Viral vector

Viral vector

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  VIRAL VECTOR Presented by; MankaMary 1st M.Sc.Microbiology
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  INTRODUCTION  Vector isa vehicle used to transfer the genetic material into a target cell.
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   Viral vectorsare tools used by molecular biologist to deliver genetic material into cells.
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  Uses of viralvectors  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.
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  Properties of ViralVectors 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
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  Types of ViralVectors DNA Viral Vectors; Adenovirus Adeno-Associated virus Herpes virus RNA Viral Virus;  Lentivirus  Retrovirus
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  Adenovirus  It causescommon cold.  It is the double stranded DNA.  It is the naked virus and it has interactions proteins which to penetrate into host cell.
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  Adeno-Associated virus  Itis a small virus which infects humans.  The virus causes a very mild immune response, lending further support to its apparent lack of pathogenicity.
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  Herpes virus  Thistype of viral vector has the ability to deliver large-scale quantities of exogenous DNA.  The main role is maintenance of transgene expression.
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  Lentivirus  Lentiviruses area 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.
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  Retrovirus  Retrovirus vectorsare 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.
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  Applications Gene Therapy:  Genetherapy 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
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  In vaccination  Virusesexpressing 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.
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  Thank You