plasmid pET28a-TIMP-2 was transformed into Escherichia coli BL21(DE3) after restriction endonuclease digestion and sequencing analysis. The expression of TIMP-2 protein was induced by isopropyl-β-D-thiogalactoside (IPTG), and the expression conditions were optimized. After purification by nickel affinity column, the fusion protein His-TIMP-2 was identified by Western blotting method and its biological activity was detected by gelatin zymography. The fusion protein His-TIMP-2 existed in the form of inclusion body in E. coli. In a certain range, the concentration of IPTG had no significant effect on the expression amount of His-TIMP-2. But in this expression system, induction temperature and time were the key parameters, and the expression amount of His-TIMP-2 in E. coli increased with the increase of induction temperature. The purified and refolded fusion protein could effectively inhibit the activity of matrix metalloproteinases expressed by human lung cancer A549 cells. The acquisition of active fusion protein lays a foundation for further study of the function and mechanism of human TIMP-2, and is of great significance for tumor therapy.

Expression, purification and biological effect of a novel single chain Fv antibody and protamine fusion protein for the targeted delivery of siRNAs to FGFR3 positive cancer cells

Background: Gain-of-function of fibroblast growth factor receptor 3 (FGFR3) is involved in the pathogenesis of many tumors. More and more studies have focused on the potential usage of therapeutic single-chain Fv (ScFv) antibodies against FGFR3. RNA interference (RNAi) has been considered as a promising therapeutic method against cancer. A tool which can deliver small interference RNAs (siRNAs) into FGFR3 positive cancer cells is very promising for anti-tumor therapy. Results: In this study, a novel fusion protein R3P, which consists of FGFR3-ScFv and protamine, was generated in Escherichia coli by inclusion body expression strategy and Ni-NTA chromatography. Its yield reached 10 mg per liter of bacterial culture and its purity was shown to be higher than 95%. 1 µg of R3P could efficiently bind to about 2.5 pmol siRNAs and deliver siRNAs into FGFR3 positive RT112 and K562 cells. Annexin V staining results showed that R3P can deliver the amplified breast cancer 1 (AIB1) siRNAs to induce RT112 cell apoptosis. Conclusion: These results indicated that R3P was a promising carrier tool to deliver siRNAs into FGFR3 positive cancer cells and to exert anti-tumor effect.

Use of green fluorescent protein labeled non-tuberculous mycobacteria to evaluate the activity quaternary ammonium compound disinfectants and antibiotics

Abstract Although infections with NonTuberculous Mycobacteria have become less common in AIDS patients, they are important opportunistic infections after surgical procedures, likely because they are ubiquitous and not efficiently killed by many commonly used disinfectants. In Venezuela there have recently been many non-tuberculous mycobacteria soft tissue infections after minor surgical procedures, some apparently related to the use of a commercial disinfectant based on a Quaternary Ammonium Compound. We studied the activity of this and other quaternary ammonium compounds on different non-tuberculous mycobacteria by transforming the mycobacteria with a dnaA-gfp fusion and then monitoring fluorescence to gauge the capacity of different quaternary ammonium compounds to inhibit bacterial growth. The minimum inhibitory concentration varied for the different quaternary ammonium compounds, but M. chelonae and M. abscessus were consistently more resistant than M. smegmatis, and M. terrae more resistant than M. bovis BCG.

A protein expression system for tandem affinity purification in Xanthomonas citri subsp. citri

Abstract Citrus canker, caused by the Gram-negative bacterium Xanthomonas citri subsp. citri (Xac), is one of the most devastating diseases to affect citrus crops. There is no treatment for citrus canker; effective control against the spread of Xac is usually achieved by the elimination of affected plants along with that of asymptomatic neighbors. An in depth understanding of the pathogen is the keystone for understanding of the disease; to this effect we are committed to the development of strategies to ease the study of Xac. Genome sequencing and annotation of Xac revealed that ∼37% of the genome is composed of hypothetical ORFs. To start a systematic characterization of novel factors encoded by Xac, we constructed integrative-vectors for protein expression specific to this bacterium. The vectors allow for the production of TAP-tagged proteins in Xac under the regulation of the xylose promoter. In this study, we show that a TAP-expression vector, integrated into the amy locus of Xac, does not compromise its virulence. Furthermore, our results also demonstrate that the polypeptide TAP can be overproduced in Xac and purified from the soluble phase of cell extracts. Our results substantiate the use of our vectors for protein expression in Xac thus contributing a novel tool for the characterization of proteins and protein complexes generated by this bacterium in vivo.

