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1.
Foods ; 12(9)2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37174346

RESUMO

Celiac disease is an immune-mediated disorder caused by the ingestion of gluten proteins. The gluten-free diet is currently the only therapy to achieve the symptoms' remission. Biotechnological approaches are currently being explored to obtain safer and healthier food for celiacs. This article analyzes consumer awareness and acceptance of advanced biotechnologies to develop gluten-free products. An online snowball sampling questionnaire was proposed to 511 Italian participants, selected among celiac and non-celiac people, from December 2020 to January 2021, during the second wave of the COVID-19 pandemic. Overall, 64% of respondents favor food biotechnology, as long as it has benefits for health or the environment. Moreover, biotechnology perception differs according to education level and type. A total of 65% of the survey participants would taste gluten-free products obtained through a biotechnological approach, and 57% would buy them at a higher price than the current market price. Our results show a change in public opinion about the usefulness of food biotechnology and its moral acceptability compared to 20 years ago. However, the study of public opinion is very complex, dealing with individuals with social, economic, and cultural differences. Undoubtedly, the scientific dissemination of genetic biotechnologies must be more effective and usable to increase the level of citizens' awareness.

2.
Front Plant Sci ; 13: 956741, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36131799

RESUMO

Monoclonal antibodies are considered to be highly effective therapeutic tools for the treatment of mild to moderate COVID-19 patients. In the present work, we describe the production of two SARS-CoV-2 human IgG1 monoclonal antibodies recognizing the spike protein receptor-binding domain (RBD) and endowed with neutralizing activity (nAbs) in plants. The first one, mAbJ08-MUT, was previously isolated from a COVID-19 convalescent patient and Fc-engineered to prolong the half-life and reduce the risk of antibody-dependent enhancement. This nAb produced in mammalian cells, delivered in a single intramuscular administration during a Phase I clinical study, was shown to (i) be safe and effectively protect against major variants of concern, and (ii) have some neutralizing activity against the recently emerged omicron variant in a cytopathic-effect-based microneutralization assay (100% inhibitory concentration, IC100 of 15 µg/mL). The second antibody, mAb675, previously isolated from a vaccinated individual, showed an intermediate neutralization activity against SARS-CoV-2 variants. Different accumulation levels of mAbJ08-MUT and mAb675 were observed after transient agroinfiltration in Nicotiana benthamiana plants knocked-out for xylosil and fucosil transferases, leading to yields of ~35 and 150 mg/kg of fresh leaf mass, respectively. After purification, as a result of the proteolytic events affecting the hinge-CH2 region, a higher degradation of mAb675 was observed, compared to mAbJ08-MUT (~18% vs. ~1%, respectively). Both nAbs showed a human-like glycosylation profile, and were able to specifically bind to RBD and compete with angiotensin-converting enzyme 2 binding in vitro. SARS-CoV-2 neutralization assay against the original virus isolated in Wuhan demonstrated the high neutralization potency of the plant-produced mAbJ08-MUT, with levels (IC100 < 17 ng/mL) comparable to those of the cognate antibody produced in a Chinese hamster ovary cell line; conversely, mAb675 exhibited a medium neutralization potency (IC100 ~ 200 ng/mL). All these data confirm that plant expression platforms may represent a convenient and rapid production system of potent nAbs to be used both in therapy and diagnostics in pandemic emergencies.

3.
J Pharm Biomed Anal ; 216: 114796, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35550279

RESUMO

In this work, an analytical platform based on the use of chromatography and mass spectrometry (MS), has been applied to the characterization of Rituximab (RTX) obtained from two plant expression systems (rice and tobacco) in comparison to the mammalian cell-derived reference monoclonal antibody (mAb). Different chromatographic approaches, hyphenated to high resolution MS (HRMS), were applied to RTX structural investigation both at middle- and peptide level. In particular, cation exchange chromatography (CEX), size exclusion chromatography (SEC), reversed phase (RPLC) and hydrophilic interaction liquid chromatographic (HILIC) methods were developed and applied on intact mAbs, IdeS-, and trypsin digests in order to address critical attributes such as primary structure, glycan composition, species-related heterogeneity, glycosylation degree, charge variants, aggregation tendency and enzymatic stability. All the collected data highlight the features and criticalities of each production approach. Production in rice results in a heterogeneous but stable product over time, suggesting the absence of proteases in seeds; while tobacco expression system leads to more homogeneous glycosylation, but protein stability seems to be a critical issue probably due to the presence of proteases. This analytical strategy represents a robust support to scientists in the selection and optimization of the best plant expression system to produce recombinant humanized mAbs.


