Overview of Gene Therapy 2.0

History of Gene Therapy

• Mendel Experiment in 1865 introducing law of heredity where prediction of inheritance are found.

• Avery and his co-researchers in 1940s found a genetic information that encoded by specific DNA

• Watson & crick suggest that DNA is in double helix formation and it can replicates and will inherit complex genetic information

• Nirenberg in 1961 deciphered triplets of genetic code

• First gene therapy journal was published in 1990, Human Gene Therapy
• Ashanti De-Silva, 4 years old with ADA-Deficient Severed Combined Immunodeficiency was treated with gene therapy

• Alain Fischer was successfully cured by gene therapy for  SCID -XI  (bubble boy)

Gene Therapy

1. Corrected genes are inserted into genome of patient's DNA to replace the "false" gene that can cause disease. 
2. A vector (eg. virus) that have been genetically altered  can help deliver the therapeutic gene to the patient's target cell to disrupt the cancerous cell growth
3. Virus genome have been manipulated to remove gene that causing disease & inserting a " correct" ones
4. Viral vector will infect target cells that happened to be in various parts of patient's body and organs

Limitation of Gene Therapy

1. Patients should be undergo various treatment / therapy in order to fully recoovered
2. The stimulation of immune response could jeopardize the gene therapy effectiveness
3. Vector that have been chosen could posses toxicity, and induce inflammatory response during therapy
4. Multi gene disorder eg. alzheimer and heart disease are difficult to treated

Post-natal Gene Therapy

Correction of deleterious effects of genetic disease which can be treated for a long term integration of gene sequences into patient's genome. Commonly, retrovirus vector could be used to correct inherited monogenetic disorders.

Type of post-natal Gene Therapy

• Replacement GT
• Gene addition

Pre-natal Gene Therapy

Targeting genetic disease that requires life-long correction of genes

Objectives of Pre-natal GT are: 

• To avoid early onset manifestation of disease that could threat life
• To obtain permanent corrections by stable transduction of cell population
• Avoid immune response againts therapeutic vectors .