What are the steps of viral gene transfer?

Viral replication involves six steps: attachment, penetration, uncoating, replication, assembly, and release. During attachment and penetration, the virus attaches itself to a host cell and injects its genetic material into it.

Can viruses deliver genes?

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 are the two main delivery methods used in gene therapy?

There are two categories of gene delivery systems such as the germline gene delivery systems and the somatic gene delivery systems. Although the germline gene delivery systems may have great potential, the germline gene therapy cannot use ethically [17, 18].

Why are viruses selected for gene delivery?

Viral gene delivery has developed from the innate ability of a virus to infect T cells, which offers many intrinsic advantages3,4: Specific cell-binding and cell-entry properties. Efficient targeting of the transgene to the nucleus of the cell. The ability to avoid intracellular degradation.

Which is a non viral method of gene delivery?

Non-viral gene delivery mediated artificially by physical method uses to introduce genetic materials through the cell membranes. The physical method of gene delivery includes needle injection, ballistic DNA injection, sono-poration, photo-poration, magneto-fection, and hydro-poration.

What are recent advances in gene delivery systems?

In this article, the recent advances in the development of gene delivery systems have reviewed, including the progress of viral gene delivery systems and non-viral gene delivery systems. The viral gene delivery systems have discussed for the viral vectors based on DNA, RNA, and oncolytic viral vectors, respectively.

When was the first non viral vector used in gene therapy?

In the same year, sickle cell anemia mice were treated by introducing the artificial therapeutics gene. The era for using a non-viral vector in gene therapy was begun when polyethylene glycol was first time used as a vector for the delivery gene into brain cells in 2003.

Where does the virus insert the transgene into the genome?

The transgene to be delivered by the virus is then inserted into the viral genome at the site created by the removal of the viral replication genes.