Assuntos
Anticorpos Monoclonais , Antineoplásicos Imunológicos , Animais , Anticorpos Monoclonais/química , Cromatografia Líquida/métodos , Mamíferos , Peptídeo Hidrolases , Espectrometria de Massas em Tandem
5.
Front Plant Sci ; 12: 786871, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34950172

RESUMO

Infectious bursal disease virus is the causative agent of Gumboro disease, a severe infection that affects young chickens and is associated with lymphoid depletion in the bursa of Fabricius. Traditional containment strategies are based either on inactivated or live-attenuated vaccines. These approaches have several limitations such as residual virulence or low efficacy in the presence of maternally derived antibodies (MDA) but, most importantly, the impossibility to detect the occurrence of natural infections in vaccinated flocks. Therefore, the development of novel vaccination strategies allowing the differentiation of infected from vaccinated animals (DIVA) is a priority. Recently, commercial vectored and experimental subunit vaccines based on VP2 have been proved effective in protecting from clinical disease and posed the basis for the development of novel DIVA strategies. In this study, an engineered version of the VP3 protein of IBDV (His-VP3) was produced in plants, successfully purified from Nicotiana benthamiana leaves, and used to develop an enzyme-linked immunosorbent assay (ELISA) for the detection of anti-VP3 antibodies. The His-VP3 ELISA was validated with a panel of 180 reference sera and demonstrated to have 100% sensitivity (95% CI: 94.7-100.0) and 94.17% specificity (95% CI: 88.4-97.6). To evaluate the application of His-VP3 ELISA as a DIVA test, the novel assay was used to monitor, in combination with a commercial kit, detecting anti-VP2 antibodies, the immune response of chickens previously immunized with an inactivated IBDV vaccine, a recombinant Turkey herpes virus carrying the VP2 of IBDV (HVT-ND-IBD) or with plant-produced VP2 particles. The combined tests correctly identified the immune status of the vaccinated specific pathogen free white-leghorn chickens. Moreover, the His-VP3 ELISA correctly detected MDA against VP3 in commercial broiler chicks and showed that antibody titers fade with time, consistent with the natural decrease of maternally derived immunity. Finally, the novel assay, in combination with a VP2-specific ELISA, demonstrated its potential application as a DIVA test in chickens inoculated with VP2-based vaccines, being able to detect the seroconversion after challenge with a very virulent IBDV strain.

6.
PLoS One ; 16(2): e0247134, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33592038

RESUMO

Infectious Bursal Disease Virus (IBDV), the etiological agent of Gumboro disease, causes mortality and immunosuppression in chickens and major losses to poultry industry worldwide. The IBDV major capsid protein VP2 is considered the best candidate for the production of novel subunit vaccines. This structural protein contains the major conformational epitopes responsible for the induction of IBDV neutralizing antibodies in chickens and has been demonstrated able to form supramolecular structures in yeast and insect cells. The aim of this study was to express an engineered version of the VP2 protein (His-pVP2) to verify its ability to self-assemble into virus-like particles in plants. The recombinant VP2 was transiently expressed by agroinfiltration in Nicotiana benthamiana and transmission electron microscopy of sucrose density gradient fractions revealed the presence of a mixed population of differently shaped particles ranging from spherical capsids, with a diameter between ~25 and ~70 nm, to tubular structures, with variable length (from 100 to 400 nm). The recombinant VP2-based particles when used for the intramuscular immunization of specific-pathogen-free chicks resulted able to induce the production of anti-IBDV specific antibodies at titers comparable to those induced by a commercial vaccine. Moreover, all the immunized birds survived to the challenge with a Moroccan very virulent IBDV strain with no major histomorphological alterations of the Bursa of Fabricius, similarly to what obtained with the commercial inactivated vaccine.


