webgecko Posted June 6, 2006 Posted June 6, 2006 Hello I have been following the ongoing worldwide study of influenza pandemics of the past, H5N1 with interest. I have a question regarding virusses in general. My Question I have heard genetic scientists talk about virusses and at this point in history we seem to know quite a lot about their genetics etc.. When it comes to their origin however, as far as I know we don't know how virusses came into being. I have heard ideas that they may be remnants of primordial dna or nucleic acid systems but this answer doesn't completely satisfy my curiosity. It seems to me that a virus is well equipped to invade the cells in many different types of body tissue and effectively destroy those cells while multiplying successfully. To me it is behaving almost like an immune agent. Could virusses in fact originate in certain animals and be manufactured as say perhaps, lymphocytes or other products of an animals immune system ? In that animal the virus would be inactive until invading agents ( bacterial ? etc ) entered. Could a virus successfully attack and destroy a multi-cellular invader ( bacteria etc ?). I think in the study of aids\HIV they have found similar virusses ( SIV ) in certain monkey species. They think that somehow SIV perhaps changed and jumped to humans. In humans the SIV variant HIV ( if this is the case ) is potentially lethal in the long term as the T cells of the immune system are targetted early and destroyed thus impairing and detroying the immune response of the host etc.. Could it be possible that SIV is actually part of the immune system of the monkey species in question ? I may be wrong but it seems possible. Would be interested to hear what others think. Thanks. Webgecko
SkepticLance Posted June 6, 2006 Posted June 6, 2006 HIV has now been found in chimpanzees. It is almost certain that it jumped into the human population when someone killed a chimp for food, and got some chimp blood in contact with an open wound. The origin of viruses is still an open question. The most frequent theory is that it was a more complex life form that evolved into a parasitic life style and devolved - losing unnecessary characteristics. This may, or may not be correct.
bascule Posted June 6, 2006 Posted June 6, 2006 I have heard genetic scientists talk about virussesand at this point in history we seem to know quite a lot about their genetics etc.. When it comes to their origin however' date=' as far as I know we don't know how virusses came into being.[/quote'] According to the Discover March '06 cover story, viruses and all other life on earth share a common ancestor: http://www.scienceforums.net/forums/showthread.php?t=18653
Nashyboyo Posted June 6, 2006 Posted June 6, 2006 Quote: "Could virusses in fact originate in certain animals and be manufactured as say perhaps, lymphocytes or other products of an animals immune system" i don't get it ?
webgecko Posted June 6, 2006 Author Posted June 6, 2006 Hi to Nashyboyo What I was saying is that maybe virusses originate from or are part of the immune systems of various animals etc.. Then they may change and jump to other species\organisms where they do damage. Influenza virusses can transfer via droplets of liquid when we sneeze or cough. My further reading from Bascule and ScepticLance indicate that my proposition may be somewhat simplistic. BUT if there was an identifiable source of various virusses this may help us to deal with them and the diseases they cause in the future ?
webgecko Posted June 6, 2006 Author Posted June 6, 2006 ScepticLance : I read a book a few years ago called the White Death which suggested that SIV\HIV may have jumped to people from a species of african green monkey which was used in the manufacture of an early polio vaccine and trialled on africans in a certain area. Early reports of HIV infection seemed to come from the population in that area. http://www.uow.edu.au/arts/sts/bmartin/dissent/documents/AIDS/ Interested to know what you think about this angle. Thanks for your other comments. Bascule: Thanks for that link to an extremely interesting article. Here is another quote from the article : Quote Some scientists go a step further. They believe that viruses played a role even earlier in the evolutionary mix. The precise order in which the three domains of life evolved—whether, say, the eukaryotes emerged before or after the archaea and bacteria—is a much-debated subject. So is the identity of the progenitor of those different domains, the so-called last universal common ancestor, or LUCA, as it was dubbed by Forterre at the first Les Treilles conference in 1996. "I'm probably one who has asserted most sternly that LUCA was viral," says Luis Villarreal, the director of the Center for Virus Research at the University of California at Irvine. "The genes and gene functions suggest that we're dealing with one of the earliest and oldest forms of life. Mimivirus really stretches our sense of scale of what a virus can be." But just how far can that scale be stretched? David Prangishvili, a virologist at the Pasteur Institute in Paris and a colleague with Forterre in studying viruses that infect archaea, now thinks that viruses swam in the primordial soup prior to the emergence of cellular life of any kind and only later became dependent on cells. Forterre is less convinced. "It is difficult for me to imagine," he says. "You need to have some type of closed system to be sure that the different reactants of the metabolism, or different mechanisms, can interact with each other and also have a kind of Darwinian evolution. You need to have individuals. I think there was an RNA world prior to the DNA world, when you had a lot of RNA cells. Maybe viruses originated at the time of the RNA cell. You need to have a cell to even obtain a virus." End Quote To repeat, "You need to have a cell to even obtain a virus.". I register the argument that virusses may predate cells but to my thinking it makes better sense that the cell came first. The Mimivirus article as a whole may indicate that this is not the case. Thanks again Web Gecko
SkepticLance Posted June 6, 2006 Posted June 6, 2006 Quote from New Scientist 6 May 2006 page 14. "HIV had been living quite happily in chimps without making them ill, but when it crossed the species barrier to humans ...." "...most scientists believe happened when blood from butchered chimps got into the human bloodstream." Not a very good quote, I know. I have seen a more definitive one recently, but I cannot seem to locate it right now.
