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1.
JCI Insight ; 4(1)2019 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-30626745

RESUMO

Ricin toxin (RT) ranks at the top of the list of bioweapons of concern to civilian and military personnel alike, due to its high potential for morbidity and mortality after inhalation. In nonhuman primates, aerosolized ricin triggers severe acute respiratory distress characterized by perivascular and alveolar edema, neutrophilic infiltration, and severe necrotizing bronchiolitis and alveolitis. There are currently no approved countermeasures for ricin intoxication. Here, we report the therapeutic potential of a humanized mAb against an immunodominant epitope on ricin's enzymatic A chain (RTA). Rhesus macaques that received i.v. huPB10 4 hours after a lethal dose of ricin aerosol exposure survived toxin challenge, whereas control animals succumbed to ricin intoxication within 30 hours. Antibody intervention at 12 hours resulted in the survival of 1 of 5 monkeys. Changes in proinflammatory cytokine, chemokine, and growth factor profiles in bronchial alveolar lavage fluids before and after toxin challenge successfully clustered animals by treatment group and survival, indicating a relationship between local tissue damage and experimental outcome. This study represents the first demonstration, to our knowledge, in nonhuman primates that the lethal effects of inhalational ricin exposure can be negated by a drug candidate, and it opens up a path forward for product development.

2.
Cell Host Microbe ; 25(1): 49-58.e5, 2019 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-30629918

RESUMO

Recent and ongoing outbreaks of Ebola virus disease (EVD) underscore the unpredictable nature of ebolavirus reemergence and the urgent need for antiviral treatments. Unfortunately, available experimental vaccines and immunotherapeutics are specific for a single member of the Ebolavirus genus, Ebola virus (EBOV), and ineffective against other ebolaviruses associated with EVD, including Sudan virus (SUDV) and Bundibugyo virus (BDBV). Here we show that MBP134AF, a pan-ebolavirus therapeutic comprising two broadly neutralizing human antibodies (bNAbs), affords unprecedented effectiveness and potency as a therapeutic countermeasure to antigenically diverse ebolaviruses. MBP134AF could fully protect ferrets against lethal EBOV, SUDV, and BDBV infection, and a single 25-mg/kg dose was sufficient to protect NHPs against all three viruses. The development of MBP134AF provides a successful model for the rapid discovery and translational advancement of immunotherapeutics targeting emerging infectious diseases.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/uso terapêutico , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/uso terapêutico , Ebolavirus/patogenicidade , Furões/virologia , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/prevenção & controle , Bem-Estar do Animal , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/isolamento & purificação , Anticorpos Neutralizantes/administração & dosagem , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/isolamento & purificação , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/administração & dosagem , Linhagem Celular , Cercopithecus aethiops , Modelos Animais de Doenças , Feminino , Filoviridae/imunologia , Infecções por Filoviridae/imunologia , Infecções por Filoviridae/prevenção & controle , Infecções por Filoviridae/virologia , Glicoproteínas/imunologia , Cobaias , Células HEK293 , Doença pelo Vírus Ebola/virologia , Humanos , Células Matadoras Naturais , Macaca , Macaca fascicularis , Masculino , Primatas , Análise de Sobrevida , Resultado do Tratamento , Proteínas Virais/imunologia
3.
Cell Host Microbe ; 25(1): 39-48.e5, 2019 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-30629917

RESUMO

Passive administration of monoclonal antibodies (mAbs) is a promising therapeutic approach for Ebola virus disease (EVD). However, all mAbs and mAb cocktails that have entered clinical development are specific for a single member of the Ebolavirus genus, Ebola virus (EBOV), and ineffective against outbreak-causing Bundibugyo virus (BDBV) and Sudan virus (SUDV). Here, we advance MBP134, a cocktail of two broadly neutralizing human mAbs, ADI-15878 from an EVD survivor and ADI-23774 from the same survivor but specificity-matured for SUDV GP binding affinity, as a candidate pan-ebolavirus therapeutic. MBP134 potently neutralized all ebolaviruses and demonstrated greater protective efficacy than ADI-15878 alone in EBOV-challenged guinea pigs. A second-generation cocktail, MBP134AF, engineered to effectively harness natural killer (NK) cells afforded additional improvement relative to its precursor in protective efficacy against EBOV and SUDV in guinea pigs. MBP134AF is an optimized mAb cocktail suitable for evaluation as a pan-ebolavirus therapeutic in nonhuman primates.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Ebolavirus/imunologia , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/prevenção & controle , Bem-Estar do Animal , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/isolamento & purificação , Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/administração & dosagem , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/isolamento & purificação , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/administração & dosagem , Anticorpos Antivirais/uso terapêutico , Antivirais , Modelos Animais de Doenças , Ebolavirus/patogenicidade , Epitopos/imunologia , Feminino , Filoviridae/imunologia , Cobaias , Doença pelo Vírus Ebola/virologia , Humanos , Imunoterapia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Proteínas Recombinantes/imunologia , Resultado do Tratamento
4.
Sci Transl Med ; 9(384)2017 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-28381540

