GENE THERAPYGENE THERAPY

- “molecular bandage”

- use of DNA as a pharmaceutical, to treat disease

STEPSSTEPS

1. Identify needed gene

2. Isolate a healthy version of the gene

3. Put into recipient

- gene will produce needed protein

Simple, right?Simple, right?

To get the gene in:

http://learn.genetics.utah.edu/content/tech/genetherapy/gttools/toolbox.swf

Viral Vectors (in vivo)

• General advantages of viral vectors:– very good at targeting and entering cells.– might be engineered to target specific types of

cells.– can be modified so that they can't replicate and

destroy the cell.

• General drawbacks of viral vectors:– A virus can't "expand" to fit a piece of genetic

material larger than it is naturally built to carry, some genes may be too big to fit into a certain type of virus.

– Viruses can cause immune responses in patients, resulting in two potential outcomes:

• Patients may get sick.• A patient's immunity to a virus may prevent him from

responding to repeated treatments.

Types of Viral Vectors• retrovirus: gene incorporates

– can cause cancer

• adenovirus– doesn’t integrate: short-lived and immunogenic

• adeno-associated virus– integrates at a specific site

• herpes virus– immunogenic, but does not integrate

Ex-vivo:

• isolate patients’ cells• treat the cells outside the body• liposomes/plasmids

– good for ex-vivo: no limit on length

SUCCESSFUL USESSUCCESSFUL USES

- retinal disease Leber's congenital amaurosis,

- X-linked SCID

- ADA-SCID

- adrenoleukodystrophy

- chronic lymphocytic leukemia (CLL)

- acute lymphocytic leukemia (ALL)

- multiple myeloma

- haemophilia

- Parkinson's disease

DRAWBACKS...DRAWBACKS...

In 2012, Glybera became the first gene therapy treatment to be approved for clinical use in either Europe or the United States after its endorsement by the European Commission

(1.6 MILLION DOLLARS PER TREATMENT!!!!!)

Slight issues...Slight issues...

- EXPENSIVE!

- can cause cancer-causing mutations

- can change gametes

- needs to be delivered to millions of the RIGHT cells

- gene doping?