In these slide I discuss about the various DNA Technology and their biological importance and modern uses of these technologies. Here I also discussed about the oligonucleotide and new pharmaceutical approaches.
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Added: Jan 18, 2022
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ASHOK MPHARM. 1 ST YEAR 210121210013 RECOMBINANT DNA technology and Drug Discovery GUIDED BY :- PROP. SANDEEP JAIN DEPT. OF PHARMACEUTICAL SCIENCES GJUS&T. HISSAR
CONTENTS… Introduction and tools in rDNA technology Basic principles in Gene Cloning Isolation and Insertion of genes Applications 5. GENE Therapy 3. New Pharmaceuticles Designed from Biotechnology Hormons Vaccines Antibiotics and Blood Factors Introduction and Mechanism Of Action 4. Oligonuleotide Therapy Introduction To Vectors Methods of Gene Delivery Recent Advancements Application of Gene Therapy Principles of DNA/RNA Estimation RECOMBINANT DNA TECHNOLOGY HYBRIDOMA TECHNOLOGY Introduction Application
RECOMBINANT DNA TECHNOLOGY INTRODUCTION A recombinant DNA molecule is produced by joining together two or more DNA segments usually originating from different organism. Also called as chimeric gene. Achieved by cutting DNA(restriction enzymes)into suitable fragments and joining together the appropriate fragments(ligation). Proteins expressed by rDNA called as recombinant proteins.
TOOLS OF GENETIC ENGINEERING 1) RESTRICTION ENDONUCLEASES(RE) 2) DNA LIGASE Cutted DNA fragments are covalently joined by this. Join the fragments by forming phosphodiester bond between phosphate group of 5’carbon of one deoxy ribose with hydroxyl group of 3’carbon of another deoxy ribose. Bacterial enzyme that can cut DNA at specific sites Recognition sequences; site in DNA which is cut by RE. Cleavage pattern; Form sticky ends which can easily pair with other DNA having complementary sticky ends. Also called as molecular scissors
INTRODUCTION
Action Of DNA ligase in the formaation of phosphodiester bonds —SOMEONE FAMOUS
BASIC PRINCIPLES STEPS IN GENE CLONING 1)Identification and isolation of desired gene. 2)Insertion of isolated DNA into a suitable vector 3)Introduction of this vector into suitable organism 4)Selection of transformed host cells 5)Multiplication/Expression/Integration followed by expression of the gene in the host
The Principle of Recombinant DNA technology
ISOLATION AND INSERTION OF GENES 1)ISOLATON OF DESIRED GENE a)Genom libraries b)Polymerase chain reaction. c)Chemical synthesis of gene 2)INSERTION OF THE GENE INTO SUITABLE VECTORS Can carry foreign DNA fragment to be cloned and are self replicating in host cells
DNA fragment to be cloned is called as DNA insert. Desired fragments can be obtained from :- Genomic libraries Libraries are collection of DNA clones in a certain vector. Genomic - made from RE DNA fragments of total genomic DNA cDNA (complementary DNA) – made from DNA synthesized from mRNA ISOLATON OF DESIRED GENE b)Polymerase chain reaction Allows the isolation of a specific segment of DNA from a small DNA (or cell sample) using DNA primers c)Chemical synthesis of gene Base sequence of protein is identified, a polynucleotide of same sequence can be synthesized chemically or enzymatically.
Can carry foreign DNA fragment to be cloned and are self replicating in host cells INSERTION OF THE GENE INTO SUITABLE VECTORS
PLASMID They are extrachromosomal,circular,self replicating DNA molecules. Eg.
They are viruses that attack bacteria. Can accept short fragments of foreign DNA into their genome. BACTERIOPHAGE
COSMID It posses the characteristics of both plasmid and bacteriophage.
