Gene therapy Flashcards
What is the purpose of DNA methylation?
Gene regulation, and related to epigenetics
What is the differences and commonalities between gene therapies and cell therapies?
Gene therapy change in the genome of exisiting cells.
Cell therapy exchange own cells for new cells
Give at least two examples of diseases where gene blocking is suitable.
When the gene is unecessary - infecitous diseases, cancer or inherited with faulty function
Which are the main cellular barriers for gene delivery? Present a suitable strategy of overcoming at least one of these barriers.
The membrane, lysosol and nuclei entry
Nucleases are also an issue, as well as that free-RNA can be recognized by toll-like receptors.
Overcoming the issue of going through the membrane > viral vectors!
Which are the most common viral vectors for gene delivery?
Retroviral and adenovirus vectors
Which are the benefits and shortcomings of using RV (retroviral) for gene delivery? Give at least one clinical example.
+ Integration, long expression, few immune safety concerns
- Insertional mutagenesis – when integrated, get other mutations
Clinical example: SCID - treat stem cells with gene through RV and put back in
Which are the benefits and shortcomings of using AAV (adeno-associated vectors) for gene delivery?
+ Moderate expression, site directed integration possible?
-No integration, inflammatory response
Which are the benefits of using AdV (adenovirus vectors) for gene delivery? Give at least one clinical example.
+ High expression
Clincal example: OTC to the liver, patient died due to inflammatory response
Provide at 4 beneficial and 4 unfavorable parameters for non-viral gene delivery vehicles using positively charged lipids/polymers.
+ Stable, large DNA, target specific cells, not induce immunological reactions
- Low transfection efficiency, transient expression, inhibited by serum, cell toxicity
How can charge of LNPs (lipid NPs) be used for targeting different organs? Give examples.
Negative > spleen
Positive > lung
What is the driver of LNP transport in specific organs?
The charge?
What is the preferred pKa for LNPs to cause endosomic escape?
pKa 6-7 – to be positive in endosome and escape through membrane rupture and burst, as well as being neutral in blood
What is the basis for cell therapies and how nanotechnology can be used to achieve desired outcomes? Provide at least one clinical example.
Exchanges cells to healthy ones.
Clinal example - SCID: Take bone marrow from patient – infect stem cells with gamma-common chain > inject into the patient > functional stem cells
What are the main steps and components involved in siRNA treatment (with LNPs)?
Dicer create siRNA duplex from dsDNA or shRNA, RISC complex bind and use siRNA as guide and cleaves.
The binding is complementary and the inhibiting mechanism is translational arrest by mRNA cleavage.
What are ASO (antisense oligomeres) therpy?
Antisense binds to sequence and prevent ribosome to translate the mRNA
