Obtención de la proteína verde fluorescente recombinante y su anticuerpo policlonal Igy

La Proteína Verde Fluorescente (Green Fluorescent Protein, GFP) es ampliamente utilizada en ensayos in vivo e in vitro. Se han generado múltiples variantes de esta proteína para diversificar sus características, como la GFP-enhancer (EGFP) que emite una señal de fluorescencia 35 veces mayor en comparación con la proteína silvestre, siendo implementada como proteína fusión en estudios de localización y estabilidad estructural, entre otros. La detección de esta proteína y sus variantes puede ser directa o indirecta, mediante el uso de anticuerpos anti-GFP. Aunque el uso de GFP es generalizado y de evidente utilidad en investigación y en docencia, los insumos para su estudio exhiben un alto costo dado que deben ser importados, constituyendo un recurso limitado en Colombia. El presente trabajo reporta la clonación y expresión de la proteína recombinante 6xHisEGFP, cuya purificación se completó a partir de la fracción soluble e insoluble del sistema heterólogo Escherichia coli mediante cromatografía de afinidad a metales inmovilizados y electroforesis preparativa, respectivamente. La proteína purificada se implementó como antígeno para la producción de anticuerpos policlonales aviares (IgY) contra la EGFP, los cuales se obtuvieron desde los huevos colectados y el suero de las sangrías de las gallinas inmunizadas. En este sentido, la estrategia metodológica planteada constituye un avance en el desarrollo de un sistema biotecnológico para la producción nacional de herramientas moleculares como los anticuerpos policlonales aviares a bajo costo.

Green Fluorescent Protein (GFP) is widely used in in vivo and in vitro assays. Multiple variants of this protein have been generated to diversify its characteristics, such as the enhancer GFP (EGFP) that emits a 35-fold higher fluorescence signal compared to the wild-type protein, being implemented as a fusion reporter in localization and structural stability studies, among others. Detection of this protein can be direct or indirect, fusing anti-GFP antibodies. Although the use of GFP is generalized and of evident utility in research and teaching, the molecular tools for its study exhibit a high cost since they must be imported, constituting a limited resource in Colombia. This work reports the cloning and expression of the recombinant protein 6xHisEGFP, which purification was completed from the soluble and insoluble fraction of the heterologous Escherichia coli system by immobilized metal affinity chromatography and preparative SDS-PAGE, respectively. The purified protein was implemented as an antigen to produce avian polyclonal antibodies (IgY) against EGFP, which were obtained from collected eggs and blood serum from immunized hens. In this sense, the proposed methodological strategy constitutes an advance in the development of a biotechnological system for the national production of molecular tools such as avian polyclonal antibodies at low-cost.

Seleção de antígenos de Leishmania infantum por imunoproteômica para emprego no diagnóstico da leishmaniose visceral humana / Selection of Leishmania infantum antigens by immunoproteomics for use in the diagnosis of human visceral leishmaniasis

O controle da leishmaniose visceral (LV) requer um diagnóstico e tratamento adequados, uma vez que o diagnóstico preciso é fundamental para um regime medicamentoso eficaz para os pacientes. Nesse contexto, as ferramentas biotecnológicas devem ser aprimoradas para o manejo clínico e a avaliação epidemiológica da doença. No entanto, existem limitações relacionadas com a sensibilidade e/ou especificidade dos antígenos usados atualmente, mostrando a necessidade de identificação de novas moléculas para serem testadas em um diagnóstico sorológico mais sensível e específico. Neste sentido, no presente estudo, uma abordagem imunoproteômica foi usada para identificar proteínas antigênicas das formas promastigotas e amastigotas da espécie Leishmania infantum, causadora de LV em nosso país, por meio de seu reconhecimento por anticorpos em soros de pacientes com a doença. Amostras de indivíduos saudáveis residentes em região endêmica da doença e de pacientes com Doença de Chagas foram utilizadas com a função de se obter proteínas mais específicas ao parasito Leishmania para serem avaliadas no diagnóstico da LV. Como resultados obtidos, um total de 29 e 21 proteínas foram identificadas nos extratos de formas promastigotas e amastigotas dos parasitos, respectivamente. Para a validação da capacidade diagnóstica, duas proteínas, endonuclease III e GTP-binding protein, foram selecionadas, clonadas, expressas e purificadas para serem testadas em experimentos de ELISA. Os resultados dos testes mostraram valores de sensibilidade e especificidade superiores a 99,0% para a identificação da LV. Os antígenos ainda exibiram um diferencial ao apresentarem baixa reatividade sorológica em pacientes curados e tratados, sugerindo a possibilidade de que as mesmas possam ser aplicadas como marcadores prognósticos da doença. Em conclusão, o estudo imunoproteômico se mostrou eficaz na seleção de proteínas antigênicas de L. infantum e duas delas, endonuclease III e GTP-binding protein, foram bem avaliadas para o diagnóstico da LV frente a um painel sorológico, além de demonstrarem um potencial para monitoramento de pacientes com LV após o tratamento.

