Explain the role of biotechnology in therapeutics.

Explanation

1.Biotechnological application in Medicine or Therapeutics.
(i) Genetically Engineered Insulin. Insulin from animal source used to cause allergy and reactions, so insulin has been draw from bacteria.
Structure of insulin . Insulin in mammals exist as pro - hormone (inactive from ) . It has A,B,C polypeptide from which D peptide is removed for becoming active from A and B chains are incorporated in the plasmid of E.coil to produce insulin chains , such A and B chains are bridged by disulpide bonds.
Preparation of insulin . It is prepared by rDNA technology genes coding for A and B chains are incorporated in the plasmind of E.coil to produce insulin chains , such A and B chains are extracted and combined to form human insulin .
2. Gene therapy. The diseases with are due to defect is some gene can be cured by incorporating the correct functional gene in body cells which will take over the non - functional genes. e.g., ADA-SCID or severe combined immunodeficiency is a hereditary defect in which infants lack antibody formation due to impairment of components of immune system (T-lymphocytes and B-lymphocytes as well in many cases). Children suffering from SCID can die of even ordinary diseases, vaccination and blood transfusion. In 25% of SCID cases, patient have a defective autosomal gene for synthesis of enzyme adenosine deaminase or ADA.
In the absence of enzyme, purine metabolism is disturbed and T-lymphocytes fail to function. ADA gene is taken out from leucocytes of a healthy person, amplified and inserted in a retrovirus from where viral genes have been taken out. A helper retrovirus devoid of packing sequence is also prepared. Lymphocytes stem cells from bone marrow of patient are taken out and injected with the two types of retroviruses, one carrying ADA. The gene begins to express in the stem cells. The cells also possess faulty gene but its effect is now supressed.
The transformed cell which are now healthy stem cells having functional ADA gene are introduced into bone marrow of the patient. The immune system become functional .
3. Vaccines. .