HIV and Visna -- Keske
There have long been allegations that HIV contains fragments of other retroviruses, or appears to be a splicing of other viruses. Different theories have proposed that it contains segments of HTLV (a leukemia retrovirus, the first human retrovirus that was discovered by Robert Gallo), or BIV (bovine leukemia virus), or visna (a sheep retrovirus). Only a few things seem clear. All of these viruses have significant similarities. SIV is genetically closer to HIV, than are these other viruses. These facts do not answer all the questions as to the ancestry of the viruses, or whether they are natural, or not.There has been at least one study to suggest that SIV appears to be descended from HIV, rather than vice-versa. It is possible that both are relatively recent descendents of a common ancestor.
Phylogenetic trees can show which subgroups of viruses bear the most similarity to each other, but cannot in themselves prove ancestral relationships.Determination of whether a virus contains fragments of other viruses is a matter of statistical analysis. It would be possible,for example, for HIV to have identifiable splices of other viruses, even if it is overall closer to SIV. These are questions for future investigation. For now, my goal has been just to get a better handle on animal retroviruses that are similar to HIV, the order in which they were discovered, how much is known about them, what record of lab experimentation is publicly available.
Under the category of retroviruses, there is a subclass known as "lentiviruses" (meaning "slow" viruses, that take a long time to incubate). Mammal lentiviruses include EIAV (horses), BIV (cattle), CAEV (goats), visna (sheep), PUMA and FIV (cats), and SIV (monkeys/chimps).
The large number of viruses would seem to suggest that they are very old. However, this theory raises some puzzles. For instance, why were they not noticed earlier? Visna is among the oldest- the first known outbreak was around 1930, in Iceland. The virus was first identified in 1949. Visna was not something that would likely go unnoticed. The outbreak in Iceland was obvious and explosive.
Similarly, SIV is now widespread among primates, and is present in most species of monkeys.Monkeys and chimps from all over the world were used were used extensively for research, in the decades preceding AIDS. Viruses similar to HIV, such as FELV and visna, were well-known, and their structure was identified in detail (see reference to follow). There had been extensive attempts to identify and catalogue animal viruses. Why would the viruses not have been discovered earlier?
These are not viruses that stayed confined in "remote villages". Somehow, we have to explain viruses that jumped species and jumped oceans and continents, from Iceland to Australia to Africa to Europe and the U.S., yet were little noticed.There are such things as wild cattle and sheep, but most are domesticated. This would lead you to imagine that explosive and deadly new viral epidemics would not go unnoticed. These viruses sometimes are not fatal, but often are. It is not simply a matter that they were harmless variations of viruses. We would have to explain why viruses that were supposed "harmless" in most species, suddenly turned malignant in multiple species, at the same time.
Presumably, all of the lentiviruses trace back to a common ancestor- one of the more interesting questions. The phylogenetic trees are today drawn without any identifiable root.We go to great lengths to imagine how humans may have picked up a monkey virus, by tribes drinking monkey blood,etc. It is even more interesting to imagine the link that spread a virus between say, cattle and monkeys.
It conjures slightly humorous images of Farmer Brown inviting his brother, Jungle Jim, out to the farm, where his pet monkey, Bonzo, got into a fight with Bessie the cow. Blood was everywhere. It must have been awful.After all, we are talking about viruses that do not spread by casual contact,even if the animals had casual contact,which they do not. They are not predators of each other, they do not have sex with each other.
You might imagine some common vector such as insects, but we have been assured that insects cannot transfer HIV, and are not likely to do so in the future, even if HIV were to mutate significantly.You might suppose that humans are the most common link among all the animals, but we supposedly got our virus variant as the last in line.
Another interesting observation is that most of the mammal lentviruses are spread by milk, sometimes, spread primarily by milk. Humans, consumers of goat's milk, sheep's milk, cow's milk, sometimes unpasteurized, have presumably been exposed to other animal lentiviruses many times. If the viruses are truly ancient, it is rather odd that we never became infected with deadly disease, until very recently.
Certainly, it is conceivable that all of these animal retroviruses are relatively recent, just like the epidemic of HIV. HIV has a phenomenal mutation rate, and has infected tens of millions of humans in the span of a few decades. There multiple strains of HIV in humans, already. Perhaps, among other mammals, it is just more of the same story.
To try to sort out this mess, I tried to focus on what seemed like the first known lentivirus, visna.I've been told visna itself may have had origins in German biological war research/testing, but I have no information on this, yet. I've also been told that EIAV may be older, but again, I am still looking into this.It was clear however, that the initial visna outbreak waswould have been well known, and of interest, to anyone doing biological war research, any time after 1930.
One cannot exactly search for what secret research might have been done with visna. Next best is to try to find out how much was known in the public arena, and when, and what kind of published experiments were done with visna. This effort, in itself, was very revealing and unsettling.
It certainly lends credence to the notion that visna could have been manipulated with destructive results.For the rest of this essay, I refer to studies that are listed in the "PUBMED" database.
First, it is clear that there was *extensive* interest and research involving visna, before the AIDS epidemic. I found dozens of published experiments, looking just at a limited time frame in the 60's and 70's. No doubt, the total experiments numbered at least in the hundreds- a great deal of interest, for a infection that was rare among sheep, and had already been eradicated in Iceland.
