5 ms·
Marvelous! I wonder why she needs a second transplant though.
by hooloovoo_zoo 4y ago
Marvelous! I wonder why she needs a second transplant though.
- t-3 4y agoIt's explained in the article that the second transplant is necessary to replace the white blood cells which should have been fully wiped out by the first transplant of modified cells.
- hooloovoo_zoo 4y agoBut why can’t the modified cells function as regular T cells in addition to the modifications?
- zaroth 4y agoI think they don’t usually last that long. The body won’t keep producing the modified cells. Plus I think the modification made them basically only good for killing the native (cancerous) T cells
- hooloovoo_zoo 4y agoCould be. It would be nice if you could maintain the modification though because then you don't have to worry about some cancerous cells surviving the first wave.
- frontierkodiak 4y agoThe article states “The first base edit disabled the T-cells targeting mechanism so they would not assault Alyssa's body”. Not an expert but I presume the ‘targeting mechanism’ is the T-cell receptor, whose activation is necessary (but not sufficient) to trigger immune response.
- hooloovoo_zoo 4y agoMaybe, but the second transplant also needs to not assault Alyssa.
- Narretz 4y agoThe second transplant is a stem cell (bone marrow) transplant, i.e. it replaces the cells that produce the t-cells. This is how leukemia therapy is normally finished after chemotherapy / radiation therapy kills the cancer cells.
- b800h 4y agoBut her body ought to start manufacturing her original T-cells at some point, right? Or are the stem cells producing them cancerous too? Doesn't say that in the article, and it doesn't seem like a reasonable inference, so there's a bit of detail missing there.
- sowbug 4y agoEven if the self-manufactured cells were healthy, the patient is vulnerable to infection with a compromised immune system, and adding more white blood cells reduces that vulnerability. Tangent: before undergoing some kinds of chemotherapy, patients are injected with drugs that stimulate white-blood-cell production. Most of your body's WBC production happens in the long bones of your body, and the sudden burst of "factory" activity makes your legs ache, the way growing pains hurt in children.
- psychphysic 4y agoThey destroyed her bone marrow twice. Leukemias are cancers of bone marrow. Usual tactic is chemo + bone marrow replacement and hope new tcells mop up cancer cells. Didn't quite work so they started with new marrow and made some changes to a supply of tcells they flooded her with. Once they couldn't find cancer they put the marrow on.
- Izikiel43 4y agoThe base therapy basically removed her immune system, the second transplant recreated it. In software terms, they did a clean install of the immune system after formatting it.