ARTICIAL CHROMOSOME VECTORS HUMAN ARTIFIAL CHROMOSOME(HAF) Synthetically produced vector DNA possesing characteristics of human chromosome
Contain several copies of plasmid but one copy of plasmid is retained in the DNA. PHAGEMID/PHASMID
Bacterial artificial chromosomes ( BACS) are bacterial plasmids derived from the F plasmid. They are capable of carrying up to 300 kb of DNA. BACTERIAL ARTIFICIAL CHROMOSOME
Behaves like yeast chromosome and can accept large pieces of foreign DNA It is capable for carrying a large DNA fragments (upto 200kb ) but its transformation efficiency is very low. YEAST ARTIFICIAL CHROMOSOME(YAC
Contain several copies of plasmid but one copy of plasmid is retained in the DNA. PHAGEMID/PHASMID
rDNA is introduced in to suitable host. Host are the living cells in which carrier of rDNA/vector can be propagated. TYPES:- INTRODUCTION OF rDNA INTO SUITABLE HOST
rDNA containing cells can be identified from non-transformed cells when a marker gene is present in it. Only the cells that posses such gene will survive. SELECTION OF TRANSFORMED CELLS
MULTIPLICATION/EXPRESSION OF GENE The multiplied copies of gene can be used in number of ways, Introduced to bacterium for production of protein. Introduced into eukaryotic host. Expression of gene
Manufacture of proteins/hormones Interferon, plasminogen activating factor, blood clotting factors, insulin, growth hormone,several enzymes etc. APPLICATIONS Diagnosis of molecular diseases: sickle cell anaemia, thalassaemia, familial hypercholesterolaemia, cystic fibrosis. Prenatal diagnosis: DNA from cells collected from amniotic fluid, chorionic villi
This is achieved by cloning a gene into a vector that will readily be taken up & incorporated into genome of a host cell. ADA deficiency has been successfully treated Gene Therapy Application in Agriculture: Genetically engineered plants are developed to resist draught & diseases. Good quality of food & increased yield of crops is also Possible.
HYBRIDOMA TECHNOLOGY
It is a hybridization technique which is used to produce antibody producing hybrid cell. Antibodies produced are called as Monoclonal antibodies INTRODUCTION
HYBRIDOMA TECHNOLOGY
APPLICATIONS DIAGNOSTIC A monoclonal antibody can be used to detect pregnancy in only 14 days after conception. Their selective binding property allow detection of low levels of human corionic gonadotropin (HCG) in urine and serum.
THERAPEUTIC Earlier horses were inoculated with Coryne bacterium diphtheriae,the resulting crude horse antiserum was used To treat diphtheria. Organ transplantation For the treatment of solid organ transplant rejection, several Mabs against T cell antigens have been evaluated. Bone marrow transplantation MAbs are being evaluated for graft versus host disease in bone marrow transplantation. APPLICATIONS
CANCER TREATMENT mAbs act directly when binding to cancer specific antigens and induce immunological response to cancer cells. Such as inducing cancer cell apoptosis ,inhibiting growth etc. APPLICATIONS
IMMUNOPURIFICATION Monoclonal antibodies can also be used to purify a substance with techniques called affinity chromatography. APPLICATIONS
NEW PHARMACEUTICALS DERIVED FROM BIOTECHNOLOGY
1. Insulin Used for treatment of diabetes HORMONES
Hepatitis B vaccine. Myobloc vaccine. Menveo vaccine. Ixiaro vaccine. MONOCLONAL ANTIBODIES Used along with immunosuppressant's. E.g. Infliximab,Basiliximab,rituximab VACCINES
They are short DNA or RNA molecules that has wide range of applications. Antisense oligonuleotides(ASO) are single strand of DNA or RNA that are complementary to a chosen sequence. They are chemically synthesized from protected phosphoramides or chemically modified nucleosides. INTRODUCTION
MECHANISM OF ACTION
