Viruses and Autoimmunity

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Bjørn A. Nexø


Most, if not all, animals have endogenous viruses i.e., copies of parts of or complete retro-viral genomes in their chromosomes. Man, for example, has in the order of 100 000 bits and pieces of retrovirus, distributed on all chromosomes. Most of these bits are grossly defective but in man about 50 can encode a protein. There is evidence several coding endogenous viruses can recombine and start an infection. I believe these coding endogenous viruses contribute to human disease. Indeed I speculate, they are the most important limitation on size and longevity of the members of a species: both these parameters are roughly proportional to the chance of making a replicating virus. In the following I will try to argue for the importance of coding endogenous viruses.

If the presence of retroviral sequences does not lead to replicating virus the situation is mostly fine. However, as soon as a virus starts replicating in an individual, the mutational level in the animal increases dramatically, by way of insertion of viral genomes at unusual places, and the animal in part loses control of its genome. This is known to result in cancer, and I believe in autoimmune disease.

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How to Cite
NEXØ, Bjørn A.. Viruses and Autoimmunity. Medical Research Archives, [S.l.], v. 10, n. 8, aug. 2022. ISSN 2375-1924. Available at: <>. Date accessed: 21 july 2024. doi:
Research Articles


1. Stoye, JP. Koala retrovirus: a genome invasion in real time. Genome Biology, 7 (11): 241,
2. Pauline L. Kamath, Daniel Elleder, Le Bao, Paul C. Cross, John H. Powell, and Mary Poss. The Population History of Endogenous Retroviruses in Mule Deer (Odocoileus hemionus). J Hered. 2014 Mar-Apr; 105(2): 173–187
3. B A Nexø and H H Krog. C-type virus protein p30 in blood from inbred mice correlates with their later incidence of leukemia. Infect Immun. 1977 Feb; 15(2): 376–381.
4. Sisir K. Chattopadhyay, Douglas R. Lowy, Natalie M. Teich, Arthur S. Levine, Wallace P. Rowe. Evidence That the AKR Murine-Leukemia-Virus Genome Is Complete in DNA of the High-Virus AKR Mouse and Incomplete in the DNA of the “Virus-Negative” NIH Mouse. Proc Natl Acad Sci U S A. 1974 Jan; 71(1): 167–171. doi: 10.1073/pnas.71.1.167.
5. Douglas R. Lowy, Sisir K. Chattopadhyay, Natalie M. Teich, Wallace P. Rowe, Arthur S. Levine. AKR Murine Leukemia Virus Genome: Frequency of Sequences in DNA of High-, Low-, and Non-Virus- Yielding Mouse Strains. Proc Natl Acad Sci U S A. 1974 Sep; 71(9): 3555–3559. doi: 10.1073/pnas.71.9.3555.
6. Vaclav Klement, Wallace P. Rowe, Janet W. Hartley, Wendell E. Pugh. Mixed culture cytopathogenicity: a new test for growth of murine leukemia viruses in tissue culture. Proc Natl Acad Sci U S A. 1969 Jul; 63(3): 753–758. doi: 10.1073/pnas.63.3.753.
7. Bikem Soygur, Leyla Sati. The role of syncytins in human reproduction and reproductive organ cancers. Reproduction. 2016 Nov;152(5):R167-78. doi: 10.1530/REP-16-0031.
8. Stehelin D, Varmus HE, Bishop JM, Vogt PK. DNA related to the transforming gene(s) of avian sarcoma viruses is present in normal avian DNA. Nature. 1976 Mar 11;260(5547):170-3. doi:10.1038/260170a0
9. Romanish , MT; Cohen, C.J.; Mager,D.L. Potential mechanisms of endogenous retroviral-mediated genomic instability in human cancer. Semin Cancer Biol. 2010, 20, 246-.
10. Fine D, Schochetman G. Type D primate retroviruses: a review. Cancer Res 1978 Oct;38(10):3123-39.
11. Haahr S, Höllsberg P. Multiple sclerosis is linked to Epstein-Barr virus infection. Rev Med Virol. 2006 Sep-Oct;16(5):297-310. doi: 10.1002/rmv.503.
12. Nexø BA, Villesen P, Nissen KK, Lindegaard HM, Rossing P, Petersen T, Tarnow L, Hansen B, LorenzenT, Hørslev-Petersen K, Jensen SB, Bahrami S, Lajer M, Schmidt KL, Parving HH, Junker P, Laska MJ. Are human endogenous retroviruses triggers of autoimmune diseases? Unveiling associations of three diseases and viral loci. Immunol Res. 2016 Feb;64(1):55-63 doi;10.1007/s12026-015-8671-z
13. Nexø BA, Christensen T, Frederiksen J, Møller-Larsen A, Oturai AB, Villesen P, Hansen B, Nissen KK, Laska MJ, Petersen TS, Bonnesen S, Hedemand A, Wu T, Wang X, Zhang X, Brudek T, Maric R, Søndergaard HB, Sellebjerg F, Brusgaard K, Kjeldbjerg AL, Rasmussen HB, Nielsen AL, Nyegaard M, Petersen T, Børglum AD, Pedersen FS. The etiology of multiple sclerosis: genetic evidence for the involvement of the human endogenous retrovirus HERV-Fc1. PLoS One. 2011 Feb 2;6(2): e16652. doi:10.1371/journal.pone.0016652.