webgecko Posted June 7, 2006 Author Posted June 7, 2006 SkepticLance This is my point exactly. Variants of SIV have also been found in chimps and HIV is supposed to be very similar to SIV. Some scientists think that SIV is the precursor to HIV. If HIV and SIV are alike then it makes sense that HIV was not making the chimps sick. It is to me like HIV is similar to an agent (SIV) that has maybe been part of the chimps' system for a long time. Why couldn't this agent actually be an immune agent ? Which brings me to another question. Are virusses at all like lymphocytes ? Lymphocytes are immune agents. Virusses can infect and destroy other organisms which have at least one (or more ) cell wall. So they could make good immune agents for some organisms. The Mimivirus article points out that there are literally millions and millions of different virusses in the world, on land, in the sea and who knows where else. BUT I think that wherever there is life, there we will find them. Virusses are flexible entities and can both enter and break free of hosts. Maybe my idea that they could be some form of immune agent is wrong. But then maybe it could bear some investigation. If we can ascertain the source of various virusses perhaps this will give us the insight\info we need to better deal with them in future. webgecko
SkepticLance Posted June 7, 2006 Posted June 7, 2006 Webgecko said : Why couldn't this agent actually be an immune agent ? Which brings me to another question. Are virusses at all like lymphocytes ? Lymphocytes are immune agents. Virusses can infect and destroy other organisms which have at least one (or more ) cell wall. So they could make good immune agents for some organisms. A virus is not an immune agent. The general life cycle of a wide range of viruses is known. Their actions are that of infecting agents, not immune agents. Are they like lymphocytes? No. Lymphocytes are complex cells with nuclei. A virus is entirely orders of magnitude smaller and simpler.
webgecko Posted June 7, 2006 Author Posted June 7, 2006 SkepticLance After further reading out on the web I guess I have to agree. I had a general misconception on the nature of lymphocytes and my argument was maybe too simplistic. You said we have a good idea of the life cycle of virusses and yet we still don't know their true origin. Again our knowledge is still incomplete. Imagine if we could harness virusses to our advantage. They can destroy cells etc so imagine if we could harness ones we are immune to which would actually attack the invaders of our bodies and destroy them. That would be a usefull technology and application for some virusses. webgecko
SkepticLance Posted June 7, 2006 Posted June 7, 2006 Webgecko. Scientists are already hard at work devising ways to use viruses. Gene therapy usually uses viruses as vectors to carry genes. Not a good technology yet, but wait for Mark II! Scientists in Georgia (the Georgia that used to be part of the USSR) are working on bacteriophages (viruses that attack bacteria) in the hopes of using them as antibiotic substitutes. etc.
bascule Posted June 7, 2006 Posted June 7, 2006 We've been using viruses for gene therapy for awhile. For example, cystic fibrosis is now treatable through a throat spray containing genetically modified viruses. However, we'll soon be building nanotechnological containers that can deliver what chemicals we want to any part of the body, even through difficult membranes to penetrate such as the blood-brain barrier.