Esophageal mucosal resection versus esophagectomy: a comparative study of surgical results in patients with advanced megaesophagus / Mucosectomia esofágica versus esofagectomia: estudo comparativo dos resultados cirúrgicos imediatos e tardios em pacientes operados por megaesôfago avançado

BACKGROUND: The surgical treatment of advanced megaesophagus has no consensus, being esophagectomy the more commonly used method. Since it has high morbimortality - inconvenient for benign disease -, in recent years an alternative has been introduced: the esophageal mucosal resection. AIM: To compare early and late results of the two techniques evaluating the operative time, length of ICU stay; postoperative hospitalization; total hospitalization; intra- and postoperative complication rates; mortality; and long-term results. METHODS: Were evaluated retrospectively 40 charts, 23 esophagectomies and 17 mucosectomies. In assessing postoperative results, interviews were conducted by using a specific questionnaire. RESULTS: Comparing the means of esophagectomy and mucosal resection, respectively, the data were: 1) surgical time - 310.2 min and 279.7 min (p> 0.05); 2) length of stay in ICU - 5 days and 2.53 days (p <0.05); 3) total time of hospitalization - 24.25 days and 20.76 days (p> 0.05); 4) length of hospital stay after surgery - 19.05 days and 14.94 days (p> 0.05); 5) presence of intraoperative complications - 65% and 18% (p <0.05); 6) the presence of postoperative complications - 65% and 35% (p> 0.05). In the assessment of late postoperative score (range 0-10) esophagectomy (n = 5) obtained 8.8 points and 8.8 points also got mucosal resection (n = 5). CONCLUSIONS: Esophageal mucosal resection proved to be good alternative for surgical treatment of megaesophagus. It was advantageous in the immediate postoperative period by presenting a lower average time in operation, the total hospitalization, ICU staying and complications rate. In the late postoperative period, the result was excellent and good in both operations. .

RACIONAL: O tratamento cirúrgico do megaesôfago avançado não é consensual sendo mais comumente usada a esofagectomia. Por tratar-se de técnica que apresenta maior morbimortalidade e empregada em doença benigna, foi introduzida nos últimos anos, como alternativa, a mucosectomia esofágica. OBJETIVO: Comparar os resultados imediatos e tardios das duas técnicas avaliando-se os tempos operatório, de internação em UTI, de internação do pós-operatório, de internação total; taxas de complicações intra-operatórias e pós-operatórias; taxa de mortalidade; e resultados a longo prazo. MÉTODOS: Foram avaliados 40 prontuários, retrospectivamente, sendo 23 esofagectomias e 17 mucosectomias. Na avaliação dos resultados pós-operatórios, foram realizadas entrevistas, mediante uso de questionário específico. RESULTADOS: Comparando-se as médias da esofagectomia e mucosectomia, respectivamente, os dados foram: 1) tempo cirúrgico - 310,2 min e 279,7 min (p>0,05); 2) tempo de internação em UTI - 5 dias e 2,53 dias (p<0,05); 3) tempo de internação total - 24,25 dias e 20,76 dias (p>0,05); 4) tempo de internação após a operação - 19,05 dias e 14,94 dias (p>0,05); 5) presença de complicações intra-operatórias - 65% e 18% (p<0,05); 6) presença de complicações pós-operatórias imediatas - 65% e 35% (p>0,05). Na avaliação do escore pós-operatório tardio (escala 0-10) a esofagectomia (n=5) obteve 8,8 pontos e também 8,8 pontos obteve a mucosectomia (n=5). CONCLUSÕES: A mucosectomia esofágica mostrou-se boa alternativa no tratamento cirúrgico do megaesôfago avançado. Foi vantajosa no pós-operatório imediato por apresentar menor média de tempo na operação, na internação total, na UTI e no índice de complicações. No pós-operatório tardio, o resultado foi excelente e bom nas duas operações. .