Second, it is clear that the detailed structure of visna was well known, well before the AIDS epidemic. In order to realize this, you don't need even to look at the abstract: the convenient title alone makes the point:
Harter DH./The detailed structure of visna-maedi virus. Front Biol. 1976;44:45-60. No abstract available.
Pautrat G, et al. [Study of the structure of Visna virus by electron microscopy]. /C R Acad Sci Hebd Seances Acad Sci D. 1971 Aug 9;273(6):653-5. PMID: 5001143; UI: 72047938.
Visna is quite similar to HIV. If its structure was known in detail, then why was it such a painful and prolonged effort to identify HIV?
Third, it is clear that researchers were attempting to infect human cells with visna, well before AIDS broke out. It could be argued that any such experiment of this type carries a degree of irresponsibility. Any time that you expose a virus to a new host, there is a danger that the virus will adapt to that host, and create a new strain of virus.
Macintyre EH, et al./ A modification in the response of human astrocytes to visna virus. Am J Vet Res. 1974 Sep;35(9):1161-3. PMID: 4370842; UI: 75021753.
Macintyre EH, et al./ Visna virus infection of sheep and human cells in vitro--an ultrastructural study. J Cell Sci. 1973 Jul;13(1):173-91. No abstract available. PMID: 4354152; UI: 73250349.
MacIntyre EH, et al./ Morphological transformation of human astrocytes by visna virus with complete virus production. Nature New Biol. 1972 May 24; 237(73):111-3. PMID: 4503847; UI: 72204414.
Macintyre EH, et al./ The establishment of a line of visna virus-producing human astrocytes (V-1181N1). Med Res Eng. 1972;11(4):7-13. PMID: 4370460; UI: 75016059.
Macintyre EH, et al/. Prolonged culture of Visna virus in human astrocytes. Beitr Pathol. 1974 Jul;152(2):163-78. No abstract available. PMID: 4369072; UI: 74306244. (The human "astrocytes" refer to cells in human nerve tissue.)
Fourth, it is interesting that researchers were experimenting with visna and simian (monkey) tissues, also. Remember that monkey kidney tissues are suspect in the contamination of vaccines. Many lab monkeys were released back into the wild intentionally, because of "no sign of disease". For AIDS-like viruses, with long incubation periods, this is in hindsight a major mistake. At the time, it helped satisfy animal-rights concerns.
August MJ, et al./ Visna virus-induced fusion of continous simian kidney cells. Arch Gesamte Virusforsch. 1974;44(2):92-101. No abstract available. PMID: 4365045; UI: 74250024.
Fifth, researchers were studying visna's interaction with the immune system:
Panitch H, et al./ Pathogenesis of visna. III. Immune responses to central nervous system antigens in experimental allergic encephalomyelitis and visna. Lab Invest. 1976 Nov;35(5):452-60. PMID: 186662; UI: 77054769.
Lab Invest 1976 Nov;35(5):444-51 Pathogenesis of visna. II. Effect of immunosuppression upon early central nervous system lesions./Nathanson N, Panitch H, Palsson PA, Petursson G, Georgsson G
Lastly, it is clear that researchers were experimenting with other cross-species transfers: sheep, goats, mice, cattle. They were attempting also to induce tumors and cancers (references to "oncogenic", and "sarcoma"):
Tamalet J, et al. [Morphological and biochemical analogies of Visna virus with oncogenic RNA viruses] pp. 19-26. Monograph. 1976 Aug 23; . English; French. No abstract available. PMID: 180153; UI: 76215618.
Lycke E, et al/. Tumor incidence in Visna virus inoculated mice. Experientia. 1976 Apr 15;32(4):514-5. PMID: 178528; UI: 76187733.
Thormar H./ Visna-maedi virus infection in cell cultures and in laboratory animals. Front Biol. 1976;44:97-114. Review. No abstract available. PMID: 182563; UI: 76257981.
Sharma DN, et al/ Jaagziekte & maedi of sheep & goats transmitted in laboratory animals. Indian J Exp Biol. 1974 Jan;12(1):95-6. No abstract available. PMID: 4372169; UI: 75040295.
Haase AT, et al./ A comparison of the high molecular weight RNAs of visna virus and Rous sarcoma virus. Virology. 1974 Jan;57(1):259-70. No abstract available. PMID: 4362024; UI: 74130620.
Haase AT, et al/ Characterization of the nucleic acid product of the visna virus RNA dependent DNA polymerase. Virology. 1974 Jan;57(1):251-8. No abstract available. PMID: 4131957; UI: 74130619.
Boothe AD, et al/. Ultrastructural studies of a visna-like syncytia-producing virus from cattle with lymphocytosis. J Virol. 1974 Jan;13(1):197-204. No abstract available. PMID: 4129840; UI: 74086415.
Haase AT, et al./ Demonstration of a DNA provirus in the lytic growth of visna virus. Nature New Biol. 1973 Oct 24;245(147):237-9. No abstract available. PMID: 4127186; UI: 74023815.
Why are so many viruses crossing species, and creating deadly new epidemics in modern times? The reader is encouraged to read the titles and abstracts of a great many experiments such as the above. You will not need a pHD in microbiology in order to gain a quite valid epiphany on the subject.
(a link has been added to view Keske's research into the 1971 Progress Report of the Special Virus Cancer Program)
Tom Keske maintains an archive of essays for non-profit distribution providing authorship is recognised at http://members.xoom.com/trkeske
Tom Keske is a Boston, Mass (US) based writer...to commission articles contact firstname.lastname@example.org