Humoral Immune Response in Mice Elicited by Combined Yeast-Derived Hepatitis B Virus Core, Surface, and Mosaic Surface Antigens

Abstract

Background: Although successful, the second-generation hepatitis B vaccine programs around the world have a small group of immunized individuals that does not respond efficiently to the vaccination. Other issues of these vaccines are individuals that are low or nonresponders and/or have incomplete protection against heterologous hepatitis B virus (HBV) genotypes/subtypes and against HBV escape mutants. In addition, there are approximately 240 million people chronically infected with HBV worldwide and 620,000 deaths per year caused by the infection. Methods: In this study we developed three Hansenula polymorpha plasmids containing the following sequences: (a) HBsAg subtype ayw, (b) HBcAg sequence subtype adw2, and (c) chimeric HBsAg (adw4/ ayw) - preS1 (adw2) - 3 repetitions of preS2 (genotypes A, B, and C). The sequences were successfully expressed and the antigens purified. Using Balb/c mice the antigens were tested in different dosage combinations. Results: Three antigens were obtained at a high purity level and with high reproducibility. We also assessed their immunogenic properties, showing that the antigens, individually or in combination, generated anti-HBs, anti-preS1, anti-preS2, and anti-HBc antibodies efficiently in mice. Conclusions: The formulation tests showed that a combination of 0.02 μg of HBs, 0.2 μg of preS1-preS2-HBs, and 0.02 μg of HBc was effective in eliciting specific antibodies in mice.

Factors influencing survival of BALB/c mice and their effects on immune efficacy in an experiment of hepatitis B immunization

“…In studies about hepatitis B immunization, it is reported that different age groups of BALB/c mice were included such as age of 4-6 weeks (Granovski et al, 2017; et al, 2017), 6-8 weeks (Gui et al, 2017;Kapadia et al, 2017;Skrastina et al, 2014;Fakharzadeh et al, 2013), 8-10 weeks (McCluskie et al, 2002Abdalla et al, 2014), 11 weeks (Perez et al, 2018), or 1,3,7 days (Weeratna et al, 2001;Ahmadian et al, 2016), among which ages of 6-8 weeks were in the majority. So it is suggested that mice of a certain age group can be selected as flexible according to different experimental requirements.…”

Thermodynamic and physical properties of Zr3Fe and ZrFe2 intermetallic compounds

“…Zr-based alloys, so-called zircaloys, containing small amount of Fe and other alloying elements are widely used in nuclear industry due to their low absorption cross-section of thermal neutrons, high corrosion resistance and hardness [1][2][3]. Moreover, Zr-Fe intermetallic compounds in zircaloys are known to improve specific mechanical properties.…”