The control of visceral leishmaniasis (VL) requires an adequate diagnosis and treatment, since an accurate diagnosis is essential for an effective medication regimen for patients. In this context, biotechnological tools must be improved for the clinical management and epidemiological assessment of the disease. However, there are limitations related to the sensitivity and / or specificity of the antigens currently used, showing the necessity to identify new molecules to be tested in a more sensitive and specific serological diagnosis. In this sense, in the present study, an immunoproteomics approach was used to identify antigenic proteins of the Leishmania infantum promastigote and amastigote forms, which causes VL in our country, through its recognition by antibodies in sera of patients with the disease. Samples from healthy individuals living in an endemic region of the disease and from patients with Chagas disease were used to obtain more specific proteins for the Leishmania parasite, aiming their future application in the VL diagnosis. As results obtained, a total of 29 and 21 proteins were identified in the extracts of parasitic promastigotes and amastigotes, respectively. For validation of the diagnostic capacity, two proteins, endonuclease III and GTP-binding protein, were selected, cloned, expressed and purified to be tested in ELISA experiments. The test results showed sensitivity and specificity values greater than 99.0% for the identification of VL. The antigens also exhibited a differential when presenting low serological reactivity in cured and treated patients, suggesting the possibility that they can be applied as prognostic markers of the disease. In conclusion, the immunoproteomic study proved to be effective in the selection of L. infantum antigenic proteins and two of them, endonuclease III and GTP-binding protein, were well evaluated for the diagnosis of VL against a serological panel, in addition, demonstrating a potential for monitoring patients with VL after treatment.

Clonamiento, expresión y seroreactividad de la proteína recombinante de ensamblaje de lipopolisacáridos - D (LptD) de Bartonella bacilliformis / Cloning, expression and seroreactivity of the recombinant lipopolysaccharide assembly protein - D (LptD) from Bartonella bacilliformis

RESUMEN Objetivo. Evaluar in silico y a nivel serológico el potencial antigénico del dominio extracelular recombinante de la proteína de ensamblaje de lipopolisacáridos - D (LptD) de Bartonella bacilliformis (dexr_LptD). Materiales y métodos. Mediante el análisis in silico se realizó la selección de una proteína de B. bacilliformis con potencial antigénico e inmunogénico. El gen de la proteína seleccionada se clonó en Escherichia coli TOP10 y se expresó en Escherichia coli BL21 (DE3) pLysS. La proteína recombinante fue expresada usando isopropil-β-D-1-tiogalactopiranósido (IPTG) y se optimizaron las condiciones de inducción. Por último, se purificó con resina Ni-IDA (His60 Ni Superflow) y se realizó un ensayo de Western Blot. Resultados. In silico, la proteína seleccionada fue LptD por estar localizada en la membrana externa y ser antigénica e inmunogénica. Las condiciones optimizadas para la inducción del dexr_LptD fueron 0,5 mM IPTG, 16 h, medio TB (Terrific Broth), etanol al 3% (v/v), 28 ºC, OD600: 1-1,5 y 200 r.p.m. La purificación se realizó en condiciones denaturantes a pequeña escala y se obtuvo 2,6 µg/mL de dexr_LptD parcialmente purificada. El ensayo de Western Blot mostró una reacción positiva entre los sueros provenientes de pacientes con la enfermedad de Carrión y dexr_LptD, ello evidencia la antigenicidad del dexr_LptD. Conclusiones. El dexr_LptD muestra antigenicidad in silico y a nivel serológico, estos resultados son base para posteriores estudios sobre candidatos vacunales contra la enfermedad de Carrión.

ABSTRACT Objective. To evaluate in silico and at the serological level the antigenic potential of the recombinant extracellular domain of the lipopolysaccharide assembly protein - D (LptD) of Bartonella bacilliformis (dexr_LptD). Materials and Methods. Through in silico analysis, we selected a B. bacilliformis protein with antigenic and immunogenic potential. The selected protein gene was cloned into Escherichia coli TOP10 and expressed in Escherichia coli BL21 (DE3) pLysS. Recombinant protein was expressed using isopropyl-β-D-1-thiogalactopyranoside (IPTG) and induction conditions were optimized. Finally, it was purified with Ni-IDA resin (His60 Ni Superflow) and a Western Blot assay was conducted. Results. In silico, the selected protein was LptD because it is located in the outer membrane and is antigenic and immunogenic. Optimized conditions for dexr_LptD induction were 0.5 mM IPTG, 16 hours, TB (Terrific Broth) medium, 3% (v/v) ethanol, 28 ºC, OD600: 1-1.5 and 200 rpm. Purification was carried out under denaturating conditions on a small scale and we obtained 2.6 μg/mL of partially purified dexr_LptD. The Western Blot assay showed a positive reaction between the sera from patients with Carrión's Disease and dexr_LptD, which shows the antigenicity of dexr_LptD. Conclusions. The dexr_LptD shows antigenicity both in silico and at the serological level, these results are the basis for further studies on vaccine candidates against Carrion's Disease.

Self-assembling protein nanocarrier for selective delivery of cytotoxic polypeptides to CXCR4+ head and neck squamous cell carcinoma tumors

Loco-regional recurrences and distant metastases represent the main cause of head and neck squamous cell carcinoma (HNSCC) mortality. The overexpression of chemokine receptor 4 (CXCR4) in HNSCC primary tumors associates with higher risk of developing loco-regional recurrences and distant metastases, thus making CXCR4 an ideal entry pathway for targeted drug delivery. In this context, our group has generated the self-assembling protein nanocarrier T22-GFP-H6, displaying multiple T22 peptidic ligands that specifically target CXCR4. This study aimed to validate T22-GFP-H6 as a suitable nanocarrier to selectively deliver cytotoxic agents to CXCR4+ tumors in a HNSCC model. Here we demonstrate that T22-GFP-H6 selectively internalizes in CXCR4+ HNSCC cells, achieving a high accumulation in CXCR4+ tumors in vivo, while showing negligible nanocarrier distribution in non-tumor bearing organs. Moreover, this T22-empowered nanocarrier can incorporate bacterial toxin domains to generate therapeutic nanotoxins that induce cell death in CXCR4-overexpressing tumors in the absence of histological alterations in normal organs. Altogether, these results show the potential use of this T22-empowered nanocarrier platform to incorporate polypeptidic domains of choice to selectively eliminate CXCR4+ cells in HNSCC. Remarkably, to our knowledge, this is the first study testing targeted protein-only nanoparticles in this cancer type, which may represent a novel treatment approach for HNSCC patients.

