gene therapy vectors Flashcards
name some single gene defects
1) severe combined immunodeficiency
2) cystic fibrosis
3) ornithine transcarbamylase
4) haemophillia
5) thalassaemia
6) sickle cell disease
7) duchenne muscular dystrophy
what is an advantage of chemical non viral vectors
they are non toxic and easy to formulate with nucleic acids and produce.
what are some problems with chemical vectors
they have some problems with specificity and targeting
name a non integrating transient expression viral vector
adenovirus
name a non integrating sustained expression viral vector
herpes virus
name a integrating sustained expression viral vector
adeno associated virus, retroviruses, lentiviruses
name advantages of virla vectors
1) efficient cell entry
2) many cell surface receptors
3) often tissue specific entry
4) can integrate or persist
5) can create disabled viruses that are replication deficient for gene therapy.
disadvantages of virla vectors
1) inflammation
2) pre existing immunity against virus
3) repeat dosing if expression not sustained
4) integrating viruses into critical genes in host.
5) expensive production
is adeno associated virus pathogenic
no
what does AAV need for growth
needs co infection with adenovirus
how can AAV establish latent infection
by entering human cells in absence of adenovirus
where does AAV integrate
in human chromosome 19
what does herpesvirus infect
non dividing cells
does herpesvirus integrate into the host genome
no
can herpesvirus establish latent infections
yes
what do adenoviruses infect
epithelial cells in respiratory and alimentray tracts, conjuctiva, bladder and kidneys. also infects non dividing cells.
advantages of adenoviruses as vectors
safe, vaccine usage, non pathogenic, large inserts, infects variety of cells.so
what are some barrier to therapy with adenoviruses
wide CAR receptor distribution, no CAR in cancer tissues, immune response to virus, inflammatory reponse, difficult to re administor.
