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Viral Immunology Mar 2021Avian influenza viruses (AIVs) infect a wide range of hosts, including humans and many avian species. Efforts have been made to control this pathogen in chickens using...
Avian influenza viruses (AIVs) infect a wide range of hosts, including humans and many avian species. Efforts have been made to control this pathogen in chickens using vaccination programs, but that has been met with varying degrees of success. Therefore, identification of more efficacious vaccination strategies is warranted. This study was undertaken to investigate the potential effects of probiotics on the immunogenicity of a beta-propiolactone-whole inactivated virus (WIV) vaccine of H9N2 subtype adjuvanted with the Toll-like receptor-21 ligand, CpG oligodeoxynucleotides 2007 (CpG). Eighty-four 1-day-old White Leghorn layers were allocated into six groups. Two out of six groups received a mixture of probiotic spp. (PROB) biweekly from days 1 35 of age. Chickens were intramuscularly vaccinated with WIV either alone or adjuvanted with AddaVax™ (WIV+Add) or CpG (WIV+CpG), and one group received saline (phosphate-buffered saline). Primary and secondary vaccinations occurred at days 14 and 28 of age, respectively. The results revealed that the group that received probiotics and was vaccinated with CpG-adjuvanted WIV H9N2 vaccine had higher hemagglutination inhibition titers than the other treatment groups at days 14 and 21 postprimary vaccination. Probiotics did not induce higher IgM or IgY titers in chickens receiving the WIV vaccine only. Concerning their effect on cell-mediated immune responses, probiotics enhanced interferon-gamma (IFN-γ) gene expression and significantly increased secretion of IFN-γ protein by splenocytes in chickens vaccinated with CpG-adjuvanted WIV H9N2. Together, these findings suggest the use of probiotics to enhance the immunogenicity of CpG-adjuvanted WIV H9N2 vaccines. Additional studies are required to better understand the specific interactions between probiotics and the gut microbiota and different types of cells of the gastrointestinal tract to decipher the underlying mechanisms of how probiotics modulate immune responses to vaccines.
Topics: Animals; Antibodies, Viral; Chickens; Influenza A Virus, H9N2 Subtype; Influenza Vaccines; Influenza in Birds; Lactobacillus; Poultry Diseases; Probiotics; Vaccines, Inactivated
PubMed: 33236974
DOI: 10.1089/vim.2020.0209 -
Clinical and Experimental Vaccine... Sep 2021One of the essential goals regarding the successful control of rabies infection is the development of a safe, effective, and inexpensive vaccine. the current study aimed...
PURPOSE
One of the essential goals regarding the successful control of rabies infection is the development of a safe, effective, and inexpensive vaccine. the current study aimed to evaluate the inactivation potential of β-propiolactone (βPL), binary ethyleneimine (BEI), and hydrogen peroxide (HO).
MATERIALS AND METHODS
Estimating the inactivation kinetics of βPL, BEI, and HO revealed that the tested inactivants could completely and irreversibly inactivate rabies virus within 2, 12, and 4 hours, respectively while maintaining its viral immunogenicity. The potency of βPL, BEI, and HO inactivated vaccines was higher than the World Health Organization acceptance limit and were in the order of 3.75, 4.21, and 3.64 IU/mL, respectively. Monitoring the humoral and cellular immunity elicited post-immunization using derived hyaluronic acid (HA) and bacillus Calmette-Guérin purified protein derivative (PPD) adjuvanted rabies vaccine candidates were carried out using enzyme-linked immunosorbent assay.
RESULTS
Results demonstrated that both adjuvants could progressively enhance the release of anti-rabies total immunoglobulin G as well as the pro-inflammatory mediators (interferon-gamma and interleukin-5) relative to time. However, a higher immune response was developed in the case of HA adjuvanted rabies vaccine compared to PPD adjuvanted one. The harmful consequences of the tested adjuvants were considered via investigating the histopathological changes in the tissues of the immunized rats using hematoxylin and eosin stain. Lower adverse effects were observed post-vaccination with HA and PPD adjuvanted vaccines compared to that detected following administration of the currently used alum as standard adjuvant.