Assuntos
Vírus da Doença Infecciosa da Bursa/patogenicidade , Proteínas Recombinantes/metabolismo , Animais , Western Blotting , Capsídeo/metabolismo , Galinhas , Ensaio de Imunoadsorção Enzimática , Vírus da Doença Infecciosa da Bursa/genética , Microscopia Eletrônica de Transmissão , Proteínas Recombinantes/genética , Virulência/genética , Virulência/fisiologia
7.
Front Plant Sci ; 11: 609910, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33381140

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has killed more than 37,000 people in Italy and has caused widespread socioeconomic disruption. Urgent measures are needed to contain and control the virus, particularly diagnostic kits for detection and surveillance, therapeutics to reduce mortality among the severely affected, and vaccines to protect the remaining population. Here we discuss the potential role of plant molecular farming in the rapid and scalable supply of protein antigens as reagents and vaccine candidates, antibodies for virus detection and passive immunotherapy, other therapeutic proteins, and virus-like particles as novel vaccine platforms. We calculate the amount of infrastructure and production capacity needed to deal with predictable subsequent waves of COVID-19 in Italy by pooling expertise in plant molecular farming, epidemiology and the Italian health system. We calculate the investment required in molecular farming infrastructure that would enable us to capitalize on this technology, and provide a roadmap for the development of diagnostic reagents and biopharmaceuticals using molecular farming in plants to complement production methods based on the cultivation of microbes and mammalian cells.

8.
Appl Microbiol Biotechnol ; 104(6): 2287-2296, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31980920

RESUMO

Infectious bursal disease is a widely spread threatening contagious viral infection of chickens that induces major damages to the Bursa of Fabricius and leads to severe immunosuppression in young birds causing significant economic losses for poultry farming. The etiological agent is the infectious bursal disease virus (IBDV), a non-enveloped virus belonging the family of Birnaviridae. At present, the treatment against the spread of this virus is represented by vaccination schedules mainly based on inactivated or live-attenuated viruses. However, these conventional vaccines present several drawbacks such as insufficient protection against very virulent strains and the impossibility to differentiate vaccinated animals from infected ones. To overcome these limitations, in the last years, several studies have explored the potentiality of recombinant subunit vaccines to provide an effective protection against IBDV infection. In this review, we will give an overview of these novel types of vaccines with special emphasis on current state-of-the-art in the use of plants as "biofactories" (plant molecular farming). In fact, plants have been thoroughly and successfully characterized as heterologous expression systems for the production of recombinant proteins for different applications showing several advantages compared with traditional expression systems (Escherichia coli, yeasts and insect cells) such as absence of animal pathogens in the production process, improved product quality and safety, reduction of manufacturing costs, and simplified scale-up.


Assuntos
Infecções por Birnaviridae/veterinária , Vírus da Doença Infecciosa da Bursa/imunologia , Plantas Geneticamente Modificadas , Vacinologia/métodos , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais , Infecções por Birnaviridae/imunologia , Infecções por Birnaviridae/prevenção & controle , Bolsa de Fabricius/imunologia , Bolsa de Fabricius/virologia , Galinhas/imunologia , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/prevenção & controle , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/imunologia , Vacinas de Subunidades/biossíntese , Vacinas de Subunidades/imunologia , Vacinas Virais/biossíntese
9.
Appl Microbiol Biotechnol ; 103(18): 7491-7504, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31332484

RESUMO

Infectious bursal disease virus (IBDV) is the cause of an economically important highly contagious disease of poultry, and vaccines are regarded as the most beneficial interventions for its prevention. In this study, plants were used to produce a recombinant chimeric IBDV antigen for the formulation of an innovative subunit vaccine. The fusion protein (PD-FcY) was designed to combine the immunodominant projection domain (PD) of the viral structural protein VP2 with the constant region of avian IgY (FcY), which was selected to enhance antigen uptake by avian immune cells. The gene construct encoding the fusion protein was transiently expressed in Nicotiana benthamiana plants and an extraction/purification protocol was set up, allowing to reduce the contamination by undesired plant compounds/proteins. Mass spectrometry analysis of the purified protein revealed that the glycosylation pattern of the FcY portion was similar to that observed in native IgY, while in vitro assays demonstrated the ability of PD-FcY to bind to the avian immunoglobulin receptor CHIR-AB1. Preliminary immunization studies proved that PD-FcY was able to induce the production of protective anti-IBDV-VP2 antibodies in chickens. In conclusion, the proposed fusion strategy holds promises for the development of innovative low-cost subunit vaccines for the prevention of avian viral diseases.


