scholarly journals Determination of Median Lethal Concentrations (Lc50) of Pathogenic Antigens and Their Applications in Vaccine Development

2020 ◽  
Author(s):  
Saganuwan Alhaji Saganuwan
Keyword(s):  
Staphylococcus Aureus ◽  
Disease Virus ◽  
Vaccine Development ◽  
Hepatitis A Virus ◽  
Lethal Dose ◽  
Vaccine Dose ◽  
Foot And Mouth Disease ◽  
Mouth Disease Virus

Abstract Objective: Lack of ideal mathematical models to qualify and quantify both pathogenicity, and virulence is a dreadful setback in development of new antimicrobials and vaccines against resistance pathogenic microorganisms. Hence, the modified arithmetical formula of Reed and Muench has been integrated with other formulas and used for determination of antigen concentration and parasites inoculums that would kill 50% of test animals (LC50).Results: Microorganisms’ antigens tested are Staphylococcus aureus, Streptococcus pneumonia, Pseudomonas aeruginosa in mice and rat, Edwardsiella ictaluri, Aeromonas hydrophila, Aeromonas veronii in fish, New Castle Disease virus in chicken, Sheep Pox Virus, Foot-and-Mouth Disease Virus and Hepatitis A virus in vitro, respectively. The LC50s for the pathogens using different routes of administrations are 1.93 x 103 (sheep poxvirus) and 1.75 x 1010 for Staphylococcus aureus (ATCC29213) in rat respectively. N is the number of vaccine dose that could neutralize the LC50.Titre index (TI) equals N log10 LC50 and provides protection against lethal dose in graded fashion which translates to protection index. Hence, parasite inoculum of 103 to 1011 could be used as basis for median lethal dose (LD50), LC50 and median bacterial concentrations (BC50) determination, pathogenic dose for immune stimulation should be sought at concentrations less than LC10.

scholarly journals Application of Median Lethal Concentration (LC50) of Pathogenic Microorganisms and Their Antigens in Vaccine Development

2020 ◽  
Author(s):  
Saganuwan Alhaji Saganuwan
Keyword(s):  
Staphylococcus Aureus ◽  
Disease Virus ◽  
Vaccine Development ◽  
Hepatitis A Virus ◽  
Lethal Dose ◽  
Vaccine Dose ◽  
Foot And Mouth Disease ◽  
Bacterial Colony ◽  
Mouth Disease Virus

Abstract Objective: Lack of ideal mathematical models to qualify and quantify both pathogenicity, and virulence is a dreadful setback in development of new antimicrobials and vaccines against resistance pathogenic microorganisms.Hence, the modified arithmetical formula of Reed and Muenchhas been integrated with other formulas and used to determine bacterial colony forming unit/ viral concentration, virulence and immunogenicity from LC50s established in the laboratories. Results: Microorganisms’antigens tested are Staphylococcus aureus, Streptococcuspneumonia, Pseudomonas aeruginosa in mice and rat, Edwardsiellaictaluri, Aeromonashydrophila, Aeromonasveronii in fish, New Castle Disease virus in chicken, Sheep Pox Virus, Foot-and-Mouth Disease Virus and Hepatitis A virus in vitro, respectively. The LC50s for the pathogens using different routes of administrations are 1.93 x 103(sheep poxvirus) and 1.75 x 1010 for Staphylococcus aureus (ATCC29213) in rat respectively. Titre index (TI) equals N log10 LC50 and provides protection against lethal dose in graded fashion which translates to protection index. N is the number of vaccine dose that could neutralize the LC50. Hence, parasite inoculum of 103 to 1011could be used as basis for determination of median lethal dose(LD50), LC50 and median bacterial concentrations (BC50)determination, pathogenic dose for immune stimulation should be sought at concentrations less than LC10.

scholarly journals Application of Median Lethal Concentration (LC50) of Pathogenic Microorganisms and Their Antigens in Vaccine Development

2020 ◽  
Author(s):  
Saganuwan Alhaji Saganuwan
Keyword(s):  
Staphylococcus Aureus ◽  
Disease Virus ◽  
Vaccine Development ◽  
Hepatitis A Virus ◽  
Lethal Dose ◽  
Vaccine Dose ◽  
Pathogenic Microorganisms ◽  
Bacterial Colony ◽  
Mouth Disease Virus

