HIV and Delta 32

[viscousmemories]

I saw this show on PBS tonight called Secrets of the Dead: Mystery of the Black Plague, which was all about a genetic mutation that sprung up around the time the Bubonic Plague appeared in medieval Europe. Apparently people with a single copy of this mutation were more likely to survive the plague, and people with two copies were frequently immune.

It seems that their descendants who still carry that mutation have the same resistance to HIV, even though the plague is a bacteria and HIV is a virus. It's pretty fascinating stuff that I've probably mutilated, so follow the link and read about it yourself, or wait for Roland to tell me if I've gone astray.

[ms_ann_thrope]

I'll have to see if that program is being repeated, sounds very interesting.

One thing jumped out at me from the linked article: the lack of CCR5-delta 32 in Africa and Asia/East Asia. Wonder how much bearing, if any, that has on the rates of HIV infection in those geographies?

In case I can't catch a re-run... did the program talk at all about how people with CCR5-delta 32 seem to be worse off than non-CCR5-delta 32 people when it comes to Hepatitis C? And did it broach the topic that maybe the "Black Death" in Europe wasn't bacterial at all, but... viral?

[viscousmemories]

Originally Posted by ms_ann_thrope

In case I can't catch a re-run... did the program talk at all about how people with CCR5-delta 32 seem to be worse off than non-CCR5-delta 32 people when it comes to Hepatitis C? And did it broach the topic that maybe the "Black Death" in Europe wasn't bacterial at all, but... viral?

I think I only caught the last 2/3 of the show, but I don't recall discussion of either of those subjects. In fact the article I linked to is a virtual transcript of what they covered.

[Godless Dave]

The show itself is a rerun from a few years ago. This immunity is something that's been known for a while but isn't much talked about in the popular press.

[Roland98]

Originally Posted by viscousmemories

I saw this show on PBS tonight called Secrets of the Dead: Mystery of the Black Plague, which was all about a genetic mutation that sprung up around the time the Bubonic Plague appeared in medieval Europe. Apparently people with a single copy of this mutation were more likely to survive the plague, and people with two copies were frequently immune.

It seems that their descendants who still carry that mutation have the same resistance to HIV, even though the plague is a bacteria and HIV is a virus. It's pretty fascinating stuff that I've probably mutilated, so follow the link and read about it yourself, or wait for Roland to tell me if I've gone astray.

LadyShea asked me about that awhile back--previous thread. As I said there, it's not 100% certain that it's due to the black plague (and indeed, the mutation seems to pre-date that event), but that's one reason it could have spread within the population.

Though the bacterium that causes plague, Yersinia pestis, is a bacterium, it's an intracellular bacterium--it replicates within your cells. So in that way, it's similar to a virus like HIV, especially because both can infect white blood cells that generally serve to protect us from infection.

The resistance to AIDS is a pretty cool story. CCR5 is one receptor HIV uses to enter our cells, and the mutation seems to reduce the virus's ability to do so--hence, homozygotes for the mutated allele (those that have 2 copies of the delta 32 gene) appear to be resistant to HIV infection. Heterozygotes (those who have one normal and one mutated copy of the gene) can be infected, but at a lower rate than homozygotes for the normal allele.

One thing jumped out at me from the linked article: the lack of CCR5-delta 32 in Africa and Asia/East Asia. Wonder how much bearing, if any, that has on the rates of HIV infection in those geographies?

Rates are obviously higher there than in Europe and America, but how much of this is due to the CCR5 allele isn't known. Even in populations of European descent, it's not a very common mutation, so it's unlikely it plays a big role in infection rates.

In case I can't catch a re-run... did the program talk at all about how people with CCR5-delta 32 seem to be worse off than non-CCR5-delta 32 people when it comes to Hepatitis C? And did it broach the topic that maybe the "Black Death" in Europe wasn't bacterial at all, but... viral?

Why Hepatitis C? And there's no reason to think we have the etiology of the Black plague wrong. Viruses and bacteria often share cell receptors, since there's simply a limited number to go around.

The show itself is a rerun from a few years ago. This immunity is something that's been known for a while but isn't much talked about in the popular press.

Nope, it's not been discussed very much. But it is a good comeback to the AIDS-denyers who point to folks who have tested HIV+ but have gone 20 or 30 years without developing AIDS. We know genotype of both the virus and the host plays a big role in the development of a number of infections, and this is a perfect example of that.

[viscousmemories]

Originally Posted by Roland98

LadyShea asked me about that awhile back--previous thread.

[Roland98]

Originally Posted by viscousmemories

No problem--you know I love rambling about this stuff anyway, and it brought up some new questions.

[viscousmemories]

Glad to be of service, then!

I like the new design of your blog. Do you really believe viruses can turn into cows?

[Dingfod]

Originally Posted by Roland98

Nope, it's not been discussed very much. But it is a good comeback to the AIDS-denyers who point to folks who have tested HIV+ but have gone 20 or 30 years without developing AIDS. We know genotype of both the virus and the host plays a big role in the development of a number of infections, and this is a perfect example of that.

Have these AIDS survivors been tested for the actual HIV virus or just for the antibodies? Perhaps I'm a bit behind the times here, I thought the only AIDS test was for HIV antibodies, not the virus itself. Set me straight.

[Roland98]

Originally Posted by viscousmemories

Glad to be of service, then!

I like the new design of your blog.

Thanks! The old template was driving me nuts, as you know, so I said fuck it and found a new one.

Do you really believe viruses can turn into cows?

Of course. You just have to have the keys to the secret EAC biology toolbox...

