RESUMEN

Porcine circovirus type 2 (PCV2) is a globally prevalent infectious pathogen affecting swine, with its capsid protein (Cap) being the sole structural protein critical for vaccine development. Prior research has demonstrated that PCV2 Cap proteins produced in Escherichia coli (E. coli) can form virus-like particles (VLPs) in vitro, and nuclear localization signal peptides (NLS) play a pivotal role in stabilizing PCV2 VLPs. Recently, PCV2d has emerged as an important strain within the PCV2 epidemic. In this study, we systematically optimized the PCV2d Cap protein and successfully produced intact PCV2d VLPs containing NLS using E. coli. The recombinant PCV2d Cap protein was purified through affinity chromatography, yielding 7.5 mg of recombinant protein per 100 ml of bacterial culture. We augmented the conventional buffer system with various substances such as arginine, ß-mercaptoethanol, glycerol, polyethylene glycol, and glutathione to promote VLP assembly. The recombinant PCV2d Cap self-assembled into VLPs approximately 20 nm in diameter, featuring uniform distribution and exceptional stability in the optimized buffer. We developed the vaccine and immunized pigs and mice, evaluating the immunogenicity of the PCV2d VLPs vaccine by measuring PCV2-IgG, IL-4, TNF-α, and IFN-γ levels, comparing them to commercial vaccines utilizing truncated PCV2 Cap antigens. The HE staining and immunohistochemical tests confirmed that the PCV2 VLPs vaccine offered robust protection. The results revealed that animals vaccinated with the PCV2d VLPs vaccine exhibited high levels of PCV2 antibodies, with TNF-α and IFN-γ levels rapidly increasing at 14 days post-immunization, which were higher than those observed in commercially available vaccines, particularly in the mouse trial. This could be due to the fact that full-length Cap proteins can assemble into more stable PCV2d VLPs in the assembling buffer. In conclusion, our produced PCV2d VLPs vaccine elicited stronger immune responses in pigs and mice compared to commercial vaccines. The PCV2d VLPs from this study serve as an excellent candidate vaccine antigen, providing insights for PCV2d vaccine research.

Asunto(s)

Anticuerpos Antivirales , Proteínas de la Cápside , Circovirus , Escherichia coli , Proteínas Recombinantes , Vacunas de Partículas Similares a Virus , Animales , Circovirus/inmunología , Circovirus/genética , Porcinos , Vacunas de Partículas Similares a Virus/inmunología , Vacunas de Partículas Similares a Virus/genética , Proteínas de la Cápside/inmunología , Proteínas de la Cápside/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Ratones , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/genética , Infecciones por Circoviridae/prevención & control , Infecciones por Circoviridae/inmunología , Enfermedades de los Porcinos/prevención & control , Vacunas Virales/inmunología , Vacunas Virales/genética , Desarrollo de Vacunas , Antígenos Virales/inmunología , Antígenos Virales/genética , Inmunoglobulina G/sangre , Análisis Costo-Beneficio , Femenino , Interferón gamma/metabolismo , Inmunogenicidad Vacunal

RESUMEN

The Coronavirus disease 2019 (COVID-19) pandemic presents an unprecedented public health crisis worldwide. Although several vaccines are available, the global supply of vaccines, particularly within developing countries, is inadequate, and this necessitates a need for the development of less expensive, accessible vaccine options. To this end, here, we used the Escherichia coli expression system to produce a recombinant fusion protein comprising the receptor binding domain (RBD) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; residues 319-541) and the fragment A domain of Cross-Reacting Material 197 (CRM197); hereafter, CRMA-RBD. We show that this CRMA-RBD fusion protein has excellent physicochemical properties and strong reactivity with COVID-19 convalescent sera and representative neutralizing antibodies (nAbs). Furthermore, compared with the use of a traditional aluminum adjuvant, we find that combining the CRMA-RBD protein with a nitrogen bisphosphonate-modified zinc-aluminum hybrid adjuvant (FH-002C-Ac) leads to stronger humoral immune responses in mice, with 4-log neutralizing antibody titers. Overall, our study highlights the value of this E. coli-expressed fusion protein as an alternative vaccine candidate strategy against COVID-19.

