Immune responses and expression of the virus-like particle antigen of the porcine encephalomyocarditis virus

Jeoung, Hye-Young,Lee, Won-Ha,Jeong, Wooseog,Ko, Young-Joon,Choi, Cheong-Up,An, Dong-Jun Elsevier 2010 Research in veterinary science Vol.89 No.2

<P><B>Abstract</B></P><P>Virus-like particles (VLPs) are particles that consist of viral capsid proteins and are structurally similar to authentic virus. To express VLPs of the porcine encephalomyocarditis virus (EMCV) and investigate their efficacy and immuno response <I>in vivo</I>, a plasmid (P12A3C-pCI) containing the P12A and 3C genes of the EMCV-K3 viral strain was constructed. The VLPs of EMCV-K3 were successfully assembled in 293FT cells on 3 days after transfection with P12A3C-pCI and were identified as particles of about 30–40nm using transmission electron microscopy (TEM). In an <I>in vivo</I> experiment, the murine cytokines induced by VLPs of naked DNA vaccine showed that the Th1 indicators IL-2, TNF-α and GM-CSF, and the Th2 indicators IL-4 and IL-10 were increased. The immunization of mice with the P12A3C-pCI plasmid induced high levels of neutralizing antibody from 128- to 256-fold and led to a significant protection ratio (90%) after challenge with EMCV-K3 (wild-type strain). These VLPs may represent a novel vaccine strategy for the control of EMCV infection on pig farms.</P>

Virus like particles- A recent advancement in vaccine development

Bishajit Sarkar,Syed Sajidul Islam,Umme Salma Zohora,Md. Asad Ullah 한국미생물학회 2019 미생물학회지 Vol.55 No.4

The unintentional reversion of various attenuated and inactivated vaccines has led the way of discovering and development of the virus like particles (VLPs) in the 1970s and 80s. The VLPs contain only the antigenic determinant portion of the structure of a target virus that is able to produce the same immune responses like the original viruses, however, since the particles do not contain any genetic material, the particles can’t infect like the actual viruses. They are able to induce both the humoral and cell mediated immune responses. Since infection doesn’t occur, this technology is a safe and reliable way to combat infectious diseases. Currently, VLPs are produced for a good number of infectious diseases and researches are going on to develop VLPs against many more diseases. Based on the structure, VLPs can be divided into two types: enveloped and non-enveloped VLPs. Enveloped VLPs have greater flexibility. To produce VLPs, various expression systems can be used: yeast, bacterial, mammalian, insect, and plant cells can be used. Insect cell culture system is mainly used in VLP production. The appropriate system should be determined based on the VLP type in question. The production and purification of all the VLPs are quite similar: the cloning of the gene for the antigenic portion, cell harvesting, disruption (if necessary), clarification, concentration and characterization, these steps are done using various means. This review summarizes the types of VLPs, their immunogenic properties, various expression systems that can be used for production and the production procedures of various VLPs.

Establish a transient expression platform for the rapid development of virus-like particle vaccine

Won Seok Gwak,Hyun Soo Kim,Soo Dong Woo 한국응용곤충학회 2018 한국응용곤충학회 학술대회논문집 Vol.2018 No.04

The virus-like particle (VLP) is similar to a pathogenic virus and has a high immunogenicity. However, in the selection of various structural proteins to form VLP, all expression systems commonly consume most of the time and suffer from various difficulties. Therefore, there is a need for a system that can rapidly determine the structural proteins required for effective VLP production. This study aims to construct a transient expression platform using insect cells to solve this problem. Plasmid-based expression vectors and baculovirus-inducible expression vectors were constructed. The vectors were evaluated for overexpression using EGFP. We also confirmed the formation of virus like particles through overexpression of virus structural proteins.

Stability of virus-like particles of red-spotted grouper nervous necrosis virus in the aqueous state, and the vaccine potential of lyophilized particles

Lan, Nguyen Thi,Kim, Hyoung Jin,Han, Hyun-Ja,Lee, Deok-Chan,Kang, Bo Kyu,Han, Sang Yoon,Moon, Hyoungjoon,Kim, Hong-Jin Elsevier 2018 Biologicals Vol.51 No.-