Assuntos
Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Imunoglobulinas/imunologia , Doenças das Aves Domésticas/prevenção & controle , Vacinas Virais/biossíntese , Animais , Antígenos Virais/biossíntese , Galinhas/imunologia , Imunoglobulinas/biossíntese , Vírus da Doença Infecciosa da Bursa , Doenças das Aves Domésticas/virologia , Vacinação , Vacinas de Subunidades/biossíntese , Proteínas Estruturais Virais/biossíntese , Proteínas Estruturais Virais/imunologia
10.
Biotechnol Lett ; 41(3): 335-346, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30684155

RESUMO

Monoclonal antibodies represent the major class of biopharmaceutical products (for therapeutics and diagnostics) with an increasing demand that reaches several tons per year worldwide. Traditional large-scale manufacturing processes are based on stirred tank bioreactors for the growth of Chinese Hamster Ovary cells (CHO) which requires high initial investments and production costs. Therefore, there is an urgent need for alternative production platforms that can at least act as a complement to the over-exploited mammalian fermentation systems. In this perspective, the use of plants for the large-scale production of biopharmaceuticals ('Molecular farming') represents an interesting and mature technology that has already proved its benefits in terms of safety, scalability, rapidity and reduced manufacturing costs. Here we discuss the recent advances in the production of monoclonal antibodies (mAbs) in plant-based platforms such as transgenic plants, tissue and cell cultures and transient expression systems.


Assuntos
Anticorpos Monoclonais/metabolismo , Produtos Biológicos/metabolismo , Biotecnologia/métodos , Plantas/metabolismo , Proteínas Recombinantes/metabolismo , Tecnologia Farmacêutica/métodos , Anticorpos Monoclonais/genética , Biotecnologia/tendências , Proteínas Recombinantes/genética , Tecnologia Farmacêutica/tendências
11.
Biotechnol J ; 14(3): e1800081, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29975457

RESUMO

Hairy root (HR) cultures represent an attractive platform for the production of heterologous proteins, due to the possibility of secreting the molecule of interest in the culture medium. The main limitation is the low accumulation yields of heterologous proteins. The aim of this study is to enhance the accumulation of a tumor-targeting antibody with a human-compatible glycosylation profile in HR culture medium. To this aim, the authors produce Nicotiana benthamiana HR cultures expressing the red fluorescent protein (RFP) to easily screen for different auxins able to induce heterologous protein secretion in the medium. The hormone 2,4-dichlorophenoxyacetic acid (2,4-D) is found to induce high accumulation levels (334 mg L-1 ) of RFP in the culture medium. The same protocol is used to improve the secretion of the tumor-targeting, CD20-specific 2B8-FcΔXF recombinant antibody from glyco-engineered ΔXTFT N. benthamiana HR cultures. The addition of 2,4-D determine a 28-fold increase of the accumulation of fully functional 2B8-FcΔXF in the culture medium, at levels of ≈16 mg L-1 . Antibody N-glycosylation profiling reveal the prominent occurrence of GnGn structures and low levels of xylose- and fucose-containing counterparts. This result is the first example of the expression of an engineered anti-CD20 antibody with a scFv-Fc format at high levels in HR.