Method and application of high efficient preparation of procalcitonin standby reference material based on protein recombination technology / 中华检验医学杂志

Objective:To construct a prokaryotic expression vector for human retinol binding protein 4 (hRBP4) that allows technicians to obtain hRBP4 purified protein with low cost, high efficiency, high concentration and high purity.Methods:The hRBP4 coding sequence provided by National Center for Biotechnology Information was optimized by E. coli codons, and a synthetic DNA fragment was cloned into the PET-28A (+) prokaryotic expression vector to construct a recombinant hRBP4 expression plasmid. The recombinant protein was transformed into E. coli BL21, and the induced expression conditions (temperature, rotate speed and isopropyl β-d-thiogalactoside concentration) were optimized. The recombinant protein was purified by His fusion tag. Results:The recombinant hRBP4 prokaryotic expression plasmid was successfully constructed, and the expression concentration and induction temperature of the recombinant protein were optimized. The results of sodium dodecyl sulfate polyacrylamide gel electrophoresis showed that a band with a relative molecular weight of 26 000 daltons was clearly visible in the purified product. The purified hRBP4 protein could be detected clinically, and there was a good linear relationship between the dilution ratio and the detection concentration.Conclusions:The recombinant hRBP4 protein has high purity, high concentration, and short production cycle. It has the potential to become a candidate for reference materials for laboratory quality evaluations.

Effects of time of recombinant luteinized hormone supplementation on pregnancy outcomes of women with advanced reproductive age during follicular-phase long protocol / 中华妇产科杂志

Objective:To investigate the effects of supplementation of recombinant luteinized hormone (rLH) and its timing on pregnancy outcomes of patients at 35 years or older with follicular-phase long protocol.Methods:Clinical data of women undergoing in vitro fertilization or intracytoplasmic sperm injection with follicular-phase long protocol was collected and retrospectively analyzed in the First Affiliated Hospital of Nanjing Medical University from January 2017 to December 2019. There were 558 patients at 35 years or older included in this study, and they were divided into three groups: group A was patients with only recombinant follicle stimulating hormone (rFSH) stimulation (127 cycles), group B was patients with rFSH plus rLH supplementation in the mid-follicular phase (141 cycles), and patients in group C received combined rFSH and rLH from the first day of ovarian stimulation (290 cycles). The basic characteristics of patients of each group were observed and the effects of ovarian simulation and pregnancy outcomes were compared among the three groups. Logistic regression model was performed to explore the association between different groups and pregnancy outcomes.Results:The basic characteristics such as age, duration of infertility, body mass index (BMI) and serum basic follicle stimulating hormone (FSH) were comparable among the three groups (all P>0.05). Anti-Müllerian hormone (AMH), antral follicles count (AFC) and basic luteinized hormone (LH) were significantly lower in group C compared to group A and group B (all P<0.05). There were statistically significant differences in initiation dosage, total dosage and duration of gonadotropin (Gn) among the three groups (all P<0.01), the initiation dosage, total dosage and duration of Gn were higher in group C than the other two groups. The number of oocytes retrieved and available embryos were significantly lower in group B and group C than group A (all P<0.001). In fresh embryo transfer cycles, significantly higher implantation rate (45.3%, 117/258) and clinical pregnancy rate (52.6%, 111/211) were found for group C when compared with group A and group B ( P=0.036, P=0.006). The live birth rate in fresh embryo transfer cycles was comparable among the three groups ( P=0.098). The implantation rate, clinical pregnancy rate and live birth rate in the subsequent frozen-thawed embryo transfer cycles did not differ significantly among the three groups (all P>0.05). There were no significantly differences in the cumulative pregnancy rate and the cumulative live birth rate among the three groups (all P>0.05). After adjusted for age, BMI, AMH, AFC, basic FSH and LH, total Gn dosage, endometrial thickness at transfer, number of oocytes retrieved, number of embryos transferred and stage of embryo transferred, in fresh embryo transfer cycles, the clinical pregnancy rate (adjusted OR=2.793, 95% CI: 1.512-5.162, P<0.001) and live birth rate (adjusted OR=2.324, 95% CI: 1.241-4.351, P=0.008) were higher in group C, while clinical pregnancy rate and live birth rate were similar between group B and group A in fresh embryo transfer cycles (all P>0.05); there was no significant difference in cumulative live birth rate among the three groups ( P>0.05). Conclusions:The supplementation of rLH from the first day of ovarian stimulation improves the pregnancy outcomes of patients at 35 years or older in fresh embryo transfer cycles during follicular-phase long protocol. However, the supplementation of rLH has no benefit on cumulative live birth rate.

Usos de la levadura Pichia pastoris en la producción de proteínas recombinantes / Uses of Pichia pastoris yeast in the production of recombinant proteins

La levadura metilotrófica Pichia pastoris (clasificada actualmente como Komagataella phaffii) es una de las más importantes para la producción de proteínas heterólogas. En el trabajo se presenta un análisis de las principales características que se ponen de manifiesto en la expresión de proteínas recombinantes expresadas en este microorganismo. Se describen las cepas disponibles para la transformación y producción de proteínas recombinantes expresadas en Pichia pastoris, los principales vectores comerciales para la expresión, los promotores más eficientes, los marcadores seleccionables, la señal de secreción, los métodos usados en las transformaciones genéticas y los patrones de glicosilación que se presentan. Se brindan recomendaciones generales acerca de los parámetros de bioprocesos como la composición del medio, el pH, la temperatura, la velocidad de aireación, la inducción y las estrategias de alimentación para alcanzar altos valores de productividad. Se presentan los resultados de las aplicaciones de Pichia pastoris en la producción de dos vacunas en Cuba, la vacuna contra la hepatitis B y la vacuna para el control de la garrapata(AU)