<P><B>Abstract</B></P> <P>Virus-like particles (VLPs) are multi protein complexes mimicking the structural properties of the native virus. The development of freeze-dried formulations of such complex protein structures remains a challenge. Red-spotted grouper nervous necrosis virus (RGNNV) causes mass mortality in fish culture, and RGNNV VLPs have been suggested to be promising vaccine candidates. In the present study, the stability of RGNNV VLPs in the liquid state was investigated over a 4-week period, along with the influence of freeze-drying on VLP stability. RGNNV VLPs were completely degraded after one week at 37 °C followed by 3 weeks at ambient temperature, and they were partially degraded after 4 weeks at 4 °C. Therefore, the inherent stability of RGNNV VLP in an aqueous milieu is insufficient for long-term storage. When RGNNV VLPs were freeze-dried in the presence or absence of sugar stabilizers, sorbitol was found to improve VLP stability whereas mannitol reduced it. VLP preparations freeze-dried with sorbitol or without stabilizer were as immunogenic as control (non-freeze dried) VLPs, whereas VLPs freeze-dried in mannitol were less immunogenic. These results indicate that freeze-dried RGNNV VLPs have potential as vaccines.</P>

Production and immunogenicity of chimeric virus-like particles containing the spike glycoprotein of infectious bronchitis virus

Lishan Lv,Xiaoming Li,Genmei Liu,Ran Li,Qiliang Liu,Huifang Shen,Wei Wang,Chunyi Xue,Yongchang Cao 대한수의학회 2014 Journal of Veterinary Science Vol.15 No.2

Infectious bronchitis virus (IBV) poses a severe threat to thepoultry industry and causes heavy economic losses worldwide. Vaccination is the most effective method of preventing infectionand controlling the spread of IBV, but currently availableinactivated and attenuated virus vaccines have somedisadvantages. We developed a chimeric virus-like particle(VLP)-based candidate vaccine for IBV protection. The chimericVLP was composed of matrix 1 protein from avian influenzaH5N1 virus and a fusion protein neuraminidase (NA)/spike 1 (S1)that was generated by fusing IBV S1 protein to the cytoplasmicand transmembrane domains of NA protein of avian influenzaH5N1 virus. The chimeric VLPs elicited significantly higherS1-specific antibody responses in intramuscularly immunizedmice and chickens than inactivated IBV viruses. Furthermore,the chimeric VLPs induced significantly higher neutralizationantibody levels than inactivated H120 virus in SPF chickens. Finally, the chimeric VLPs induced significantly higher IL-4production in mice. These results demonstrate that chimericVLPs have the potential for use in vaccines against IBV infection.

Recent vaccine technology in industrial animals

김현일,이유경,강상철,한범구,최기명 대한백신학회 2016 Clinical and Experimental Vaccine Research Vol.5 No.1

Various new technologies have been applied for developing vaccines against various animal diseases. Virus-like particle (VLP) vaccine technology was used for manufacturing the porcine circovirus type 2 and RNA particle vaccines based on an alphavirus vector for porcine epidemic diarrhea (PED). Although VLP is classified as a killed-virus vaccine, because its structure is similar to the original virus, it can induce long-term and cell-mediated immunity. The RNA particle vaccine used a Venezuela equine encephalitis (VEE) virus gene as a vector. The VEE virus partial gene can be substituted with the PED virus spike gene. Recombinant vaccines can be produced by substitution of the target gene in the VEE vector. Both of these new vaccine technologies made it possible to control the infectious disease efficiently in a relatively short time.

Protection against lethal challenge by Ebola virus-like particles produced in insect cells

Sun, Y.,Carrion, R.,Ye, L.,Wen, Z.,Ro, Y.T.,Brasky, K.,Ticer, A.E.,Schwegler, E.E.,Patterson, J.L.,Compans, R.W.,Yang, C. Academic Press 2009 Virology Vol.383 No.1

Ebola virus-like particles (VLPs) were produced in insect cells using a recombinant baculovirus expression system and their efficacy for protection against Ebola virus infection was investigated. Two immunizations with 50 μg Ebola VLPs (high dose) induced a high level of antibodies against Ebola GP that exhibited strong neutralizing activity against GP-mediated virus infection and conferred complete protection of vaccinated mice against lethal challenge by a high dose of mouse-adapted Ebola virus. In contrast, two immunizations with 10 μg Ebola VLPs (low dose) induced 5-fold lower levels of antibodies against GP and these mice were not protected against lethal Ebola virus challenge, similar to control mice that were immunized with 50 μg SIV Gag VLPs. However, the antibody responses against GP were boosted significantly after a third immunization with 10 μg Ebola VLPs to similar levels as those induced by two immunizations with 50 μg Ebola VLPs, and vaccinated mice were also effectively protected against lethal Ebola virus challenge. Furthermore, serum viremia levels in protected mice were either below the level of detection or significantly lower compared to the viremia levels in control mice. These results show that effective protection can be achieved by immunization with Ebola VLPs produced in insect cells, which give high production yields, and lend further support to their development as an effective vaccine strategy against Ebola virus.