RESUMO

As observed during the 2013-2016 Ebola virus disease epidemic, containment of filovirus outbreaks is challenging and made more difficult by the lack of approved vaccine or therapeutic options. Marburg and Ravn viruses are highly virulent and cause severe and frequently lethal disease in humans. Monoclonal antibodies (mAbs) are a platform technology in wide use for autoimmune and oncology indications. Previously, we described human mAbs that can protect mice from lethal challenge with Marburg virus. We demonstrate that one of these mAbs, MR191-N, can confer a survival benefit of up to 100% to Marburg or Ravn virus-infected rhesus macaques when treatment is initiated up to 5 days post-inoculation. These findings extend the small but growing body of evidence that mAbs can impart therapeutic benefit during advanced stages of disease with highly virulent viruses and could be useful in epidemic settings.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Infecções por Filoviridae/tratamento farmacológico , Filoviridae/fisiologia , Doença do Vírus de Marburg/tratamento farmacológico , Marburgvirus/fisiologia , Animais , Proteção Cruzada , Infecções por Filoviridae/virologia , Cobaias , Humanos , Macaca fascicularis , Macaca mulatta , Doença do Vírus de Marburg/virologia , Projetos Piloto
5.
Clin Vaccine Immunol ; 23(9): 795-9, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27466351

RESUMO

PB10 is a murine monoclonal antibody against an immunodominant epitope on ricin toxin's enzymatic subunit. Here, we characterize a fully humanized version of PB10 IgG1 (hPB10) and demonstrate that it has potent in vitro and in vivo toxin-neutralizing activities. We also report the minimum serum concentrations of hPB10 required to protect mice against 10 times the 50% lethal dose of ricin when delivered by injection and inhalation.


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais/administração & dosagem , Antitoxinas/administração & dosagem , Substâncias para a Guerra Química/toxicidade , Envenenamento/terapia , Ricina/toxicidade , Animais , Anticorpos Monoclonais/isolamento & purificação , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais Humanizados/isolamento & purificação , Anticorpos Monoclonais Humanizados/farmacologia , Antitoxinas/isolamento & purificação , Antitoxinas/farmacologia , Modelos Animais de Doenças , Feminino , Camundongos Endogâmicos BALB C , Análise de Sobrevida , Resultado do Tratamento
6.
Proc Natl Acad Sci U S A ; 113(16): 4458-63, 2016 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-27044104

RESUMO

Countermeasures against potential biothreat agents remain important to US Homeland Security, and many of these pharmaceuticals could have dual use in the improvement of global public health. Junin virus, the causative agent of Argentine hemorrhagic fever (AHF), is an arenavirus identified as a category A high-priority agent. There are no Food and Drug Administration (FDA) approved drugs available for preventing or treating AHF, and the current treatment option is limited to administration of immune plasma. Whereas immune plasma demonstrates the feasibility of passive immunotherapy, it is limited in quantity, variable in quality, and poses safety risks such as transmission of transfusion-borne diseases. In an effort to develop a monoclonal antibody (mAb)-based alternative to plasma, three previously described neutralizing murine mAbs were expressed as mouse-human chimeric antibodies and evaluated in the guinea pig model of AHF. These mAbs provided 100% protection against lethal challenge when administered 2 d after infection (dpi), and one of them (J199) was capable of providing 100% protection when treatment was initiated 6 dpi and 92% protection when initiated 7 dpi. The efficacy of J199 is superior to that previously described for all other evaluated drugs, and its high potency suggests that mAbs like J199 offer an economical alternative to immune plasma and an effective dual use (bioterrorism/public health) therapeutic.


