Ch 5 Flashcards
gene therapy
using DNA as a therapeutic (in contrast to drug therapy)
in general, a mutated gene must be fixed by either…
a) adding the normal gene or b) replacing the nutated gene with a normal gene
how are cancer cells killed?
using genes
what are DNA vaccines?
genes to combat infection disease
somatic cells
cells derived from the basic germ layers of the body that DO NOT pass their genetic information to the next generation
germ cells
cells that give rise to the gametes and DO pass their genetic information to the next generation
gastrulation
forms the basic “germ layers” of the body and creates the germ cells for the next generation
direct delivery of somatic cell gene therapy
packaged into a delivery vehicle such as a retrovirus and injected into the patient
somatic cell gene therapy
a) genetically identical iPSCs are generated from the patient B) adult stem cells are isolated and propagated in the laboratory
cell based delivery
therapeutic gene is packaged into a delivery vehicle such as a retrovirus and introduced into the cells
challenges of somatic gene therapy
must get therapeutic gene into relevant cells’ nucleus, gene must be expressed long term, safety concerns
in direct delivery, a “delivery vehicle” such as what is used to target the gene to the tissue
inactive virus
foreign genes tend to be what?
“silenced”
safety concerns to somatic gene therpay
removal of engineered cells could prove difficult, 1999 death due to a massive adverse immune response to virus, side affects from the integration of foreign DNA
what is the U.S. policy on somatic cell gene therapy?
FDA has approved experimental trials, but no products have been approved
in 2000, a sever combined immune disease (SCID) gene therapy trial resulted in what?
development of leukemia in some of the treated patients
research in somatic cell gene therapy
development of gene delivery vehicles that don’t rely on viruses, new ways to destroy, introduce, or repair genes, demonstrating treatments in animal models, using patient-specific induced pluripotent stem cells (iPSCs) to correct genetic defects and then creating the appropriate tissue
reproductive (germline) gene therappy
gene therapy to alter the genetic constitution of germ cells
what does gene therapy do?
affects all cells of the body, not targeted to a specific tissue, manipulates the genome of a person before they are born, imposes a permanent change that is passed on to subsequent generations
germline gene therapy: making “transgenic animals”
1) deliver a gene into the nucleus of a fertilized one cell embryo (zygote) 2) develop to blastocyst and implant into a female uterus 3) test to verify the gene is present in the offspring
animals can be engineered to produce 2-3 times more what?
muscle mass
transgenics work well for what?
adding a gene
to repair or replace a gene with transgenics currently requires what?
cells that can be cultured in a dish
germline gene therapy via reproductive cloning:
1) genetically modify skin cells, 2) perform SCNT, 3) implant