RESUMEN

BACKGROUND AND AIM: Canine parvovirus (CPV) is one of the most common viral infections in dogs, causing acute hemorrhagic gastroenteritis and high mortality. Vaccination effectively prevents CPV infection. However, the currently available CPV vaccines have concerns such as maternal immunity interference, shedding of virus vaccine, and false-positive result based on polymerase chain reaction after vaccination. A subunit vaccine can overcome these problems. This study aimed to express the recombinant 35 kDa fragment of the VP2 protein (consisting of epitopes 1-7) and the recombinant full-length VP2 protein (consisting of epitopes 1-10) and to study the ability of these two recombinant proteins to react with rabbit anti-CPV polyclonal antibodies. MATERIALS AND METHODS: The full length and 35 kDa fragment of VP2 gene of CPV were cloned into the pBAD202 Directional TOPO™ expression vector and expressed in E. coli. The recombinant full-length and the recombinant 35 kDa fragment proteins of VP2 were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting. RESULTS: The recombinant full-length and the recombinant 35 kDa fragment VP2 genes were successfully cloned and expressed. The optimum concentrations of arabinose and induction time for the recombinant full-length and the recombinant 35 kDa fragment VP2 proteins were 0.2% for 6 h and 0.02% for 6 h, respectively. The recombinant full-length and the recombinant 35 kDa fragment VP2 protein molecular weights were approximately 81 and 51 kDa, respectively. The recombinant full-length and the recombinant 35 kDa fragment VP2 proteins specifically interacted with rabbit anti-CPV polyclonal antibodies. CONCLUSION: These results suggest that the recombinant 35 kDa fragment and the recombinant full-length VP2 proteins may be useful in developing a CPV diagnostic test or vaccine.

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OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic caused by the SARS-CoV2 virus continues to pose a serious threat to public health worldwide. The development of rapid diagnostic kits can assist the Tzu Chi Foundation in supporting global volunteers working to provide relief during the current pandemic. MATERIALS AND METHODS: In this study, nucleotide sequences derived from publicly available viral genome data for several domains of the SARS-CoV2 spike and nucleocapsid (N) proteins were chemically synthesized, with codon optimization for Escherichia coli protein expression. No actual viral particles were involved in these experiments. The synthesized sequences were cloned into an E. coli expression system based on pQE80L, and expressed viral proteins were subsequently purified using Ni-affinity chromatography. Western blotting was conducted using human antiviral sera to assess the response of codon-modified viral proteins to COVID-19 patient sera. RESULTS: N protein was expressed in amounts large enough to support large-scale production. The N-terminal domain, receptor-binding domain (RBD), Region 3, and the S2 domain were expressed in small but sufficient amounts for experiments. Immunoblotting results showed that anti-N IgG and anti-N IgM antibodies were detected in most patient sera, but only 60% of samples reacted with the recombinant RBD and S2 domain expressed by E. coli. CONCLUSION: The results indicated that codon-optimized SARS-CoV2 viral proteins can be expressed in E. coli and purified for rapid antibody detection kit preparation, with the codon-optimized N protein, RBD, and S2 protein demonstrating the most potential.

RESUMEN

Helicobacter pylori infection can cause a variety of gastrointestinal diseases. In severe cases, there is a risk of gastric cancer. Antibiotics are often used for clinical treatment of H. pylori infections. However, because of antibiotic overuse in recent years and the emergence of multidrug-resistant bacteria, there is an urgent need to develop new treatment methods and drugs to achieve complete eradication of H. pylori. Endolysins and holins encoded by bacterial viruses (i.e., phages) represent a promising avenue of investigation. These lyase-based antibacterial drugs act on the bacterial cell wall to destroy the bacteria. Currently, a type of endolysin that has been studied more frequently acts on the amide bond between peptidoglycans, and holin is a transmembrane protein that can punch holes in the cell membrane. However, as a Gram-negative bacterium, H. pylori possesses a layer of impermeable lipopolysaccharides on the cell wall, which prevents endolysin interaction with the cell wall. Therefore, we designed a genetic linkage between an endolysin enzyme and a holin enzyme with a section of polypeptides (e.g., polycations and hydrophobic peptides) that enable penetration of the outer membrane. These complexes were designated "artilysins" and were efficiently expressed in Escherichia coli. In vitro bacteriostasis experiments showed that the purified artilysins had strong bacteriostatic effects on H. pylori. In addition, the surface of H. pylori was perforated and destroyed, as confirmed by electron microscopy, which was proved that artilysins had bacteriolytic effect on H. pylori.

