Gene therapy is a technique used to substitute defective genes that cause diseases with functional genes. It involves identifying the defective gene, extracting DNA, inserting a functional gene, and reinserting the modified DNA. There are two main types of gene therapy - somatic cell gene therapy, which treats only the individual and is not hereditary, and germline cell gene therapy, which could affect future generations but may be most effective. Gene therapy delivers the new genes via viral or bacterial vectors and holds promise to cure genetic diseases but also poses risks such as immune reactions or unintended effects.

1. BACTERIAL GENE
THERAPY
BETH RAWSON

2. WHAT GENE THERAPY?
• A technique used to substitute defective
genes in an individual with genes that do
work.
• These defects cause diseases and illnesses.
• The scientific world is trying to understand the
way our body reacts without these genes and
why our genes sometimes aren’t “on.”

3. When did it Start?
• James Watson and Francis Crick learned about the double helix of DNA in 1953.
• Gene therapy evolved in the Recombinant DNA Era, in the 1980s.

4. What Happens?
1. Cut a piece of DNA with restriction
enzymes
2. Insert the pieces into a plasmid
3. Analyze gene
4. Define defect or disease
5. Make a plan for treatment (example in
steps 6 and 7)
6. Replace defective cells with “normal”
cells
7. Insert new cells into patient through
vectors

5. Types of Gene Therapy
• Somatic Cells: • Germline Cells:
1. Majority of cells in the 1. Cells exist in sperm
human body and eggs
2. Not passed on to 2. Potential of having
future generations negative effect for
3. Less controversial and future generations
more effective if 3. Potentially most
started sooner effective

6. Somatic Cells
• Cells are removed from
body before treatment.
• Grown in lab, fix gene and
insert back into body
through blood stream.
• Many cells to work with.
• Higher risk for older children
or young adults.
• Used to treat illnesses such
as cancer, cystic fibrosis, and
muscular dystrophy.

7. Germline Cells
• Correct abnormalities of
gene involved in
reproduction.
• Abnormalities are seen
before becoming tissue.
• Controversial- “playing
God” with unformed tissue.
• Most effective during
embryonic stage.
• Potential negative affects
on future generations.

8. Vector Deliveries
1. EX-VIVO METHOD
• Outside living body.
• “Normal cells” are inserted in
vector.
• Blood cells with defective gene
are removed from patient.
• Patient’s blood is mixed with
viruses from vector.
• Combination of new and old cells
are put back into the patient.
• Protein is produced to fight
disease.

9. Vector Deliveries
2. IN-VIVO METHOD
• Inside living body.
• Does not use patient’s cells.
• Vectors are given “new” and
“affective” cells.
• New cells put into patient’s
bloodstream.
• New cells bind with targeted
diseased cells.
• Reverses effect of gene.

10. BACTOFECTION:
Newer method of gene therapy.
• Uses bacteria for a direct transfer of the gene to the
individual.
• Bacterial strains deliver the genes to the plasmid and
into the cells.
• Bacteria used as “vehicle” to transfer genetic
information to the cell.

11. Positive Aspects
• Has “incredible therapeutic
potential.”
• Potential to find cures to
genetic diseases.
• Defects can be eliminated
and not passed on to future
children.
• Stops suffering of patient and
family.

12. Negative Aspects
• Immune system can destroy the
vector.
• Very expensive for patient.
• “Make the rich, richer, and the
poor, poorer.”
• “Designer babies” may be made.
• Harmful effects.
• Against religious beliefs.
• “Playing with God and Mother
Nature.”

13. WORKS CITED
• Bergeson, Emilie R. "The Ethics of Gene Therapy." The Ethics of Gene Therapy. Web.
15 May 2012.
<http://www.ndsu.edu/pubweb/~mcclean/plsc431/students/bergeson.htm>.
• Bose, Debopriya. “Gene Therapy Pros and Cons.” Web. 15. 2012.
<http://www.buzzle.com/articles/gene-therapy-pros-and-cons.html>
• "Gene Therapy Reverses Type 1 Diabetes in Mice, Study Finds." ScienceDaily.
ScienceDaily, 06 June 2011. Web. 9 May 2012.
<http://www.sciencedaily.com/releases/2011/06/110606092738.htm>.
• Nature.com. Nature Publishing Group. Web. 15 May 2012.
<http://www.nature.com/gt/journal/v13/n2/full/3302635a.html>.
• "Types of Gene Therapy." « Walesgenepark.co.uk. Web. 15 May 2012.
<http://www.walesgenepark.co.uk/types-of-gene-therapy-2>.