How does SV40 transform cells?
SV40 transforms cells that are nonpermissive for viral productive infection. Infection of permissive cells, such as the CV1 or BSC40 lines of African green monkey kidney cells, results in cell death and the production of about 300 infectious progeny virions per infected cell (Figure 2a).
How does SV40 immortalization work?
Thus, SV40-LT leads to the two-step immortalization of primary cells . Through its interaction with p53 and pRB, SV40 T antigen abolishes their inhibition of the cell cycle and permits continuous proliferation. After multiple divisions, the cells are in a high-risk stage.
What is SV40 ori?
The SV40 origin can be used to increase the level of transcription in cells that are transfected with the plasmid because the plasmid is replicated. It is also reported that by using selectable markers in conjunction with the SV40 origin stable cell lines can be produced.
Why do viruses have icosahedral symmetry?
Most viruses have icosahedral or helical capsid structure, although a few have complex virion architecture. An icosahedron is a geometric shape with 20 sides, each composed of an equilateral triangle, and icosahedral viruses increase the number of structural units in each face to expand capsid size.
What is the role of large T antigen in SV40 pathogenesis?
The large and small tumor antigens (T antigens) are the major regulatory proteins encoded by SV40. Large T antigen is responsible for both viral and cellular transcriptional regulation, virion assembly, viral DNA replication, and alteration of the cell cycle.
What does T antigen do?
What does SV40 stand for?
Simian virus 40. A virus that infects some types of monkeys. It may also infect humans, and was found in some polio vaccines tested in the early 1960s. Although the virus has been shown to cause cancer in laboratory animals, there is no evidence that it causes cancer in people.
Is a helical virus?
Helical viruses can be enveloped or naked. The first virus described, tobacco mosaic virus, is a naked helical virus. In fact, most plant viruses are helical, and it is very uncommon that a helical plant virus is enveloped. In contrast, all helical animal viruses are enveloped.