4

So, I came across following website (http://www.delta-32.com/ccr5-delta32.html) talking about these 1% of the population being resistant to HIV.

According to this website

The virus HIV normally enters a cell via its CCR5 receptors, especially in the initial stage of a person becoming infected. But in people with receptors crippled by the CCR5-delta32 mutation, entry of HIV by this means is blocked, providing resistance to HIV for people with delta 32 mutation on both genes (called homozygous carriers) and greatly slowing progress of the disease in people with a delta 32 mutation on one of the two genes (called heterozygous carriers).

So my question is whether it would be possible to take those cells from HIV resistant people and "transplant" them to patients with HIV?

I am probably missing a point (I am not a biologist) and I apologise in advance if the question is silly.

  • there is bunch of reasons for why it wont work but long story short the most important reason is another person wbc reject your body and attacks it. basically what it dose with any foreign antigens. – M.shadow Aug 4 '16 at 20:46
5

This is not a silly question. While transfusing white blood cells, with the CCR5 mutation isn't a solution because these cells will be rejected by the recipient's body (and also because those cells have a limited life time), transplantation of so called "stem cells" have provided promising results in HIV+ patients with blood cancer undergoing stem cell transplantation.

So to summarise (the protocol is quite complicated but since you mentioned you are not in the biomedical field, I will try to explain it in a simple way), these patients receive an ablative chemotherapy (+/- total body irradiation) in order to destroy all their "cancerous" cells. They then get transplanted with stem cells from a donor which has the CCR5-delta32 mutation. These cells then replace the previous population of white blood cells (which have been killed during the ablative phase) leading transplanted individuals to become HIV resistant.

So, now, you must wonder while this has not been more used?

  1. Because this method is very toxic and associated with several complications (ex: patients undergoing this high risk ablative therapy are at risk of developing infections during the process as their immune cells get destroyed)
  2. Patients need to take immunsuppresive therapy for a long time to avoid rejection of the transplanted stem cells and theses drugs are also associated with side effects
  3. Studies have still to show whether this method is at least as effective (in terms of short and long term outcomes) as taking HIV drugs (which become more and more efficient) in healthy individuals (remember that this method was used in HIV+ patients with blood cells cancer, who, anyway, needed a chemotherapy)

Hope this provides some clarification to your question!

Here two references (which provide a good understanding for the layperson)

http://www.nature.com/news/stem-cell-transplants-may-purge-hiv-1.13297

http://www.nature.com/news/2009/090211/full/news.2009.93.html

Not the answer you're looking for? Browse other questions tagged or ask your own question.