Non-Carrier Nanoparticles Adjuvant ModularProtein Vaccine in a Particle-Dependent Manner

Nanoparticles are increasingly used to adjuvant vaccine formulations due to their biocompatibility, ease of manufacture and the opportunity to tailor their size, shape, and physicochemical properties. The efficacy of similarly-sized silica (Si-OH), poly (D,L-lactic-co-glycolic acid) (PLGA) and poly caprolactone (PCL) nanoparticles (nps) to adjuvant recombinant capsomere presenting antigenic M2e modular peptide from Influenza A virus (CapM2e) was investigated in vivo. Formulation of CapM2e with Si-OH or PLGA nps significantly boosted the immunogenicity of modular capsomeres, even though CapM2e was not actively attached to the nanoparticles prior to injection (i.e., formulation was by simple mixing). In contrast, PCL nps showed no significant adjuvant effect using this simple-mixing approach. The immune response induced by CapM2e alone or formulated with nps was antibody-biased with very high antigen-specific antibody titer and less than 20 cells per million splenocytes secreting interferon gamma. Modification of silica nanoparticle surface properties through amine functionalization and pegylation did not lead to significant changes in immune response. This study confirms that simple mixing-based formulation can lead to effective adjuvanting of antigenic protein, though with antibody titer dependent on nanoparticle physicochemical properties

Influence of DNA-protein interactions on purification and assembly of virus-like particles

Modular virus-like-particles (VLPs), presenting foreign antigens on their surface, are promising candidates for a wide range of future vaccines. A viable production pathway is the expression and purification of viral structural proteins and their subsequent in vitro assembly into VLPs, in a bioprocess environment. One promising approach is the use of murine polyomavirus major capsid protein VP1 as a carrier of modular epitopes from vaccine targets. This platform technology uses E. coli as an expression system and showed promising results in creating VLP vaccines candidates directed at influenza, Group A Streptococcus and other infectious pathogens. However, like other viral capsomeres and viral structures, purification using chromatography techniques remains a challenge as conventional high capacity ion exchange matrices suffer from low binding capacities. In this work the role of DNA-protein interaction during the purification of VLP precursor capsomeres is investigated. It is found that modular VP1 capsomeres coat DNA molecules forming large DNA-protein complexes that are unable to access the pores of chromatographic resins resulting in inefficient column binding. By increasing the salt concentration of the buffer above 0.3M NaCl, the DNA-protein complexes dissociate. At intermediate salt concentrations salt-tolerant ion-exchange resins can be used to efficiently capture and purify VP1 capsomeres, as the salt breaks the aggregates but is insufficient to interfere with binding to the salt-tolerant matrix. This approach increases the binding capacity of VLP precursor proteins by at least a magnitude over published laboratory-based methods. Please click Download on the upper right corner to see the full abstract

Structural-based designed modular capsomere comprising HA1 as low-cost poultry influenza vaccine

Influenza is a severe respiratory tract infection caused by influenza viruses. The increasing number of highly pathogenic avian influenza (HPAI) virus outbreaks, generally H5 and H7 subtypes, underlines the threat of a possible pandemic. The recent HPAI H5 outbreak in domestic poultry and wild birds in US from December 2014 to June 2015, affecting almost 50 million birds and resulting in $3.3 billion economic losses due to the death and culling of poultry, has demonstrated the lack of capabilities to control the rapid spread of avian influenza. Poultry vaccination has been shown to not only reduce the virus spread in animals but also reduce the virus transmission to humans, preventing potential pandemic development. However, existing vaccine technologies could not respond to a new virus outbreak rapidly and at a cost and scale that is commercially viable for mass poultry vaccination. Here, we developed modular capsomeres, building blocks of virus-like particle, as a low-cost poultry influenza vaccine. Modified murine polyomavirus (MuPyV) VP1 capsomere was used to present structural-based designed influenza Hemagglutinin (HA1) antigen. Six constructs of modular capsomeres presenting three truncated versions of HA1 and two constructs of modular capsomeres presenting non-modified HA1 have been generated. Modular capsomeres presenting HA1 were successfully produced in stable forms using Escherichia coli, without the need for protein refolding process. This adjuvanted modular capsomere (CapHA1) induced strong antibody responses (almost 105 endpoint titre) when administered into chickens, similar to titres obtained in the group administered with insect cell-based HA1 proteins. Based on our process simulation, 320 million doses of modular capsomere vaccines can be produced in 2.3 days, at a cost of less than 1 cent per dose. The result presented here indicated that this platform for bacterially-produced modular capsomere could potentially translate into a rapid-response and low-cost vaccine manufacturing technology suitable for poultry vaccination