Pichia pastoris metylotrofic yeast (currently classified as Komagataella phaffii) is one of the most important yeast for the production of heterologous proteins. The work presents an analysis of the main characteristics that are marked in the production of recombinant proteins expressed in Pichia pastoris. It describes the strains available for the transformation and production of recombinant proteins expressed in P. pastoris, the main commercial vectors for expression, the most efficient promoters, selectable markers, the secretion signal, the methods used in genetic transformations and glycosylation patterns that occur. General recommendations are provided on bioprocess parameters such as media composition, pH, temperature, aeration velocity, induction, and feeding strategies to achieve high productivity values. The results of Pichia pastoris applications for the production of two vaccines in Cuba, the hepatitis B vaccine and the tick control vaccine are shown(AU)

Expression of recombinant PreS2-S protein from the hepatitis B virus surface antigen in Pichia pastoris

The aim of this work is the expression of the PreS2-S region of surface antigen of hepatitis B virus (HBV) in yeast Pichia pastoris. A cDNA fragment encoding the Pres2-S protein of HBV was cloned to yeast transfer vectors. Based on cloned new plasmids pPIC3.5-PreS2-S (8707 bp) and pPIC9-PreS2-S (8980 bp) the recombinant strains of P. pastoris producing the PreS2-S region of surface antigen of HBV were obtained. The PAGE electrophoresis and immunoblotting of obtained recombinant PreS2-S protein confirm the molecular weight (34 kDa) and high specificity to the HBV antibodies)AU)

El objetivo de este trabajo es la expresión de la región PreS2-S del antígeno de superficie del virus de la hepatitis B en la levadura Pichia pastoris. Se clonó un fragmento de ADNc que codifica la proteína PreS2-S del VHB en vectores de transferencia de levadura. A partir de los nuevos plásmidos clonados pPIC3.5-PreS2-S (8707 pb) y pPIC9-PreS2-S (8980 pb) se obtuvieron las cepas recombinantes de P. pastoris productoras de la región PreS2-S del antígeno de superficie del VHB. La electroforesis PAGE y la inmunotransferencia de la proteína PreS2-S recombinante obtenida confirman el peso molecular (34 kDa) y la alta especificidad a los anticuerpos contra el VHB(AU)

Comparison of protein precipitation methods for sample preparation prior to proteomic analysis of Chinese hamster ovary cell homogenates

BACKGROUND: Chinese hamster ovary (CHO) cells are the workhorse for obtaining recombinant proteins. Proteomic studies of these cells intend to understand cell biology and obtain more productive and robust cell lines for therapeutic protein production in the pharmaceutical industry. Because of the great importance of precipitation methods for the processing of samples in proteomics, the acetone, methanol-chloroform (M/C), and trichloroacetic acid (TCA)-acetone protocols were compared for CHO cells in terms of protein recovery, band pattern resolution, and presence on SDS-PAGE. RESULTS: Higher recovery and similar band profile with cellular homogenates were obtained using acetone precipitation with ultrasonic bath cycles (104.18 ± 2.67%) or NaOH addition (103.12 ± 5.74%), compared to the other two protocols tested. TCA-acetone precipitates were difficult to solubilize, which negatively influenced recovery percentage (77.91 ± 8.79%) and band presence. M/C with ultrasonic homogenization showed an intermediate recovery between the other two protocols (94.22 ± 4.86%) without affecting protein pattern on SDS-PAGE. These precipitation methods affected the recovery of low MW proteins (< 15 kDa). CONCLUSIONS: These results help in the processing of samples of CHO cells for their proteomic study by means of an easily accessible, fast protocol, with an almost complete recovery of cellular proteins and the capture of the original complexity of the cellular composition. Acetone protocol could be incorporated to sample-preparation workflows in a straightforward manner and can probably be applied to other mammalian cell lines as well.

Expressão e caracterização da glicoproteína D do herpesvírus equídeo 1 em Pichia pastoris / Expression and characterization of equid herpesvirus 1 glycoprotein D in Pichia pastoris

O herpesvírus equídeo 1 (EHV-1) apresenta distribuição mundial e causa graves prejuízos à equideocultura. É agente de surtos de doença respiratória, reprodutiva e neurológica, em equídeos jovens e adultos. A glicoproteína D (gD) do envelope viral é essencial para ligação e penetração em células permissivas e direcionamento do sistema imunológico do hospedeiro, induz respostas imunes humorais e celulares, sendo um antígeno apropriado para ser utilizado em vacinas e imunodiagnóstico. O objetivo deste trabalho foi expressar e caracterizar a gD do EHV-1 em Pichia pastoris para posterior utilização como antígeno em técnicas de imunodiagnóstico e formulação de vacinas recombinantes. Uma sequência de DNA que codifica uma forma truncada da gDEHV-1 foi clonada no vetor pPICZαA de expressão em P. pastoris. Obteve-se uma proteína de ~41 kDa, como esperado. A proteína apresentou glicosilação entre 4 kDa e 16 kDa, demonstrada por deglicosilação enzimática. A proteína recombinante foi caracterizada antigenicamente e imunogenicamente por Western blot, utilizando-se anticorpos policlonais equinos anti-EHV-1, e por ELISA indireto em modelo murino, demonstrando que a gD recombinante manteve epítopos similares aos da proteína nativa. Esses resultados sugerem que a gDEHV-1 é um antígeno promissor para uso como imunobiológico no controle do EHV-1.(AU)

