Plant-produced SARS-CoV-2 antibody engineered towards enhanced potency and in vivo efficacy.

Prevention of severe COVID-19 disease by SARS-CoV-2 in high-risk patients, such as immuno-compromised individuals, can be achieved by administration of antibody prophylaxis, but producing antibodies can be costly. Plant expression platforms allow substantial lower production costs compared to traditional bio-manufacturing platforms depending on mammalian cells in bioreactors. In this study, we describe the expression, production and purification of the originally human COVA2-15 antibody in plants.

Exploring the Potentiality of a Plant Platform for Monoclonal Antibody Production in Veterinary Medicine.

Canine atopic dermatitis (CAD) is an allergic, inflammatory, and pruritic skin disease associated with the production of IgE antibodies against environmental allergens and mainly house dust mite allergens. This complex dermatological pathology involves Interleukin 31 (IL-31) as a central itch mediator. One of the most effective CAD treatments is a caninized monoclonal antibody (mAb) called Lokivetmab.

A fast and easy one-step purification strategy for plant-made antibodies using Protein A magnetic beads.

A major difficulty to reach commercial- scale production for plant-made antibodies is the complexity and cost of their purification from plant extracts. Here, using Protein A magnetic beads, two monoclonal antibodies are purified in a one-step procedure directly from non-clarified crude plant extracts. This technique provides significant savings in terms of resources, operation time, and equipment.

Cell wall biochemical alterations during Agrobacterium-mediated expression of haemagglutinin-based influenza virus-like vaccine particles in tobacco.

Influenza virus-like particles (VLPs) have been shown to induce a safe and potent immune response through both humoral and cellular responses. They represent promising novel influenza vaccines. Plant-based biotechnology allows for the large-scale production of VLPs of biopharmaceutical interest using different model organisms, including Nicotiana benthamiana plants.

Generation and characterization of a trackable plant-made influenza H5 virus-like particle (VLP) containing enhanced green fluorescent protein (eGFP).

Medicago, Inc. has developed an efficient virus-like particle (VLP) vaccine production platform using the Nicotiana benthamiana expression system, and currently has influenza-based products targeting seasonal/pandemic hemagglutinin (HA) proteins in advanced clinical trials. We wished to generate a trackable HA-based VLP that would allow us to study both particle assembly in plants and VLP interactions within the mammalian immune system.

Modulating secretory pathway pH by proton channel co-expression can increase recombinant protein stability in plants.

Eukaryotic expression systems are used for the production of complex secreted proteins. However, recombinant proteins face considerable biochemical challenges along the secretory pathway, including proteolysis and pH variation between organelles. As the use of synthetic biology matures into solutions for protein production, various host-cell engineering approaches are being developed to ameliorate host-cell factors that can limit recombinant protein quality and yield.

Biochemical composition of haemagglutinin-based influenza virus-like particle vaccine produced by transient expression in tobacco plants.

Influenza virus-like particles (VLPs) are noninfectious particles resembling the influenza virus representing a promising vaccine alternative to inactivated influenza virions as antigens. Medicago inc. has developed a plant-based VLP manufacturing platform allowing the large-scale production of GMP-grade influenza VLPs.

HIV-1 tropism testing and clinical management of CCR5 antagonists: Quebec review and recommendations.

HIV-1 tropism assays play a crucial role in determining the response to CCR5 receptor antagonists. Initially, phenotypic tests were used, but limited access to these tests prompted the development of alternative strategies. Recently, genotyping tropism has been validated using a Canadian technology in clinical trials investigating the use of maraviroc in both experienced and treatment-naive patients.

Plant N-glycan profiling of minute amounts of material.

Development of convenient strategies for identification of plant N-glycan profiles has been driven by the emergence of plants as an expression system for therapeutic proteins. In this article, we reinvestigated qualitative and quantitative aspects of plant N-glycan profiling. The extraction of plant proteins through a phenol/ammonium acetate procedure followed by deglycosylation with peptide N-glycosidase A (PNGase A) and coupling to 2-aminobenzamide provides an oligosaccharide preparation containing reduced amounts of contaminants from plant cell wall polysaccharides.

Expression of multiple proteins using full-length and deleted versions of cowpea mosaic virus RNA-2.

The use of multiple copies of vectors based on either full-length or deleted versions of cowpea mosaic virus RNA-2 for the production of heteromeric proteins in plants was investigated. Co-infiltration of two full-length RNA-2 constructs containing different marker genes into Nicotiana benthamiana in the presence of RNA-1 showed that the two foreign proteins were efficiently expressed within the same cell in inoculated tissue. Furthermore, the proteins were co-localized to the same subcellular compartments, an essential prerequisite for heteromer formation.

An in-built proteinase inhibitor system for the protection of recombinant proteins recovered from transgenic plants.

Proteolytic degradation represents a significant barrier to the efficient production of several recombinant proteins in plants, both in vivo during their expression and in vitro during their recovery from source tissues. Here, we describe a strategy to protect recombinant proteins during the recovery process, based on the coexpression of a heterologous proteinase inhibitor acting as a 'mouse trap' against the host proteases during extraction. After confirming the importance of trypsin- and chymotrypsin-like activities in crude protein extracts of potato (Solanum tuberosum L.

Cel6B of Thermobifidus fusca and a Cel5-CBM6 of Ruminococcus albus containing a cellulose binding site show synergistic effect on hydrolysis of native plant cellulose.

Hydrolysis of cellulose requires two different types of cellulases: exo- and endocellulase. Here, we investigated for the hydrolysis of cellulose by two types of cellulases, an endoglucanase (Cel5) from Ruminococcus albus fused with the xylanase A cellulose binding domain II (CBM6) of Clostridium stercorarium and Thermobifidus fusca E3, an exoglucanase (Cel6B). Cel5-CBM6 or Cel6B showed a linear relationship between the production of soluble sugars and the incubation time when native alfalfa cellulose was used as a substrate.

A comparative study between an endoglucanase IV and its fused protein complex Cel5-CBM6.

The recombinant endoglucanase IV (Cel5; encoded by egIV) of Ruminococcus albus was compared with protein Cel5-CBM6 comprised of Cel5 fused at the C-terminus with the single-cellulose binding domain II (CBM6) of Clostridium stercorarium xylanase A, in order to improve its binding ability. Previous analyses using ball-milled cellulose had suggested that a cellulose binding domain of xylanase A could enhance cellulase activity, especially with insoluble substrates. Comparison of the catalytic activities of Cel5 and Cel5-CBM6 were determined using carboxymethylcellulose, Avicel, and filter paper as substrates.