Assuntos
Anticorpos Monoclonais/farmacologia , Anticorpos Antivirais/farmacologia , Febre Hemorrágica Americana/tratamento farmacológico , Febre Hemorrágica Americana/imunologia , Animais , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/genética , Anticorpos Antivirais/imunologia , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Cobaias , Humanos , Vírus Junin , Camundongos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/farmacologia
7.
Virology ; 490: 49-58, 2016 03.
Artigo em Inglês | MEDLINE | ID: mdl-26828465

RESUMO

Middle East Respiratory Syndrome Coronavirus (MERS-CoV) was identified in 2012 as the causative agent of a severe, lethal respiratory disease occurring across several countries in the Middle East. To date there have been over 1600 laboratory confirmed cases of MERS-CoV in 26 countries with a case fatality rate of 36%. Given the endemic region, it is possible that MERS-CoV could spread during the annual Hajj pilgrimage, necessitating countermeasure development. In this report, we describe the clinical and radiographic changes of rhesus monkeys following infection with 5×10(6) PFU MERS-CoV Jordan-n3/2012. Two groups of NHPs were treated with either a human anti-MERS monoclonal antibody 3B11-N or E410-N, an anti-HIV antibody. MERS-CoV Jordan-n3/2012 infection resulted in quantifiable changes by computed tomography, but limited other clinical signs of disease. 3B11-N treated subjects developed significantly reduced lung pathology when compared to infected, untreated subjects, indicating that this antibody may be a suitable MERS-CoV treatment.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Anticorpos Antivirais/administração & dosagem , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/patologia , Pulmão/patologia , Coronavírus da Síndrome Respiratória do Oriente Médio/fisiologia , Animais , Infecções por Coronavirus/virologia , Modelos Animais de Doenças , Humanos , Pulmão/virologia , Macaca mulatta , Masculino
8.
J Immunol Methods ; 422: 111-7, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25865265

RESUMO

We have produced and characterized two chimeric human IgG1 monoclonal antibodies that bind different immunodominant epitopes on Vibrio cholerae lipopolysaccharide (LPS). MAb 2D6 IgG1 recognizes Ogawa O-polysaccharide antigen, while mAb ZAC-3 IgG1 recognizes core/lipid A moiety of Ogawa and Inaba LPS. Both antibodies were expressed using a Nicotiana benthamiana-based rapid antibody-manufacturing platform (RAMP) and evaluated in vitro for activities associated with immunity to V. cholerae, including vibriocidal activity, bacterial agglutination and motility arrest.


Assuntos
Anticorpos Antibacterianos/imunologia , Anticorpos Monoclonais/imunologia , Epitopos Imunodominantes/imunologia , Imunoglobulina G/imunologia , Vibrio cholerae/imunologia , Anticorpos Antibacterianos/biossíntese , Anticorpos Antibacterianos/genética , Anticorpos Monoclonais/biossíntese , Anticorpos Monoclonais/genética , Antígenos de Bactérias/imunologia , Quimera/imunologia , Clonagem Molecular , Epitopos/imunologia , Humanos , Imunoglobulina G/biossíntese , Imunoglobulina G/genética , Lipopolissacarídeos/imunologia , Antígenos O/imunologia , Tabaco/genética
9.
Toxicon ; 92: 36-41, 2014 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-25260254

RESUMO

Due to the fast-acting nature of ricin, staphylococcal enterotoxin B (SEB), and Clostridium perfringens epsilon toxin (ETX), it is necessary that therapeutic interventions following a bioterrorism incident by one of these toxins occur as soon as possible after intoxication. Moreover, because the clinical manifestations of intoxication by these agents are likely to be indistinguishable from each other, especially following aerosol exposure, we have developed a cocktail of chimeric monoclonal antibodies that is capable of neutralizing all three toxins. The efficacy of this cocktail was demonstrated in mouse models of lethal dose toxin challenge.


Assuntos
Anticorpos Monoclonais/farmacologia , Toxinas Bacterianas/toxicidade , Bioterrorismo/prevenção & controle , Enterotoxinas/toxicidade , Envenenamento/prevenção & controle , Proteínas Recombinantes de Fusão/farmacologia , Ricina/toxicidade , Animais , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Testes de Neutralização
10.
Nature ; 514(7520): 47-53, 2014 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-25171469

