Human Gene Therapy

[Genecks]

http://en.wikipedia.org/wiki/Human_gene_therapy

 

I read that a virus will inject its DNA into a somatic cell in the body and then create therapeutic proteins that are required for an organism. I kept reading and learned that this injection, in situations, would lead to a permanent cure for a defect in an organism.

 

Questions:

Is the virus fought off and eventually erased from the human organism?

Is the virus a permanent addition of the human creature after injection?

[jeskill]

http://en.wikipedia.org/wiki/Human_gene_therapy

 

I read that a virus will inject its DNA into a somatic cell in the body and then create therapeutic proteins that are required for an organism. I kept reading and learned that this injection' date=' in situations, would lead to a permanent cure for a defect in an organism.

 

Questions:

Is the virus fought off and eventually erased from the human organism?

Is the virus a permanent addition of the human creature after injection?[/quote']

 

It's not the virus that becomes a permanent addition, but a particular gene that the virus injects into the cell. This gene addition is permanent.

 

One bacteria that's been really important in understanding this system is Agrobacterium tumefaciens. They produce cankers on the trees by injecting specific genes into the tree's cells that cause the tree cells to overexpress growth hormones, among other things. Even if you get rid of the bacteria, the canker doesn't go away because the genes that caused this change are still in the cells.

[sabbath]

But are you saying that such is also the case in humans as in trees? Does the transferred gene become a permanent add on to the human organism?

 

Is this what they mean by parallel evolution?

 

What if for example the host cell becomes destroyed? and all other traces of the virus for that matter?

[WillTheNewf]

Your talking about one cell here.. There are trillions in your body. It takes HIV YEARS to kill only a type of cell in our body. I dont think your putting your questions into perspective

[DrZoidberg]

I remember doing an essay on germline gene therapy a few years back, so not sure if the situation is the same today but for what i knew....

 

Yes, the body does attack the virus and this is one of the problems with using a viral DNA vector, the virus is attacked before it can inject its package. Secondly it is important to make sure the virus injects the DNA into the correct target cell (e.g. correct insulin gene into right pancreatic cells), so synthesising a virus which can evade the immune system to deliver DNA to the right target AND have a limited lifespan (so not to persist) is the current obstacle in gene therapy (although there are other vectors being explored).