CONCLUSION
Our findings suggested that HA and PPD could serve as a promising platform for the development of newly adjuvanted rabies vaccines with elevated immune enhancing potentials and lower risk of health hazards.
PubMed: 34703805
DOI: 10.7774/cevr.2021.10.3.229 -
Virus Research Nov 2021Inactivated viral preparations are important resources in vaccine and antisera industry. Of the many vaccines that are being developed against COVID-19, inactivated...
Inactivated viral preparations are important resources in vaccine and antisera industry. Of the many vaccines that are being developed against COVID-19, inactivated whole-virus vaccines are also considered effective. β-propiolactone (BPL) is a widely used chemical inactivator of several viruses. Here, we analyze various concentrations of BPL to effectively inactivate SARS-CoV-2 and their effects on the biochemical properties of the virion particles. BPL at 1:2000 (v/v) concentrations effectively inactivated SARS-CoV-2. However, higher BPL concentrations resulted in the loss of both protein content as well as the antigenic integrity of the structural proteins. Higher concentrations also caused substantial aggregation of the virion particles possibly resulting in insufficient inactivation, and a loss in antigenic potential. We also identify that the viral RNA content in the culture supernatants can be a direct indicator of their antigenic content. Our findings may have important implications in the vaccine and antisera industry during COVID-19 pandemic.
Topics: Animals; Antigens, Viral; Antiviral Agents; COVID-19; COVID-19 Vaccines; Chlorocebus aethiops; Flocculation; Humans; Immune Sera; Propiolactone; RNA, Viral; SARS-CoV-2; Vaccines, Inactivated; Vero Cells; Virion; Virus Inactivation
PubMed: 34487766
DOI: 10.1016/j.virusres.2021.198555 -
Vaccine May 2019Yellow fever (YF) is a high-lethality viral disease, endemic in tropical regions of South America and Africa, with a population of over 900 million people under risk. A...
Yellow fever (YF) is a high-lethality viral disease, endemic in tropical regions of South America and Africa, with a population of over 900 million people under risk. A highly effective attenuated vaccine, produced in embryonated eggs, has been used for about 80 years. However, egg-based production limits manufacturing capacity, and vaccine shortage led to the emergency use of a fractional dose (1/5) by the WHO in an outbreak in Africa in 2016 and by Brazilian authorities during an outbreak in 2018. In addition, rare but fatal adverse events of this vaccine have been reported since 2001. These two aspects make clear the need for the development of a new vaccine. In an effort to develop an inactivated YF vaccine, Bio-Manguinhos/FIOCRUZ started developing a new vaccine based on the production of the attenuated 17DD virus in serum-free conditions in Vero cells propagated in bioreactors, followed by chromatography-based purification and β-propiolactone inactivation. Virus purification was studied in this work. Capture was performed using an anion-exchange membrane adsorber (Sartobind® Q), resulting in a virus recovery of 80.2 ± 4.8% and a residual DNA level of 1.3 ± 1.6 ng/dose, thus in accordance with the recommendations of the WHO (<10 ng/dose). However, the level of host cell proteins (HCP) was still high for a human vaccine, so a second chromatography step was developed based on a multimodal resin (Capto™ Core 700). This step resulted in a virus recovery of 65.7 ± 4.8% and decreased HCP levels to 345 ± 25 ppm. The overall virus recovery in these chromatography steps was 52.7%. SDS-PAGE of the purified sample showed a band with molecular mass of 56 kDa, thus consistent with the virus envelope protein (E) and corresponding to 96.7% of identified proteins. A Western blot stained with an antibody against the E protein showed a single band, confirming the identity of the sample.
Topics: Animals; Chlorocebus aethiops; Chromatography; Vaccines, Inactivated; Vero Cells; Virus Cultivation; Yellow Fever Vaccine; Yellow fever virus
PubMed: 31047674
DOI: 10.1016/j.vaccine.2019.04.077 -
Journal of Virology Apr 2017Beta-propiolactone (BPL) is an inactivating agent that is widely used in the vaccine industry. However, its effects on vaccine protein antigens and its mechanisms of...
