Gene Therapy Mostafa A. Askar NCRRT By M.Sc. In Molecular Biology Molecular Immunology Specialist NCRRT

Lecture Content Definition of Gene Therapy Aim of Gene Therapy Types of Gene Therapy General Principles of Gene Therapy DNA delivery in Gene Therapy; How & With What Gene Therapy Approach Gene Therapy Problems Inherited Diseases Treated by Gene Therapy; Trails

Lecture Content Definition of Gene Therapy Aim of Gene Therapy Types of Gene Therapy General Principles of Gene Therapy DNA delivery in Gene Therapy; How & With What Gene Therapy Approach Gene Therapy Problems Inherited Diseases Treated by Gene Therapy; Trails

Definition of Gene Therapy Gene Therapy: is the insertion, alteration, or removal of genes within an individual's cells and biological tissues to treat disease. It is a technique for correcting defective genes.

Lecture Content Definition of Gene Therapy Aim of Gene Therapy Types of Gene Therapy General Principles of Gene Therapy DNA delivery in Gene Therapy; How & With What Gene Therapy Approach Gene Therapy Problems Inherited Diseases Treated by Gene Therapy; Trails

Aim of Gene Therapy The most common form of gene therapy involves the insertion of functional genes into an unspecified genomic location in order to replace a mutated gene, but other forms involve directly correcting the mutation or modifying normal gene that enables a viral infection.

Lecture Content Definition of Gene Therapy Aim of Gene Therapy Types of Gene Therapy General Principles of Gene Therapy DNA delivery in Gene Therapy; How & With What Gene Therapy Approach Gene Therapy Problems Inherited Diseases Treated by Gene Therapy; Trails

Somatic gene therapy In Utero gene therapy Germ line gene therapy Types of gene therapy Somatic gene therapy In Utero gene therapy Germ line gene therapy

Somatic gene therapy In the case of somatic gene therapy, the therapeutic genes are transferred into the somatic cells of a patient. Any modifications and effects will be restricted to the individual patient only, and will not be inherited by the patient's offspring or later generations.

In Utero gene therapy It involves gene therapy of fetuses whilst in the womb. There is some concern that the germline will be affected.

Germ line gene therapy In this case; Germ cells (Ex. sperm or eggs) are modified by the introduction of functional genes, which are integrated into their genomes. Therefore, the change due to therapy would be heritable and would be passed on to later generations.

Lecture Content Definition of Gene Therapy Aim of Gene Therapy Types of Gene Therapy General Principles of Gene Therapy DNA delivery in Gene Therapy; How & With What Gene Therapy Approach Gene Therapy Problems Inherited Diseases Treated by Gene Therapy; Trails

General principles of Gene therapy Identification and characterization of gene Cloning of gene Choice of vector Method of delivery Expression of gene

Characteristics of the ideal vector Non-pathogeneic. Capable of integrating DNA into host genome at a single site. Able to carry large amounts of DNA. Unable to cause immune response. Target cells specifically.

Lecture Content Definition of Gene Therapy Aim of Gene Therapy Types of Gene Therapy General Principles of Gene Therapy DNA delivery in Gene Therapy; How & With What Gene Therapy Approach Gene Therapy Problems Inherited Diseases Treated by Gene Therapy; Trails

Viral vectors. Non-viral delivery. DNA delivery is mainly accomplished by either: Viral vectors. Non-viral delivery.

Vectors Adenoviruses Adeno Associated viruses Reto viruses Herpes Simplex viruses

Adenoviruses * dsDNA Viruses. * Non-integrating viruses. * Infect dividing & non-dividing cells.

Adenovirus vector in Gene Therapy

Adenoviruses Advantages. Non-oncogenic. Relatively easy to culture Adenoviruses Advantages * Non-oncogenic. * Relatively easy to culture. * Proteins functions are known. * Complete DNA sequence is available. Adenoviruses Disadvantages Transient expression leads to multiple injections

* RNA Viruses. * Incorporating Viruses. * Infect dividing cells. Retroviruses * RNA Viruses. * Incorporating Viruses. * Infect dividing cells.

Retroviruses Advantages * Their ability to integrate in host DNA. Disadvantages * Infect ONLY dividing cells * Integration is random, causing “Insertional Mutgenesis”.

Non-viral delivery in gene therapy Particle bombardment Receptor-mediated uptake Liposomes

Particle bombardment Particle bombardment. DNA is fired through the cell walls and membranes on metal particles. This method was originally developed to get DNA into plants. However, it has also been used to make transgenic animals and is occasionally used for humans.

Receptor-mediated uptake Receptor-mediated uptake. DNA is attached to a protein that is recognized by a cell surface receptor. When the protein enters the cell, the DNA is taken in with it.

Liposomes Liposomes are spherical vesicles composed of phospholipid. They have been used in around 10% of gene therapy trials.

Lecture Content Definition of Gene Therapy Aim of Gene Therapy Types of Gene Therapy General Principles of Gene Therapy DNA delivery in Gene Therapy; How & With What Gene Therapy Approach Gene Therapy Problems Inherited Diseases Treated by Gene Therapy; Trails

Antisense Gene Therapy

Gene Therapy to Induce Apoptosis

Anti-Angiogenic Gene Therapy

Lecture Content Definition of Gene Therapy Aim of Gene Therapy Types of Gene Therapy General Principles of Gene Therapy DNA delivery in Gene Therapy; How & With What Gene Therapy Approach Gene Therapy Problems Inherited Diseases Treated by Gene Therapy; Trails

Problems with Gene Therapy Short Lived 2. Immune Response 3. Viral Vectors may cause disease once inside

Problems with Gene Therapy 4. Multigene Disorders Heart disease, high blood pressure, Alzheimer’s, arthritis and diabetes are hard to treat because you need to introduce more than one gene 5. May induce a tumor if integrated in a tumor suppressor gene because insertional mutagenesis

Lecture Content Definition of Gene Therapy Aim of Gene Therapy Types of Gene Therapy General Principles of Gene Therapy DNA delivery in Gene Therapy; How & With What Gene Therapy Approach Gene Therapy Problems Inherited Diseases Treated by Gene Therapy; Trails

Gene Therapy trials for inherited diseases Lung Cystic Fibrosis (CF).

Diseases Treated by Gene Therapy Bone Marrow Adenosene Deaminase Deficency(ADA) Brain (Alzheimer’s disease) Liver (Factor VIII deficiency.)

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