van der Kuyl, A.C.

English

International Migration, Integration and Social Cohesion online publications

UvA-DARE is a service provided by the library of the University of Amsterdam (https://dare.uva.nl)UvA-DARE (Digital Academic Repository)Endogenous retrovirus sequences and their usefulness to the hostvan der Kuyl, A.C.Publication date1997Published inTrends in MicrobiologyLink to publicationCitation for published version (APA):van der Kuyl, A. C. (1997). Endogenous retrovirus sequences and their usefulness to thehost. Trends in Microbiology, 5, 339.General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s)and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an opencontent license (like Creative Commons).Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, pleaselet the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the materialinaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letterto: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. Youwill be contacted as soon as possible.Download date:09 Mar 2023C O M M E N T  171,954-960 13 Edlin, B.R. et al. (1992) New Engl. J. Med. 326, 1514-1521 14 Pearson, M.L. et al. (1992) Ann. Intern. Med. 117, 191-196 15 Kimberlin, D.W. and Whitley, R.J. (1996) J. Antimicrob. Chemother. 37, 403-421 16 Sacks, S.L. et al. (1989} Ann. Intern. Med. 111, 893-899 17 Ljungman, P. et al. (1990)J. Infect. Dis. 162, 244-248 18 Kost, R.G. et al. (1993) New Engl. J. Med. 329, 1777-1782 19 Saffin, S. et al. (1991)Ann. Intern. Med. 115, 19-21 20 Kyslik, P. et al. (1993) Biotechnol. Bioeng. 41,325-329 21 Lee, S.W. and Edlin, G. (1985) Gene 39, 173-180 22 Lenski, R.E., Simpson, S.C. and Nguyen, T.T. (1994)J. Bacteriol. 176, 3140-3147 23 Godwin, D. and Slater, J.H. (1979} J. Gen. Microbiol. 111,201-210 24 Bouma, J.E. and Lenski, R.E. (1988) Nature 335, 251-252 L e t t e r s  Endogenous retrovirus sequences and their usefulness to the host M ammalian genomes contain an estimated 1-5% of retrovirus-related sequences, a figure that reaches 10-30% if all retrotranscribed sequences are included. Considering the millions of years in which virus and host have coexisted, it seems likely that the efficient integration and spread of these sequences in a host genome offers some benefits to the host, as well as to the virus. Recent reviews by Garfinkel I and Best 2 in this journal have shed some light on the value of retrosequences in the host genome. Apart from the role of retroelements in repairing double-stranded breaks in genomic DNA (Ref. 1), the recruitment of endogenous gag and env sequences in the battle against new virus infections 2 might be important to the host, as superinfection and/or replication of retroviruses is prevented in cells where related gag or env genes are expressed. In the two cases described by Best et al. 2, a truncated retroviral genome is located near a strong cellular promoter. This might be a chance occurrence; however, for complete retroviruses a similar mechanism could be proposed. If a replicating retrovirus is present in a cell, superinfection of this cell by a related virus is prevented 3'4. It is possible that the env protein non-competitively binds to viral receptors on the cell surface. Individuals that are able to prevent retrovirus infection of themselves and their offspring (where infection might be lethal), even if this is by means of the expression of endogenous retrovirus sequences, could have a selective advantage, especially in times of pathogenic retrovirus epidemics. This could explain why proviral genomes become fixed in a population, often in large numbers in many species. Most of these integrations have ancient origins and are shared between all individuals of a species. Of course, deleterious integrations into important genes will quickly be selected against. The higher level of expression of retroviral sequences in placental tissue could also be explained by these protective effects. To expand its lifespan, integration into a host germ line is a good and safe option for a virus. Consequently, targeting to oocytes or the early embryo is common for at least some 1 types of retroviruses. Another protective effect of retroviral 2 expression in the placenta could arise from the immunosuppressive effects of the peptides encoded by the env 3 gene of many retroviruses s, which would contribute to the local 4 suppression of the mother's immune system, which in turn inhibits foetus 5 rejection. Response from Stoye, Le Tissier and Best W e are in perfect agreement with Dr van der Kuyl concerning the potential ability of intact endogenous proviruses to restrict novel infection. Although both of our examples involve deletions of viral long terminal repeats (LTRs) and the use of cellular promoters for transcription, we did not state that such events were required and did not intend to imply that they might be. Indeed, the Fvl  open reading frame is transcribed at very low levels: in fact, lower than one might expect from a retroviral LTR. The immunosuppressive properties of a peptide derived from the transmembrane region of an exogenous retrovirus were first In summary, some types of retroviruses and their host species have developed a symbiotic coexistence, with the virus finding shelter in the host genome, and the host using the viral sequences for defence against new infections. Antoinette C. van der Kuyl Dept of Human Retrovirology, Academic Medical Centre, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands References Garfinkel, D.J. (1997) Trends Microbiol. 5,173-175 Best, S., Le Tissier, P.R. and Stoye, J.P. (1997) Trends MicrobioI. 5, 313-318 Steck, F.T. and Rubin, M. (1966) Virology 29, 642-653 Hart, A.R. and Cloyd, M.W. (1990) Virology 177, 1-10 Cianciolo, G.J. et al. (1985)Science 230, 453-455 described over ten years ago, and this potential property of endogenous proviruses has been invoked on many occasions. However, we are not aware of any experimental data showing a physiological role played by this region of an endogenous retrovirus. Experiments to address this issue in an incisive fashion, once and for all, would be very welcome. Jonathan P. Stoye, Paul R. Le Tissier National Institute for Medical Research, The Ridgeway, Mill Hill, London, UK N-W7 1AA; Steve Best The Wellcome Trust Centre for Human Genetics, Windmill Road, Oxford, UK OX3 7BN T R E N I ) S  I N  M I C R ( ) B I O L ( ) G Y  339 V O L .  5 N O .  9 S E P T E M B E R  1 9 9 7  

Endogenous retrovirus sequences and their usefulness to the host

https://pure.uva.nl/ws/files/3231051/3014_28734y.pdf

Endogenous retrovirus sequences and their usefulness to the host

Abstract

Similar works

Full text

Available Versions

International Migration, Integration and Social Cohesion online publications