ABSTRACT
INTRODUCTION: Rabbit hemorrhagic disease is an acute highly contagious infection associated with two genotypes of pathogenic Lagovirus. Antibodies to major capsid protein (Vp60) are protective. The aim of the work â is an evaluation of antigenic and immunogenic activity of virus-like particles (VLPs) based on recombinant major capsid proteins of both genotypes of rabbit hemorrhagic disease virus (RHDV) (recVP60-GI1 and recVP60-GI2). MATERIALS AND METHODS: Baculovirus-expressed VLPs were evaluated using electron microscopy and administered to clinically healthy 1.53 month old rabbits in a dose of 50 g. Rabbits were challenged with 103 LD50 of virulent strains Voronezhsky-87 and Tula 21 days post immunization. Serum samples were tested for the presence of RHDV-specific antibodies. RESULTS: VLPs with hemagglutination activity forming VLP 3040 nm in size were obtained in Hi-5 cell culture. Specific antibody titers in rabbits measured by ELISA were 1 : 200 to 1 : 800 on 21th day post immunization with VLPs. Immunogenic activity of recVP60-GI1 VLPs was 90 and 40%, while it was 30 and 100% for recVP60-GI2 VLPs after the challenge with RHDV genotypes 1 and 2 respectively. The immunogenicity of two VLPs in mixture reached 100%. DISCUSSION: VLPs possess hemagglutinating, antigenic and immunogenic activity, suggesting their use as components in substances designed for RHDV specific prophylaxis in rabbits. Results of the control challenge experiment demonstrated the need to include the antigens from both RHDV genotypes in the vaccine. CONCLUSION: Recombinant proteins recVP60-GI1 and recVP60-GI2 form VLPs that possess hemagglutinating an antigenic activity, and provide 90100% level of protection for animals challenged with RHDV GI1 and GI2 virulent strains.
Subject(s)
Caliciviridae , Hemorrhagic Disease Virus, Rabbit , Lagovirus , Animals , Rabbits , Hemorrhagic Disease Virus, Rabbit/genetics , Capsid Proteins/genetics , Recombinant Proteins/geneticsABSTRACT
In recent years, members of the Coronaviridae family have caused outbreaks of respiratory diseases (MERS, SARS, and COVID-19). At the same time, the potential of radiation-induced inactivation of this group of viruses have been little studied, although radiation technologies can be widely used both in the processing of personal protective equipment and in the sterilization of vaccines. In the present work, the effect of 10 MeV electron beams and 7.6 MeV bremsstrahlung on the coronavirus infection pathogen (transmissible gastroenteritis virus) has been studied in vitro. In the given experimental conditions, irradiation with photons turned out to be more effective. The virus-containing suspension frozen at -86°C was the most resistant to radiation: the dose required for complete inactivation of the virus in this case was from 15 kGy, while for the liquid suspension and lyophilized form the sterilizing dose was from 10 kGy. At lower radiation doses for all samples during passaging in cell culture, residual infectious activity of the virus was observed. These differences in the efficiency of inactivation of liquid and frozen virus-containing samples indicate a significant contribution of the direct effect of radiation.
ABSTRACT
BACKGROUND: Rоtaviruses are amоng the leading causes of severe diarrhea in children all over the Wоrld. Vaccination is considered to be the mоst effective way to cоntrоl the disease. Currently available vaccines for prevention of rоtavirus infection are based on live attenuated rotavirus strains human оr animal origin. OBJECTIVES: The aim of this investigation was to study the biological and genetic properties of an actual epidemic human rotavirus A (RVA) strain Wa G1P[8] genotype. METHODS: RVA Wa reproduction in a monolayer continuous cell lines, purification and concentration of RVA antigen, PAAG electrophoresis and Western-Blot, electrophoresis of viral genomic RNA segments, sequencing. RESULTS: Human RVA G1P[8] Wa strain biological and molecular genetic properties were assessed in the process of the adaptation to MARC145 continuous cell line. Cell cultured RVA antigen was purified, concentrated and then characterized by the method of PAAG electrophoresis and immunoblot. To verify RVA Wa genome identity, electrophoresis of viral genomic RNA segments was performed. The lack of accumulation of changes in the RVA Wa genome during adaptation to various cell cultures and during serial passages was demonstrated by sequencing fragments of the viral genome. CONCLUSIONS: RVA Wa strain is stable, it possesses high biological activity: it has been successfully adapted to the MARC145 cell line and RVA Wa virus titer after the adaptation reached 7,5-7,7 lg TCID50/ml. The identity of the cultivated RVA to the original strain Wa G1P[8] was confirmed.
