Genes Flashcards

1
Q

How many defective genes are there per person?

A

400

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are examples of genetic disorders?

A

Haemophilia A and B
Cystic fibrosis
Muscular dystrophy
Sickle cell disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the three mechanisms of gene therapy?

A

Replace disease causing gene
Inactivate disease causing gene
Introduce new gene to help treat disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is GTMP?

A

Gene therapy medicinal products
Contains recombinant nucleic acids
Administered to regulate replace add or delete a genetic sequence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is genotoxicity?

A

If integrated into host genome can disrupt tumour suppressor genes and enhance proto onco genes leading to cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is gene inhibition?

A

Add blocking gene so cell functions normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is cytotoxic gene therapy?

A

Add suicide gene to diseased cell gene makes toxic products cell dies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is immune system engineering?

A

T cell can’t recognise tumour so T cell gets receptor specific for tumour, targets tumour and tumour cell dies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is humeral immune response?

A

B. Cells produce antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is cell mediated immune response?

A

Driven by T cells macrophages and cytokines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What viral vectors will integrate into the host genome?

A

Retrovirus
Lentivirus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What viral vectors won’t integrate into the host genome?

A

HSV-1
Adeno associated virus (AAV)
Adenovirus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What family of viruses are AAV a part of?

A

Parvo virus family

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the disadvantage of AAV as a vector?

A

Is complex and expensive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is an example of a disease that AAV vectors are used in gene delivery?

A

Lipoprotein lipase deficiency
Inherited genetic condition – rare
Defective LDL gene = increased fat in blood
AAV delivers functioning LDL gene to muscle cells (IM)
Muscle cells produce lipoprotein lipase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is CAR – T cell therapy?

A

remove patient’s blood and get T cells
Insert CAR gene (Chimeric antigen receptor)
Grow millions of Car T cells
Car T cells bind to cancer cells and kill

17
Q

What are limitations of Car T cell therapy?

A

Neurological toxicity leading to confusion and delirium
On target off tumour toxicity-bind to normal b cells
allergy to CAR

18
Q

What is ADA – SKID?

A

Deficiency in ADA gene leading to unhealthy lymphocytes and severely impaired immune system

19
Q

How is gene delivery used in ADA – SKID?

A

Bone marrow derived blood forming stem cells collected
Healthy ADA gene added to stem cells via gamma retrovirus
Modified stem cells are copied
Patient gets chemo to wipe out faulty stem cells
New stem cells are infused to the bone marrow

20
Q

How does immunogenicity work?

A

Before treatment screen for antibodies against therapeutic AAV
After treatment antibody has been made and prevents subsequent administration of same AAV vector
Natural killer cells target transgene. Can damage host.

21
Q

What are the limitations of viral vectors?

A

Cost
Genotoxicity
Immunogenicity
Packaging required

22
Q

What are examples of non-viral gene delivery systems?

A

Impalefection- gene delivery using nano particles
Electroporation - large electrical pulse disturbs phospholipid bilayer
Micro injection - glass micropipettes/metal micro injection directly into nucleus. Very fast, no marker gene needed
Gene gun-Hi velocity micro projectiles- genes in gold micro carrier and loaded into cartridge

23
Q

What are examples of chemical methods of gene delivery?

A

Liposomes
Polymers
An organic nano particles

24
Q

What is an example of a polymer used in gene delivery?

A

Polyethylenimine (PEI)

25
Q

What is an example of a lipid vector?

A

Lipofectin (cationic liposomes)
Positive liposome has negative DNA fused into it via membrane membrane fusion and endocytosis – electrostatic interactions
Forms stable overall positive lipoplex taken up by negative cell into nucleus

26
Q

What can be added to liposomes to shield from immune system?

A

PEG
Increases particle circulation time in vivo
Reduces macrophage detection