Equine herpesvirus 1 (EHV-1) has a worldwide distribution and causes serious damage to horse breeding. It is an agent of respiratory, reproductive and neurological disease outbreaks in young and adult equids. Viral envelope glycoprotein D (gD) is essential for binding and penetration into permissive cells and targeting the host immune system, inducing humoral and cellular immune responses, and is an appropriate antigen for use in vaccines and immunodiagnostics. The objective of this work was to express in Pichia pastoris and to characterize EHV-1 gD for later use as an antigen in immunodiagnostic techniques and formulation of recombinant vaccines. A DNA sequence encoding a truncated form of gDEHV-1 has been cloned into the P. pastoris expression vector pPICZαA. A protein of ~41 kDa was obtained as expected. The protein presented glycosylation between 4 kDa and 16 kDa, demonstrated by enzymatic deglycosylation. The recombinant protein was antigenically and immunogenically characterized by Western blot using equine polyclonal anti-EHV-1 antibodies, and by indirect ELISA in a murine model, demonstrating that the recombinant gD maintained epitopes similar to those of the native protein. These results suggest that gDEHV-1 is a promising antigen for use as an immunobiological in the control of EHV-1.(AU)

Produção da proteína recombinante Interferon-ß1b na plataforma se síntese proteica livre de célula / Cell-free protein synthesis of recombinant Interferon-ß1b

Biofármacos e produtos imunobiológicos representam uma parcela significativa no mercado farmacêutico global. Cerca de 400 milhões de pessoas em todo o mundo dependem desses produtos e, muitas vezes, necessitarão delas para o resto de suas vidas. Até o momento, a tecnologia convencional para síntese dessas proteínas recombinantes é a expressão baseada em células. Porém, este sistema está frequentemente associado a problemas como a degradação da proteína-alvo devido à presença de nucleases e proteases, agregação com formação de corpos de inclusão e perda de molde de DNA. A plataforma de síntese proteica livre de células (do inglês Cell-Free Protein Synthesis ou CFPS) tem surgido como uma alternativa à expressão baseada em célula, permitindo a síntese de diversas proteínas, inclusive as de difícil expressão, na forma solúvel, em elevado rendimento e com capacidade de escalonamento. Este estudo buscou sintetizar a proteína interferon-ß1b humano recombinante (rhINF-ß1b) no sistema CFPS. Através de um trabalho de bioinformática, otimizou-se a sequência nucleotídica da proteína para expressão em lisado de E. coli e construiu-se um vetor de expressão linear, contendo promotor T7, RBS, região codificadora e um terminador T7. O sistema CFPS aceita molde de DNA no formato linear, que possui a vantagem de agilidade na preparação, sem a necessidade das etapas de clonagem, transformação, cultivo, extração e purificação do DNA. Também foi testado a expressão em DNA plasmidial, em que o gene do IFN foi clonado em vetor TOPO-TA Cloning. Para comparar os níveis de expressão foi utilizado esses mesmos vetores no sistema baseado em célula, com cepas de BL21(DE3) e Rosetta(DE3). Apesar da proteína de interesse não ter sido sintetizada com sucesso no sistema CFPS, foram dados alguns passos importantes para atingir este objetivo. No futuro, uma das prioridades é padronizar um sistema livre de células do laboratório capaz de fornecer um elevado rendimento para síntese de proteínas

Biopharmaceutical and immunobiological products represent a growing share of the global pharmaceutical market. Around 400 million people worldwide are dependent of such proteins and, often, they are going to need for the rest of their lives. So far, the most employed biopharmaceutical production technology is cell-based expression. However, this system is usually associated with problems such as degradation of proteins due to the presence of endogenous nucleases or proteases, aggregation with inclusion bodies formation and loss of DNA template. Cell-Free Protein Synthesis (CFPS) platform has emerged as an alternative to cell-based expression, allowing synthesis of many types of proteins, including difficult-to-express proteins, proteins in soluble form, in high yield and possibility to scale up or down the process. This work sought to synthesize recombinant human interferon-ß1b (rhINF-ß1b) in CFPS system. Through a bioinformatics study, a nucleotide sequence of the target protein was optimized for expression in E. coli lysate and a linear DNA template was designed, containing a T7 promoter, a RBS, a coding sequence and a T7 terminator. The CFPS system accepts linear template DNA, which has the advantage of agility in the preparation, without the need for the steps of cloning, transformation, cultivation, extraction and purification of DNA template. Expression in plasmid DNA was also tested, wherein the IFN gene was cloned into TOPO-TA Cloning vector. To compare expression levels, the same vectors were used in the cell-based system with BL21 (DE3) and Rosetta (DE3) strains. Although the protein of interest was not successfully synthesized in the CFPS system, some important steps were taken to achieve this goal. In the future, one of the priorities is to standardize the lysate preparation for a high throughput protein production

Evaluation of three recombinant proteins for the development of ELISA and immunochromatographic tests for visceral leishmaniasis serodiagnosis

BACKGROUND Visceral Leishmaniasis (VL) is an infectious disease that is a significant cause of death among infants aged under 1 year and the elderly in Brazil. Serodiagnosis is a mainstay of VL elimination programs; however, it has significant limitations due to low accuracy. OBJECTIVE This study aimed to evaluate three recombinant Leishmania infantum proteins (rFc, rC9, and rA2) selected from previous proteomics and genomics analyses to develop enzyme-linked immunosorbent assay (ELISA) and immunochromatographic tests (ICT) for the serodiagnosis of human VL (HVL) and canine VL (CVL). METHODS A total of 186 human (70 L. infantum-infected symptomatic, 20 other disease-infected, and 96 healthy) and 185 canine (82 L. infantum-infected symptomatic, 27 L. infantum-infected asymptomatic, and 76 healthy) sera samples were used for antibody detection. FINDINGS Of the three proteins, rA2 (91.5% sensitivity and 87% specificity) and rC9 (95.7% sensitivity and 87.5% specificity) displayed the best performance in ELISA-HVL and ELISA-CVL, respectively. ICT-rA2 also displayed the best performance for HVL diagnosis (92.3% sensitivity and 88.0% specificity) and had high concordance with immunofluorescence antibody tests (IFAT), ELISA-rK39, IT-LEISH®, and ELISAEXT. ICT-rFc, ICT-rC9, and ICT-rA2 had sensitivities of 88.6%, 86.5%, and 87.0%, respectively, with specificity values of 84.0%, 92.0%, and 100%, respectively for CVL diagnosis. MAIN CONCLUSIONS The three antigens selected by us are promising candidates for VL diagnosis regardless of the test format, although the antigen combinations and test parameters may warrant further optimisation.