La Escuela de Salud Pública de México: innovación educativa y tecnológica en el nuevo milenio / School of Public Health of Mexico: Educational and technological innovation in the new millennium

Este artículo fue concebido para analizar la función de la Escuela de Salud Pública de México (ESPM) desde el año 2000 hasta el presente. Uno de sus puntos centrales es el análisis del proceso de reorientación de la labor educativa de la escuela con la finalidad de responder a los retos en materia de salud y educación surgidos a finales del siglo XX. Para exponer cómo ha evolucionado dicho proceso, retomamos tres ejes rectores que caracterizan la labor de la escuela en la actualidad: el cambio de modelo pedagógico, la incorporación de las tecnologías de la información y las comunicaciones, y la profesionalización de la docencia. Con la exposición de este tema, y a través del contraste entre el pasado y el presente, buscamos completar la historia de trabajo ininterrumpido de la Escuela durante sus 92 años de existencia, que ha trascendido los confines del país.

This article was conceived to analyze the work of the School of Public Health of Mexico (ESPM for is acronym in Spanish) from the year 2000 to the present day. One of the highlights that we will examine is the reorientation of the educational work of the school in order to meet the challenges in health and education that emerged during the end of the twentieth century. In order to explain the evolution of this process, we will describe the three main guiding principles that characterize the present work of the school: the pedagogical model's change, the incorporation of the information and communication technologies, and the professionalization in teaching. The purpose of this work is to define those guiding principles, and to expose, through the contrast between past and present, the complete history of uninterrupted work of the School of Public Health of Mexico during its ninety-two years of existence, that has gone beyond the boundaries of the country.

Nurses’ attitudes regarding the importance of families in pediatric nursing care / Actitudes de enfermeras sobre la importancia de las familias en los cuidados de enfermería en pediatría / Atitudes de enfermeiros em face da importância das famílias nos cuidados de enfermagem em pediatria

Affective, cognitive and behavioral components affect nurses´ attitudes to include families in the care processes. The purpose of this study was to investigate the attitudes of nurses about the importance of including families in nursing care. Data collection was performed in pediatric and maternal-child unit of a Brazilian university hospital. A sample of 50 nurses completed the Portuguese version of the instrument Families’Importance in Nursing Care-Nurses’ Attitudes (FINC-NA). The results indicated that nurses have supportive attitudes regarding families participation in nursing care. Attitudes of lower support for involving families in nursing care were found among nurses with older age, more time in the profession and who had no previous contact with contents related to Family Nursing. The application of the instrument in other contexts of assistance may help to illuminate important aspects of the challenges to implementing a family-centered approach in clinical practice.



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El propósito de este estudio fue identificar las actitudes de los enfermeros sobre la importancia de incluir a las familias en el cuidado de enfermería. La recolección de datos se llevó a cabo en las unidades de pediatría y materno-infantil de un hospital universitario brasileño. Una muestra de 50 enfermeras completó la versión en portugués del el instrumento Families’ Importance in Nursing Care-Nurses’ Attitudes (FINC-NA). Los resultados indicaron las puntuaciones más altas en dimensiones indicativas de actitudes de apoyo a la participación de las familias en el cuidado. Enfermeras con más tiempo en la profesión y que no tenían conocimiento previo de enfermería de familia tuvieron puntuaciones que indican actitudes de menor apoyo para involucrar a las familias en el cuidado de enfermería. La aplicación de este instrumento en otro tipo de asistencia contextos puede ayudar a iluminar aspectos importantes de los desafíos para la implementación de un enfoque centrado en la familia, en la práctica clínica.
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Objetivo Identificar as atitudes dos enfermeiros sobre a importância de incluir as famílias nos cuidados de enfermagem. Método Estudo de abordagem quantitativa descritiva, cuja coleta de dados foi realizada em unidades de pediatria e materno-infantil de um hospital universitário brasileiro. Uma amostra de 50 enfermeiros completou a versão em português da escala Families Importance in Nursing Care-Nurses Attitudes (FINC-NA). Resultados Indicaram escores mais elevados em dimensões indicativas de atitudes de apoio sobre a participação das famílias no cuidado de enfermagem. Enfermeiros com mais tempo na profissão e que não tiveram conhecimento prévio de enfermagem da família apresentaram escores indicativos de atitudes de menor apoio para envolver as famílias no cuidado de enfermagem. Conclusão A aplicação desse instrumento em outros contextos de assistência poderá contribuir para iluminar importantes aspectos relacionados aos desafios para a implementação de uma abordagem centrada na família na prática clínica e subsidiar o desenvolvimento de pesquisas mais amplas.
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Determinants of emergency contraception non-use among women in unplanned or ambivalent pregnancies / Determinantes del no uso de la anticoncepción de emergencia entre mujeres con embarazo no planeado u ambivalente / Determinantes do não uso da anticoncepção de emergência entre mulheres com gravidez não planejada ou ambivalente

