Medical Biotechnology - Applications, Gene Therapy, and CRISPR PDF

Cell Biology and Biochemistry (CBB) Topic 5: Biochemical Applications Learning Outcomes Apply the concepts of organic compounds, biomolecules and cell biology to applications in various industries. I. Describe the applications of basic organic compounds, biomolecules, and cell biology k...

Cell Biology and Biochemistry (CBB) Topic 5: Biochemical Applications Learning Outcomes Apply the concepts of organic compounds, biomolecules and cell biology to applications in various industries. I. Describe the applications of basic organic compounds, biomolecules, and cell biology knowledge in the food, biomedical, biotechnology, veterinary, pharmaceutical and chemical industries. II. Explain the potential benefits and risks involved in the application of modern cell biology and biochemistry techniques in various industries.  Pharmaceu tical Science Food Veterin Science ary and Scienc Nutrition Biochemi e cal Applicati ons Medical Chemic Biotechnol al ogy Enginee ring Medical Biotechnology Medical Biotechnology Gene Therapy Introduction of genes into existing cells to prevent or cure a wide range of diseases. It is a technique for correcting defective genes responsible for disease development. Two types of gene therapy: Depending on which types of cells are being treated Somatic gene therapy Transfer of a section of DNA to any cell of the body that doesn’t produce sperm or egg Effects of gene therapy will not be passed onto the patient's children Germline gene therapy Transfer of a section of DNA to cells that produce eggs or sperm Effects of gene therapy will be passed onto patient’s children and subsequent generations Medical Biotechnology Concept of DNA, RNA and Protein Messenger RNA (mRNA) plays a vital role in translating the instructions in DNA into the proteins of life. If a gene is damaged it creates damaged mRNA, which goes on to create damaged proteins and, ultimately disease. Gene therapy will carefully select to correct the effect of a mutated gene that is causing disease.  Medical Biotechnology Tools for gene editing Vectors- vehicles used in gene therapy to transfer the desired gene into a target cell. 2 main classes of vectors: Viral vectors Retrovirus vector system Adeno virus vector system Adeno associated virus vector Herpes simplex virus vector Non-viral vectors Pure DNA construct Lipid nanoemulsions DNA polymer conjugates Human artificial Comparison between Viral and Non viral vector system Viral Vectors Nonviral Vectors Definition Viral vectors are gene Nonviral vectors are delivery vehicles that gene delivery vehicles deliver foreign genetic that deliver foreign material into cells using a genetic material into a viral genome cell by using inorganic particles, lipid-based vector, polymer-based vector, and peptide- based vectors Chemical, Biological agent Chemical agents Biological, Physical Agent Biosafety Has risk to biosafety Has no risk to biosafety Efficiency and More efficient and highly Less efficient and Specificity specific barely specific Single Dose/ Multiple Single dose delivery Multiple or repeated  Medical Biotechnology- gene editing tools DNA editing using nucleases (molecular scissors): enzymes capable of cleaving the phosphodiester bond between nucleotides of nucleic acids. Exonucleases- digest nucleic acids from the ends Endonucleases act on regions in the middle of target molecules Zinc finger nucleases (ZFNs), Transcription activator-like effector nucleases (TALENs) Clustered Regularly Interspaced Short  Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) CRISPR is a hallmark of bacterial defense system that forms the basis for CRISPR-Cas9 genome editing technology. CRISPR was first discovered in archaea, a bacterial immune system known to defend against invading viruses. CRISPR-Cas9 is a system that can be programmed to target specific stretches of genetic code and to edit DNA at precise locations.  CRISPR/Cas9 system- how does it work? Target the right gene Scientists engineer a piece of RNA that is a match for the DNA they want to edit. This is called the guide RNA. Bind the target An enzyme called Cas9 binds to a piece of DNA and temporarily unwinds a section of the DNA. Cut the DNA If the guide RNA matches a section of the DNA, the Cas9 enzyme cuts both strands of the DNA double helix. Repair and edit the DNA Machinery inside the cell rushes to fix the broken DNA. One repair process uses a similar-looking, unbroken piece of DNA as a template to stitch the broken pieces back together. Scientists can introduce tailor-made DNA into the cell — tricking the repair machinery into using the engineered DNA as the template for stitching Case Study: Severe Combined Immune Deficiency (SCID) Children with SCID lack the ability to produce a working immune system. The human immune system constantly patrols, protects and defends the body from all types of “enemies”: bacteria, fungi, viruses. A child with SCID: can't produce T cells doesn't have working B cells (because there are no T cells for them to work with) has virtually no immune system constant risk for pneumonia, thrush and diarrhoea Case Study: Severe Combined Immune Deficiency (SCID) What causes SCID? Most common type, known as SCID-X1 (for “X-linked severe combined immunodeficiency”), involves a defect in a gene on the X chromosome. SCID-X1 affects only male children since they only have 1 X- chromosome. However, girls can be “carriers” and can pass the disorder on to their own sons later in life. SCID Treatment Options Antibody infusions Stem cell/Bone marrow transplant Gene Therapy: SCID-X1 or Adenosine deaminase (ADA) Case Study: Beta thalassemia Beta thalassemia is a blood disorder that reduces the production of hemoglobin. Hemoglobin is the iron- containing protein in red blood cells that carries oxygen to cells throughout the body. In people with beta thalassemia, low levels of hemoglobin lead to a lack of oxygen in many parts of the body. Affected individuals also have a Case Study: beta-Thalassemia treatment Current therapies for beta- thalassemia include life long monthly supportive red blood cell transfusions together with iron chelation or curative allogeneic HSC transplantation. CRISPR-Cas9 clinical trials targeting and cleaving BCL11a by CRISPR Therapeutics and Vertex Pharmaceuticals. BCL11a a gene encoding a protein that normally suppresses the production of hemoglobin F in healthy Case Study: Cystic Fibrosis Cystic fibrosis is a rare genetic disorder that affects mostly the lungs. Long term issues include difficulty breathing and coughing up mucus as result of frequent lung infections. Cystic fibrosis is inherited in an autosomal recessive manner. It caused by the presence of mutations in both copies of the gene for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. Case Study: Cystic Fibrosis Currently, there is no cure for cystic fibrosis. Lung infections are treated with antibiotics which may be given intravenously, inhaled or by mouth. Lung transplantation may be an option if lung function continues to worsen. Gene therapy Inserting the correct version of CFTR gene into an individual’s cell and let the new copy of CFTR gene become a permanent part of their genome. Example of genomic medicines in clinical and preclinical stages of development from Sangamo Therapeutics