1. Gene Therapy
(Zinc-finger nuclease, Crisper-CAS 9)

2. Genetic Basis of Disease
SICKLE CELL ANEMIA IS CAUSED BY A SINGLE POINT MUTATION ON A SINGLE GENE.

3. CORRECT MUTATION = CURE DISEASE!

4. Zinc Nucleases

5. Gene Therapy
Attempt to correct diseases caused by a single defective gene by transplanting cells with healthy copies of gene
= mutated gene
= normal gene
Intro video 1st 2 min good

6. Gene Therapy
Corrected version of gene is inserted in VECTOR – most often vector is a modified VIRUS such as Adenovirus or Lentivirus.
New generation viruses are unable to replicate, and are engineered to reduce immune system response. Adenovirus can be expressed by injection into nucleus without being incorporated into chromosome (avoids incorrect insertion into normal genes).

7. Challenges of Gene Therapy- What could possibly go wrong?
Theory is wonderful – cure disease by correcting genetic mistakes or introducing new beneficial protein – practically very difficult to do
Gene Therapy is very high risk
Only used for life-threating diseases known to be caused by a single gene

8. Challenges of Gene Therapy- What could possibly go wrong?
(1999) IMMUNE SYSTEM REJECTION – 1 case of 19 year old male dying 4 days after start of therapy due to massive immune system response
(Early 2000’s) Random insertion of viral DNA into healthy genes – 3 cases of patients developing leukemia
Will transformed cells reproduce and successfully compete with abnormal cells? If not therapeutic impact is only temporary.
Regulation of gene expression – how can we get inserted DNA to be expressed in appropriate amounts at the appropriate times?

9. Severe Combined Immunodeficiency (SCID)
Immune cells do not develop
“Bubble Boy” – children with SCID have been isolated in “bubbles” or mini space suits to avoid exposure to disease

10. SCID animation
Dana Farber video
Procedure used for treating patients with SCID – immune deficiency disease. This disease is caused by MUTATION IN ONE GENE AND IS USUALLY FATAL. 6 PATIENTS “CURED”.

11. Cure for Blindness: Gene Therapy reverses sight loss and is long-lasting
2016: Significant sustained improvement over two years in vision for 32 patients in UK, US, Canada and Germany

12. Hemophilia (Blood clotting disorder)
2017
Video CNBC Nov. 2018
April First Successful Gene Therapy for Hemophilia A Induces Normal or Near Normal Blood clotting Factor VIII Levels for 11 out 13 patients

13. Immunotherapy – activating immune system to fight cancer is currently biggest area of gene therapy research
2018 Nobel Prize in Physiology and Medicine awarded to James Allison and Tasuku Honjo for developing field of immunotherapy – exploring ways to activate immune system against cancer.

14. HALLMARKS OF CANCER CELLS

15. IMMUNOTHERAPY: CAR T targets CD-19 protein common on surface of Non-Hodgkin’s Lymphoma and acute lymphoblastic Leukemia cancers
CAR T immunotherapy

17. Frontiers of Gene Therapy: Using CRISPR-cas9 to fix disease in cells
Stage 1 Hunter’s in vivo
2018 PRACTICAL CONCERNS: OFF-SITE CUT PROBLEM (CUTS OR INSERTS IN WRONG PLACE) HAS NOT YET BEEN SOLVED
ETHICAL CONCERNS: SHOULD WE PURSUE TECHNOLOGY THAT COULD LEAD TO “DESIGNER” BABIES – SELECT SPECIFIC TRAITS

19. Hunter direct injection