Process simulation based decisional tool to evaluate strategies for continuous downstream bioprocess implementation - A CDMO perspective

To maintain a competitive space in the rapidly expanding and highly competitive market, many biopharmaceutical companies are outsourcing to contract development and manufacturing organizations (CDMOs) to accelerate research and development, shorten the time to market, alleviate internal capacity and technical constraints, and reduce risks associated with production [1]. To acquire new and maintain current clients, CDMOs must have strong, diverse technical offerings for development, manufacture, and testing of products with competitive pricing and timelines [2]. Adopting innovative technologies like continuous downstream processing can help debottleneck the process and reduce processing time, which is the most appealing to CDMOs as it translates to an increased number of batches per year. The majority of continuous processing assessments to date have focused on cost of goods and not on the time reduction potential [3-7]. End-to-end continuous downstream processing is not always practical as CDMOs must accommodate a wide range of molecules and processes. Hence, it is imperative to evaluate and customize continuous production based on client needs. Application of process simulation as a decisional tool to select an appropriate downstream processing strategy was evaluated. Two modelling programs were evaluated: BioSolve Process and SuperPro Designer®. Fully continuous and hybrid (continuous Protein A operation only) downstream processing were assessed for a 2000 L fed-batch bioreactor producing 1, 5, and 10 g/L of monoclonal antibody at 40 and 200 kg production demands. Hybrid and continuous processing decreased batch duration by 20% and 60%, respectively. Continuous processing was more favorable for higher titer processes (≥ 5 g/L). The largest cost reductions were observed for 5 and 10 g/L titer processes during 40 kg production. The results highlight the business case for continuous downstream bioprocessing especially at a CDMO. Selection of a processing method will be influenced by a range of factors and the impact can easily be assessed using process simulation. Therefore, it is recommended that CDMOs use process simulation to ensure the most favorable processing strategy is selected. [1] O. Gassmann, A. Schuhmacher, M. von Zedtwitz, G. Reepmeyer, The Make-or-Buy Challenge: How to In-and Outsource Innovation, Leading Pharmaceutical Innovation, Springer2018, pp. 79-110. [2] R. Hernandez, Contract Biomanufacturing Firms Become More Specialized, BioPharm International, 28 (2015) 22-27. [3] D. Pollard, M. Brower, Y. Abe, A.G. Lopes, Standardized Economic Cost Modeling for Next-Generation MAb Production, BioProcess Int, (2016). [4] A. Xenopoulos, A new, integrated, continuous purification process template for monoclonal antibodies: process modeling and cost of goods studies, Journal of biotechnology, 213 (2015) 42-53. [5] J. Hummel, M. Pagkaliwangan, X. Gjoka, T. Davidovits, R. Stock, T. Ransohoff, R. Gantier, M. Schofield, Modeling the Downstream Processing of Monoclonal Antibodies Reveals Cost Advantages for Continuous Methods for a Broad Range of Manufacturing Scales, Biotechnology journal, (2018) 1700665. [6] J. Pollock, J. Coffman, S.V. Ho, S.S. Farid, Integrated continuous bioprocessing: Economic, operational, and environmental feasibility for clinical and commercial antibody manufacture, Biotechnology progress, 33 (2017) 854-866. [7] S. Klutz, L. Holtmann, M. Lobedann, G. Schembecker, Cost evaluation of antibody production processes in different operation modes, Chemical Engineering Science, 141 (2016) 63-74

Design and optimization of membrane chromatography process for monoclonal antibody charge variant separation

Please click Additional Files below to see the full abstract

The structure of the caspase recruitment domain of BinCARD reveals that all three cysteines can be oxidized

