microbiology,biotechnology etc

1. VIRAL VECTOR
Presented by;
Manka Mary
1st M.Sc.Microbiology

2. INTRODUCTION
 Vector is a vehicle used to transfer the genetic
material into a target cell.

3.  Viral vectors are tools used by molecular biologist to
deliver genetic material into cells.

4. Uses of viral vectors
 Virus are obligate intracellular parasites.
 Very efficient at transferring viral DNA into host
cells.
 Specific target cells depending on the viral
attachment proteins’
 Gene replacement non essential genes of virus are
deleted and exogenous genes are inserted.

5. Properties of Viral Vectors
Safety:
 Deletion of the viral genome critical for viral
replication e.g helper virus.
Low Toxicity.
Stability:
 Some viruses are genetically unstable and can rapidly
rearrange their genomes.
Identification;
 Viral vectors are often give certain genes that helps
identify which cells took up the viral gene e.g
antibiotic resistance genes

6. Types of Viral Vectors
DNA Viral Vectors;
Adenovirus
Adeno-Associated virus
Herpes virus
RNA Viral Virus;
 Lentivirus
 Retrovirus

7. Adenovirus
 It causes common cold.
 It is the double stranded DNA.
 It is the naked virus and it has interactions proteins which to penetrate into
host cell.

8. Adeno-Associated virus
 It is a small virus which infects humans.
 The virus causes a very mild immune response,
lending further support to its apparent lack of
pathogenicity.

9. Herpes virus
 This type of viral vector has the ability to deliver large-scale
quantities of exogenous DNA.
 The main role is maintenance of transgene expression.

10. Lentivirus
 Lentiviruses are a type of retrovirus that are able to integrate into non-
dividing cells and do not require mitotic cell division in order to function.
 Instead, the genome enters the cell DNA via reverse transcription and is
incorporated in a random position of the cell genome.

11. Retrovirus
 Retrovirus vectors are commonly used and known to integrate into the
genome of the infected cell in a stable and permanent fashion.
 Reverse transcriptase in the virus allows integration into the host genome.

12. Applications
Gene Therapy:
 Gene therapy is a technique for correcting defective
genes responsible for disease development.
 There are following delivery system for gene therapy:
Physical methods
Non-viral vectors
Viral vectors

14. In vaccination
 Viruses expressing pathogen proteins are currently
being developed as vaccines against these pathogens,
based on the same rationale as DNA vaccines.
 A viral vaccine induces expression of pathogen
proteins within host cells. Since viral vaccines
contain only a small fraction of pathogen genes, they
are much safer and sporadic infection by the pathogen
is impossible.
 Adenoviruses are being actively developed as
vaccines.

16. Thank You