L1 Recombinant Proteins of HPV Tested for Antibody Forming Using Sera of HPV Quadrivalent Vaccine

Virus-like particles (VLPs) derived from human papillomavirus (HPV) L1 capsid proteins were used for HPV quadrivalent recombinant vaccine. The HPV quadrivalent vaccine is administrated in a 3-dose regimen of initial injection followed by subsequent doses at 2 and 6 months to prevent cervical cancer, vulvar, and vaginal cancers. The type 6, 11, 16, or 18 of HPV infection is associated with precancerous lesions and genital warts in adolescents and young women. The HPV vaccine is composed of viral L1 capsid proteins are produced in eukaryotic expression systems and purified in the form of VLPs. Four different the L1 protein of 3 different subtypes of HPV: HPV11, HPV16, and HPV18 were expressed in Escherichia coli divided into 2 fragments as N- and C-terminal of each protein in order to examine the efficacy of HPV vaccine. Vaccinated sera failed to recognize N-terminal L1 HPV type 16 and type 18 by western blot while they detected N-terminal L1 protein of HPV type 11. Moreover, the recombinant C-terminal L1 proteins of type 16 was non-specifically recognized by the secondary antibody conjugated with horseradish peroxidase. This expression and purification system may provide simple method to obtain robust recombinant L1 protein of HPV subtypes to improve biochemical analysis of antigens with immunized sera.

Advances in chloroplast expression of recombinant proteins in higher plants / 生物工程学报

In recent years, gene engineering is developing rapidly and many recombinant proteins have been expressed. The use of plant bioreactor to express specific pharmaceutical proteins provides a new way for the prevention and treatment of some important diseases in human beings. Nowadays, chloroplast genetic transformation and expression system has become a research hotspot in plant bioreactor. Higher plant chloroplasts have unique advantages in the expression of recombinant proteins due to their special structures and inherited characteristics: such as high expression, site-specific integration, and the maternal inheritance characteristics of exogenous genes. The maternal inheritance of chloroplast is helpful for biological safety of transgene escaping by pollens. Many important pharmaceutical proteins have been successfully expressed in plant chloroplasts. As a chloroplast transformation model of higher plants, tobacco has made significant progress in the expression of pharmaceutical proteins, such as vaccine antigens, antibodies, and other important recombinant proteins. Chloroplast genetic transformation in higher plants also provides new techniques and methods for the study of chloroplast gene expression and regulation mechanisms. In order to provide a new idea for the development of chloroplast expression platform and the expression of important pharmaceutical proteins, this review outlined the progress of chloroplast genetic transformation system in higher plants, including the chloroplast transformation principle, vector construction, expression of recombinant proteins and important pharmaceutical proteins, and the effects of recombinant proteins expression on plant metabolism and traits.

The effects of recombinant human platelet derived growth factor-BB on biological behaviours of human retinal vascular endothelial cells / 中华实验眼科杂志

Objective This study was to investigate the role of recombinant human platelet derived growth factor-BB(rhPDGF-BB) in the proliferation and migration of human retinal vascular endothelial cells (hRVECs).Methods hRVECs were cultured in DMEM with 10％ fetal bovine serum.The rhPDGF-BB at the concentrations of 10,50 and 200 ng/ml were added into the medium of exponential phase-growth cells for 24 and 48 hours,respectively,and no rhPDGF-BB was added in the normal control group.The proliferation of the cells (absorbancy) was assayed by cell counting kit 8 (CCK8) method.Cell scratch test was employed to evaluate the relative migration area of cells (migrated acellular area/initial acellular area).The relative expression of rhPDGF-BB recepter (rhPDGF-BBR) mRNA in the cells was detected by reverse transcription PCR.The relative expression of VEGF mRNA and integrin mRNA in the cells was detected using real-time fluorescence quantitative PCR.Results hRVECs grew well and a expressing band according with rhPDGF-BBR prime was displayed.The absorbancy values of thecells were 1.01±0.05,1.09±0.04,1.10±0.02 and 1.13±0.05 in the normal control group and 10,50,200 ng/ml rhPDGF-BB groups at 24 hours after culture,and those in the 10,50 and 200 ng/ml rhPDGF-BB groups were significantly increased in comparison with the normal control group (t =2.504,3.430,3.483,all at P＜0.05).The relative migrated areas of the cells in the normal control group and 10,50,200 ng/ml rhPDGF-BB groups were 0.42±0.10,0.38±0.09,0.55±0.06 and 0.61±0.05 at 24 hours after culture,and those at 48 hours were 0.75±0.06,0.81 ±0.02,0.87±0.02 and 0.98±0.02,showing significant differences among the groups (Fgroup =16.283,P =0.000;Ftime =209.129,P=0.000),and the relative migrated areas was depended upon the rhPDGF-BB dose and time.The relative expressions of integrin mRNA were 1.06 ± 0.02,1.30 ±0.10,1.20 ± 0.16 and 1.27 ± 0.08,and those of VEGF mRNA were 0.97±0.05,1.06±0.16,1.58 ±0.18 and 1.66 ±0.21 in the normal control group and 10,50 ng/ml,200 ng/ml rhPDGF-BB groups,respectively,and increased expressions of integrin mRNA and VEGF mRNA were found in the 50 and 200 ng/ml rhPDGF-BB groups compared with the normal control group (integrin mRNA:t =3.900,4.014,both at P ＜ 0.05;VEGF mRNA:t =6.940,7.210,both at P ＜ 0.05).Conclusions rhPDGF-BB/rhPDGF-BBR signal promotes the proliferation and migration of hRVECs probably by up-regulating the expressions of integrin and VEGF.