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Hydrophobins are small, secreted amphiphilic proteins produced by filamentous fungi. Due to their charming ability to self-assemble at different interfaces, several efforts have been made in recent years to produce hydrophobins at a large scale for industrial applications. However, producing soluble and functional hydrophobins in bacterial expression systems is challenging because all hydrophobins contain eight conserved cysteine residues, resulting in the formation of inclusion bodies. Here, two cysteine mutants for both class I and class II hydrophobins were successfully produced in Escherichia coli in soluble form. Subsequent experiments systematically demonstrated that those two mutants preserved the ability to self-assemble at water-water, air-water and oil-water interfaces similarly to native hydrophobins. We also found that disulfide bridges differently influenced the self-assembly of hydrophobins. They were not involved in the self-assembly of the class I hydrophobin HGFI, but directly affected the self-assembly of the class II hydrophobin HFBI. Our study demonstrated that the bacterial expression system was suitable for producing soluble and functional hydrophobin mutants, which have the potential to replace native hydrophobins produced in other complicated production systems.

Asunto(s)

Bacillus subtilis/genética , Escherichia coli/metabolismo , Proteínas Fúngicas/biosíntesis , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Interacciones Hidrofóbicas e Hidrofílicas , Mutación , Tamaño de la Partícula , Solubilidad , Propiedades de Superficie

RESUMEN

Antimicrobial peptides (AMPs) are peptides exhibiting broad-spectrum antimicrobial activities and considered as potential therapeutic agents. LsGRP1C, a novel AMP derived from defense-related LsGRP1 protein of Lilium, was proven to inhibit kinds of bacteria and fungi via alteration of microbial membrane permeability and induction of fungal programmed cell death-like phenomena by in vitro assays using synthetic LsGRP1C. In this study, the prokaryotic production of LsGRP1C recombinant protein containing an N-terminal fusion partner of the yeast small ubiquitin-like modifier (SUMO) was achieved by using optimized Escherichia coli host and purification buffer system, which lead to a high yield of soluble SUMO-LsGRP1C fusion protein. In vitro assay revealed that E. coli-expressed SUMO-LsGRP1C exhibited even better antifungal activity as compared to synthetic LsGRP1C. Meanwhile, the ability of SUMO-LsGRP1C in conducting fungal membrane permeabilization and programmed cell death was verified by SYTOX Green staining and 4',6-diamidino-2-phenylindole staining/terminal deoxynucleotidyl transferase dUTP nick-end labeling assays, respectively, indicating that E. coli-expressed SUMO-LsGRP1C shares identical modes of action with synthetic LsGRP1C. Herein, this E. coli expression system enables the effective and convenient production of antimicrobial LsGRP1C in a form of SUMO-fused recombinant protein.

Asunto(s)

Antifúngicos/farmacología , Péptidos Catiónicos Antimicrobianos/genética , Péptidos Catiónicos Antimicrobianos/farmacología , Escherichia coli/genética , Lilium/química , Antiinfecciosos/química , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/farmacología , Antifúngicos/química , Antifúngicos/metabolismo , Péptidos Catiónicos Antimicrobianos/biosíntesis , Péptidos Catiónicos Antimicrobianos/química , Permeabilidad de la Membrana Celular/efectos de los fármacos , Clonación Molecular , Fragmentación del ADN/efectos de los fármacos , Proteínas Fúngicas/genética , Hongos/efectos de los fármacos , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Modificadoras Pequeñas Relacionadas con Ubiquitina/genética , Esporas Fúngicas/efectos de los fármacos

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Protein-DNA interactions are central to the control of gene expression across all forms of life. The development of approaches to rigorously model such interactions has often been hindered both by a lack of quantitative binding data and by the difficulty in accounting for parameters relevant to the intracellular situation, such as DNA looping and thermodynamic non-ideality. Here, we review these considerations by developing a thermodynamically based mathematical model that attempts to simulate the functioning of an Escherichia coli expression system incorporating two of the best characterised prokaryotic DNA binding proteins, Lac repressor and lambda CI repressor. The key aim was to reproduce experimentally observed reporter gene activities arising from the expression of either wild-type CI repressor or one of three positive-control CI mutants. The model considers the role of several potentially important, but sometimes neglected, biochemical features, including DNA looping, macromolecular crowding and non-specific binding, and allowed us to obtain association constants for the binding of CI and its variants to a specific operator sequence.

