There has been a story in the news about a man in Germany given a bone marrow transplant with a gene that prevents the HIV virus from attaching to receptors. Thus the HIV virus can’t attach and infect the person.
But I got to wondering, would the person still have HIV virus in the system? In otherwords could he be a carrier? Not infected himself but still be able to give the virus to others.
I know HIV hides in the brain and there is the blood/brain barrier to deal with.
Although the news is saying he’s “cured” they always use the quotes and I was more interested in seeing if the man was still harbouring the virus, but not being infected by it, thus being able to infect others.
These people (I was actually only aware there was one such individual, his name is Steve Crohn, but I guess they’ve found more) are to my understanding, HIV negative. There was a PBS show about this. IIRC, immunity to HIV was oddly linked to people whose ancestors survived the Black Plague. That is to say, a certain mutation figured in immunity to each, and in Plague zones, most of the people without it died.
Until someone who actually knows what they’re talking about comes around, the general idea is that if HIV can’t attach itself to a cell, it can’t get in, which means it can’t replicate. Normally, HIV gets into a cell and uses that cell’s existing machinery to make many copies of itself. If this isn’t possible, there won’t be copies of the virus floating around.
The mutation is in a cell surface receptor - the protein that acts as the “dock” for HIV to latch onto and get itself in. Apparently (and I think there’s more work to be done here), the virus can’t attach to the cell, so it can’t get in, so it can’t replicate.
So in answer to the OP’s question, the person would not be a carrier of HIV. If any HIV got into his system, it wouldn’t be able to reproduce, and would be eliminated fairly quickly. As for the transplant recipient, they can’t detect any virus anywhere, including in brain tissue samples they’ve taken, but they can’t really rule it out completely without testing every cell in his body, which would have some unpleasant side effects…
Could you explain more about this? How do free-floating viruses get cleaned out of the system, and how quickly? Also, what’s the lifespan of a free-floating HIV virion? And re: lying dormant, are we talking about viruses working their way inside cells, but then not actively reproducing until months/years later?
HIV isn’t really my field, but I can tell you what I know.
HIV’s devastating effects require it to infect immune cells and kill them. Without the ability to get in through the back door, so to speak, I would expect that a person’s immune system could clear an HIV infection like any other virus. I don’t know that for sure - it’s just what I’d expect. I don’t know what the lifespan of the virus is in a system where it can’t infect, but HIV is a pretty unstable virus in general, so I wouldn’t expect it to be terribly long. I could be wrong, though.
As for lying dormant, that’s another one of the virus’s tricks. As a retrovirus, it can copy its RNA genome to DNA, which can then integrate into the host’s genome and just wait until some signal makes it pop back out and start reproducing. When it’s integrated, it’s just a stretch of DNA like any other in your cell, and it can remain that way indefinitely. A huge percentage of our genome appears to be made up of retroviruses that integrated into our DNA and then lost the ability to pop themselves back out.
One other thing. So far, it appears that this mutation prevents HIV infection, but if HIV is one thing, it’s adaptable. It mutates like crazy, so this may not be a long-term hope. All it takes is one virus to pick up the ability to recognize this other protein, and we’re back to square one. That’s what makes this disease such a bugger.
The November 2008 issue of scientific american has some articles on HIV and it discusses the people that are immune. Don’t remember if it answers the OP’s questions, but lots of good info.