RESUMO

Without an approved vaccine or treatments, Ebola outbreak management has been limited to palliative care and barrier methods to prevent transmission. These approaches, however, have yet to end the 2014 outbreak of Ebola after its prolonged presence in West Africa. Here we show that a combination of monoclonal antibodies (ZMapp), optimized from two previous antibody cocktails, is able to rescue 100% of rhesus macaques when treatment is initiated up to 5 days post-challenge. High fever, viraemia and abnormalities in blood count and blood chemistry were evident in many animals before ZMapp intervention. Advanced disease, as indicated by elevated liver enzymes, mucosal haemorrhages and generalized petechia could be reversed, leading to full recovery. ELISA and neutralizing antibody assays indicate that ZMapp is cross-reactive with the Guinean variant of Ebola. ZMapp exceeds the efficacy of any other therapeutics described so far, and results warrant further development of this cocktail for clinical use.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Anticorpos Antivirais/uso terapêutico , Doença pelo Vírus Ebola/tratamento farmacológico , Imunização Passiva , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/imunologia , Reações Cruzadas/imunologia , Ebolavirus/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Guiné , Cobaias , Doença pelo Vírus Ebola/sangue , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/virologia , Macaca mulatta/imunologia , Macaca mulatta/virologia , Masculino , Dados de Sequência Molecular , Alinhamento de Sequência , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/imunologia , Viremia/tratamento farmacológico , Viremia/imunologia , Viremia/virologia
11.
Proc Natl Acad Sci U S A ; 111(16): 5992-7, 2014 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-24711420

RESUMO

Respiratory syncytial virus (RSV) can cause devastating lower respiratory tract infections in preterm infants or when other serious health problems are present. Immunoprophylaxis with palivizumab (Synagis), a humanized IgG1 mAb, is the current standard of care for preventing RSV infection in at-risk neonates. We have explored the contribution of effector function to palivizumab efficacy using a plant-based expression system to produce palivizumab N-glycan structure variants with high homogeneity on different antibody isotypes. We compared these isotype and N-glycoform variants with commercially available palivizumab with respect to both in vitro receptor and C1q binding and in vivo efficacy. Whereas the affinity for antigen and neutralization activity of each variant were indistinguishable from those of palivizumab, their Fcγ receptor binding profiles were very different, which was reflected in either a reduced or enhanced ability to influence the RSV lung titer in challenged cotton rats. Enhanced Fcγ receptor binding was associated with reduced viral lung titers compared with palivizumab, whereas abrogation of receptor binding led to a drastic reduction in efficacy. The results support the hypotheses that classic antibody neutralization is a minor component of efficacy by palivizumab in the cotton rat and that antibody-dependent cell-mediated cytotoxicity activity can significantly enhance the efficacy of this antiviral mAb.


Assuntos
Anticorpos Antivirais/química , Anticorpos Antivirais/uso terapêutico , Polissacarídeos/metabolismo , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Infecções por Vírus Respiratório Sincicial/imunologia , Vírus Sinciciais Respiratórios/imunologia , Sigmodontinae/virologia , Animais , Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/farmacologia , Complemento C1q/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/patologia , Pulmão/virologia , Masculino , Testes de Neutralização , Ligação Proteica/efeitos dos fármacos , Receptores Fc/metabolismo , Vírus Sinciciais Respiratórios/efeitos dos fármacos , Sigmodontinae/imunologia , Resultado do Tratamento
12.
Clin Vaccine Immunol ; 21(5): 777-82, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24574537

RESUMO

Recent incidents in the United States and abroad have heightened concerns about the use of ricin toxin as a bioterrorism agent. In this study, we produced, using a robust plant-based platform, four chimeric toxin-neutralizing monoclonal antibodies that were then evaluated for the ability to passively protect mice from a lethal-dose ricin challenge. The most effective antibody, c-PB10, was further evaluated in mice as a therapeutic following ricin exposure by injection and inhalation.


Assuntos
Antitoxinas/administração & dosagem , Imunização Passiva/métodos , Planticorpos/administração & dosagem , Envenenamento/prevenção & controle , Ricina/antagonistas & inibidores , Ricina/toxicidade , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Neutralizantes/administração & dosagem , Feminino , Camundongos Endogâmicos BALB C , Análise de Sobrevida , Resultado do Tratamento
13.
MAbs ; 5(2): 263-9, 2013 Mar-Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23396091