Objective To analyze the determinants of emergency contraception non-use among women in unplanned and ambivalent pregnancies. Method Cross-sectional study with a probabilistic sample of 366 pregnant women from 12 primary health care units in the city of São Paulo, Brazil. A multinomial logistic regression was performed, comparing three groups: women who used emergency contraception to prevent ongoing pregnancies (reference); women who made no use of emergency contraception, but used other contraceptive methods; and women who made no use of any contraceptive methods at all. Results Cohabitation with a partner was the common determinant of emergency contraception non-use. No pregnancy risk awareness, ambivalent pregnancies and no previous use of emergency contraception also contributed to emergency contraception non-use. Conclusion Apart from what is pointed out in the literature, knowledge of emergency contraception and the fertile period were not associated to its use. .

Objetivo Analizar los determinantes del no uso de la anticoncepción de emergencia entre las mujeres con embarazo no planeado o ambivalente. Método Estudio transversal en una muestra probabilística de 366 mujeres embarazadas de 12 Unidades Básicas de Salud de São Paulo. Mediante regresión logística multinomial, se comparó tres grupos de mujeres: aquellas que usaron la anticoncepción de emergencia para prevenir el embarazo en curso (referencia), aquellas que usaron algún método anticonceptivo, pero no la anticoncepción de emergência; y aquellas que no usaron ningún método. Resultados Los hallazgos mostraron que vivir com la pareja fue el determinante común del no uso de la anticoncepción de emergencia. No tener conciencia del riesgo de embarazo, estar en un embarazo ambivalente y nunca tener utilizado la anticoncepción de emergencia también fueron associados con su no uso para prevenir el embarazo en curso. Conclusión Contrariamente a lo que reporta la literatura, el conocimiento de la anticoncepción de emergencia y el período fértil no mostró asociación con el no uso. .

Objetivo Analisar os determinantes do não uso da anticoncepção de emergência entre mulheres com gravidez não planejada ou ambivalente. Método Estudo transversal com amostra probabilística de 366 gestantes de 12 Unidades Básicas de Saúde da cidade de São Paulo. Por meio de regressão logística multinomial, compararam-se três grupos de mulheres: as que usaram anticoncepção de emergência para prevenir a gravidez em curso (referência); as que usaram algum método contraceptivo, mas não anticoncepção de emergência; e as que não usaram nenhum método. Resultados Os achados mostraram que morar com o parceiro foi o determinante comum do não uso da anticoncepção de emergência. Não ter consciência do risco de engravidar, estar em uma gravidez ambivalente e nunca ter usado anticoncepção de emergência também foram associados ao seu não uso para prevenir a gravidez em curso. Conclusão Diferentemente do que relata a literatura, o conhecimento sobre anticoncepção de emergência e sobre o período fértil não mostrou qualquer associação ao não uso. .