MUSCULAR DYSTROPHY Group of diseases that cause weakening and breakdown of muscles. ASO therapy used to remove mutated exon. ASO AS THERAPEUTIC AGENT 2. CANCER The high specificity of binding of ASO to their target mRNA make these compounds useful as therapeutic agents against human cancer. Suppresses malignant cells
THALASSEMIA Antisense 2'-Omethylribooligonucleotides Were targeted against specific sequence elements in mutated human beta-globin and can repair thalassemia. ARTHRITIS Fibroblast-like cells obtained from RA synovium were stimulated with interleukin-1beta and treated with antisense or sense oligonucleotides targeting proliferating cell. ASO AS THERAPEUTIC AGENT
ASTHMA ASOs directed against chemokine receptor,granulocyte-macrophage colony stimulating factor are designed to inhibit allergic inflammation. AMYLOIDOSIS DIABETES LIMITATIONS High doses required. Half life in plasma is short Protected against nucleophilic attack. ASO AS THERAPEUTIC AGENT
GENE THERAPY
Gene therapy is a clinical procedure in which a gene or other DNA sequence used to treat a disease. TYPES INTRODUCTION
VIRAL VECTORS Viral DNA has been removed and is introduced into hosts. E.g. Adenoviruses,Adeno associated virus,retro virus,Lenti virus. NON-VIRAL VECTORS Pure DNA construct. DNA molecular conjugates. Lipoplexes. Human artificial chromosome. VECTORS
PHYSICAL METHODS METHODS OF GENE DELIVERY MICROINJECTION 2. CHEMICAL METHODS Using detergent mixtures Lipofection
BLINDNESS Cure blindness of inherited condition. HOW IT WORKS; used harmless viruses enable access to the cells beneath the retina of patients. CANCER Used to treat various types of cancer. HOW IT WORKS; Normal WBC taken from cancer patients infected with retrovirus that deliver genes to cells. RECENT ADVANCES & APPLICATION OF GENE THERAPY
PARKINSON’S DISEASE Improved the weakness of the symptoms such as tremors, motor skill problems,and rigidity. HIV Under clinical trials CYSTIC FIBROSIS Adenovirus vector was used to deliver a normal ion channel protein(CFTR) to airway cells in a patient’s nose or lungs. RECENT ADVANCES & APPLICATION OF GENE THERAPY
SEVERE COMBINED IMMUNODEFICIENCY Due to defect of gene coding Adenosine deaminase.Gene of ADA is introduced for its treatment ORNITHINE TRANSCARBOXYLASE (OTC)DEFICIENCY Leads to accumulation of ammonia and can be corrected by gene therapy. RECENT ADVANCES & APPLICATION OF GENE THERAPY
THALASSEMIA It is an inherited autosomal recessive blood disease. Gene transfer of a regulated β-globin gene in would reduce the imbalance between a-and β-globin chains in erythroid cells. RECENT ADVANCES & APPLICATION OF GENE THERAPY
CLINICAL TRIALS Alzheimers disease Hepatitis-B AIDS CANCER Brain, Ovarian,Small cell lung, Prostrate, Breast cancer. Chronic granulomatous disease . RECENT ADVANCES & APPLICATION OF GENE THERAPY
Important applications in PCR. DIPHENYLAMINE METHOD Diphenylamine + deoxy ribose PRINCIPLES OF DNA & RNA ESTIMATION Blue coloured complex(absorbs at 595nm) Concentration Vs Absorbance plotted.
SPECTROPHPTOMETRIC METHOD Sample is exposed to wavelength at 260nm and photo detectors measures the light that passes through the sample. AGAROSE GEL ELECTROPHORESIS Used to separate nucleic acid based on their size under the influence of electric field. Nucleic acids are negatively charged, on applying electric field they move to anode based on size and seperated
ANALYSIS WITH FLUORESCENT DYE TAGGING Sample is tagged with fluorescent dye. Intensity of the dye that bind to nucleic acids is measured. SPECTROPHPTOMETRIC METHOD
REFERENCES https://www.slideshare.net/DivyaV44/recombinant-dna-technology-and-drug-discovery 2 . B.D.Singn.Text book of biotechnology. Kalyani Publishers.;2006(1);11-104.