Khadijeh Fanayi, Mehdi Ajorloo , Sayed Hamid Reza Mozhgani , Shiva Irani , Alireza Gholami ,
Volume 72, Issue 5 (8-2014)
Abstract
Background: Rabies is an acute encephalitis that causes more than 60,000 deaths worldwide. The only way to save individuals bitten by a rabies-infected animal is the timely use of effective vaccines. Treatment with new generation vaccines is expensive. Therefore, there is a global movement towards the production of less expensive vaccines which retain and improve upon the quality and effectiveness of the vaccine. Production and evaluation of non-classical vaccines is one of the approaches taken in this regard. In this study, we describe a new eukaryotic expression system to express the nucleoprotein N gene of rabies virus which, if suitable, may be evaluated for anti-rabies vaccine production.
Methods: The complete sequence of the N gene of rabies virus PV subtype was amplified by real-time polymerase chain reaction and cloned into the pCDNA3.1(+) vector. The cloned gene was excised from the vector by restriction enzyme digestion and sequenced. Due to mutations detected in the N gene, the gene coding sequence was purchased as a recombinant pGH/N vector. Vector pGH/N was amplified and following enzymatic digestion, the excised N gene was once again cloned into vector pCDNA3.1(+). Successful cloning was confirmed using restriction digests and quick check. The recombinant vector pCDNA3.1(+)/N was transformed into cultured BSR cells and protein N expression was analyzed using fluorescent antibody test (FAT).
Results: Electrophoresis confirmed amplification of the nucleoprotein N gene and subsequent restriction enzyme digestion showed that the N gene had been successfully cloned into the recombinant pCDNA3.1(+)/N vector. However, DNA sequencing revealed the presence of mutations within the N gene. Restriction digest of the commercial pGH/N vector showed that the N gene had been excised from the vector. Successful cloning of the N gene into the pCDNA3.1(+) expression vector was confirmed using restriction digests and quick check. Protein expression in BSR cells was assayed by immunostaining with anti-ribonucleocapsid FITC-conjugated antibody and visually confirmed by fluorescence microscopy.
Conclusion: This study showed that the protein N of rabies virus subtype PV can be expressed in a eukaryotic expression system using the pCDNA3.1(+) expression vector.
Farzaneh Sheikholeslami , Safoora Gharibzadeh , Gharibzadeh , Nargess Miyandehi , Farzaneh Ahmadnejad , Saeed Godeyri Eslami , Javad Vaez , Ali Moradi ,
Volume 77, Issue 12 (3-2020)
Abstract
Background: Potency evaluation of rabies vaccine is a cheap, fast, high precision and consistent with ethical values is critical, so researchers have modified a variety of methods such as: National Institute of Health (NIH) method, Single Radial Immunodiffusion (SRID) and so on. The purpose of the present study was to replace an in vitro method consistent with medical ethics criteria instead of an in vivo method. By recognizing that the potency of the rabies vaccine depends on the amount of glycoprotein antigen content and the monoclonal antibody detect the correct folding of antigen of the rabies virus, then the glycoprotein content could be represent of vaccine potency.
Methods: In this study, we designed an immune-capture enzyme-linked immunosorbent assay (ELISA) with three antibodies (capture, primary and secondary) to determine the existent amount of viral glycoprotein in different rabies vaccines, and compared the results at the same time with measuring potency of those vaccines using the NIH method. This applied study was conducted from September 2016 to September 2018 at the Research Laboratory of the World Health Organization Collaborating Center for reference and research on rabies at the Pasteur Institute of Iran in Tehran.
Results: The slope of the standard line was calculated to R2=0.98 (P=0.0013). In the humans’ vaccines, the mean lied between 5.554-7.336 (SD=0.0463-0.1039) and the coefficient of variation was 0.778-2.436 (SD=0.0041-0.2724), at the same time in the animals’ vaccines the mean were 2.293-5.993 (SD=0.0041-0.2724) and the coefficient of variation was calculated 0.182-4.546. For animal vaccines the Pearson correlation coefficient is 0.99 and for the human vaccines this coefficient was 0.95. Also, the concordance correlation coefficient for animal vaccines was 0.98 and for human vaccines is 0.95, indicating a moderate to high concordance in both animals and humans vaccines.
Conclusion: The designed Immuno-capture ELISA kit had a proper acceptance criterion, intermediate precision, good linearity and robustness for measuring the glycoprotein level of the vaccine, which was directly related to the vaccine potency.