Assuntos
Anticorpos Monoclonais/genética , Raízes de Plantas/genética , Anticorpos de Cadeia Única/genética , Antígenos CD20/genética , Fucose/genética , Glicosilação , Humanos , Proteínas Luminescentes/genética , Plantas Geneticamente Modificadas/genética , Engenharia de Proteínas/métodos , Proteínas Recombinantes/genética , Xilose/genética
12.
J Sci Food Agric ; 98(2): 737-750, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28675480

RESUMO

BACKGROUND: Lettuce is a leafy vegetable that is extensively commercialized as a ready-to-eat product because of its widespread use in human nutrition as salad. It is well known that washing treatments can severely affect the quality and shelf-life of ready-to-eat vegetables. The study presented here evaluated the effect of two washing procedures on fresh-cut lettuce during storage. RESULTS: An omics approach was applied to reveal global changes at molecular level induced by peracetic acid washing in comparison with sodium hypochlorite treatment. Microbiological analyses were also performed to quantify total bacterial abundance and composition. The study revealed wide metabolic alterations induced by the two sanitizers. In particular, transcriptomic and proteomic analyses pointed out a number of transcripts and proteins differentially accumulated in response to peracetic acid washing, mainly occurring on the first day of storage. In parallel, different microbiota composition and significant reduction in total bacterial load following washing were also observed. CONCLUSION: The results provide useful information for the fresh-cut industry to select an appropriate washing procedure preserving fresh-like attributes as much as possible during storage of the end product. Molecular evidence indicated peracetic acid to be a valid alternative to sodium hypochlorite as sanitizer solution. © 2017 Society of Chemical Industry.


Assuntos
Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ácido Peracético/farmacologia , Hipoclorito de Sódio/farmacologia , Eletroforese em Gel Bidimensional/métodos , Espectrometria de Massas/métodos , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Polimorfismo de Fragmento de Restrição , Proteômica/métodos , Transcriptoma
13.
Biotechnol Bioeng ; 115(3): 565-576, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29178403

RESUMO

Anti-CD20 recombinant antibodies are among the most promising therapeutics for the treatment of B-cell malignancies such as non-Hodgkin lymphomas. We recently demonstrated that an immunocytokine (2B8-Fc-hIL2), obtained by fusing an anti-CD20 scFv-Fc antibody derived from C2B8 mAb (rituximab) to the human interleukin 2 (hIL-2), can be efficiently produced in Nicotiana benthamiana plants. The purified immunocytokine (IC) bearing a typical plant protein N-glycosylation profile showed a CD20 binding activity comparable to that of rituximab and was efficient in eliciting antibody-dependent cell-mediated cytotoxicity (ADCC) of human PBMC against Daudi cells, indicating its fuctional integrity. In this work, the immunocytokine devoid of the typical xylose/fucose N-glycosylation plant signature (IC-ΔXF) and the corresponding scFv-Fc-ΔXF antibody not fused to the cytokine, were obtained in a glyco-engineered ΔXylT/FucT N. benthamiana line. Purification yields from agroinfiltrated plants amounted to 20-35 mg/kg of leaf fresh weight. When assayed for interaction with FcγRI and FcγRIIIa, IC-ΔXF exhibited significantly enhanced binding affinities if compared to the counterpart bearing the typical plant protein N-glycosylation profile (IC) and to rituximab. The glyco-engineered recombinant molecules also exhibited a strongly improved ADCC and complement-dependent cytotoxicity (CDC). Notably, our results demonstrate a reduced C1q binding of xylose/fucose carrying IC and scFv-Fc compared to versions that lack these sugar moieties. These results demonstrate that specific N-glycosylation alterations in recombinant products can dramatically affect the effector functions of the immunocytokine, resulting in an overall improvement of the biological functions and consequently of the therapeutic potential.


Assuntos
Interleucina-2 , Leucócitos Mononucleares/metabolismo , Plantas Geneticamente Modificadas , Polissacarídeos , Proteínas Recombinantes de Fusão , Anticorpos de Cadeia Única , Humanos , Interleucina-2/biossíntese , Interleucina-2/química , Interleucina-2/genética , Interleucina-2/farmacologia , Leucócitos Mononucleares/citologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Polissacarídeos/biossíntese , Polissacarídeos/genética , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Engenharia de Proteínas , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/farmacologia , Anticorpos de Cadeia Única/biossíntese , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/isolamento & purificação , Anticorpos de Cadeia Única/farmacologia , /metabolismo
14.
PLoS One ; 11(11): e0167086, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27893815

