What are the different types of viral vectors?
There are several types of viral vectors that can be used to deliver nucleic acids into the genetic makeup of cells including retrovirus, lentivirus, adenovirus, adeno-associated virus and herpes simplex virus–each with its own advantages and disadvantages for specific applications.
What are the function of retroviruses?
A retrovirus is a virus that uses RNA as its genetic material. When a retrovirus infects a cell, it makes a DNA copy of its genome that is inserted into the DNA of the host cell. There are a variety of different retroviruses that cause human diseases such as some forms of cancer and AIDS.
How retroviral vectors are used in gene therapy?
The most important advantage that retroviral vectors offer is their ability to transform their single stranded RNA genome into a double stranded DNA molecule that stably integrates into the target cell genome. This means that retroviral vectors can be used to permanently modify the host cell nuclear genome.
Why are retroviruses used?
The retrovirus DNA is inserted at random into the host genome. Because of this, it can be inserted into oncogenes. In this way some retroviruses can convert normal cells into cancer cells. Some provirus remains latent in the cell for a long period of time before it is activated by the change in cell environment.
What are non viral vectors?
The non-viral vectors are Naked DNA, particle based and chemical based. They are administered by direct administration (plasmid DNA/Naked DNA)/ chemical /physical. Most of cardiovascular clinical trials use non-viral vectors as a mode of gene transfer.
What is non viral vectors?
How can viruses be used as vectors?
Certain viruses are often used as vectors because they can deliver the new gene by infecting the cell. The viruses are modified so they can’t cause disease when used in people. Some types of virus, such as retroviruses, integrate their genetic material (including the new gene) into a chromosome in the human cell.
What is a retroviral vector?
A retroviral vector consists of proviral sequences that can accommodate the gene of interest, to allow incorporation of both into the target cells. The vector also contains viral and cellular gene promoters, such as the CMV promoter, to enhance expression of the gene of interest in the target cells.
What is retroviral DNA and how is it produced?
Once inside the host cell’s cytoplasm, the virus uses its own reverse transcriptase enzyme to produce DNA from its RNA genome, the reverse of the usual pattern, thus retro (backwards). The new DNA is then incorporated into the host cell genome by an integrase enzyme, at which point the retroviral DNA is referred to as a provirus.
What is the best retroviral vector for gene therapy?
For example, the most popular retroviral vector for use in gene therapy trials has been the lentivirus Simian immunodeficiency virus coated with the envelope proteins, G-protein, from Vesicular stomatitis virus. This vector is referred to as VSV G-pseudotyped lentivirus, and infects an almost universal set of cells.
What is a retrovirus and how does it work?
A retrovirus is a type of RNA virus that inserts a copy of its genome into the DNA of a host cell that it invades, thus changing the genome of that cell.