Impairing methylations at ribosome RNA, a point mutation-dependent strategy for aminoglycoside resistance: The rsmG case / Mutaciones en genes modificadores de ARN ribosómico y la resistencia a aminoglucósidos: el caso del gen rsmG

Introduction: Aminoglycosides like streptomycin are well-known for binding at specific regions of ribosome RNA and then acting as translation inhibitors. Nowadays, several pathogens have been detected to acquire an undefined strategy involving mutation at non structural ribosome genes like those acting as RNA methylases. rsmG is one of those genes which encodes an AdoMet-dependent methyltransferase responsible for the synthesis of m 7 G527 in the 530 loop of bacterial 16S rRNA. This loop is universally conserved, plays a key role in ribosomal accuracy, and is a target for streptomycin binding. Loss of the m 7 G527 modification confers low-level streptomycin resistance and may affect ribosomal functioning. Objectives: After taking into account genetic information indicating that some clinical isolates of human pathogens show streptomycin resistance associated with mutations at rsmG , we decided to explore new hot spots for mutation capable of impairing the RsmG in vivo function and of promoting low-level streptomycin resistance. Materials and methods: To gain insights into the molecular and genetic mechanism of acquiring this aminoglycoside resistance phenotype and the emergence of high-level streptomycin resistance in rsmG mutants, we mutated Escherichia coli rsmG and also performed a genotyping study on rpsL from several isolates showing the ability to grow at higher streptomycin concentrations than parental strains. Results: We found that the mutations at rpsL were preferentially present in these mutants, and we observed a clear synergy between rsmG and rpsL genes to induce streptomycin resistance. Conclusion: We contribute to understand a common mechanism that is probably transferable to other ribosome RNA methylase genes responsible for modifications at central sites for ribosome function.

Introducción. Los aminoglucósidos son moléculas antibióticas capaces de inhibir la síntesis de proteínas bacterianas tras su unión al ribosoma procariota. La resistencia a aminoglucósidos está clásicamente asociada a mutaciones en genes estructurales del ribosoma bacteriano; sin embargo, varios estudios recientes han demostrado, de forma recurrente, la presencia de un nuevo mecanismo dependiente de mutación que no involucra genes estructurales. El gen rsmG es uno de ellos y se caracteriza por codificar una metiltransferasa que sintetiza el nucleósido m 7 G527 localizado en el loop 530 del ribosoma bacteriano, este último caracterizado como sitio preferencial al cual se une la estreptomicina. Objetivo. Partiendo de las recientes asociaciones clínicas entre las mutaciones en el gen rsmG y la resistencia a estreptomicina, este estudio se propuso la caracterización de nuevos puntos calientes de mutación en este gen que puedan causar resistencia a estreptomicina usando Escherichia coli como modelo de estudio. Materiales y métodos. Se indagó sobre el mecanismo genético y molecular por el cual se adquiere la resistencia a estreptomicina y su transición a la resistencia a altas dosis mediante mutagénesis dirigida del gen rsmG y genotipificación del gen rpsL . Resultados. Se encontró que la mutación N39A en rsmG inactiva la proteína y se reportó un nuevo conjunto de mutaciones en rpsL que confieren resistencia a altas dosis de estreptomicina. Conclusiones. Aunque los mecanismos genéticos subyacentes permanecen sin esclarecer, se concluyó que dichos patrones secuenciales de mutación podrían tener lugar en otros genes modificadores del ARN bacteriano debido a la conservación evolutiva y al papel crítico que juegan tales modificaciones en la síntesis de proteínas.

Production and immunogenicity of chimeric virus-like particles containing the spike glycoprotein of infectious bronchitis virus

Infectious bronchitis virus (IBV) poses a severe threat to the poultry industry and causes heavy economic losses worldwide. Vaccination is the most effective method of preventing infection and controlling the spread of IBV, but currently available inactivated and attenuated virus vaccines have some disadvantages. We developed a chimeric virus-like particle (VLP)-based candidate vaccine for IBV protection. The chimeric VLP was composed of matrix 1 protein from avian influenza H5N1 virus and a fusion protein neuraminidase (NA)/spike 1 (S1) that was generated by fusing IBV S1 protein to the cytoplasmic and transmembrane domains of NA protein of avian influenza H5N1 virus. The chimeric VLPs elicited significantly higher S1-specific antibody responses in intramuscularly immunized mice and chickens than inactivated IBV viruses. Furthermore, the chimeric VLPs induced significantly higher neutralization antibody levels than inactivated H120 virus in SPF chickens. Finally, the chimeric VLPs induced significantly higher IL-4 production in mice. These results demonstrate that chimeric VLPs have the potential for use in vaccines against IBV infection.