Indicaciones del factor VII recombinante activado en hemorragia obstétrica grave / Use of recombinant activated Factor VII in severe obstetric hemorrhage

Resumen OBJETIVO: Describir la situación final de salud de las pacientes con hemorragia obstétrica grave (≥ 1000 mL) en quienes se indicó factor VII recombinante activado como parte del tratamiento e identificar las complicaciones atribuibles a este medicamento. MATERIALES Y MÉTODOS: Estudio retrospectivo, transversal y descriptivo efectuado en pacientes con hemorragia obstétrica grave atendidas en el Hospital Civil de Guadalajara Dr. Juan I Menchaca entre 2001 y 2017 y tratadas con factor VII recombinante activado. Se identificaron los antecedentes de importancia y se calculó la dosis promedio y cantidad de dosis de factor VII recombinante activado; se valoró la respuesta hemostática y se determinó si la diferencia en cantidad de sangrado, administración de hemoderivados y parámetros hematológicos antes y después de utilizar factor VII recombinante activado fue significativa. RESULTADOS: Se identificaron 10 pacientes en quienes se aplicó factor VII recombinante activado. La causa de hemorragia obstétrica grave fue atonía uterina en seis casos. La dosis promedio de factor VII recombinante activado fue de 91 mcg/kg. En 8 pacientes se administró una dosis y 2 dosis en 2 pacientes. En todas las pacientes se logró la hemostasia; el sangrado disminuyó significativamente posterior a la administración del factor VII recombinante activado (5075 vs 928 mL; p = 0.000) lo mismo que la cantidad de concentrados eritrocitarios trasfundidos (7 vs 3; p = 0.006). Una paciente no requirió histerectomía, otra tuvo tromboembolia pulmonar, que se trató sin problemas y ninguna paciente falleció. CONCLUSIÓN: El factor VII recombinante activado como hemostático en hemorragia obstétrica grave mostró resultados favorables y evitó la histerectomía en una paciente. Requiere vigilancia estrecha de las complicaciones trombóticas.

Abstract OBJECTIVE: To describe outcome of patients with severe obstetric hemorrhage (≥ 1000 mL) treated with rFVIIa as part of the management and to detect complications related to its use. MATERIALS AND METHODS: Retrospective, cross-sectional and descriptive study carried out in patients with severe obstetric hemorrhage treated at the Hospital Civil de Guadalajara Dr. Juan I Menchaca between 2001 and 2017 and treated with activated recombinant factor VII. We identified relevant antecedents, average dose and number of doses of rFVIIa, and hemostatic response. We determined if quantity of bleeding, administration of blood products and hematological parameters before and after using rFVIIa was significantly different. RESULTS: We identified ten patients with rFVIIa administration. The cause of severe obstetric hemorrhage was uterine atony in six cases. The average dose of rFVIIa was 91 mcg/kg; one dose was administered in eight patients and two doses in two patients. Hemostasis was achieved in all patients, bleeding decreased significantly after administration of rFVIIa (5075 mL vs 928 mL, p = 0.000) and the number of erythrocyte concentrates required 7vs 3, p = 0.006). One patient did not require a hysterectomy after rFVIIa administration; one patient presented pulmonary thromboembolism and recovered without complications, no patient died. CONCLUSION: rFVIIa administration as a hemostatic in severe obstetric hemorrhage had favorable results, preventing hysterectomy in one patient. Follow-up requires close monitoring of thrombosis.

Novos adjuvantes vacinais: importante ferramenta para imunoterapia da leishmaniose visceral / New vaccine adjuvants: an important tool for immunotherapy of visceral leishmaniasis

Atualmente, muitas das vacinas em desenvolvimento são aquelas compostas de proteínas antigênicas individuais de parasitas ou uma combinação de vários antígenos individuais que são produzidos como produtos recombinantes obtidos por técnicas de biologia molecular. Dentre elas a Leish-111f e sua variação Leish-110f tem ganhado destaque na proteção contra a LV e LC e alcançaram estudos de fase II em seres humanos. A eficácia de uma vacina é otimizada pela adição de adjuvantes imunológicos. No entanto, embora os adjuvantes tenham sido usados por mais de um século, até o momento, apenas alguns adjuvantes são aprovados para o uso em humanos, a maioria destinada a melhorar a eficácia da vacina e a produção de anticorpos protetores específicos do antígeno. os mecanismos de ação dos adjuvantes imunológicos são diversos, dependendo da sua natureza química e molecular sendo capazes de ativar células imunes especificas que conduzem a respostas imunes inatas e adaptativas melhoradas. embora o mecanismo de ação molecular detalhado de muitos adjuvantes ainda seja desconhecido, a descoberta de receptores Toll-like (TLrs) forneceu informações críticas sobre o efeito imunoestimulador de numerosos componentes bacterianos que envolvem interação com receptores TLrs, mostrando que estes ligantes melhoram tanto a qualidade como a quantidade de respostas imunes adaptativas do hospedeiro quando utilizadas em formulações de vacinais direcionadas para doenças. o potencial desses adjuvantes de TLr em melhorar o design e os resultados de várias vacinas está em constante evolução, à medida que novos agonistas são descobertos e testados em modelos experimentais e estudos clínicos de vacinação. Nesta revisão, é apresentado um resumo do progresso recente no desenvolvimento de proteínas recombinantes de segunda geração e adjuvantes de TLr, sendo o foco principal nos TLr4 e suas melhorias.