The caspase recruitment domain (CARD) is present in death-domain superfamily proteins involved in inflammation and apoptosis. BinCARD is named for its ability to interact with Bcl10 and inhibit downstream signalling. Human BinCARD is expressed as two isoforms that encode the same N-terminal CARD region but which differ considerably in their C-termini. Both isoforms are expressed in immune cells, although BinCARD-2 is much more highly expressed. Crystals of the CARD fold common to both had low symmetry (space group P1). Molecular replacement was unsuccessful in this low-symmetry space group and, as the construct contains no methionines, first one and then two residues were engineered to methionine for MAD phasing. The double-methionine variant was produced as a selenomethionine derivative, which was crystallized and the structure was solved using data measured at two wavelengths. The crystal structures of the native and selenomethionine double mutant were refined to high resolution (1.58 and 1.40 Å resolution, respectively), revealing the presence of a cis-peptide bond between Tyr39 and Pro40. Unexpectedly, the native crystal structure revealed that all three cysteines were oxidized. The mitochondrial localization of BinCARD-2 and the susceptibility of its CARD region to redox modification points to the intriguing possibility of a redox-regulatory role

Characterizing Enterovirus 71 and Coxsackievirus A16 Virus-like Particles Production in Insect Cells

Enterovirus 71 (EV71) and Coxsackievirus A16 (CVA16) are two viruses commonly responsible for hand, foot and mouth disease (HFMD) in children. The lack of prophylactic or therapeutic measures against HFMD is a major public health concern. Insect cell-based EV71 and CVA16 virus-like particles (VLPs) are promising vaccine candidates against HFMD and are currently under development. In this paper, the influence of insect cell line, incubation temperature, and serial passaging effect and stability of budded virus (BV) stocks on EV71 and CVA16 VLP production was investigated. Enhanced EV71 and CVA16 VLP production was observed in Sf9 cells compared to High Five (TM) cells. Lowering the incubation temperature from the standard 27 degrees C to 21 degrees C increased the production of both VLPs in Sf9 cells. Serial passaging of CVA16 BV stocks in cell culture had a detrimental effect on the productivity of the structural proteins and the effect was observed with only 5 passages of BV stocks. A 2.7x higher production yield was achieved with EV71 compared to CVA16. High-resolution asymmetric flow field-flow fractionation couple with multi-angle light scattering (AF4-MALS) was used for the first time to characterize EV71 and CVA16 VLPs, displaying an average root mean square radius of 15 +/- 1 nm and 15.3 +/- 5.8 nm respectively. This study highlights the need for different approaches in the design of production process to develop a bivalent EV71 and CVA16 vaccine. (C) 2015 Elsevier Inc. All rights reserved

Characterization of the Plasmodium falciparum M17 leucyl aminopeptidase. A protease involved in amino acid regulation with potential for antimalarial drug development

Amino acids generated from the catabolism of hemoglobin by intra-erythrocytic malaria parasites are not only essential for protein synthesis but also function in maintaining an osmotically stable environment, and creating a gradient by which amino acids that are rare or not present in hemoglobin are drawn into the parasite from host serum. We have proposed that a Plasmodium falciparum M17 leucyl aminopeptidase (PfLAP) generates and regulates the internal pool of free amino acids and therefore represents a target for novel antimalarial drugs. This enzyme has been expressed in insect cells as a functional 320-kDa homo-hexamer that is optimally active at neutral or alkaline pH, is dependent on metal ions for activity, and exhibits a substrate preference for N-terminally exposed hydrophobic amino acids, particularly leucine. PfLAP is produced by all stages in the intra-erythrocytic developmental cycle of malaria but was most highly expressed by trophozoites, a stage at which hemoglobin degradation and parasite protein synthesis are elevated. The enzyme was located by immunohistochemical methods and by transfecting malaria cells with a PfLAP-green fluorescent protein construct, to the cytosolic compartment of the cell at all developmental stages, including segregated merozoites. Amino acid dipeptide analogs, such as bestatin and its derivatives, are potent inhibitors of the protease and also block the growth of P. falciparum malaria parasites in culture. This study provides a biochemical basis for the antimalarial activity of aminopeptidase inhibitors. Availability of functionally active recombinant PfLAP, coupled with a simple enzymatic readout, will aid medicinal chemistry and/or high throughput approaches for the future design/discovery of new antimalarial drugs

Method of producing baculovirus

The present invention is directed to a method for producing commercial quantities of Baculovirus using a combination of methods involving producing occlusion bodies with infectious baculovirus in caterpillar larvae and large numbers of viral particles with serial passages in cell culture. A two step method was developed by initially producing infectious virus in caterpillar larvae and then using the resultant infectious virus as an inoculum for a limited number of serial passages in cell culture so to produce large amounts of infectious baculovirus