Hepatitis C Virus Core Protein Is Efficiently Released into the Culture Medium in Insect Cells

Choi, Soo-Ho,Kim, So-Yeon,Park, Kyu-Jin,Kim, Yeon-Joo,Hwang, Soon-Bong Korean Society for Biochemistry and Molecular Biol 2004 Journal of biochemistry and molecular biology Vol.37 No.6

Hepatitis C virus (HCV) is a causal agent of the chronic liver infection. To understand HCV morphogenesis, we studied the assembly of HCV structural proteins in insect cells. We constructed recombinant baculovirus expression vectors consisting of either HCV core alone, core-E1, or core-E1-E2. These structural proteins were expressed in insect cells and were examined to assemble into particles. Neither core-E1 nor core-E1-E2 was capable of assembling into virus-like particles (VLPs). It was surprising that the core protein alone was assembled into core-like particles. These particles were released into the culture medium as early as 2 days after infection. In our system, HCV structural proteins including envelope proteins did not assemble into VLPs. Instead, the core protein itself has the intrinsic capacity to assemble into amorphous core-like particles. Furthermore, released core particles were associated with HCV RNA, indicating that core proteins were assembled into nucleocapsids. These results suggest that HCV may utilize a unique core release mechanism to evade the hosts defense mechanism, thus contributing to the persistence of HCV infection.

Hepatitis C Virus Core Protein Is Efficiently Released into the Culture Medium in Insect Cells

( Soo Ho Choi ),( So Yeon Kim ),( Kyu Jin Park ),( Yeon Joo Kim ),( Soon Bong Hwang ) 생화학분자생물학회 2004 BMB Reports Vol.37 No.6

Hepatitis C virus (HCV) is a causal agent of the chronic liver infection. To understand HCV morphogenesis, we studied the assembly of HCV structural proteins in insect cells. We constructed recombinant baculovirus expression vectors consisting of either HCV core alone, core-El, or core-El-E2. These structural proteins were expressed in insect cells and were examined to assemble into particles. Neither core-El nor core-El-E2 was capable of assembling into virus-like particles (VLPs). It was surprising that the core protein alone was assembled into core-like particles. These particles were released into the culture medium as early as 2 days after infection. In our system, HCV structural proteins including envelope proteins did not assemble into VLPs. Instead, the core protein itself has the intrinsic capacity to assemble into amorphous core-like particles. Furthermore, released core particles were associated with HCV RNA, indicating that core proteins were assembled into nucleocapsids. These results suggest that HCV may utilize a unique core release mechanism to evade the hosts defense mechanism, thus contributing to the persistence of HCV infection.

Proteomic Characterization of Influenza H5N1 Virus-like Particles and Their Protective Immunogenicity

Song, Jae-Min,Choi, Chi-Won,Kwon, Sang-Oh,Compans, Richard. W.,Kang, Sang-Moo,Kim, Seung Il American Chemical Society 2011 JOURNAL OF PROTEOME RESEARCH Vol.10 No.8

<P>Recombinant virus-like particles (VLPs) have been shown to induce protective immunity. Despite their potential significance as promising vaccine candidates, the protein composition of VLPs produced in insect cells has not been well characterized. Here we report a proteomic analysis of influenza VLPs containing hemagglutinin (HA) and matrix M1 proteins from a human isolate of avian influenza H5N1 virus (H5 VLPs) produced in insect cells using the recombinant baculovirus expression system. Comprehensive proteomic analysis of purified H5 VLPs identified viral proteins and 37 additional host-derived proteins, many of which are known to be present in other enveloped viruses. Proteins involved in different cellular structures and functions were found to be present in H5 VLPs including those from the cytoskeleton, translation, chaperone, and metabolism. Immunization with purified H5 VLPs induced protective immunity, which was comparable to the inactivated whole virus containing all viral components. Unpurified H5 VLPs containing excess amounts of noninfluenza soluble proteins also conferred 100% protection against lethal challenge although lower immune responses were induced. These results provide important implications consistent with the idea that VLP production in insect cells may involve similar cellular machinery as other RNA enveloped viruses during synthesis, assembly, trafficking, and budding processes.</P><P>Virus-like particles (VLPs) have been shown to induce protective immunity, indicating a new platform of promising vaccine candidates. We have performed comprehensive proteomic analysis of influenza H5 pandemic potential VLP vaccines. We identified influenza viral proteins as well as host- and vector-derived proteins. The results suggest that VLP production may involve similar cellular machinery as other enveloped viruses during synthesis, assembly, trafficking, and budding processes.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jprobs/2011/jprobs.2011.10.issue-8/pr200086v/production/images/medium/pr-2011-00086v_0004.gif'></P>