PHA 338 - Biotechnology and Biopharmaceutical L4

Biologic

Large molecule derived from living cells used to treat, diagnose, or prevent disease

Examples of biologics

Therapeutic peptides, proteins, RNA, DNA, monoclonal antibodies, antisense nucleotides, fusion proteins

Biologics size compared to small molecule drugs

Biologics are 200–1000 times larger and more complex

Biosimilar

Similar but not identical copy of an original biologic medicine

First FDA-approved biosimilar in the US

Zarxio (filgrastim) by Sandoz in 2015

Biopharmaceuticals

Pharmaceutical products produced by biotechnology methods using living organisms or their components

Biopharmaceutical products

Usually protein- or nucleic acid-based drugs used for therapy or diagnosis

Pharmaceutical biotechnology

Use of living organisms or cells to perform industrial or manufacturing processes

Major biotechnological products

Protein drugs, oligonucleotide drugs, monoclonal antibodies, gene therapy, vaccines

Techniques used in biotechnology

Recombinant DNA, monoclonal antibody production, PCR, gene therapy, antisense technology

Protein drug

Protein used therapeutically to replace or supplement natural proteins

Peptide

Polypeptide with fewer than 40 amino acids

Protein

Polypeptide with more than 40 amino acids

Protein structure importance

Protein function depends on its non-covalent 3D structure

Kogenate FS

Recombinant antihemophilic factor VIII used to treat hemophilia A

Hemophilia A

Caused by deficiency of factor VIII

Mechanism of antihemophilic factor

Raises factor VIII levels to aid blood clotting

Erythropoietin

Glycoprotein that stimulates red blood cell production

Uses of erythropoietin

Treats anemia associated with CRF, chemotherapy, dialysis, and AZT therapy

Examples of erythropoietin drugs

Epoetin alfa (Epogen, Procrit), Darbepoetin alfa (Aranesp)

Interferon

Protein with antiviral and anticancer activity

Types of interferons

Type I alpha and Type II gamma

Interferon beta-1b (Betaseron)

Recombinant interferon used for relapsing-remitting multiple sclerosis

Interferon beta-1a (Avonex, Rebif)

Used to slow progression of relapsing multiple sclerosis

Antisense oligonucleotide drug

Drug that blocks DNA transcription or RNA translation

Central dogma of biology

DNA → RNA → Protein

Purpose of antisense drugs

Block production of disease-causing proteins

Antisense technology

Uses complementary nucleotide sequence to bind mRNA

Advantages of antisense drugs

Specificity, broad applicability, rational design, efficiency, low manufacturing cost

Mechanism of antisense drugs

Blocks translation or causes RNase-mediated degradation of mRNA

Vitravene (Fomivirsen)

First marketed antisense drug used for CMV retinitis

Mechanism of fomivirsen

Binds HCMV mRNA and blocks viral replication

Mipomersen (Kynamro)

Antisense drug used for homozygous familial hypercholesterolemia (HoFH)

HoFH

Homozygous familial hypercholesterolemia causing extremely high cholesterol

Orphan drug

Drug developed for rare diseases affecting fewer than 200,000 people in the US

Golodirsen (Vyondys 53)

Antisense drug for Duchenne muscular dystrophy

Mechanism of golodirsen

Binds exon 53 of DMD gene to increase dystrophin production

Efavirenz (Sustiva)

Non-nucleoside reverse transcriptase inhibitor for HIV

Mechanism of efavirenz

Inhibits reverse transcriptase to reduce HIV replication

DNA in biotechnology

DNA stores genetic information and directs protein synthesis

DNA bases

Adenine, Thymine, Guanine, Cytosine

DNA base pairing

A pairs with T, G pairs with C

Recombinant DNA (rDNA)

Combining DNA fragments from different sources

Enzymes used in rDNA technology

Restriction endonucleases and DNA ligase

Purpose of recombinant DNA technology

Produce large quantities of specific DNA or proteins

Plasmid DNA

Small circular DNA molecule separate from chromosomal DNA

Function of plasmids

Replicate independently and carry foreign genes

Use of rDNA technology

Produce human proteins in organisms like E. coli

DNA probe technology

Uses labeled DNA to detect viral infection or genetic defects

GMO

Genetically modified organism

Vaccine

Suspension of attenuated or killed microorganisms used to induce immunity

Purpose of vaccines

Prevent disease by stimulating immune response

Two main types of immunity

Natural immunity and acquired (humoral) immunity

Natural immunity

Inborn immunity present without prior exposure

Types of natural immunity

Species immunity, racial immunity, individual immunity

Acquired immunity

Immunity developed after exposure to antigens or antibodies

Active immunity

Immunity produced by the body after exposure to antigen

Natural active immunity

Develops after infection and recovery

Artificial active immunity

Develops after vaccination

Passive immunity

Transfer of ready-made antibodies from another source

Natural passive immunity

Maternal antibodies transferred through placenta

Types of vaccines

Bacterial vaccines, viral vaccines, cancer vaccines

Inactivated bacterial vaccine

Bacteria killed with chemicals or heat

Examples of inactivated vaccines

IPV, rabies vaccine, hepatitis A vaccine

Live attenuated vaccine

Live organism modified so it does not cause disease

Subunit (acellular) vaccine

Vaccine containing only antigenic components of bacteria or virus

Examples of subunit vaccines

Hib vaccine and acellular pertussis vaccine

Whole virion vaccine

Contains entire virus particles

Examples of live attenuated viral vaccines

Measles and yellow fever vaccines

Examples of inactivated viral vaccines

Seasonal influenza and hepatitis A vaccines

Subvirion vaccine

Chemically split viral vaccine

Virus-like particle (VLP) vaccine

Noninfectious particles resembling viruses without genetic material

Cancer vaccine

Vaccine designed to stimulate immune response against cancer cells

Tumor-associated antigens (TAAs)

Antigens found on tumor cells recognized by immune cells

Types of cancer vaccines

Autologous, allogenic, anti-idiotypic, gene therapy

Autologous tumor vaccine

Made from patient’s own tumor cells

Allogenic tumor vaccine

Made from tumor cells from another patient

Anti-idiotypic vaccine

Uses antibodies that mimic antigens

Gene therapy

Transfer of genetic material into cells to correct gene defects

Vector used in gene therapy

Retrovirus

Purpose of gene therapy

Replace defective genes or add new cell functions

Antibody (immunoglobulin)

Y-shaped protein produced by B cells that binds antigens

Function of antibodies

Identify and neutralize foreign substances

Antigen

Foreign substance recognized by antibodies

Basic structure of antibody

Two heavy chains and two light chains

Fab region

Antigen-binding region of antibody

Fc region

Tail region that activates immune system

Five classes of antibodies

IgG, IgM, IgA, IgD, IgE

Monoclonal antibody

Antibody produced from identical clones of one B cell

Polyclonal antibody

Mixture of antibodies produced by different B cells

Hybridoma technology

Method used to produce monoclonal antibodies

Hybridoma

Fusion of B cell and myeloma cell

Purpose of HAT medium in hybridoma technology

Selects for hybridoma cells that can survive and produce antibodies

PCR (Polymerase Chain Reaction)

Technique used to amplify DNA sequences

Main purpose of PCR

Produce millions of copies of DNA

Biotechnology

Use of living organisms or systems to create products or processes

PCR (Polymerase Chain Reaction)

A laboratory technique used to amplify specific DNA sequences

Purpose of PCR

Produce millions of copies of DNA for analysis or diagnosis

Main steps of PCR

Denaturation, annealing, extension

Denaturation in PCR

Heating DNA strands to separate them