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Order Lefavirales
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
The numerous vaccine candidates that were able to induce strong protection from the lethal influenza virus challenge in experimental animals were engineered by the insertion of the influenza hemagglutinin gene into the baculovirus genome. This technique allowed the hemagglutinin display on the baculovirus surface, while the baculovirus particles served as an adjuvant. Thus, the hemagglutinin genes of different influenza subtypes were tested: H1N1 (Abe et al. 2003; Prabakaran et al. 2010, 2011; Choi et al. 2013), H5N1 (Lu et al. 2007; Prabakaran et al. 2008, 2010; Wu et al. 2009), H6 (Syed Musthaq et al. 2014), H7N9 (Prabarakan et al. 2014). Recently, a baculovirus vaccine expressing the hemagglutinin of H7N9 strain A/Chicken/Jiaxing/148/2014 was prepared (Hu et al. 2019). The baculovirus generated in this study showed favorable growth characteristics in insect cells, good safety profile, and induced high-level hemagglutination inhibition antibody titer. Moreover, this vaccine demonstrated better efficacy than inactivated whole-virus vaccine JX148, provided complete protection of chickens against challenge with the H7N9 virus, and effectively inhibited viral shedding.
Peptide Vaccine
Published in Mesut Karahan, Synthetic Peptide Vaccine Models, 2021
Joel Lim Whye Ern, Tan Shen Leng, Tee Yi Na, Palaniarajan Vijayaraj Kumar
Moreover, VLPs were also produced by using BVES where the insect cell lines are obtained from Spodoptera frugiperda (Sf9 and Sf21) and Trichoplusia ni (Tn5).For instances, Cervarix® which is the HPV available in the market was produced using this system. VLPs produced through this system are able to perform complex PTMs as compared to bacteria and yeast. One of the barriers of this system is the side effects of baculovirus infection on the secretory machinery of the host insect cell and may lead to the low production of secreted and membrane-bound proteins and thus affect the amount of the extracted cell lines.
Structural Determination of the Polycystin-2 Channel by Electron Cryo-Microscopy
Published in Jinghua Hu, Yong Yu, Polycystic Kidney Disease, 2019
The BacMam protocol includes four steps: subcloning into a BacMam compatible vector, recombinant bacmids production, baculovirus generation, and protein expression in mammalian cell culture (Figure 2.1). The target gene is first subcloned into a BacMam compatible vector with the transposon element for bacmid generation in DH10Bac E. coli cells. Positive clones are selected using blue–white screening, and extracted bacmids are introduced into an insect cell host to produce baculoviruses for protein expression in the mammalian host.
Virus-like particle-based nanocarriers as an emerging platform for drug delivery
Published in Journal of Drug Targeting, 2023
Bingchuan Yuan, Yang Liu, Meilin Lv, Yilei Sui, Shenghua Hou, Tinghui Yang, Zakia Belhadj, Yulong Zhou, Naidan Chang, Yachao Ren, Changhao Sun
The VLP antigen of the HPV VLP vaccine (Cervarix) developed by GSK was prepared using the insect baculovirus expression vector system (BEVS). The insect cell line was used to produce the commercial HPV L1-VLP vaccine. In addition, at least seven VLPs at different stages of development were isolated from recombinant insect cells as vaccine candidates [129]. Owing to the unique advantages of the insect cell expression system, this system has been widely used in the laboratory or industrial production of VLPs [130]. Sf9 (Spodoptera frugiperda) and High Five (Trichoplusia ni) insect cells were commonly used. BEVS insect cells can be cultured on a large scale in serum-free medium and recombinant protein expression can be modified through translation. To express exogenous viral protein genes in insect cells, it is necessary to construct a vector based on modified baculoviruses. To obtain VLPs containing a variety of structural proteins, insect cell lines are infected with a range of viruses. Co-infection is a commonly accepted strategy because it manipulates the relative expression levels of the corresponding structural proteins [131].
Advances in influenza virus-like particles bioprocesses
Published in Expert Review of Vaccines, 2019
Laurent Durous, Manuel Rosa-Calatrava, Emma Petiot
Polishing steps allow for final formulation of the vaccine candidates. Buffer exchange and removal of the remaining contaminants are commonly needed to respond to quality requirements. Table 3 summarizes the criteria for influenza vaccine manufacturing also applied to influenza-VLP products. The main criterion for influenza vaccine is the HA antigen content of 15 µg per strain and vaccine dose. Host-cell DNA and host-cell protein (HCP) content must also respond to quality requirements for vaccine manufacturing [12,110]. According to the European Pharmacopoeia, the threshold value for residual HCP is 40 µg per virus strain and vaccine dose [80]. Despite their apparent lack of human pathogenicity, residual baculovirus levels should also be ‘as low as possible’ [12]. Thus, in the case of processes using baculoviruses, an additional inactivation step, using beta-propiolactone, was proposed as performed in Novavax’s process (Figure 2).
Challenges in the development of egg-independent vaccines for influenza
Published in Expert Review of Vaccines, 2019
Claudia Maria Trombetta, Serena Marchi, Ilaria Manini, Giacomo Lazzeri, Emanuele Montomoli
Virus-Like Particles (VLPs) are structures composed of functional proteins that are able to assemble and mimic the organization and conformation of the native virus, but without the viral genome, and thus unable to replicate. This feature makes VLPs safe but, at the same time, the host is presented with a whole, but inactive, virus that is able to induce a humoral and cellular immune response [144–148]. One approach to the production of VLPs is the use of insect cells (Spodoptera frugiperda Sf9) infected by recombinant baculoviruses bearing the HA, NA and Matrix 1 (M1) influenza genes, which induce the expression of these proteins and generate VLPs. The insect cell-baculovirus expression vector system has proved to be a productive method for influenza vaccines, and has some important advantages: vaccine production is rapid, the procedure is easy and yields are high. Moreover, these vaccines are safe, as baculovirus is found in vegetable matter and cannot replicate in mammalian cells; nor does the development, manufacture and administration of the vaccine require the use of live virus [144,149–151]. However, the significant co-production of enveloped baculovirus particles may impact significantly vaccine efficacy. These contaminants if not removed or inactivated may contribute markedly to the immunogenicity of the VLP-based vaccines. Since baculovirus particles and VLPs are difficult to separate, chemical inactivation treatments needed to eliminate baculovirus infectivity may impair the quality of the produced VLPs (Table 1) [146].