Beta-propiolactone (BPL) is an inactivating agent that is widely used in the vaccine industry. However, its effects on vaccine protein antigens and its mechanisms of action remain poorly understood. Here we present cryo-electron microscopy (cryo-EM) structures of BPL-treated coxsackievirus A16 (CVA16) mature virions and procapsids at resolutions of 3.9 Å and 6.5 Å, respectively. Notably, both particles were found to adopt an expanded conformation resembling the 135S-like uncoating intermediate, with characteristic features including an opened 2-fold channel, the externalization of the N terminus of VP1 capsid protein, and the absence of pocket factor. However, major neutralizing epitopes are very well preserved on these particles. Further biochemical analyses revealed that BPL treatment impairs the abilities of CVA16 particles to bind to the attachment receptor heparan sulfate and to a conformation-dependent monoclonal antibody in a BPL dose-dependent manner, indicating that BPL is able to modify surface-exposed amino acid residues. Taken together, our results demonstrate that BPL treatment may induce alteration of the overall structure and surface properties of a nonenveloped viral capsid, thus revealing a novel mode of action of BPL. Beta-propiolactone (BPL) is commonly used as an inactivating reagent to produce viral vaccines. It is recognized that BPL inactivates viral infectivity through modification of viral nucleic acids. However, its effect on viral proteins remains largely unknown. Here, we present high-resolution cryo-EM structures of BPL-treated coxsackievirus A16 (CVA16) mature virions and procapsids, which reveals an expanded overall conformation and characteristic features that are typical for the 135S-like uncoating intermediate. We further show that the BPL concentration affects the binding of inactivated CVA16 particles to their receptor/antibody. Thus, BPL treatment can alter the overall structure and surface properties of viral capsids, which may lead to antigenic and immunogenic variations. Our findings provide important information for future development of BPL-inactivated vaccines.
Topics: Antibodies, Monoclonal; Antibodies, Viral; Capsid; Cryoelectron Microscopy; Disinfectants; Enterovirus; Propiolactone; Virus Inactivation
PubMed: 28148783
DOI: 10.1128/JVI.00038-17 -
International Journal of Molecular... Jan 2020[6]-Gingerol from ginger has received considerable attention as a potential cancer therapeutic agent because of its chemopreventive and chemotherapeutic effects, as well...
[6]-Gingerol from ginger has received considerable attention as a potential cancer therapeutic agent because of its chemopreventive and chemotherapeutic effects, as well as its safety. In the current study, we examined [6]-gingerol as a natural scavenger of nine ultimate chemical carcinogens to which we are frequently exposed: glycidamide, styrene oxide, aflatoxin B1 exo-8,9-epoxide, -propiolactone, ethylene oxide, propylene oxide, 2-cyanoethylene oxide, chloroethylene oxide, and vinyl carbamate epoxide. To evaluate [6]-gingerol efficacy, we expanded our research with the examination of glutathione-the strongest natural scavenger in human cells. The corresponding activation free energies were calculated using Hartree-Fock method with three flexible basis sets and two implicit solvation models. According to our results, [6]-gingerol proves to be an extremely effective scavenger of chemical carcinogens of the epoxy type. On the other hand, with the exception of aflatoxin B1 exo-8,9-epoxide, glutathione represents a relatively poor scavenger, whose efficacy could be augmented by [6]-gingerol. Moreover, our quantum mechanical study of the alkylation reactions of chemical carcinogens with [6]-gingerol and glutathione provide valuable insights in the reaction mechanisms and the geometries of the corresponding transition states. Therefore, we strongly believe that our research forms a solid basis for further computational, experimental and clinical studies of anticarcinogenic properties of [6]-gingerol as well as for the development of novel chemoprophylactic dietary supplements. Finally, the obtained results also point to the applicability of quantum chemical methods to studies of alkylation reactions related to chemical carcinogenesis.
Topics: Aflatoxin B1; Alkylation; Anticarcinogenic Agents; Carcinogens; Catechols; Cell Line; Chemoprevention; Epoxy Compounds; Ethylene Oxide; Fatty Alcohols; Zingiber officinale; Humans; Propiolactone; Urethane
PubMed: 31973096
DOI: 10.3390/ijms21030695 -
Molecular Immunology Jul 2022Viral inactivation for antibody induction purposes, among other applications, should ensure biosafety, completely avoiding the risk of infectivity, and preserving viral...