Abstract Objective: Lack of ideal mathematical models to qualify and quantify both pathogenicity, and virulence is a dreadful setback in development of new antimicrobials and vaccines against resistance pathogenic microorganisms. Hence, the modified arithmetical formula of Reed and Muench has been integrated with other formulas and used to determine bacterial colony forming unit/ viral concentration, virulence and immunogenicity. Results: Microorganisms’antigens tested are Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa in mice and rat, Edwardsiella ictaluri, Aeromonas hydrophila, Aeromonas veronii in fish, New Castle Disease virus in chicken, Sheep Pox Virus, Foot-and-Mouth Disease Virus and Hepatitis A virus in vitro, respectively. The LC50s for the pathogens using different routes of administrations are 1.93 x 103(sheep poxvirus) and 1.75 x 1010 for Staphylococcus aureus (ATCC29213) in rat respectively. Titer index (TI) equals N log10 LC50 and provides protection against lethal dose in graded fashion which translates to protection index. N is the number of vaccine dose that could neutralize the LC50. Hence, parasite inoculum of 103 to 1011may be used as basis for determination of LC50 and median bacterial concentrations (BC50).Pathogenic dose for immune stimulation should be sought at concentration about LC10.

scholarly journals Factors Required for the Uridylylation of the Foot-and-Mouth Disease Virus 3B1, 3B2, and 3B3 Peptides by the RNA-Dependent RNA Polymerase (3Dpol) In Vitro

2005 ◽  
Vol 79 (12) ◽  
pp. 7698-7706 ◽  
Author(s):  
Arabinda Nayak ◽  
Ian G. Goodfellow ◽  
Graham J. Belsham
Keyword(s):  
Rna Polymerase ◽  
Disease Virus ◽  
Rna Synthesis ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Coding Region ◽  
Mouth Disease Virus ◽  
Foot And Mouth ◽  
Positive Strand Rna

ABSTRACT The 5′ terminus of picornavirus genomic RNA is covalently linked to the virus-encoded peptide 3B (VPg). Foot-and-mouth disease virus (FMDV) is unique in encoding and using 3 distinct forms of this peptide. These peptides each act as primers for RNA synthesis by the virus-encoded RNA polymerase 3Dpol. To act as the primer for positive-strand RNA synthesis, the 3B peptides have to be uridylylated to form VPgpU(pU). For certain picornaviruses, it has been shown that this reaction is achieved by the 3Dpol in the presence of the 3CD precursor plus an internal RNA sequence termed a cis-acting replication element (cre). The FMDV cre has been identified previously to be within the 5′ untranslated region, whereas all other picornavirus cre structures are within the viral coding region. The requirements for the in vitro uridylylation of each of the FMDV 3B peptides has now been determined, and the role of the FMDV cre (also known as the 3B-uridylylation site, or bus) in this reaction has been analyzed. The poly(A) tail does not act as a significant template for FMDV 3B uridylylation.

scholarly journals Lithium chloride inhibits early stages of foot-and-mouth disease virus (FMDV) replication in vitro

2017 ◽  
Vol 89 (11) ◽  
pp. 2041-2046 ◽  
Author(s):  
Fu-Rong Zhao ◽  
Yin-Li Xie ◽  
Ze-Zhong Liu ◽  
Jun-Jun Shao ◽  
Shi-Fang Li ◽  
...  
Keyword(s):  
Disease Virus ◽  
Lithium Chloride ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Early Stages ◽  
Mouth Disease Virus ◽  
Foot And Mouth ◽  
Fmdv Replication

scholarly journals Impairment of the DeISGylation Activity of Foot-and-Mouth Disease Virus Lpro Causes Attenuation In Vitro and In Vivo

2020 ◽  
Vol 94 (13) ◽  
Author(s):  
Gisselle N. Medina ◽  
Paul Azzinaro ◽  
Elizabeth Ramirez-Medina ◽  
Joseph Gutkoska ◽  
Ying Fang ◽  
...  
Keyword(s):  
Disease Virus ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Type I ◽  
Mouth Disease Virus ◽  
Foot And Mouth ◽  
Infected Cells ◽  
Viral Attenuation

