Ancient Trade-Off May Explain Why Humans Get HIV

New Scientist ^ | 6-21-2007 | Roxanne Khamsi

[blam]

Ancient trade-off may explain why humans get HIV

19:00 21 June 2007
NewScientist.com news service
Roxanne Khamsi

A protein that protected our human ancestors against a virus that ravaged other primates may now be responsible for our susceptibility to HIV, a new study suggests.

The discovery could help scientists predict which viruses found in other species are most likely to cross over and lethally infect humans.

The idea that early humans had an immune system that differed from other primates first came about after biologists sequenced the chimp genome.

The chimp sequence contains 130 copies of a virus called Pan troglodytes endogenous retrovirus, or PtERV1. Retroviruses often have the ability to insert themselves into an organism's DNA. But PtERV1 is completely absent from the human genome.

Reviving ancient life

Studies have also shown that the human version of an antiviral protein called TRIM5-alpha differs dramatically to the version of this protein found in other primate species. TRIM5-alpha offers immune protection by binding to virus-containing capsules inside cells and prompting their destruction.

Michael Emerman at the Fred Hutchinson Cancer Research Center in Seattle, US, and colleagues decided to test whether our unique version of TRIM5-alpha could explain why PtERV1 did not invade our genome.

The team generated TRIM5-alpha from human, chimp and gorilla genes in order to see how well various versions of the protein protected against PtERV1 in cat cells grown in a laboratory dish.

There was one problem though: active versions of PtERV1 no longer exist and the copies of this retrovirus found in primate DNA are woefully degraded.

So Emerman's team looked for commonalities among the chimp versions of the virus to partly reconstruct the ancient form of PtERV1. From this ancient sequence they produced part of the PtERV1-containing capsule, and attached it to

[Rodney King]

If it explains it, it explains about 5% of it. IV drug use explains another five, and taking it in the rear explains the other 90%.

[sgtbono2002]

Mostly humans get HIV from having homosexual sex.
A few inherit it at birth and others get it from bi-sexual males.Some from blood transfusions,but in the end if you stay away from having sex with homosexuals ,your chances of getting it are slim.

Now if I could get someone to come to Southern Maryland and tell me why so many of us down here are dying of Cancer, I would be interested.

[Michael.SF.]

as the old saying goes: when all else fails, follow directions.

That being said, if things were used for what they were designed for, the problem would decrease dramatically:

[WorkingClassFilth]

Another factor that may have been overlooked in this study is the unlikelyhood of our ancestors having their @sses pounded in gay bathouses. On an evolutionary note, the mythic gay gene is clearly a message from mother nature to discontinue this line of genetic experimentation.

Fruitism = bad; Genetic diversity = good.

[Cheburashka]

You forgot sharing needles, but the point is made. Certain behavior is risky, avoiding those behaviors solves the problem.

[Unassuaged]

I agree with you, about the First World. I do not think africians are having gay sex all over the place, but I have never been there and do not know for sure.

[ndt]

"If it explains it, it explains about 5% of it. IV drug use explains another five, and taking it in the rear explains the other 90%."

If you can't get it, you don't get it. Got it?

[SunkenCiv]

Spread Of Endogenous Retrovirus K Is Similar In The DNA Of Humans And Rhesus Monkeys
adapted from Public Library Of Science materials
ScienceDaily
Friday, October 12, 2007

According to paleontologic and molecular studies, the chimpanzee (Pan troglodytes) is the closer relative to the humans (Homo sapiens) and that both lineages had a common ancestor at 5 to 7 million years ago.

Moreover, the human-chimp lineage split from that of the rhesus monkey (Macaca mulatta) around 25 million years ago. However, by studying the population dynamics of complete copies of primate endogenous retrovirus family K (ERV-K) in the genomes of humans, chimpanzee and rhesus monkey, a surprising pattern was observed.

The study by Romano and colleagues being published this week on PLoS One revealed that human ERV-K had a similar demographic signature to that of the rhesus monkey, both differing greatly from that of the chimpanzee. The data suggested that the humans and rhesus have been purging ERV-K copies from their genomes while the chimpanzee ERV-K population kept the signature of increasing numbers of ERV-K amplification in the genome of ancestral primates during the last 20 million years.

[SunkenCiv]

Human Ancestors Went Out Of Africa And Then Came Back... [1998]
ScienceDaily | Friday, August 7, 1998 | adapted from New York University materials
Posted on 12/17/2007 8:37:11 PM EST by SunkenCiv
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