Viral inactivation for antibody induction purposes, among other applications, should ensure biosafety, completely avoiding the risk of infectivity, and preserving viral immunogenicity. β-propiolactone (BPL) is one of the most used reagents for viral inactivation, despite its high toxicity and recent difficulties related to importation, experienced in Brazil during the SARS-CoV-2 pandemic. In this context, the main objectives of this work were to test different inactivation procedures for SARS-CoV-2 and to evaluate the induction of neutralizing antibodies in mice immunized with antigenic preparations obtained after viral treatment with formaldehyde (FDE), glutaraldehyde (GDE), peroxide hydrogen (HO), as well as with viral proteins extract (VPE), in parallel with BPL. Verification of viral inactivation was performed by subsequent incubations of the inactivated virus in Vero cells, followed by cytopathic effect and lysis plaques observation, as well as by quantification of RNA load using reverse transcription-quantitative real time polymerase chain reaction. Once viral inactivation was confirmed, cell culture supernatants were concentrated and purified. In addition, an aliquot inactivated by BPL was also subjected to viral protein extraction (VPE). The different antigens were prepared using a previously developed microemulsion as adjuvant, and were administered in a four-dose immunization protocol. Antibody production was comparatively evaluated by ELISA and Plaque Reduction Neutralization Tests (PRNT). All immunogens evaluated showed some level of IgG anti-SARS-CoV-2 antibodies in the ELISA assay, with the highest levels presented by the group immunized with FDE-inactivated viral antigen. In the PRNT results, except for VPE-antigen, all other immunogens evaluated induced some level of neutralizing anti-SARS-CoV-2 antibodies, and the FDE-antigen stood out again with the most expressive values. Taken together, the present work shows that FDE can be an efficient and affordable alternative to BPL for the production of inactivated SARS-CoV-2 viral antigen.
Topics: Animals; Antibodies, Viral; Antigens, Viral; COVID-19; Chlorocebus aethiops; Disease Models, Animal; Hydrogen Peroxide; Mice; SARS-CoV-2; Vero Cells
PubMed: 35644072
DOI: 10.1016/j.molimm.2022.05.012 -
Vaccine Jun 2022The All-Japan Influenza Vaccine Study Group has been developing a more effective vaccine than the current split vaccines for seasonal influenza virus infection. In the...
Inactivated whole influenza virus particle vaccines induce neutralizing antibodies with an increase in immunoglobulin gene subclones of B-lymphocytes in cynomolgus macaques.
The All-Japan Influenza Vaccine Study Group has been developing a more effective vaccine than the current split vaccines for seasonal influenza virus infection. In the present study, the efficacy of formalin- and/or β-propiolactone-inactivated whole virus particle vaccines for seasonal influenza was compared to that of the current ether-treated split vaccines in a nonhuman primate model. The monovalent whole virus particle vaccines or split vaccines of influenza A virus (H1N1) and influenza B virus (Victoria lineage) were injected subcutaneously into naïve cynomolgus macaques twice. The whole virus particle vaccines induced higher titers of neutralizing antibodies against H1N1 influenza A virus and influenza B virus in the plasma of macaques than did the split vaccines. At challenge with H1N1 influenza A virus or influenza B virus, the virus titers in nasal swabs and the increases in body temperatures were lower in the macaques immunized with the whole virus particle vaccine than in those immunized with the split vaccine. Repertoire analyses of immunoglobulin heavy chain genes demonstrated that the number of B-lymphocyte subclones was increased in macaques after the 1st vaccination with the whole virus particle vaccine, but not with the split vaccine, indicating that the whole virus particle vaccine induced the activation of vaccine antigen-specific B-lymphocytes more vigorously than did the split vaccine at priming. Thus, the present findings suggest that the superior antibody induction ability of the whole virus particle vaccine as compared to the split vaccine is attributable to its stimulatory properties on the subclonal differentiation of antigen-specific B-lymphocytes.