ABSTRACT Foot-and-mouth disease virus (FMDV) leader proteinase (Lpro) affects several pathways of the host innate immune response. Previous studies in bovine cells demonstrated that deletions (leaderless [LLV]) or point mutations in Lpro result in increased expression of interferon (IFN) and IFN-stimulated genes (ISGs), including, among others, the ubiquitin-like protein modifier ISG15 and the ubiquitin specific peptidase USP18. In addition to its conventional papain-like protease activity, Lpro acts as a deubiquitinase (DUB) and deISGylase. In this study, we identified a conserved residue in Lpro that is involved in its interaction with ISG15. Mutation W105A rendered Escherichia coli-expressed Lpro unable to cleave the synthetic substrate pro-ISG15 while preserving cellular eIF4G cleavage. Interestingly, mutant FMDV W105A was viable. Overexpression of ISG15 and the ISGylation machinery in porcine cells resulted in moderate inhibition of FMDV replication, along with a decrease of the overall state of ISGylation in wild-type (WT)-infected cells. In contrast, reduced deISGylation was observed upon infection with W105A and leaderless virus. Reduction in the levels of deubiquitination was also observed in cells infected with the FMDV LproW105A mutant. Surprisingly, similarly to WT, infection with W105A inhibited IFN/ISG expression despite displaying an attenuated phenotype in vivo in mice. Altogether, our studies indicate that abolishing/reducing the deISGylase/DUB activity of Lpro causes viral attenuation independently of its ability to block the expression of IFN and ISG mRNA. Furthermore, our studies highlight the potential of ISG15 to be developed as a novel biotherapeutic molecule against FMD. IMPORTANCE In this study, we identified an aromatic hydrophobic residue in foot-and-mouth disease virus (FMDV) leader proteinase (Lpro) (W105) that is involved in the interaction with ISG15. Mutation in Lpro W105 (A12-LproW105A) resulted in reduced deISGylation in vitro and in porcine-infected cells. Impaired deISGylase activity correlated with viral attenuation in vitro and in vivo and did not affect the ability of Lpro to block expression of type I interferon (IFN) and other IFN-stimulated genes. Moreover, overexpression of ISG15 resulted in the reduction of FMDV viral titers. Thus, our study highlights the potential use of Lpro mutants with modified deISGylase activity for development of live attenuated vaccine candidates, and ISG15 as a novel biotherapeutic against FMD.

5 PRODUCTION OF TRANSGENIC LIVESTOCK USING A LENTIVIRUS EXPRESSING MULTIPLE SHORT INTERFERING RNAs TARGETING FOOT AND MOUTH DISEASE VIRUS

2011 ◽  
Vol 23 (1) ◽  
pp. 109
Author(s):  
M. Peoples ◽  
M. Westhusin ◽  
K. Tessanne ◽  
C. Long
Keyword(s):  
Disease Virus ◽  
Lentiviral Vector ◽  
Tissue Sample ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Antibiotic Selection ◽  
Viral Particles ◽  
Transgenic Livestock ◽  
Mouth Disease Virus

One goal of transgenic livestock production is developing animals with enhanced production characteristics. Transgenic animals with resistance to viral disease could greatly reduce economic losses. The use of short interfering RNA (siRNA) or short hairpin RNA (shRNA) targeting viral genomes have shown great promise in vitro for both human and animal applications. However, because of the rapid mutation rate, viruses are able to escape single siRNA inhibition. One method to reduce the chances of a functional escape virus is to target its genome with multiple shRNAs simultaneously. The goal of this research project was to produce a recombinant lentiviral vector that expresses three unique shRNAs targeting different regions of the foot and mouth disease virus (FMDV) and use it to produce transgenic livestock. In these initial experiments we used the goat as our model system. Previously, we confirmed that three distinct siRNAs individually could reduce the ability of the FMDV virion to replicate in vitro. Based upon these results we produced a recombinant lentiviral vector that utilised three bovine Pol III promoters (7sk, H1, U6-2), each transcribing a different effective shRNA targeting FMDV. In addition, the vector also contained the fluorescent marker zsGreen and an antibiotic resistance gene. The lentiviral vector was co-transfected with pCMV and pMDG into 293T cells to produce replication incompetent retroviral particles. The supernatant was collected and ultra-centrifuged (50 000 × g for 1.5 h) to concentrate the viral particles resulting in a high-titer viral preparation (>109 mL–1 infective viral particles). To produce the transgenic caprine offspring, three embryo donors were superovulated and naturally bred. Nineteen zygotes were surgically collected from the oviduct 24 h after mating. Recombinant lentivirus was microinjected into the zygote perivitelline space. Immediately following the injections, four goat embryos were surgically transferred into the oviduct of each synchronized recipient. Pregnancy was determined by ultrasound at Day 30 in 2 of 5 recipients that received embryos. One pregnancy was carried to term resulting in triplets; 1 live birth, and 2 stillborn. The placenta and tissue sample of the live goat both contained a subpopulation of zsGreen positive cells when analysed with fluorescent microscopy. A fibroblast cell line was derived from the tissue sample and placed under antibiotic selection. Results indicate that only the fluorescent cells also expressed a resistance to antibiotic selection. RNA was collected from the fibroblast cells and mature shRNA production was confirmed using the QuantiMir kit (System Biosystems). Expression of all 3 mature shRNAs was verified in these cells. This data further supports that the entire transgene was integrated into the genome. This is the first report of transgenic livestock produced that expresses multiple shRNAs targeting a viral genome.

