Genetherapy1
- 1. GENE THERAPY PRESENTED BY- PRIYA CHHIKARA M. PHARMACY 1ST YEAR (PHARMACOLOGY) 190000803001 DEPARTMENT OF PHARMACEUTICAL SCIENCES CHAUDHARY BANSI LAL UNIVERSITY BHIWANI-127021 1.
- 2. CONTENTS Definition History of gene therapy Types of gene therapy Methods of somatic gene therapy Gene transfer techniques Clinical applications Recent development 2.
- 3. GENE Gene is a unit of DNA or segment of DNA that is usually located on a chromosome and that controls the development of one or more traits and is the basic unit by which genetic information is passed from parent to offspring. 3.
- 4. GENE THERAPY…. 1. It is a corrective therapy for hereditary disease. 2. Gene therapy is collection of methods that allow correction of a gene defect that has been either diagnosed in child or embryo. 3. Replacing a mutated gene that causes disease with a healthy copy of the gene. 4. The most common form of gene therapy involves inserting a normal gene to replace an abnormal gene. 4.
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- 6. HISTORY OF GENE THERAPY 1960:- the concepts of gene therapy was introduced. 1990:- the first clinical gene therapy is given to 4 years old girl named “ASHANTI DE SILVA” in September 14,1990 with ADA (adenosine deaminase) deficiency. ADA deficiency is one form of SCID ( severe combined immune deficiency) The disease is caused by a mutation(defect) in a gene, which codes for enzyme adenosine deaminase. 6.
- 7. Types of gene therapy germ-line gene therapy Somatic gene therapy 7.
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- 11. There are mainly two approaches for the transfer of genes in somatic gene therapy Somatic gene therapy In vivo gene therapy Ex vivo gene therapy 11
- 12. IN VIVO GENE THERAPY Direct delivery of therapeutic gene into target cell into patient body. Carried out by viral and non viral vector systems. This is done in case of tissues whose individual cells can’t be cultured In-vitro in sufficient numbers (e.g Brain cells). In-vivo gene transfer is necessary when cultured cells can’t be re-implanted in patients effectively. 12
- 13. EXAMPLE OF IN-VIVO GENE THERAPY In patients with cystic fibrosis, a protein called cystic fibrosis transmembrane regulator ( CFTR ) is absent due to a gene defect. CFTR present on 7th chromosome no. In the absence of CFTR chloride ions concentrate within the cells and it draws water from surrounding. This leads to the accumulation of sticky mucous in respiratory tract and lungs or pancreas and bile duct also. Treated by in-vivo replacement of defective gene by Adenovirus vector. 1 3
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- 15. EX VIVO GENE THERAPY The approach can be applied to the tissues like hematopoietic cells and skin cells which can be removed from the body, genetically corrected outside the body and reintroduced into the patient body where they become survive for a long period of time. 1 5
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- 19. GENE TRANSFER TECHNIQUES 1.Transformation 2.Conjugation 3.Electroporation 4.Liposome-mediated gene transfer 5.Transduction 6.Direct transfer of DNA 19
- 20. CONJUGATION Conjugation is a natural microbial recombination process. During conjugation, two live bacteria (a donor and a recipient) come together, join by cytoplasmic bridges and transfer single stranded DNA ( from donor to recipient). Inside the recipient cell, the new DNA may integrate with the chromosome or may remain free. Plasmid insert DNA is transferred from cell to another. 20
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- 22. ELECTROPORATION PRINCIPLE:- High voltage electric pulses can induce cell plasma membrane to fuse. Thus, electroporation is technique involving electric field-mediated membrane permeabilization. Electric shock can also induce cellular uptake of exogenous DNA from the suspended solution. It is a simple and rapid technique for introducing genes into the cells from various organisms( micro-organisms, plants and animals). 2 2
- 23. PROCESS Cells are placed in a solution containing DNA Subjected to electrical shock to cause holes in the membrane. The foreign DNA fragments enter through the holes into the cytoplasm and then to nucleus. Advantages:- Versatile and effective to all cells. efficient method Disadvantages:- Cell damage. 2 3
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- 25. LIPOSOME-MEDIATED GENE THERAPY Liposomes are circular lipid molecules, which have an aqueous interior that can carry nucleic acid. Positively charged liposomes very efficiently complex with DNA, bind to cells and transfer DNA rapidly. On treatment of DNA fragment with liposomes, the DNA pieces get encapsulated inside liposomes. These liposomes can adhere to cell membrane and fuse with them to transfer DNA fragments. DNA enters the cell and then to the nucleus 25
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- 27. DIRECT TRANSFER OF DNA It is possible to directly transfer the DNA into the cell nucleus. Microinjection and particle bombardment are the two techniques commonly used for this purpose. Microinjection Process of using a glass micropipette to insert microscopic substances into a single living cell. Normally performed under a specialized optical microscope setup called a micromanipulator. Used to create transgenic organisms. Particle bombardment/ gene gun No need of virus Employs a high- pressure delivery system to shoot tissue with gold or tungsten 27
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- 30. CLINICAL APPLICATIONS Gene therapy is being used in many ways. 1. Replace defective genes. 2. Genetic disorder 3. Autoimmune disease:- rheumatoid arthritis 4. Disease involve several genes and the environmental intract:- diabetes 5. Cystic fibrosis 6. SCID( severe combined immunodeficiency) disease 7. Hemophilia 8. Parkinson's disease 9. Cancer 10.Gene therapy cures blindness 3 0
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