simian virus 40

2. INTRODUCTION
SIMIAN VIRUS -40
 SV40 is an abbreviation for virus 40 or simian ,
polymavirus that is found in both monkeys and humans. It
was named for the effect it produced on infected monkey
cells, which developed an unusual number of vacuole. Like
other polyomaviruses, SV40 is a DNA virus that has the
potential to cause tumors in animals, but most often persists
as a latent infection.
 The discovery of SV40 revealed that between 1955 and

3.  It is a spherical virus with a circular double
stranded that encodes 5 proteins ie,T,t,VP1 VP2
and VP3.T protein is essential for viral replication
and the rest proteins form capsid of virus.
SV40 genome used to develop 3 types of vector,
 Transducing Vectors
 Transforming Vectors
 Plasmid Vectors

4. Structure of sv-40

5. SV40 vectors

6. SV40 Transducing Vectors
 These vectors produce viral particles after infection
to monkey cells.
 These vectors should contain SV40 origin including
surrounding region with transcriptional signals.
 These genes encode for T,VP1,VP2 and VP3.

7. SV40 Plasmid Vector
 These vectors replicate in monkey cells (Rhesus) but
not packaged into virions.
 They contain ori and T encoding gene.
 There no size limit on such vectors and some of Ecoli
and monkey shuttle vectors.
 Plasmid vectors are unstable in monkey cells,
generally used in transient transformation.

8. SV40 Large T-antigen

9.  These vectors don’t replicate. They serve as vehicle for
transforming DNAs that may become integrated into
host DNA.
 These vectors are shuttle vectors.
 SV40 segments used in these vectors transcription
regulatory sequences and polyadenylation sites.
Co-transfection: Integration of two genes together
in a genome.
NON-REPLICATING VECTORS

10.  Vectors with ori and genes for VP1, VP2 & VP3 will
replicate and produce virions in COS lines.
 Here no helper virus is required since such a vector in
early genes (T gene) replaced by DNA insertion.
EARLY region REPLACMENT VECTORS
late REPLACMENT VECTORS
 Here region encoding VP1,VP2&VP3 may be replaced
by vector through DNA insertion, SVGT-5.
 A vector of this type is used for infection of host cells
in conjugation with another virus, i.e., helper virus.

11. Thank You