gene therapy and cell replacement therapy

Question 1

what is Gene therapy

Answer 1

is the use of genetic material to treat or prevent disease

Question 2

what is in vivo

Answer 2

the gene is inserted directly into the person

Question 3

what is ex vivo

Answer 3

the person’s cells are removed from the body then injected with the gene before inserting the cell back into the body

Question 4

what is adenovirus

Answer 4

a vector that is often used to transport genes in gene therapy

Question 5

describe type 1 diabetes

Answer 5

diabetes (type 1) is an autoimmune disease where T-cells attack beta cells causing a lack of insulin

Question 6

how can gene therapy be used to treat type 1 diabetes

Answer 6

Gene therapy can be used in several different ways, one of these is reprogramming alpha cells to beta cells

Question 7

describe the process of gene therapy in on type 1 diabetes

Answer 7

virus-containing proteins is inserted into the pancreas

these proteins change gene expression and cause alpha cells to produce insulin

these new beta cells are resistant to attack by T-cells as they are slightly different to regular ones

this would not be a last ‘cure’ and has been shown to work in mice for 4 months

Question 8

describe the process of ex-vivo

Answer 8

1. cells are removed from the patient
2. in the laboratory, a virus is altered so that it cannot reproduce
3. a gene is inserted into the virus
4. the altered virus is mixed with cells from the patient
5. the cells from the patient become genetically altered
6. the altered cells are injected into the patient
7. the genetically altered cells produce the desired protein or hormone

Question 9

explain the importance of receptors in targeting the correct cells to insert genes

Answer 9

receptors can be thought of as docking stations that only allow specific vehicles to park. the specialized vehicle that contains a genetic therapy, called a vector, must be able to dock onto a receptor so that the therapy can be taken up by the cell. each cell features distinct receptors on its surface, allowing us to target just the right cells for a given therapy

Question 10

explain why basal cells are targeted in gene editing

Answer 10

because they have the ability to divide and differentiate into other cell types to replenish lost cells. As cells die off the basal cells with permanently repaired DNA generate new cells that contain the correct CFTR gene sequence.

Question 11

how are cell-based therapies different to gene therapy?

Answer 11

cell-based therapy involves removing cells from the airway to create space. a niche for the delivery of gene-edited cells. cells are taken from the same patient corrected via gene editing in the lab and delivered into the airway where they will generate new basal cells

Gene therapy delivers a correct copy of the genetic instructions to cells in the lungs with the correct mRNA or DNA sequences cells would be able to produce normal CFTR proteins that move to the cell’s surface. over time the correct copy of the genetic instructions is degraded or are lost as the cells die. regular, repeat treatments will be needed to ensure there is enough CFTR protein present to hydrate mucus.