webgecko Posted June 8, 2006 Author Posted June 8, 2006 Thanks for letting me in on these new virus technologies. To finish on the HIV\SIV thing. It occurs to me that some variants of HIV and SIV seem to do no harm in different primates ( for HIV also seen in some people ). There are people looking into this I know. We need to find out why. I don't know a lot about the Immune system. I am assuming lymphocytes must have some way of differentiating between local cells etc and invaders or strangers. Do our cells have chemical markers so the lymphocytes can do this ? It seems strange to me that SIV is considered a viral stranger in certain primates and yet the immune systems of these animals do not destroy the SIV ( because we can detect it ). Something interesting is happening there. Either these primates ( and perhaps people i.e. HIV ) have something different with their cells or it is the distinct SIV variant which can't infect their cells. It still leads me to say, hey maybe SIV is NOT a stranger there as opposed to HIV in people which obviously is. Virusses may not be lymphocytes but does this preclude the possibility that at some point in the past that they were actually manufactured in the bodies of animals ( everywhere it seems as they are present all over the planet on land, sea etc in their millions ). There has been a hell of a lot of life on this planet for a long time giving plenty of opportunity for virus production. Virusses could have been manufactured in certain animals and then perhaps devolved into a parasitic life style which has been suggested ( general analogy only ) above. Anyways I hope they get a handle on how to defend us better against those pesky critters soon. Virusses cause some nasty problems with people. webgecko
abciximab Posted December 10, 2006 Posted December 10, 2006 Interesting... if viruses were ever produced by living forms, though, you would think they'd have some beneficial purpose. Are there any cases of species infection with a virus that is good? The thing about HIV to remember is that the virus itself does not kill a person. AIDS patients generally die from a secondary infection due to things like Pneumonia, Tuberculosis, or Esophagitis. The reason they get these infections is because the virus manages to destroy our immune cells - lymphocytes and macrophages - and we cannot defend ourselves against these normally treatable pathogens. So what HIV does is just insert DNA into our immune cells that says "replicate me!" but the cells replicate too many copies and just explode and die. From an evolutionary success standpoint, HIV is actually a "stupid" virus. As the guy in the above study said, "you need to have a cell to even obtain a virus." By biting the hand that feeds it, HIV and any lethal virus is killing itself off as it kills its host. The harm done by a virus is not in its own defense (like a bacterial toxin is), it's a very unintentional side effect. My point: SIV being inocuous in monkeys and harmful in humans is NOT a defense from the monkey to keep humans away, just a mere difference in the species' reaction to the particle. In simians the virus does not snowball in replication so fast that the monkey can't produce more immune cells as fast as they are being destroyed. My thoughts on viruses are that they are kind of a life-mistake. I don't think they can have too intentional a purpose because of several factors. First of all, they replicate very sloppily. If they were specifically designed for a purpose they would likely have evolved regulations on their replication, in the way highly conserved DNA of all other species is regulated if it has a useful purpose. Also, they are not really alive. A virus is just DNA or RNA in a shell, that says "make more of me!" AFAIK (please correct me if I'm wrong), viruses are not a major part of any ecosystem as nutrition, commensals, or symbiotes. In other words, if you erased viruses from the world, would any ecosystem fail? That's why I lean to the side that thinks they were possibly an altered take on life in the beginning; a random aggregation of particles that happened to have function without serving a purpose.
SkepticLance Posted December 11, 2006 Posted December 11, 2006 abciximab said AFAIK (please correct me if I'm wrong), viruses are not a major part of any ecosystem as nutrition, commensals, or symbiotes. While viruses are not nutrients, commensals or symbionts, their impact as parasites and pathogens is dramatic. In the ocean, there are 100,000,000 virus particles per ml of seawater. If this has no significant ecological effect, then I would be most surprised. In terrestrial ecosystems, viruses are equally abundant. They are the cause of a very big proportion of animal and plant diseases, causing death and debilitation wholesale. They have a massive ecological impact. A leading theory as to their evolution is that they began as bacterial parasites, and 'devolved' into a much simpler form. This can be seen in some of the small bacteria today that live an entirely parasitic life style. For example : Mycoplasma genitalium is a very simplified bacterium, which has lost most of its genes relating to metabolic regulation, as compared to free living, non parasitic bacteria. It is well on the way to becoming virus-like.