RESUMO

The overall quality of recombinant IgG antibodies in plants is dramatically compromised by host endogenous proteases. Different approaches have been developed to reduce the impact of endogenous proteolysis on IgGs, notably involving site-directed mutagenesis to eliminate protease-susceptible sites or the in situ mitigation of host protease activities to minimize antibody processing in the cell secretory pathway. We here characterized the degradation profile of H10, a human tumour-targeting monoclonal IgG, in leaves of Nicotiana benthamiana also expressing the human serine protease inhibitor α1-antichymotrypsin or the cysteine protease inhibitor tomato cystatin SlCYS8. Leaf extracts revealed consistent fragmentation patterns for the recombinant antibody regardless of leaf age and a strong protective effect of SlCYS8 in specific regions of the heavy chain domains. As shown using an antigen-binding ELISA and LC-MS/MS analysis of antibody fragments, SlCYS8 had positive effects on both the amount of fully-assembled antibody purified from leaf tissue and the stability of biologically active antibody fragments containing the heavy chain Fc domain. Our data confirm the potential of Cys protease inhibitors as convenient antibody-stabilizing expression partners to increase the quality of therapeutic antibodies in plant protein biofactories.


Assuntos
Anticorpos Monoclonais/metabolismo , Inibidores de Cisteína Proteinase/farmacologia , Imunoglobulina G/imunologia , Neoplasias/terapia , Plantas Geneticamente Modificadas/metabolismo , Sequência de Aminoácidos , Anticorpos Monoclonais/imunologia , Cistatinas/farmacologia , Humanos , Imunoglobulina G/metabolismo , Solanum lycopersicum/metabolismo , Neoplasias/imunologia , Peptídeo Hidrolases/química , Peptídeo Hidrolases/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Folhas de Planta/imunologia , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/imunologia , Proteólise , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , /genética , alfa 1-Antiquimotripsina/farmacologia
15.
Biotechnol J ; 11(9): 1209-20, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27313150

RESUMO

Hairy root (HR) cultures derived from Agrobacterium rhizogenes transformation of plant tissues are an advantageous biotechnological manufacturing platform due to the accumulation of recombinant proteins in an otherwise largely protein free culture medium. In this context, HRs descending from transgenic Nicotiana tabacum plants were successfully used for the production of several functional mAbs with plant-type glycans. Here, we expressed the tumor-targeting monoclonal antibody mAb H10 in HRs obtained either by infecting a transgenic N. tabacum line expressing H10 with A. rhizogenes or a glyco-engineered N. benthamiana line (ΔXTFT) with recombinant A. rhizogenes carrying mAb H10 heavy and light chain cDNAs. Selected HR clones derived from both plants accumulated mAb H10 in the culture medium with similar yields (2-3 mg/L). N-glycosylation profiles of antibodies purified from HR supernatant revealed the presence of plant-typical complex structures for N. tabacum-derived mAb H10 and of GnGn structures lacking xylose and fucose for the ΔXTFT-derived counterpart. Both antibody glyco-formats exhibited comparable antigen binding activities. Collectively, these data demonstrate that the co-infection of ΔXTFT Nicotiana benthamiana with recombinant A. rhizogenes is an efficient procedure for the generation of stable HR cultures expressing the tumor-targeting mAb H10 with a human-compatible glycosylation profile, thus representing an important step towards the exploitation of root cultures for the production of 'next generation' human therapeutic antibodies.


Assuntos
Anticorpos Monoclonais/biossíntese , Raízes de Plantas/genética , Polissacarídeos/química , Agrobacterium tumefaciens/genética , Agrobacterium tumefaciens/crescimento & desenvolvimento , Anticorpos Monoclonais/química , Anticorpos Monoclonais/genética , Fucose/metabolismo , Glicosilação , Humanos , Neoplasias/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/microbiologia , Proteínas Recombinantes/metabolismo , /microbiologia
16.
FEMS Microbiol Lett ; 363(1): fnv209, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26511951