scholarly journals In vitro comparison of foot-and-mouth disease virus subtype variants causing disease in vaccinated cattle

1978 ◽  
Vol 80 (3) ◽  
pp. 451-459 ◽  
Author(s):  
E. C. Anderson ◽  
W. J. Doughty ◽  
J. Anderson ◽  
D. Baber
Keyword(s):  
Disease Virus ◽  
Vaccine Strain ◽  
Complement Fixation ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Radial Immunodiffusion ◽  
Antibody Concentration ◽  
Mouth Disease Virus ◽  
Foot And Mouth

SummaryFoot-and-mouth disease virus isolates of types O, A and SAT 2, from diseased animals in herds routinely vaccinated twice a year were compared antigenically with the vaccine strains in the complement-fixation, neutralization and radial immunodiffusion tests. It was found that strains which had readily infected vaccinated cattle had R values against the vaccine strain in the complement- fixation and radial immunodiffusion tests of 30 or less, while strains causing primary outbreaks with little spread had R values of 30–40. Threefold differences in humoral neutralizing antibody concentration between the field variant and the vaccine strain in sera from vaccinated animals were likely to be significant in terms of protection.

scholarly journals Foot-and-Mouth Disease Virus Assembly: Processing of Recombinant Capsid Precursor by Exogenous Protease Induces Self-Assembly of Pentamers In Vitro in a Myristoylation-Dependent Manner

2009 ◽  
Vol 83 (21) ◽  
pp. 11275-11282 ◽  
Author(s):  
Stewart Goodwin ◽  
Tobias J. Tuthill ◽  
Armando Arias ◽  
Richard A. Killington ◽  
David J. Rowlands
Keyword(s):  
Disease Virus ◽  
Receptor Binding ◽  
Virus Assembly ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Precursor Protein ◽  
Capsid Precursor ◽  
Mouth Disease Virus ◽  
Foot And Mouth

ABSTRACT The assembly of foot-and-mouth disease virus (FMDV) particles is poorly understood. In addition, there are important differences in the antigenic and receptor binding properties of virus assembly and dissociation intermediates, and these also remain unexplained. We have established an experimental model in which the antigenicity, receptor binding characteristics, and in vitro assembly of capsid precursor can be studied entirely from purified components. Recombinant capsid precursor protein (P1 region) was expressed in E scherichia coli as myristoylated or unmyristoylated protein. The protein sedimented in sucrose gradients at 5S and reacted with monoclonal antibodies which recognize conformational or linear antigen determinants on the virion surface. In addition, it bound the integrin αvβ6, a cellular receptor for FMDV, indicating that unprocessed recombinant capsid precursor is both structurally and antigenically similar to native virus capsid. These characteristics were not dependent on the presence of 2A at the C terminus but were altered by N-terminal myristoylation and in mutant precursors which lacked VP4. Proteolytic processing of myristoylated precursor by recombinant FMDV 3Cpro in vitro induced a shift in sedimentation from 5S to 12S, indicating assembly into pentameric capsid subunits. Nonmyristoylated precursor still assembled into higher-order structures after processing with 3Cpro, but these particles sedimented in sucrose gradients at approximately 17S. In contrast, mutant precursors lacking VP4 were antigenically distinct, were unable to form pentamers, and had reduced capacity for binding integrin receptor. These studies demonstrate the utility of recombinant capsid precursor protein for investigating the initial stages of assembly of FMDV and other picornaviruses.

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