RESUMEN

Frutalin is a homotetrameric partly glycosylated α-D-galactose-binding lectin of biomedical interest from Artocarpus incisa (breadfruit) seeds, belonging to the jacalin-related lectins family. As other plant lectins, frutalin is a heterogeneous mixture of several isoforms possibly with distinct biological activities. The main problem of using such lectins as biomedical tools is that "batch-to-batch" variation in isoforms content may lead to inconstant results. The production of lectins by recombinant means has the advantage of obtaining high amounts of proteins with defined amino-acid sequences and more precise properties. In this mini review, we provide the strategies followed to produce two different forms of frutalin in two different microbial systems: Escherichia coli and Pichia pastoris. The processing and functional properties of the recombinant frutalin obtained from these hosts are compared to those of frutalin extracted from breadfruit. Emphasis is given particularly to recombinant frutalin produced in P. pastoris, which showed a remarkable capacity as biomarker of human prostate cancer and as apoptosis-inducer of cancer cells. Recombinant frutalin production opens perspectives for its development as a new tool in human medicine.

RESUMEN

Human erythropoietin (hEpo) is an essential regulator of erythrocyte production that induces the division and differentiation of erythroid progenitor cells in the bone marrow into mature erythrocytes. It is widely used for the treatment of anemia resulting from chronic kidney disease, chemotherapy, and cancer-related therapies. Active hEpo, and hEpo analogs, have been purified primarily from mammalian cells, which has several disadvantages, including low yields and high production costs. Although an Escherichia coli (E. coli) expression system may provide economic production of therapeutic proteins, it has not been used for the production of recombinant hEpo (rhEpo) because it aggregates in inclusion bodies in the E. coli cytoplasm and is not modified post-translationally. We investigated the soluble overexpression of active rhEpo with various protein tags in E. coli, and found out that several tags increased the solubility of rhEpo. Among them maltose binding protein (MBP)-tagged rhEpo was purified using affinity and gel filtration columns. Non-denaturing electrophoresis and MALDI-TOF MS analysis demonstrated that the purified rhEpo had two intra-disulfide bonds identical to those of the native hEpo. An in vitro proliferation assay showed that rhEpo purified from E. coli had similar biological activity as rhEpo derived from CHO cells. Therefore, we report for the first time that active rhEpo was overexpressed as a soluble form in the cytoplasm of E. coli and purified it in simple purification steps. We hope that our results offer opportunities for progress in rhEpo therapeutics.

Asunto(s)

Eritropoyetina/aislamiento & purificación , Eritropoyetina/metabolismo , Escherichia coli/metabolismo , Proteínas Recombinantes de Fusión/aislamiento & purificación , Proteínas Recombinantes de Fusión/metabolismo , Secuencia de Aminoácidos , Línea Celular , Proliferación Celular , Clonación Molecular , Eritropoyetina/química , Eritropoyetina/genética , Escherichia coli/genética , Humanos , Proteínas de Unión a Maltosa/genética , Datos de Secuencia Molecular , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Solubilidad

RESUMEN

OBJECTIVE: To express the recombinant human nerve growth factor by using codon mutation of Escherichia coli(rhβ-NGF), separate and purify the expression products, and determine the biological activity.

RESUMEN

Objective To produce human papillomavirus type 6(HPV-6)virus-like particles with Escherichia coli expression system and study its immunogenicity.Methods HPV-6 L1 gene was inserted into pmkaryotic expression vector pTO-T7 and then expressed in Escherichia coli ER2566.The HPV-6 L1 protein was purified by ammonium sulfate precipitation,ion-exchange chromatography,and hydrophobic interaction chromatography.Then the purified HPV-6 L1 self-assembled into virus-like particle after removing 1,4dithiothreitol(DTr).The morphology of the virus-like particles was investigated with dynamic light scatter and transmission electron microscopy,and the immunogenicity was determined with in vitro pseudownons neutralization as8ay.Results HPV-6 L1 was expressed in soluble form in Escherichia coli.Following the removal of DTT,purified HPV-6 L1 protein could assemble into virus-like particles as 25 am in the radius.And the animal immunization test showed HPV-6 virus-like particles can elite hish titer neutralizing antibodies.Conclusion The bacterially expressed HPV-6 L1 VLP is highly immunogenieity and easy to produce.And it can be good candidate of HPV-6 vaccine.