Generation and Immunity Testing of a Recombinant Adenovirus Expressing NcSRS2-NcGRA7 Fusion Protein of Bovine Neospora caninum

Neospora caninum is the etiologic agent of bovine neosporosis, which affects the reproductive performance of cattle worldwide. The transmembrane protein, NcSRS2, and dense-granule protein, NcGRA7, were identified as protective antigens based on their ability to induce significant protective immune responses in murine neosporosis models. In the current study, NcSRS2 and NcGRA7 genes were spliced by overlap-extension PCR in a recombinant adenovirus termed Ad5-NcSRS2-NcGRA 7, expressing the NcSRS2-NcGRA7 gene, and the efficacy was evaluated in mice. The results showed that the titer of the recombinant adenovirus was 10(9)TCID50/ml. Three weeks post-boost immunization (w.p.b.i.), the IgG antibody titer in sera was as high as 1:4,096. IFN-gamma and IL-4 levels were significantly different from the control group (P<0.01). This research established a solid foundation for the development of a recombinant adenovirus vaccine against bovine N. caninum.

Construction of three different recombinant scorpion fusion proteins with bifunctional activity.

This is the first report of three different fusion proteins with an antitumor-analgesic peptide obtained from Chinese scorpion Buthus martensii Karsch (BmKAGAP). The fusion proteins were constructed in the form of chimeric toxins, aiming to obtain bifunctional analgesic and antitumor activity. The fusion proteins consisted of luteinizing hormone-releasing hormone (LHRH), three different types of flexible linkers (L1, Ser-Ser-His-His-His-His-His-His-Ser-Ser-Gly-Leu-Val-Pro-Arg-Gly-Ser-His-Met; L2, Gly-Gly-Gly-Ser-Gly-Gly-Gly-Ser; L3, Ser-Gly-Gly-Ser-Gly-Gly-Ser-Gly-Gly-Gly-Ser-Ser-Gly-Gly-Ser-Gly-Gly-Gly-Gly-Ser-Gly-Gly-Gly-Gly-Ser), and BmKAGAP. The genes coding three fusion proteins were cloned and expressed in E. coli in soluble form. Following two successive column chromatographic separations, purified fusion proteins were obtained. These fusion proteins exhibited analgesic activity in mice and were cytotoxic to a hepatocellular carcinoma cell line Hep3B.

APO-1/Fas gene: Structural and functional characteristics in systemic lupus erythematosus and other autoimmune diseases.

Systemic lupus erythematosus (SLE) is an autoimmune disorder affecting multiple organ systems. It is characterized by the presence of autoantibodies reactive against various self-antigens. Susceptibility to SLE is found to be associated with many major histocompatibility complex (MHC) and non-MHC genes, one of which is APO-1/Fas gene, which is present on chromosome 10 in humans. The APO-1/Fas promoter contains consensus sequences for binding of several transcription factors that affect the intensity of Fas expression in cells. The mutations in the APO-1/Fas promoter are associated with risk and severity in various autoimmune diseases and other malignancies. The APO-1/Fas receptor is expressed by many cell types. Two forms of APO-1/Fas protein that are involved in regulation of apoptosis have been identified. Fas receptor-mediated apoptosis plays a physiological and pathological role in killing of infected cell targets. In this review, we have focused on APO-1/Fas gene structure, promoter variants and its association with SLE and other autoimmune diseases. Functional aspects of Fas receptor in apoptosis are also discussed.

Binding characteristics of sperm with recombinant human zona pellucida glycoprotein-3 coated beads.

