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[The types of virus-specific structures in cells of human origin producing oncornaviruses]
Abstract:
In the cell cytoplasm of human tissue cultures Detroit-6 and AO which produce B type oncorna-virus, two types of virus-specific structures were revealed. Structures of type I were aggregated fibrils of 3 and 6 nm diametre. Structures of type II were nucleoids of A-particles of 70-80 nm diametre. They were rather well separated from cell components by centrifugation sucrose density gradient and repeated centrifugation in the sucrose concentration gradient. Fibrils were found in the density regions of the equilibrium gradient of 1.26 and 1.19 g/cm3, whereas A-particles were detected in the sones of the density of 1.29 and 1.23-124 g/cm3. Their sedimentation coefficients in the sucrose concentration gradients were about 150S and 250S, respectively. From both structure types similar RNA classes were extracted sedimenting in 60S, 45S and 35S regions (sucrose concentration gradient). In addition, 20S RNA was found within the 150S structures. Both structures sa. However, hydridization degree of RNA isolated from both structures with DNA synthesized enzymatically on extracellular various (DNA I) and A-particles (DNA II) was different. With DNA-I, 50-80% of RNA isolated from the type I structures and less than 20% of RNA extracted from the type II structures were hybridized. At the same time, strictly opposite situation (50-80% of RNA II and 20% of RNA I) was observed for DNA-II. These data show lack of genetic connection between these types of cytoplasmic structures and possible role of type I structures in reproduction of oncorna-virus type B.
Insights
Two distinct virus-specific structures in human cells producing B type oncornavirus were identified. Genetic analysis suggests these structures are not interconnected, with Type I fibrils potentially involved in oncornavirus reproduction.
Area of Science:
- Virology
- Molecular Biology
- Cell Biology
Context:
- Human tissue cultures (Detroit-6 and AO) were studied for their production of B type oncornavirus.
- The research focused on identifying and characterizing virus-specific structures within the cell cytoplasm.
Purpose:
- To reveal and differentiate virus-specific structures in the cytoplasm of human cells producing B type oncornavirus.
- To investigate the genetic relationship and potential roles of these identified structures in viral reproduction.
Summary:
- Two types of virus-specific structures were identified: Type I (aggregated fibrils, 3-6 nm) and Type II (A-particle nucleoids, 70-80 nm).
- Separation via sucrose density gradient centrifugation revealed distinct densities and sedimentation coefficients for both structure types.
- RNA analysis showed similar RNA classes (60S, 45S, 35S) in both structures, with additional 20S RNA in Type I. Hybridization studies indicated a lack of genetic connection, suggesting Type I structures may be involved in B type oncornavirus reproduction.
Impact:
- Provides insights into the heterogeneity of virus-associated structures within infected cells.
- Differentiates potential roles of distinct cytoplasmic structures in the viral life cycle.
- Highlights the importance of characterizing viral components for understanding pathogenesis and developing interventions.