RESUMO

Severe lower respiratory tract infection in infants and small children is commonly caused by respiratory syncytial virus (RSV). Palivizumab (Synagis(®)), a humanized IgG1 monoclonal antibody (mAb) approved for RSV immunoprophylaxis in at-risk neonates, is highly effective, but pharmacoeconomic analyses suggest its use may not be cost-effective. Previously described potent RSV neutralizers (human Fab R19 and F2-5; human IgG RF-1 and RF-2) were produced in IgG format in a rapid and inexpensive Nicotiana-based manufacturing system for comparison with palivizumab. Both plant-derived (palivizumab-N) and commercial palivizumab, which is produced in a mouse myeloma cell line, showed protection in prophylactic (p < 0.001 for both mAbs) and therapeutic protocols (p < 0.001 and p < 0.05 respectively). The additional plant-derived human mAbs directed against alternative epitopes displayed neutralizing activity, but conferred less protection in vivo than palivizumab-N or palivizumab. Palivizumab remains one of the most efficacious RSV mAbs described to date. Production in plants may reduce manufacturing costs and improve the pharmacoeconomics of RSV immunoprophylaxis and therapy.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Anticorpos Neutralizantes/uso terapêutico , Vírus Sincicial Respiratório Humano/imunologia , Tabaco/imunologia , Animais , Anticorpos Monoclonais Humanizados/economia , Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Neutralizantes/economia , Anticorpos Neutralizantes/imunologia , Modelos Animais de Doenças , Humanos , Palivizumab , Infecções por Vírus Respiratório Sincicial/imunologia , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Infecções por Vírus Respiratório Sincicial/virologia , Sigmodontinae , Resultado do Tratamento
14.
Proc Natl Acad Sci U S A ; 108(51): 20690-4, 2011 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-22143789

RESUMO

No countermeasures currently exist for the prevention or treatment of the severe sequelae of Filovirus (such as Ebola virus; EBOV) infection. To overcome this limitation in our biodefense preparedness, we have designed monoclonal antibodies (mAbs) which could be used in humans as immunoprotectants for EBOV, starting with a murine mAb (13F6) that recognizes the heavily glycosylated mucin-like domain of the virion-attached glycoprotein (GP). Point mutations were introduced into the variable region of the murine mAb to remove predicted human T-cell epitopes, and the variable regions joined to human constant regions to generate a mAb (h-13F6) appropriate for development for human use. We have evaluated the efficacy of three variants of h-13F6 carrying different glycosylation patterns in a lethal mouse EBOV challenge model. The pattern of glycosylation of the various mAbs was found to correlate to level of protection, with aglycosylated h-13F6 providing the least potent efficacy (ED(50) = 33 µg). A version with typical heterogenous mammalian glycoforms (ED(50) = 11 µg) had similar potency to the original murine mAb. However, h-13F6 carrying complex N-glycosylation lacking core fucose exhibited superior potency (ED(50) = 3 µg). Binding studies using Fcγ receptors revealed enhanced binding of nonfucosylated h-13F6 to mouse and human FcγRIII. Together the results indicate the presence of Fc N-glycans enhances the protective efficacy of h-13F6, and that mAbs manufactured with uniform glycosylation and a higher potency glycoform offer promise as biodefense therapeutics.


Assuntos
Ebolavirus/metabolismo , Fucose/imunologia , Animais , Anticorpos Monoclonais/química , Antivirais/química , Complemento C1q/química , Ebolavirus/imunologia , Feminino , Fucose/química , Glicosilação , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/prevenção & controle , Humanos , Sistema Imunitário , Imunização Passiva , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Ressonância de Plasmônio de Superfície , Tabaco
15.
PLoS One ; 6(10): e26040, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22039433

RESUMO

BACKGROUND: Fc-glycosylation of monoclonal antibodies (mAbs) has profound implications on the Fc-mediated effector functions. Alteration of this glycosylation may affect the efficiency of an antibody. However, difficulties in the production of mAbs with homogeneous N-glycosylation profiles in sufficient amounts hamper investigations of the potential biological impact of different glycan residues. METHODOLOGY/PRINCIPAL FINDINGS: Here we set out to evaluate a transient plant viral based production system for the rapid generation of different glycoforms of a monoclonal antibody. Ebola virus mAb h-13F6 was generated using magnICON expression system in Nicotiana benthamiana, a plant species developed for commercial scale production of therapeutic proteins. h-13F6 was co-expressed with a series of modified mammalian enzymes involved in the processing of complex N-glycans. Using wild type (WT) plants and the glycosylation mutant ΔXTFT that synthesizes human like biantennary N-glycans with terminal N-acetylglucosamine on each branch (GnGn structures) as expression hosts we demonstrate the generation of h-13F6 complex N-glycans with (i) bisected structures, (ii) core α1,6 fucosylation and (iii) ß1,4 galactosylated oligosaccharides. In addition we emphasize the significance of precise sub Golgi localization of enzymes for engineering of IgG Fc-glycosylation. CONCLUSION: The method described here allows the efficient generation of a series of different human-like glycoforms at large homogeneity of virtually any antibody within one week after cDNA delivery to plants. This accelerates follow up functional studies and thus may contribute to study the biological role of N-glycan residues on Fcs and maximizing the clinical efficacy of therapeutic antibodies.