RESUMO

With the growing demand of fresh-cut vegetables, a variety of packaging films are produced specifically to improve safety and quality of the fresh vegetables over the storage period. The aim of our work was to evaluate the influence of different packaging films on the quality of fresh-cut lettuce analyzing changes in bacterial community composition and modifications at the proteome level, by means of culture-dependent/culture-independent methods and differential gel electrophoresis combined with mass spectrometry analysis. Total viable counts indicated the presence of a highly variable and complex microbial flora, around a mean value of 6.26 log10 CFU g(-1). Analysis of terminal-restriction fragment length polymorphism data indicated that bacterial communities changed with packaging films and time, showing differences in community composition and diversity indices between the commercially available package (F) and the new packages (A and C), in the first days after packaging. Also proteomic analysis revealed significant changes, involving proteins related to energy metabolism, photosynthesis, plant defense and oxidative stress processes, between F and A/C packages. In conclusion, microbiological and proteomic analysis have proved to be powerful tools to provide new insights into both the composition of leaf-associated bacterial communities and protein content of fresh-cut lettuce during the shelf-life storage process.


Assuntos
Bactérias/classificação , Bactérias/isolamento & purificação , Biota , Embalagem de Alimentos , /microbiologia , Proteoma/análise , Contagem de Colônia Microbiana , Eletroforese , Genômica , Espectrometria de Massas , Técnicas Microbiológicas , Polimorfismo de Fragmento de Restrição , Proteômica
17.
Plant Biotechnol J ; 14(1): 240-51, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25879373

RESUMO

Anti-CD20 murine or chimeric antibodies (Abs) have been used to treat non-Hodgkin lymphomas (NHLs) and other diseases characterized by overactive or dysfunctional B cells. Anti-CD20 Abs demonstrated to be effective in inducing regression of B-cell lymphomas, although in many cases patients relapse following treatment. A promising approach to improve the outcome of mAb therapy is the use of anti-CD20 antibodies to deliver cytokines to the tumour microenvironment. In particular, IL-2-based immunocytokines have shown enhanced antitumour activity in several preclinical studies. Here, we report on the engineering of an anti-CD20-human interleukin-2 (hIL-2) immunocytokine (2B8-Fc-hIL2) based on the C2B8 mAb (Rituximab) and the resulting ectopic expression in Nicotiana benthamiana. The scFv-Fc-engineered immunocytokine is fully assembled in plants with minor degradation products as assessed by SDS-PAGE and gel filtration. Purification yields using protein-A affinity chromatography were in the range of 15-20 mg/kg of fresh leaf weight (FW). Glycopeptide analysis confirmed the presence of a highly homogeneous plant-type glycosylation. 2B8-Fc-hIL2 and the cognate 2B8-Fc antibody, devoid of hIL-2, were assayed by flow cytometry on Daudi cells revealing a CD20 binding activity comparable to that of Rituximab and were effective in eliciting antibody-dependent cell-mediated cytotoxicity of human PBMC versus Daudi cells, demonstrating their functional integrity. In 2B8-Fc-hIL2, IL-2 accessibility and biological activity were verified by flow cytometry and cell proliferation assay. To our knowledge, this is the first example of a recombinant immunocytokine based on the therapeutic Rituximab antibody scaffold, whose expression in plants may be a valuable tool for NHLs treatment.


Assuntos
Antígenos CD20/imunologia , Interleucina-2/biossíntese , /genética , Agrobacterium/metabolismo , Sequência de Aminoácidos , Citotoxicidade Celular Dependente de Anticorpos , Western Blotting , Humanos , Extratos Vegetais/metabolismo , Folhas de Planta/metabolismo , Planticorpos/química , Planticorpos/isolamento & purificação , Plantas Geneticamente Modificadas , Ligação Proteica , Engenharia de Proteínas , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
18.
Bioengineered ; 6(5): 299-302, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26186119

RESUMO

We have recently characterized the degradation profiles of 2 human IgG1 monoclonal antibodies, the tumor-targeting mAb H10 and the anti-HIV mAb 2G12. Both mAbs were produced in plants either as stable transgenics or using a transient expression system based on leaf agroinfiltration. The purified antibodies were separated by 1DE and protein bands were characterized by N-terminal sequencing. The proteolytic cleavage sites identified in the heavy chain (HC) of both antibodies were localized in 3 inter-domain regions, suggesting that the number of proteolytic cleavage events taking place in plants is limited. One of the cleavage sites, close to the hinge region, was common to both antibodies.


