1. Gene Therapy
Yerr baby!!!!

2. The main advances in medicine
Improved sanitation systems
Surgery with anesthesia
Vaccines and antibiotics
And the fourth will be Gene Therapy

3. What is gene therapy?
The selective delivery of genes into a patients cells
create missing proteins
replace defective disease causing genes
Over 4,000 conditions are caused by damage to a single gene, many others by several genes

4. Gene therapy techinques
Ex-vivo “outside the body”
adding blood cells with new DNA to the blood stream
but has a limited time span
Using bacteria like E.coli to produce billions of copies of a human gene
Using viruses to carry the gene to specific cells in the body

5. What do you need? A cutting enzyme called a Restriction enzyme
It cuts foreign DNA that enter bacteria, e.g. Eco. R1
A circular DNA molecule from a bacteria called a
Plasmid
The E. coli bacteria has dozens of different plasmids
A section of the human DNA containing the gene you need
An enzyme to join the bacterial DNA and human DNA called
ligase

6. Restriction Enzymes Found in many bacteria
A defense mechanism which cuts foreign DNA
The DNA is not cut randomly, but at specific sequences called
Recognition sequences
The restriction enzyme Eco.R1 found in strain C, E. coli bacteria
They don’t make straight cuts, but produce sticky ends
These sticky ends can rejoin by forming hydrogen bonds and the sugar-phosphates rejoining with the help of the enzyme ligase
The DNA produced by restriction enzymes cutting is called gDNA
We know of 200 different restriction enzymes

7. Plasmids
The Plasmid pSC101 was isolated from E. coli. It is useful for gene therapy because it has only one sequence of GATTC in its entire molecule
Plasmids can be used to replicate DNA segments of up to 4,000 base pairs in length
For longer length viruses must be used.

8. Using Bacterial Plasmid
Cut the Bacterial Plasmid using restriction enzyme called Eco R1

10. This produces a hole in the circular Plasmid DNA
Eco. R1 only cuts at the sequence GAATTC
This produces two identical ends

11. Plasmid
Also treat human DNA with Eco.R1 and you get a section of DNA containing the gene you want with two complementary ends as well!
Short sequence of DNA with sticky ends approaches a Plasmid.
Human DNA

13. Bacterial DNA
Human DNA
The newly completed piece of DNA is called
Recombinant DNA

14. Using this Recombinant DNA
Gene cloning can now be used to produce millions of copies

15. A Plasmid with human DNA is put back into a E. coli
The bacteria expresses the DNA.
The bacteria then divides to produce millions of copies bacteria and human gene.

16. A Plasmid cut by a restriction enzyme
Foreign DNA spliced into Plasmid by
Plasmid enters bacterial cell
Segment of DNA approaches
DNA ligase joins phosphates and sugars

17. Using viruses
Viruses can be used to transfer large pieces of human DNA to a location in the Human body.
Viruses are made up of a molecule of nucleic acid and a protein coat.
Their nucleic acid codes for protein coats, replication, enzymes to break-in and out of particular cells.
You remove the part of the nucleic acid that does not code for the above functions and add foreign DNA.
The virus can then be put into the blood stream and it will enter the cell it is designed to attack and transfer its code into that cell.

18. Some current uses of gene therapy and later cosmetic uses
Some current uses & trials of gene therapy
Introduction of genes for new blood vessels for clogged arteries
Introduction of genes into the blood stream that interferes with the replication of HIV
Human growth hormone for Dwarfism
Insulin production
Glowing mice
Replacing the cytoplasm in eggs to produce healthier eggs
Some current uses of gene therapy and later cosmetic uses

19. The future?
Injecting genes into the blood stream which are then carried to the target cells by viral carriers where they unload their genetic material.
This is then used by the body to produce proteins that fight the disease.
For the next decade gene therapy will only be used on somatic cells (only effect the patient and not their offspring)
You and bioethicists will have to decide the future!