pag992007 Posted September 23, 2007 Posted September 23, 2007 Just jumping in in the subject. A lot of viruses are dormant in the cell genome. A lot of cell genomes are contaminated by viruses. However, would the virus a conscious device designed by a cell to defend itself... hmmm... not likely. An anti-bacterial (cell) product, specific toxin, protein, acidity, etc. is already pretty effective. To assemble a complex structure to aim at another cell, release more than 15 to 200Kb of DNA and avoid a self-infection is another thing. Unless it<s a program suicide... and cell are good at this. I am not against a cell based theory where a virus would emerge from a cell. Especially when we think about aberrant events. Per example, would the mitochondria would be of a virus nature? A virus infection that became symbiotic. That would be the reverse theory. Also, it does not take much to make a virus artificially, a string of DNA, a lipid/protein envelope. The new liposome transfection kits shows this clearly. That could be the ancestor... an aberrant cell event. While started, that Frankestein defective cell, was able to benefit from a high and uncontrollable replication rate, therefore high mutation and a constant exposition to their host, adapting, getting better at replicating, compacting even more the information, mastering the art of mutation. I guess more studies are required. Especially studying the genomes of viral particles isolated from different organisms collected in frozen tissues (Phylogenetic analyses with current forms).
Mirabelle Posted September 24, 2007 Posted September 24, 2007 ScepticLance : I read a book a few years ago called the White Death which suggested that SIV\HIV may have jumped to people from a species of african green monkey which was used in the manufacture of an early polio vaccine and trialled on africans in a certain area. Early reports of HIV infection seemed to come from the population in that area. http://www.uow.edu.au/arts/sts/bmartin/dissent/documents/AIDS/ Interested to know what you think about this angle. Thanks for your other comments. There's a book entitled The River by Edward Hooper that details out the early outbreaks in the Congo region of Africa and the possible modes of transmission that spread the virus worldwide. He also tracks the early outbreaks to a few specific lots of OPV produced by Koprowski while in the Congo by passing the virus through the kidney tissue of a monkey (the type of monkey it was is not known for sure). This lot of OPV was used to inoculate the local tribes in the region and additional uncontrolled vaccinations in the United States prisons. Great book but it requires a lot of focus. Sorry to go off topic.
PhDP Posted September 24, 2007 Posted September 24, 2007 There's a book entitled The River by Edward Hooper that details out the early outbreaks in the Congo region of Africa and the possible modes of transmission that spread the virus worldwide. He also tracks the early outbreaks to a few specific lots of OPV produced by Koprowski while in the Congo by passing the virus through the kidney tissue of a monkey (the type of monkey it was is not known for sure). This lot of OPV was used to inoculate the local tribes in the region and additional uncontrolled vaccinations in the United States prisons.Great book but it requires a lot of focus. Sorry to go off topic. This hypothesis was disproved by phylogenetics; http://www.nature.com/nature/links/010426/010426-4.html
Mirabelle Posted September 24, 2007 Posted September 24, 2007 Interesting, but I don't believe it as conclusive in disproving the OPV/HIV theory. The OPV/HIV theory could not be disproved by the testing described in that article due to the fact that the OPV sample used in that testing was the CHAT pool 10A-11, this was not the final formulated vaccine that was used in the mass vaccination trials in question. It was the "pool" the vaccine "batches" were derived from. Sadly, there are no archives of these final vaccine products. I am not convinced either for or against the OPV/HIV theory. I do not feel there are sufficient evidence, specimens, and most of all documentation of the production of the vaccines used in these trials to pass judgment. Even the sworn statements are based off 40-50 year old memories. I’m lucky to remember work I did 5 years ago. However, I have learned the importance of documentation, archives, ethics, and cGCPs.