Assuntos
Anticorpos Monoclonais/química , Anticorpos Monoclonais/metabolismo , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/metabolismo , Engenharia de Proteínas/métodos , Proteólise , Sequência de Aminoácidos , Anticorpos Monoclonais/genética , Sítios de Ligação , Humanos , Dados de Sequência Molecular , Plantas Geneticamente Modificadas/genética , Ligação Proteica
19.
Plant Biotechnol J ; 13(2): 235-45, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25283551

RESUMO

Plants are promising hosts for the production of monoclonal antibodies (mAbs). However, proteolytic degradation of antibodies produced both in stable transgenic plants and using transient expression systems is still a major issue for efficient high-yield recombinant protein accumulation. In this work, we have performed a detailed study of the degradation profiles of two human IgG1 mAbs produced in plants: an anti-HIV mAb 2G12 and a tumour-targeting mAb H10. Even though they use different light chains (κ and λ, respectively), the fragmentation pattern of both antibodies was similar. The majority of Ig fragments result from proteolytic degradation, but there are only a limited number of plant proteolytic cleavage events in the immunoglobulin light and heavy chains. All of the cleavage sites identified were in the proximity of interdomain regions and occurred at each interdomain site, with the exception of the VL /CL interface in mAb H10 λ light chain. Cleavage site sequences were analysed, and residue patterns characteristic of proteolytic enzymes substrates were identified. The results of this work help to define common degradation events in plant-produced mAbs and raise the possibility of predicting antibody degradation patterns 'a priori' and designing novel stabilization strategies by site-specific mutagenesis.


Assuntos
Anticorpos Monoclonais/metabolismo , Imunoglobulina G/metabolismo , Proteólise , Sequência de Aminoácidos , Anticorpos Monoclonais/química , Glicosilação , Immunoblotting , Dados de Sequência Molecular , Plantas Geneticamente Modificadas , Análise de Sequência de Proteína
20.
J Biomol Struct Dyn ; 32(4): 630-47, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23672348

RESUMO

Biomaterials research for the discovery of new generation nanoparticles is one of the most active areas of nanotechnology. In the search of nature-made nanometer-sized objects, plant virus particles appear as symmetrically defined entities that can be formed by protein self-assembly. In particular, in the field of plant virology, there is plenty of literature available describing the exploitation of plant viral cages to produce safe vaccine vehicles and nanoparticles for drug delivery. In this context, we have investigated on the use of the artichoke mottled crinkle virus (AMCV) capsid both as a carrier of immunogenic epitopes and for the delivery of anticancer molecules. A dual approach that combines both in silico tools and experimental virology was applied for the rational design of immunologically active chimeric virus-like particles (VLPs) carrying immunogenic peptides. The atomic structures of wild type (wt) and chimeric VLPs were obtained by homology modeling. The effects of insertion of the HIV-1 2F5 neutralizing epitope on the structural stability of chimeric VLPs were predicted and assessed by detailed inspection of the nanoparticle intersubunit interactions at atomic level. Wt and chimeric VLPs, exposing on their surface the 2F5 epitope, were successfully produced in plants. In addition, we demonstrated that AMCV capsids could also function as drug delivery vehicles able to load the chemotherapeutic drug doxorubicin. To our knowledge, this is the first systematic predictive and empirical research addressing the question of how this icosahedral virus can be used for the production of both VLPs and viral nanoparticles for biomedical applications.


Assuntos
Portadores de Fármacos/química , Desenho de Fármacos , Epitopos/química , Engenharia Genética , Nanopartículas , Vírus de Plantas , Sequência de Aminoácidos , Epitopos/imunologia , HIV-1/genética , HIV-1/imunologia , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Vírus de Plantas/genética , Vírus de Plantas/imunologia , Conformação Proteica , Alinhamento de Sequência , Relação Estrutura-Atividade , Proteínas Virais/química , Proteínas Virais/genética
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