Assuntos
Anticorpos Monoclonais/biossíntese , Ebolavirus/imunologia , Anticorpos Monoclonais/imunologia , Cromatografia Líquida , Eletroforese em Gel de Poliacrilamida , Glicosilação , Planticorpos/imunologia , Espectrometria de Massas por Ionização por Electrospray , Tabaco/imunologia
16.
Plant Biotechnol J ; 8(5): 638-54, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20514694

RESUMO

Plants have been proposed as an attractive alternative for pharmaceutical protein production to current mammalian or microbial cell-based systems. Eukaryotic protein processing coupled with reduced production costs and low risk for mammalian pathogen contamination and other impurities have led many to predict that agricultural systems may offer the next wave for pharmaceutical product production. However, for this to become a reality, the quality of products produced at a relevant scale must equal or exceed the predetermined release criteria of identity, purity, potency and safety as required by pharmaceutical regulatory agencies. In this article, the ability of transient plant virus expression systems to produce a wide range of products at high purity and activity is reviewed. The production of different recombinant proteins is described along with comparisons with established standards, including high purity, specific activity and promising preclinical outcomes. Adaptation of transient plant virus systems to large-scale manufacturing formats required development of virus particle and Agrobacterium inoculation methods. One transient plant system case study illustrates the properties of greenhouse and field-produced recombinant aprotinin compared with an US Food and Drug Administration-approved pharmaceutical product and found them to be highly comparable in all properties evaluated. A second transient plant system case study demonstrates a fully functional monoclonal antibody conforming to release specifications. In conclusion, the production capacity of large quantities of recombinant protein offered by transient plant expression systems, coupled with robust downstream purification approaches, offers a promising solution to recombinant protein production that compares favourably to cell-based systems in scale, cost and quality.


Assuntos
Anticorpos Monoclonais/biossíntese , Aprotinina/biossíntese , Engenharia Genética/métodos , Plantas Geneticamente Modificadas/metabolismo , Proteínas Recombinantes/biossíntese , Anticorpos Monoclonais/imunologia , Aprotinina/imunologia , Vírus de Plantas , Plantas Geneticamente Modificadas/imunologia , Proteínas Recombinantes/imunologia , Rhizobium
17.
Curr Microbiol ; 49(1): 22-7, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15297925

RESUMO

Binding and competition of five Bacillus thuringiensis toxins--Cry1Ab, Cry1Ac, Cry1Ba, Cry1Ca, and Cry1Ea--for midgut binding sites from three pests, Spodoptera frugiperda, Diatraea saccharalis, and Diatraea grandiosella, were investigated as part of a strategy to develop tropical transgenic maize resistant to several stemborers. On S. frugiperda, Cry1Ab and Cry1Ac compete for the same binding site; Cry1Ba and Cry1Ca compete for a second binding site. Cry1Ea recognizes a third specific binding site in S. frugiperda and does not compete with any of the other toxins. On D. grandiosella and D. saccharalis, Cry1Ac competes with Cry1Ab and not with Cry1Ba and Cry1Ca. Cry1Ba and Cry1Ca recognize each a specific binding site and do not compete with any of the other four toxins. Cry1Ea does not recognize any binding site on Diatraea species. Combinations of toxins are proposed to develop transgenic maize resistant to the three stemborers while allowing resistance management.


Assuntos
Bacillus thuringiensis/metabolismo , Proteínas de Bactérias/farmacologia , Toxinas Bacterianas/farmacologia , Endotoxinas/farmacologia , Lepidópteros/microbiologia , Zea mays/parasitologia , Animais , Bacillus thuringiensis/genética , Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/metabolismo , Sítios de Ligação , Ligação Competitiva , Endotoxinas/metabolismo , Proteínas Hemolisinas , Larva/citologia , Larva/efeitos dos fármacos , Larva/metabolismo , Lepidópteros/efeitos dos fármacos , Lepidópteros/metabolismo , Controle Biológico de Vetores , Plantas Geneticamente Modificadas
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