Topics: Animals; Antibodies, Neutralizing; Antibodies, Viral; B-Lymphocytes; Genes, Immunoglobulin; Humans; Influenza A Virus, H1N1 Subtype; Influenza Vaccines; Influenza, Human; Macaca fascicularis; Orthomyxoviridae Infections; Vaccination; Vaccines, Inactivated; Virion
PubMed: 35641357
DOI: 10.1016/j.vaccine.2022.05.045 -
Journal of Extracellular Vesicles Dec 2022The interaction of SARS-CoV-2 infection with extracellular vesicles (EVs) is of particular interest at the moment. Studying SARS-CoV-2 contaminated-EV isolates in...
The interaction of SARS-CoV-2 infection with extracellular vesicles (EVs) is of particular interest at the moment. Studying SARS-CoV-2 contaminated-EV isolates in instruments located outside of the biosafety level-3 (BSL-3) environment requires knowing how viral inactivation methods affect the structure and function of extracellular vesicles (EVs). Therefore, three common viral inactivation methods, ultraviolet-C (UVC; 1350 mJ/cm ), β-propiolactone (BPL; 0.005%), heat (56°C, 45 min) were performed on defined EV particles and their proteins, RNAs, and function. Small EVs were isolated from the supernatant of SARS-CoV-2-infected human lung epithelial Calu-3 cells by stepwise centrifugation, ultrafiltration and qEV size-exclusion chromatography. The EV isolates contained SARS-CoV-2. UVC, BPL and heat completely abolished SARS-CoV-2 infectivity of the contaminated EVs. Particle detection by electron microscopy and nanoparticle tracking was less affected by UVC and BPL than heat treatment. Western blot analysis of EV markers was not affected by any of these three methods. UVC reduced SARS-CoV-2 spike detectability by quantitative RT-PCR and slightly altered EV-derived β-actin detection. Fibroblast migration-wound healing activity of the SARS-CoV-2 contaminated-EV isolate was only retained after UVC treatment. In conclusion, specific viral inactivation methods are compatible with specific measures in SARS-CoV-2 contaminated-EV isolates. UVC treatment seems preferable for studying functions of EVs released from SARS-CoV-2 infected cells.
Topics: Humans; SARS-CoV-2; Virus Inactivation; COVID-19; Extracellular Vesicles; Lung; Epithelial Cells
PubMed: 36468940
DOI: 10.1002/jev2.12291 -
Vaccine Aug 2015Yellow fever is an acute infectious disease caused by prototype virus of the genus Flavivirus. It is endemic in Africa and South America where it represents a serious...
Yellow fever is an acute infectious disease caused by prototype virus of the genus Flavivirus. It is endemic in Africa and South America where it represents a serious public health problem causing epidemics of hemorrhagic fever with mortality rates ranging from 20% to 50%. There is no available antiviral therapy and vaccination is the primary method of disease control. Although the attenuated vaccines for yellow fever show safety and efficacy it became necessary to develop a new yellow fever vaccine due to the occurrence of rare serious adverse events, which include visceral and neurotropic diseases. The new inactivated vaccine should be safer and effective as the existing attenuated one. In the present study, the immunogenicity of an inactivated 17DD vaccine in C57BL/6 mice was evaluated. The yellow fever virus was produced by cultivation of Vero cells in bioreactors, inactivated with β-propiolactone, and adsorbed to aluminum hydroxide (alum). Mice were inoculated with inactivated 17DD vaccine containing alum adjuvant and followed by intracerebral challenge with 17DD virus. The results showed that animals receiving 3 doses of the inactivated vaccine (2 μg/dose) with alum adjuvant had neutralizing antibody titers above the cut-off of PRNT50 (Plaque Reduction Neutralization Test). In addition, animals immunized with inactivated vaccine showed survival rate of 100% after the challenge as well as animals immunized with commercial attenuated 17DD vaccine.
Topics: Animals; Antibodies, Neutralizing; Antibodies, Viral; Bioreactors; Chlorocebus aethiops; Disinfectants; Immunity, Humoral; Immunization Schedule; Mice, Inbred C57BL; Neutralization Tests; Propiolactone; Survival Analysis; Vaccines, Inactivated; Vero Cells; Virus Cultivation; Yellow Fever; Yellow Fever Vaccine; Yellow fever virus
PubMed: 25862300
DOI: 10.1016/j.vaccine.2015.03.077