BIotherapeutics Flashcards
What is the projected size of the biologics market by 2025?
Expected to be a $200 billion market by 2025
What microorganisms produce a significant amount of antibiotics?
Actinomycetes and fungi are responsible for the production of a lot of antibiotics (secondary metabolites)
How do nucleic acid vaccines work?
DNA plasmid enters nucleus, translated into mRNA for expression of protein
OR
mRNA can be injected. More direct (no transcription required, only translation), but less stable than DNA
Ex. Covid-19 mRNA vaccines
What are antisense oligonucleotides (ASO)?
ASOs are short NDA analogues that hybridize with the complementary mRNA in a sequence-specific manner
Hybridization of ASO to target mRNA can result in specific inhibition of gene expression (reduced translation, helps normalized gene over-expression)
How exactly do antisense oligonucleotides inhibit gene expression?
There are two places where ASOs can limit gene expression
- If ASO enters the nucleus, it can bind to pre-mRNA and prevent the formation of a 5’ cap, inhibit exon splicing, and activates nucleases
- If ASO enters the cytosol, ASO will bind to the processed mRNA, before translation occurs. This blocking results in steric hindrance with RNA polymerases or ASO will activate RNAases (RNA breakdown)
All of these actions effectively reduce the amount of protein produced (inhibition)
What are some gene therapy techniques?
- Most common technique:
A normal gene is inserted into a non-coding location. This is done to replace a nonfunctional gene - Abnormal gene is swapped for normal gene through homologous recombination
- Abnormal gene is repaired via selective reverse mutation
- Modify the regulation of how much the gene expression
What happens in ex-vivo gene therapy?
Take sample from patient
Culture cell
Transfer gene into cell (via virus or plasmid)
Insert cultured cells back into patient
What happens in in-vivo gene therapy?
Some organs are less suited for ex-vivo therapy, so we use in-vivo when dealing with lung, brain, and heart tissue
Inject plasmid into target tissue
What was the first FDA-approved gene therapy?
Luxturna was the first gene therapy and it was used to prevent genetic retinal dystrophy
Luxturna works by introducing a normal copy of the RPE65 gene, a gene when mutated was associated with retinal dystrophy
What are the basic building blocks of an antibody?
2 heavy chains
2 light chains
Heavy and light changes are bonded to each other with a disulfide linkage
How are antibodies used in cancer therapy?
- Antibodies that attract Natural Killer cells after binding to cancer cells
- Antibody-toxin conjugates (toxin is directed to cancer cells, avoids prolonged contact with healthy tissue)
- Radioactive antibody binds to cancer cell and delivers localized “radiotherapy”
What are polyclonal antibodies?
A protein may contain more than one site that can elicit an immune response. These sites are called epitopes. An antibody can be created for each epitope, resulting in many different antibodies for a single protein.
How are monoclonal antibodies made?
Immunize mouse with antigen
Isolate antibodies specific to antigen
Fuse mouse antibody forming cell (plasma cells) with tumour cell. This forms a hybridoma
The hybridoma is a antibody manufacturing cell (has both the ability to create antibodies at a high rate for a prolonged period of time)
What are the differences between polyclonal and monoclonal antibodies?
Polyclonal antibodies:
Cheaper
Mixed population of antibodies
Bind to different epitopes
Monoclonal antibodies:
Expensive
Single antibody species
Bind to single specific site
How can HER2+ tumours be treated?
Herceptin (Trastuzumab) will reduce the production of HER2 protein in tumour cells