Background & objectives: An inability or decreased ability of spermatozoa to bind to the zona pellucida (ZP), an extracellular glycoproteinaceous matrix surrounding egg, is one of the plausible causes of idiopathic infertility. It will be clinically useful to distinguish this condition from other causes of infertility. An assay system, investigating binding of human sperm with ZP glycoprotein may prove useful in this regard. We attempted to develop a simple assay system to analyse the binding of capacitated human spermatozoa to human zona pellucida glycoprotein-3 (ZP3) using baculovirus-expressed recombinant human ZP3 coated beads. Methods: Recombinant baculovirus-expressed ZP3 was purified, labelled with biotin and coated on streptavidin sepharose beads. An in vitro assay system was optimized to study binding of capacitated human sperm to ZP3 coated beads. Results: A higher percentage of baculovirus-expressed recombinant human ZP3 coated beads showed significant (P<0.05) binding of capacitated human sperm as compared to beads coated with fetuin. An inhibition in the binding of sperm to ZP3 coated beads was observed in presence of cold recombinant human ZP3. Further, prior incubation of ZP3 coated beads with monoclonal antibodies (MAbs) against ZP3 but not against ZP2 resulted in the decrease in number of sperm bound to bead. Interpretation & conclusion: An in vitro assay system to study the binding of human sperm to ZP3- primary sperm receptor was established, which may be useful to determine the functional competence of spermatozoa.

A new method for purification of functional recombinant GST-cyclophilin A protein from E. coli.

The expression of glutathione-S-transferase (GST) fusion protein is extensively utilized in the study of protein-protein interactions. In the commonly used purification method, the overexpressed GST fusion protein is bound to the glutathione (GSH)-coupled resins via affinity chromatography, and then eluted by an excessive quantity of reduced GSH. However, this technique has certain limitations, such as low product purity, retention of GSH in the sample, as well as relatively high cost. To overcome these limitations, in this study, elution buffer containing 2% formic acid was utilized rather than GSH to elute the GST-fusion protein, and thereafter the acidic samples were neutralized using collecting buffer. By using this method, highly purified GST-cyclophilin A (CypA) fusion protein was obtained, without affecting the structural and functional characteristics such as PPIase and chaperone activities. Moreover, the procedure is also cost-effective, due to the low cost of formic acid as compared with GSH.

Cloning of an ovule specific promoter from Arabidopsis thaliana and expression of beta-glucuronidase.

Tissue specific expression of transgenes in plant species has several advantages over constitutive expression. Identification of ovule specific promoters would be useful in genetic engineering of plants with a variety of desirable traits such as genetically engineered parthenocarpy, female sterile plants or seedless fruits. Relative inaccessibility and difficulty in harvesting adequate amounts of tissue at known developmental stages has impeded the progress in cloning of promoters involved in ovule development. In the present study an ovule specific promoter was cloned from Arabidopsis AGL11 gene and used to express GUS (beta-glucuronidase) gene in transgenic Arabidopsis. Histochemical staining of GUS appeared in the center of young ovary (ovules), but no detectable GUS activity was observed in vegetative plant tissues, sepals, petals and androecium. AGL11 gene promoter can be useful to modify the developmental path of plants by expressing either plant hormones or lethal genes for agronomic purpose.

Preparation and identification of scFv and bsFv against transferrin receptor / 华中科技大学学报（医学）（英德文版）

To obtain single chain variable fragment (scFv) and bivalent single chain variable fragment (bsFv) against transferrin receptor, up-stream and down-stream primers were designed according to the complementary sequences of FR1 region of variable heavy (VH) and FR4 of variable light (VL), respectively, which contained inter-linker G4S and the restriction endonuclease SfiI, AscI and NotI. Two pieces of scFv fragments were first amplified through PCR and then inserted into plasmid pAB1, which could express scFv protein once induced by IPTG in the host bacteria. To express scFv and bsFv, E. coli TG1 was cultured in LB broth and was induced by IPTG. The restriction enzyme digestion map and DNA sequencing demonstrated that scFv and bsFv genes were successfully inserted into the expression plasmid. SDS-PAGE and Western blotting revealed the protein band at 35kD and 60kD, which were consistent with the molecular weight of scFv and bsFv respectively. Flow cytometry showed that scFv and bsFv harbored the specific binding activity with TfR expressed in various tumor cells, and the avidity of bsFv was higher than that of the parent scFv.