Lecture 23 Flashcards
Introducing genes to treat diseases
gene therapy
Germ-line gene therapy: genes are introduced into the germ cells to – future generations.
genetically alter
Somatic cell gene therapy: normal genes are added to the – of at least some of the body’s cells to ameliorate the effects of a defective gene
nuclei
Some Goals of Gene Therapy:
Replace – genes with normal genes to cure diseases
defective
Some Goals of Gene Therapy: introduce genes which will enhance –
immune defenses
Some Goals of Gene Therapy: introduce – into cancer cells
suicide genes
Some Goals of Gene Therapy: alter – of genes in the cell
regulation
Some Goals of Gene Therapy: stop the replication of –
viruses
Genes can be introduced to cells in culture (ex vivo) or –
in the patient (in vivo)
+ Adenovirus
Infects many cell types
- Adenovirus
Does not integrate into host genome and can be lost.
+ Adeno-associated virus (AAV)
Integrates into host genome at specific site and cannot be lost
- Adeno-associated virus (AAV)
difficult to work with
- Simple retrovirus
integrate near genes
+ complex retrovirus (lentivirus)
Integrates into host genome and cannot be lost
Integration is not random – occurs away from genes
+ Herpes Simplex Virus (HSV)
DNA stays in nucleus without integrating into genome
- Herpes Simplex Virus (HSV)
only infects nervous system cells
Non-viral methods of gene transfer
liposome/lipolpex or naked DNA
– are spheres of lipid molecules surrounding an aqueous interior (bilayer); limited amount of DNA will fit in it
liposome
– are lipids with positive charge so attract both DNA and cell wall
No immune response, but not as efficient as virus at transferring DNA
lipolplex
Direct injection of – into muscle cells was found to be expressed
Could be used to make insulin, blood clotting factors or as vaccines to viruses.
naked DNA
Ex vivo usually targets – which are stem cells that generate all other blood cells
hematopoietic stem cells (HSC)