Have these AIDS survivors been tested for the actual HIV virus or just for the antibodies? Perhaps I'm a bit behind the times here, I thought the only AIDS test was for HIV antibodies, not the virus itself. Set me straight.

No, you're correct--the test is for the antibodies, which means they've been exposed. But why one person is exposed and develops AIDS in 10 years, when another person is exposed at the same time and is still perfectly healthy 20 years later has not been well understood. Differences in host genetics is a perfectly plausible answer--some hosts are just not as amenable to viral replication as others.

[Adora]

Originally Posted by viscousmemories

It seems that their descendants who still carry that mutation have the same resistance to HIV, even though the plague is a bacteria and HIV is a virus. It's pretty fascinating stuff that I've probably mutilated, so follow the link and read about it yourself, or wait for Roland to tell me if I've gone astray.

Interesting. I hope SBS picks it up and shows it here (as they do with a lot of PBS stuff).

I also heard that in some parts of sub-Saharan Africa, groups of female prostitutes have built up strong resistance to HIV infection (and maybe total immunity). It's interesting, and there's a bit of an article here about it. And a more scientific article.

[Godwhacker]

I saw another show (can't recall which educationally oriented network) that examined the idea that the black death may not have been the plague, and showed some pretty compelling evidence that it might not have been. For example, the speed to the spread of the plague, as well as the spread of the illness into areas where rats were not common, etc.

The symptoms described in some texts were also reported to be more consistent with a hemmoragic fever type illness (e.g., ebola, marburg) than plague. If true, then the resistance to HIV illness may make more sense, given that both would be caused by a virus.

[ms_ann_thrope]

Originally Posted by Roland98

Why Hepatitis C?

Could be Hep B as well, I guess, but whilst Googling I came across this abstract and thought it interesting. Could be entirely meaningless though.

And there's no reason to think we have the etiology of the Black plague wrong. Viruses and bacteria often share cell receptors, since there's simply a limited number to go around.

No argument from me that yersinia pestis causes bubonic plague. But I'm also intrigued by the theory that the "Black Death" that swept Europe in the 1300's was maybe actually a viral hemorrhagic fever and not bubonic plague. Or that two plagues could've been going on at the same time.

Microbes are neat, but I'm pretty out of the loop anymore, so forgive me if this has all been disproven.

[Roland98]

Originally Posted by Godwhacker

I saw another show (can't recall which educationally oriented network) that examined the idea that the black death may not have been the plague, and showed some pretty compelling evidence that it might not have been. For example, the speed to the spread of the plague, as well as the spread of the illness into areas where rats were not common, etc.

The symptoms described in some texts were also reported to be more consistent with a hemmoragic fever type illness (e.g., ebola, marburg) than plague. If true, then the resistance to HIV illness may make more sense, given that both would be caused by a virus.

I've seen that hypothesis, but it's been published in a (very expensive) book, and never in the scientific literature. Since then, DNA has been extracted from the dental pulp of corpses who died during the Black death, and Y. pestis DNA has been amplified from several. Given that and our modern experience with pneumonic plague, it's pretty UNambiguous that this was indeed the culprit.

[Roland98]

Originally Posted by ms_ann_thrope

Could be Hep B as well, I guess, but whilst Googling I came across this abstract and thought it interesting. Could be entirely meaningless though.

Ah, okay. It wouldn't be surprising if that mutation had varied effects on outcomes with other infectious agents, but the Hep C link isn't clear yet. There are other papers (such as this one) have found the opposite--that the CCR5 delta mutation increases clearance of Hep C. Jury's still out on that one.

No argument from me that yersinia pestis causes bubonic plague. But I'm also intrigued by the theory that the "Black Death" that swept Europe in the 1300's was maybe actually a viral hemorrhagic fever and not bubonic plague. Or that two plagues could've been going on at the same time.

Microbes are neat, but I'm pretty out of the loop anymore, so forgive me if this has all been disproven.

They could have been co-circulating, but from everything I've read, if there was a hemorrhagic fever outbreak at the time, it was probably just hemorrhagic versions of either yellow fever or smallpox, which were known to sporadically pop up across Europe. There's no evidence that there were large-scale epidemics of hemorrhagic illnesses distinct from bubonic plague during that period, but sure, the occasional case could muck things up as far as historical reporting.

[viscousmemories]

Originally Posted by Roland98

Given that and our modern experience with pneumonic plague, it's pretty ambiguous that this was indeed the culprit.

Do you mean is pretty unambiguous that plague was the culprit, or ambiguous that it was something else?

[Roland98]

Originally Posted by Adora

Interesting. I hope SBS picks it up and shows it here (as they do with a lot of PBS stuff).

I also heard that in some parts of sub-Saharan Africa, groups of female prostitutes have built up strong resistance to HIV infection (and maybe total immunity). It's interesting, and there's a bit of an article here about it. And a more scientific article.

Thanks, hadn't seen that study before. The difference with that one (in contrast to the CCR5 ones) is that it's likely not an inheirited difference (as the CCR5 delta allele is), but simply a difference in the response of their immune systems, likely due to their environment (including the microenvironment--that is, the sum of pathogens they're exposed to). My first thought is to wonder if they're co-infected with another virus that drives the cytokine responses they're seeing. For instance, co-infection with HIV and GB virus C (aka hepatitis G) has been found, in some studies, to increase longevity with HIV, though I'm not sure if it alters cytokine expression patterns.

[Roland98]

Originally Posted by viscousmemories

Do you mean is pretty unambiguous that plague was the culprit, or ambiguous that it was something else?

Bah, sorry, writing too fast. Yes, unambiguous. I'll change it so as to not further confuse folks.