Sunday, 6 December 2015

The Daft Designer Does It Again

Cellular defense against latent colonization foiled by human cytomegalovirus UL138 protein | Science Advances

Here's a little challenge to Michael Behe and his chums from the Discovery Institute.

No, it's not to explain how it came about because that's too easy. It's to explain why it came about. The problem is not that it is irreducibly complex but that it is irredeemably stupid.

Here's the situation:

A family of viruses, the herpesviruses, has a mechanism for overcoming the human immune system when it infects cells. It basically hides inside the cell nucleus looking for all the world like part of the normal genome and only in certain situations does it come out of hiding, start replicating and destroying cells by cell lysis. This liberates millions of viruses to go off and infect new hosts. At that point, the human immune system recognises this 'lytic' form, makes antibodies and usually quickly wipes out the active form of the virus. But the latent form is still hiding in the nucleus of other cells and gets reproduced into other cells when infected cells divide, safe and sound where the immune system can't get at it.

The herpesviruses cause chickenpox, cold sores, genital herpes, shingles, mononucleosis, some cancers and in newborn babies with an immature immune system, deafness, mental disability and death. One form, the human cytomegalovirus (HCMV) is highly infectious and infects very high numbers of people globally. Once you have the infection you are stuck with it for life.

Basically, the survival of the virus depends on it staying latent and it does this by co-opting a protein, Daxx, in the nucleus which is part of the intrinsic immune system and normally prevents viruses replicating - which is exactly what this virus wants. In a nasty little trick, HCMV uses the immune system against itself and so shuts down the detection process.

Now a new study has found that, not only are human cells fighting back and have evolved a process for reactivating the latent virus using proteins called lysine demethylases, but that HCMV is already overcoming that line of defense. The viruses bring a protein called UL138 into the cells with them and use this to block the lysine demethylases. Quite how it works is still to be discovered because UL138 remains outside the nucleus but seems to exert its effect inside the nucleus.

Abstract
Intrinsic immune defenses mediated by restriction factors inhibit productive viral infections. Select viruses rapidly establish latent infections and, with gene expression profiles that imply cell-autonomous intrinsic defenses, may be the most effective immune control measure against latent reservoirs. We illustrate that lysine-specific demethylases (KDMs) are restriction factors that prevent human cytomegalovirus from establishing latency by removing repressive epigenetic modifications from histones associated with the viral major immediate early promoter (MIEP), stimulating the expression of a viral lytic phase target of cell-mediated adaptive immunity. The viral UL138 protein negates this defense by preventing KDM association with the MIEP. The presence of an intrinsic defense against latency and the emergence of a cognate neutralizing viral factor indicate that “arms races” between hosts and viruses over lifelong colonization exist at the cellular level.*

S. H. Lee, E. R. Albright, J.-H. Lee, D. Jacobs, R. F. Kalejta.
Cellular defense against latent colonization foiled by human cytomegalovirus UL138 protein.
Science Advances
, 2015; 1 (10): e1501164 DOI: 10.1126/sciadv.1501164

*Copyright © 2015, The Authors.
Reprinted under terms of Creative Commons Attribution-NonCommercial license (CC-BY 4.0)

So, what we have here is a typical host-parasite arms race in progress. Over millions of years viruses have invaded cells and hosts have evolved to destroy or neutralise the viruses; viruses have evolved to overcome these defences and so on. We are now at the stage in this arms race between herpes viruses and humans where humans have begun to evolve a method for beating the viruses ability to hide by switching off the detection mechanism, by making them come out of hiding, and viruses are evolving the ability to switch that off again.

And so round and round we go, generation after generation, both humans and viruses running just to stand still with some human casualties in the process but not enough to threaten the viruses supply of available hosts and humans have never been able to hit the viruses hard enough to wipe them out. There is absolutely no problem here for scientific evolution; in fact the entire thing, including the evolution of parasites, is predictable. It would be a problem for the TOE if we didn't have parasites and arms races. They are ultimately pointless because evolution doesn't have a point; they are mindlessly idiotic because evolution doesn't have a mind and they are amoral and devoid of compassion because evolution doesn't have morals or compassion.

But for those who still believe in creationism and intelligent (sic) design, they represent a major problem for the theory. So now, for those creationists who haven't worked out what the question is yet and so haven't stopped reading: what on Earth is this arms race for? Theistic creationism believes an intelligent creator (and only one intelligent creator) created everything for a purpose. Additionally, most religious apologists who promote this notion, this intelligent creator is maximally benevolent and wishes to maximise the good in the Universe.

Why then did it create viruses to infect cells and make the host sick, then create a defence for the host to overcome these viruses, then redesign the viruses to overcome the 'problem' of the hosts' defences, then.... and so on, apparently ad infinitum, to the ultimate benefit of neither host nor parasite? In short, why would an intelligent designer keep building problems into its creation for which it then needs to design a solution, which creates another problem.

Why would any intelligent designer design hosts and parasites so that a solution for one is a problem for the other to overcome? Of course the standard dogma is that, for some reason, in order to maximise the good in the Universe this intelligent (sic) designer invented sin (no really!) so viruses are just it's way of showing it loves us (stay with me here...) and anyway it's not for us to question the intelligent (sic) designer. It's intelligent, so whatever it does is intelligent and that's that. But, why then did it design a defense system to minimise the harm these sin-justified viruses do? How can that be intelligent. It's a bit like locking criminals up then giving them the means to make keys.

Could it be that the designer isn't intelligent and doesn't have a plan? In other words, there isn't intelligent design because there isn't an intelligent designer?

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4 comments :

  1. Nicely stated article. I have pointed this kind of unintelligent design to the credulous audience of Stephen C. Meyer on his FB page. Unfortunately the unintelligent design movement is never receptive of scientific reality or forthcoming with clear answers. Or any coherent answers for that matter. His PA threatens me with banning, creationist fans of Stephen become feisty, and all the while never an actual answer is provided. According to their research team... They will not be forced to provide answers until they are ready. Rob

    ReplyDelete
    Replies
    1. Research team? I.e. searching through the Bible looking for something they can twist around to make it look scientific? Presumably, they will only ever be ready to answer these questions when they have gone away and there is no longer anyone trying to get and answer.

      Delete
    2. Just took a quick look at that FB page. It look like they simply shout down questions they can't deal with and abuse the poster. Just smugly self-satisfied creationists eagerly lapping up anything Meyer gives them. Nice way to earn a living if you're not too bothered about truth or intellectual integrity.

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    3. I can't imagine what the creationist definition of scientific research is Rosa. I've been looking at what type of studies they claim are peer reviewed and directly support ID creationism. What I've found is that these journals generally have a feel of a trade publication, for creationists by creationists. I've found that the typical creationist mindset is that most anything is able to be revised and reworked to suit the current vision or version of events. Meyer is good at this kind of semantic game, but ultimately a failure in pushing his agenda further than his credulous followers.

      Happy New Year Rosa!
      Rob

      Delete

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