Adenovirus
Adenoviral expression systems are increasingly being used as a mammalian cell expression vectors and in the production of recombinant vaccines as they have several advantages over other viral expression systems.
Adenovirus
Adeno viruses are medium-sized (90–100 nm), non enveloped (naked) icosahedral viruses composed of a nucleocapsid and a double-stranded linear DNA genome ~ 36Kb. There are 53 described serotypes in humans, which are responsible for 5–10% of upper respiratory infections in children, and many infections in adults as well.Viruses of the family Adenoviridae infect various species of vertebrates, including humans. Adenoviruses were first isolated in human adenoids, from which the name is derived, and are classified as group I under the Baltimore classification scheme.
Recombinant, replication deficient adenoviral expression vectors where first developed by Dr Frank Graham and his colleagues at McMaster University, Canada. Adenoviral expression systems are increasingly being used as a mammalian cell expression vectors and in the production of recombinant vaccines as they have several advantages over other viral expression systems.
- Stable maintanence of foreign gene -The viral particle does not undergo recombination at a high rate and is very stable, which means the inserted foreign gene is maintained without change through successive rounds of viral replication. High transient expression of foreign protein is possible.
- Broad host range and low pathogenicity in humans - The viral particle replicates very efficiently in different mammalian cell types. Over 53 different human serotypes have been isolated so far and this offers considerable versatility to select different viruses based on the application needs.
- Very attractive vector for gene therapy experiments - Unlike retroviral vectors which integrate randomly into the host genome, adenoviral vector remains epichromosomal and does not knock out any human genes and is very attractive vehicle for carrying foreign genes in gene therapy experiments.
- Simultaneous expression of multiple genes -There are vectors available for simultaenous expression of different genes using a single expression casettte or co-transfection using different adenoviral vectors.
- Collection and concentration of viral particles is easy - Even after reaching high titers, the viral particle remains concentrated within the cell , making collection and concentration easy.It is also easy to manipulate this vector and one can obtain high viral titers, 1000-10000 PFU in infected cells.
- Scale up and growth in suspension cultures- Adenoviral vectors can be used for growth in suspension ccell cultures, making it amenable to scale-up production when needed.
For more information on the adenoviral expression sytem, to discuss the different vectors options that is best suited for your application and for a quote pleaseThis email address is being protected from spambots. You need JavaScript enabled to view it..
References:
1. Frank L Graham and Ludvik Prevec in Methods in molecular biology, Edition 7, 1991.