many of the vaccines in development are currently composed of individual antigenic proteins from parasites or a combination of several individual antigens that are produced as recombinant products obtained by molecular biology techniques. Among them, Leish-111f and its Leish-110f variation have gained prominence in protection against LV and LC and already have Phase II clinical trials in humans. The efficacy of a vaccine is optimized by the addition of immunological adjuvants. However, although adjuvants have been used for more than a century, until present date, only a few adjuvants are approved for use in humans, most intended to improve vaccine efficacy, the production of antigen-specific protective antibodies and an appropriate cell-immune response. The mechanisms of action of immunological adjuvants are diverse depending on their chemical and molecular nature being able to activate specific immune cells leading to improved innate and adaptive immune responses. Although the molecular mechanism of action of many adjuvants is still unknown, the discovery of Toll-like receptors (TLrs) has provided critical information on the immunostimulatory effect of numerous bacterial components involving interaction with TLr showing that these ligands improve both the quality as the amount of host adaptive immune responses when used in vaccine formulations. The potential of these TLr adjuvants in improving the design and results of many vaccines is in constantly evolution as new molecules agonists are discovered and tested in experimental models and clinical trials as well. In this review, a summary of recent progress in the development of second generation recombinant proteinsand adjuvants of TLr is presented, being the main focus in TLr4 and its improvements.

Impact of sodium butyrate and mild hypothermia on metabolic and physiological behaviour of CHO TF 70R cells

Background: To reduce costs associated with productivity of recombinant proteins in the biopharmaceutical industry, research has been focused on regulatory principals of growth and survival during the production phases of the cell culture. The main strategies involve the regulation of cell proliferation by the modulation of cell cycle control points (G1/S or G2/M) with mild hypothermia and the addition of sodium butyrate (NaBu). In this study, batch culture strategies were evaluated using CHO TF 70R cells producing the recombinant human tissue plasminogen activator (rh-tPA), to observe their individual and combined effect on the cellular physiological state and relevant kinetic parameters. Results: NaBu addition has a negative effect on the mitochondrial membrane potential (ΔΨm), the values of which are remarkably diminished in cultures exposed to this cytotoxic compound. This effect was not reflected in a loss of cell viability. NaBu and mild hypothermic conditions increased the doubling time in the cell cultures, suggesting that these strategies triggered a general slowing of each cell cycle phase in a different way. Finally, the individual and combined effect of NaBu and mild hypothermia produced an increase in the specific rh-tPA productivity in comparison to the control at 37°C without NaBu. Nevertheless, both strategies did not have a synergistic effect on the specific productivity. Conclusions: The combination of NaBu addition and mild hypothermic condition causes an impact on physiological and metabolic state of CHO TF 70R cells, decreasing cell growth rate and improving glucose consumption efficiency. These results therefore provide a promising strategy to increase specific productivity of rh-tPA.

Recombinant Activated Factor VII as a Second Line Treatment for Postpartum Hemorrhage / 대한구급학회지

BACKGROUND: Severe or massive postpartum hemorrhage (PPH) has remained a leading cause of maternal mortality for decades across the world and it results in critical obstetric complications. Recombinant activated factor VII (rFVIIa) has emerged as a gold standard adjunctive hemostatic agent for the treatment of life-threatening PPH refractory to conventional therapies although it remains off-licensed for use in PPH. We studied the effects of rFVIIa on coagulopathy, transfusion volume, prognosis, severity change in Korean PPH patients. METHODS: A retrospective review of medical records between December 2008 and March 2011 indicating use of rFVIIa in severe PPH was performed. We compared age, rFVIIa treatment, transfusion volume, and Sequential Organ Failure Assessment (SOFA) score at the time of arrival in the emergency department and after 24 hours for patients whose SOFA score was 8 points or higher. RESULTS: Fifteen women with SOFA score of 8 and above participated in this study and eight received rFVIIa administration whereas seven did not. Patients' mean age was 31.7 ± 7.5 years. There was no statistically significant difference in initial and post-24 hours SOFA scores between patients administered rFVIIa or not. The change in SOFA score between initial presentation and after 24 hours was significantly reduced after rFVIIa administration (P = 0.016). CONCLUSIONS: This analysis aimed to support that the administration of rFVIIa can reduce the severity of life-threatening PPH in patients. A rapid decision regarding the administration of rFVIIa is needed for a more favorable outcome in severe PPH patients for whom there is no effective standard treatment.

Construction and expression of anti IL-4R single antibody of prokaryotic expression vector / 天津医药

Objective To construct anti-IL-4R murine anti-human single-chain variable fragment (scFvs) antibodies through BL21 (DE3) prokaryotic expression system. Methods The anti-IL-4R scFv sequence was optimizated on the basis of previous findings. The optimized scFv sequence was analyzed. The recombinant plasmid pET-32a-scFv was constructed. The recombinant plasmid was detected through enzyme identification, and was turned into BL21 (DE3) prokaryotic expression bacteria to express the pET-32a-scFv recombinant protein in E.coli BL21 (DE3). The purification and renaturation were researched, and SDS-PAGE analysis was studied. The molecular weight of ScFv against IL-4R was analyzed by SDS-PAGE. The expression of the fusion protein was detected by Western-blot assay. Results The length of fusion gene scFv-MLT sequence was 761 bp. The molecular weight of the recombinant expression of proteins of anti-IL-4R single antibody was approximately 45 ku. The recombinant proteins showed high specificity with anti-6 × His-tag antibody. Conclusion This experiment successfully constructs pET-32a-scFv prokaryotic expression system of recombinant protein with high immune reactivity, which provides the basis for further study of anti-IL-4R single chain antibody as drug target.