Paralith Posted September 24, 2007 Posted September 24, 2007 From an evolutionary success standpoint, HIV is actually a "stupid" virus. As the guy in the above study said, "you need to have a cell to even obtain a virus." By biting the hand that feeds it, HIV and any lethal virus is killing itself off as it kills its host. The harm done by a virus is not in its own defense (like a bacterial toxin is), it's a very unintentional side effect. The damage done by a virus to its host may be an "unintentional side effect," but I don't think that makes the virus "stupid." When it comes to viruses and other such pathogens, the ease with which they can be spread and the speed with which they kill their hosts go hand in hand. A virus which has evolved to spread very quickly can afford to be very virulent, as it will likely have already spread to a new host even before it kills its current host. However, a virus that has not evolved to spread as easily can't afford to kill its host so quickly; it needs the host to stay alive at least long enough to spread to a new, healthy host. And considering the speed at which HIV is spreading across human populations, I think it can afford to be fairly deadly. My thoughts on viruses are that they are kind of a life-mistake. I don't think they can have too intentional a purpose because of several factors. First of all, they replicate very sloppily. If they were specifically designed for a purpose they would likely have evolved regulations on their replication, in the way highly conserved DNA of all other species is regulated if it has a useful purpose. Also, they are not really alive. A virus is just DNA or RNA in a shell, that says "make more of me!" (emphasis mine - paralith) AFAIK (please correct me if I'm wrong), viruses are not a major part of any ecosystem as nutrition, commensals, or symbiotes. In other words, if you erased viruses from the world, would any ecosystem fail? But isn't that what all life is anyway? DNA in a fleshy (if you're an animal, anyway) box that's trying to make more of itself. You have to be careful when you start saying organisms have things like intentions and purposes. The only intention and purpose life can be argued to have is to replicate itself. Thus it doesn't matter if viruses replicate "sloppily," because sloppy or not, as long as it works, that's all that matters. And clearly, viruses work. And they can be damn hard to stop. They can also be an important form of population control, enabling a given ecosystem to maintain a diversity of species instead of being taken over by just one, for example.
pioneer Posted October 1, 2007 Posted October 1, 2007 Viri are a good application for a H-potential analysis. The reason a virus ends up where it does in the cell, is configurational equilibrium. It defines a configurational potential and goes to the place in the cell where that allows it to define equilibrium. The idea that any cell can produces viri, is not supported with any evidence. The reason this is so, when RNA/DNA is produced, its configurational equilibrium within the cell keeps it close to the nucleus. To go beyond that causes it to enter nonequilibrium. When a virus enters, it begins in no-man's land for RNA/DNA. It is not designed to be easily transported out, so it is stuck in nonequilibrium. So it needs to diffuse to the area within the cell, where its configurational potential is minimized. This so happens to be near the DNA. A good analogy is going to a school dance. Each social group or clique will find a spot where birds of a feather gather together. If one arrived late, like a vius, they are allowed to enter, since they have the school ID. One looks around and then diffuse toward the area where your friends are assembled. In the case of a virus, it checks it protein coat at the protein equilibrium area, i.e, recyled, and continues to diffuse to where there are other nuclei acid counterparts. An interesting case is HIV. It is does not go after all cells. It targets cell differentiations connected to the immune system. These cellular gradients are the only one's that define the equilibrium position needed to do some damage. In other words, if we take a digestive cell, HIV gets sort of stumped, because these cellular grids cause it to come up short. One possible strategy is to use this to our advantage. We take cells that are not good target cells for HIV and inject them with HIV. What should happen, the cell's H-grid will become pertubated, so the cell can munch, causing a genetic response. This will give us the types of genes, in non affectable cells, that can deal with HIV. These genes are buried within the immune differentiations, packed away due to its unique differentiation. We then splice these genes into the active grid of the immune cells.
Blade Posted October 3, 2007 Posted October 3, 2007 Source: http://www.space.com/scienceastronomy/planetearth/flu_in_space_000121.html Germs from Outer Space! Researchers Say Flu Bugs Rain Down from Beyond. Who knows personally i don't think it is from space but it could be the stratosphere. Where can be virusus up there i think. But probably most virusus are home grown. (from this planet.) solarradiation might change the virus. I think there was something in the news a long time ago about the comit hale bob and it's dust from the comittale and the flu.
DrDNA Posted October 4, 2007 Posted October 4, 2007 Source:http://www.space.com/scienceastronomy/planetearth/flu_in_space_000121.html Germs from Outer Space! Researchers Say Flu Bugs Rain Down from Beyond. Who knows personally i don't think it is from space but it could be the stratosphere. Where can be virusus up there i think. But probably most virusus are home grown. (from this planet.) solarradiation might change the virus. I think there was something in the news a long time ago about the comit hale bob and it's dust from the comittale and the flu. Interesting article, but it appears to be total speculation. Is the Indian journal Current Science generally considered reputible? I can't recall ever seeing it.
Blade Posted October 4, 2007 Posted October 4, 2007 Interesting article, but it appears to be total speculation. Is the Indian journal Current Science generally considered reputible? I can't recall ever seeing it. the article refers to two names. Sir Fred Hoyle (1915-2001) http://www.kirjasto.sci.fi/hoyle.htm Chandra Wickramasinghe http://www.asiantribune.com/index.php?q=node/2788 They both are scientists.
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now