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Biophysical and biochemical properties of CR326 human hepatitis A virus
Abstract:
CR326 human hepatitis A virus purified by isopycnic banding from infected marmoset sera was shown to consist of 27 mmu spherical particles on electron microscopic examination. The particles were identified as hepatitis A virus by tests by infectivity and by specific neutralization of infectivity with convalescent human hepatitis A serum. Also, identical 27 mmu viruses in liver extracts gave specific reactions with hepatitis A antisera when tested by immune electron microscopy. The buoyant density of the virus in CsCl was 1.34 and it was heat (60 C), ether, and acid stable but was destroyed by heat (100 C), formalin (1:4000), and ultraviolet irradiation. Electron microscopic studies of sections of infected marmoset liver showed intracytoplasmic virus particles, usually in vesicles. Presumptive findings for RNA, together with the intracytoplasmic location of the virus, indicated the virus to be of RNA-type. The attributes of the virus indicate it is closely related to the enterovirus family and not to hepatitis B virus.
Insights
Researchers isolated and characterized the CR326 human hepatitis A virus (HAV). This RNA-type virus, identified in marmoset sera and liver, shares characteristics with the enterovirus family.
Area of Science:
- Virology
- Hepatitis Research
- Infectious Diseases
Background:
- Hepatitis A virus (HAV) is a significant human pathogen.
- Understanding HAV's physical and chemical properties is crucial for developing diagnostics and therapeutics.
- Previous characterization of HAV isolates has been limited.
Purpose of the Study:
- To purify and characterize the CR326 strain of human hepatitis A virus.
- To determine the physical and chemical properties of the CR326 HAV isolate.
- To ascertain the viral particle's classification and relationship to other virus families.
Main Methods:
- Isopycnic banding for virus purification from infected marmoset sera.
- Electron microscopy for particle visualization and size determination.
- Infectivity assays and neutralization tests with convalescent human HAV serum.
- Immune electron microscopy on liver extracts.
- Buoyant density determination in CsCl.
- Stability assays (heat, ether, acid, formalin, UV irradiation).
Main Results:
- Purified CR326 HAV consisted of 27 nm spherical particles.
- Particles were confirmed as HAV by infectivity and neutralization tests.
- Identical viruses were detected in liver extracts.
- Buoyant density in CsCl was 1.34 g/cm³.
- The virus demonstrated stability to heat (60°C), ether, and acid, but was inactivated by heat (100°C), formalin, and UV irradiation.
- Intracytoplasmic virus particles were observed in infected marmoset liver sections, suggesting an RNA-type virus.
- HAV showed close relation to the enterovirus family.
Conclusions:
- The CR326 isolate is a human hepatitis A virus with characteristic enterovirus-like properties.
- Its physical and chemical stability profile provides insights into HAV's resilience.
- The findings support the classification of HAV within the enterovirus family.