1
|
Bamunusinghe D, Skorski M, Buckler-White A, Kozak CA. Xenotropic Mouse Gammaretroviruses Isolated from Pre-Leukemic Tissues Include a Recombinant. Viruses 2018; 10:v10080418. [PMID: 30096897 PMCID: PMC6116186 DOI: 10.3390/v10080418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 07/28/2018] [Accepted: 08/03/2018] [Indexed: 11/16/2022] Open
Abstract
Naturally-occurring lymphomagenesis is induced by mouse leukemia viruses (MLVs) carried as endogenous retroviruses (ERVs). Replicating the ecotropic MLVs recombines with polytropic (P-ERVs) and xenotropic ERVs (X-ERVs) to generate pathogenic viruses with an altered host range. While most recovered nonecotropic recombinants have a polytropic host range, the X-MLVs are also present in the pre-leukemic tissues. We analyzed two such isolates from the AKR mice to identify their ERV progenitors and to look for evidence of recombination. AKR40 resembles the active X-ERV Bxv1, while AKR6 has a Bxv1-like backbone with substitutions that alter the long terminal repeat (LTR) enhancer and the envelope (env). AKR6 has a modified xenotropic host range, and its Env residue changes all lie outside of the domain that governs the receptor choice. The AKR6 segment spanning the two substitutions, but not the entire AKR6 env-LTR, exists as an ERV, termed Xmv67, in AKR, but not in the C57BL/6 mice. This suggests that AKR6 is the product of one, not two, recombination events. Xmv67 originated in the Asian mice. These data indicate that the recombinant X-MLVs that can be generated during lymphomagenesis, describe a novel X-ERV subtype found in the AKR genome, but not in the C57BL/6 reference genome, and identify residues in the envelope C-terminus that may influence the host range.
Collapse
Affiliation(s)
- Devinka Bamunusinghe
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892-0460, USA.
| | - Matthew Skorski
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892-0460, USA.
| | - Alicia Buckler-White
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892-0460, USA.
| | - Christine A Kozak
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892-0460, USA.
| |
Collapse
|
2
|
Sequence Diversity, Intersubgroup Relationships, and Origins of the Mouse Leukemia Gammaretroviruses of Laboratory and Wild Mice. J Virol 2016; 90:4186-98. [PMID: 26865715 DOI: 10.1128/jvi.03186-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 02/03/2016] [Indexed: 12/12/2022] Open
Abstract
UNLABELLED Mouse leukemia viruses (MLVs) are found in the common inbred strains of laboratory mice and in the house mouse subspecies ofMus musculus Receptor usage and envelope (env) sequence variation define three MLV host range subgroups in laboratory mice: ecotropic, polytropic, and xenotropic MLVs (E-, P-, and X-MLVs, respectively). These exogenous MLVs derive from endogenous retroviruses (ERVs) that were acquired by the wild mouse progenitors of laboratory mice about 1 million years ago. We analyzed the genomes of seven MLVs isolated from Eurasian and American wild mice and three previously sequenced MLVs to describe their relationships and identify their possible ERV progenitors. The phylogenetic tree based on the receptor-determining regions ofenvproduced expected host range clusters, but these clusters are not maintained in trees generated from other virus regions. Colinear alignments of the viral genomes identified segmental homologies to ERVs of different host range subgroups. Six MLVs show close relationships to a small xenotropic ERV subgroup largely confined to the inbred mouse Y chromosome.envvariations define three E-MLV subtypes, one of which carries duplications of various sizes, sequences, and locations in the proline-rich region ofenv Outside theenvregion, all E-MLVs are related to different nonecotropic MLVs. These results document the diversity in gammaretroviruses isolated from globally distributedMussubspecies, provide insight into their origins and relationships, and indicate that recombination has had an important role in the evolution of these mutagenic and pathogenic agents. IMPORTANCE Laboratory mice carry mouse leukemia viruses (MLVs) of three host range groups which were acquired from their wild mouse progenitors. We sequenced the complete genomes of seven infectious MLVs isolated from geographically separated Eurasian and American wild mice and compared them with endogenous germ line retroviruses (ERVs) acquired early in house mouse evolution. We did this because the laboratory mouse viruses derive directly from specific ERVs or arise by recombination between different ERVs. The six distinctively different wild mouse viruses appear to be recombinants, often involving different host range subgroups, and most are related to a distinctive, largely Y-chromosome-linked MLV ERV subtype. MLVs with ecotropic host ranges show the greatest variability with extensive inter- and intrasubtype envelope differences and with homologies to other host range subgroups outside the envelope. The sequence diversity among these wild mouse isolates helps define their relationships and origins and emphasizes the importance of recombination in their evolution.
Collapse
|
3
|
Beck-Engeser GB, Ahrends T, Knittel G, Wabl R, Metzner M, Eilat D, Wabl M. Infectivity and insertional mutagenesis of endogenous retrovirus in autoimmune NZB and B/W mice. J Gen Virol 2015; 96:3396-3410. [PMID: 26315139 DOI: 10.1099/jgv.0.000271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Murine leukaemia virus has been suggested to contribute to both autoimmune disease and leukaemia in the NZB mouse and in the (NZB × NZW) F1 (abbreviated B/W) mouse. However, with apparently only xenotropic but no ecotropic virus constitutively expressed in these mice, few mechanisms could explain the aetiology of either disease in either mouse strain. Because pseudotyped and/or inducible ecotropic virus may play a role, we surveyed the ability of murine leukaemia virus in NZB, NZW and B/W mice to infect and form a provirus. From the spleen of NZB mice, we isolated circular cDNA of xenotropic and polytropic virus, which indicates ongoing infection by these viruses. From a B/W lymphoma, we isolated and determined the complete sequence of a putative ecotropic NZW virus. From B/W mice, we recovered de novo endogenous retroviral integration sites (tags) from the hyperproliferating cells of the spleen and the peritoneum. The tagged genes seemed to be selected to aid cellular proliferation, as several of them are known cancer genes. The insertions are consistent with the idea that endogenous retrovirus contributes to B-cell hyperproliferation and progression to lymphoma in B/W mice.
Collapse
Affiliation(s)
- Gabriele B Beck-Engeser
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94143-0414, USA
| | - Tomasz Ahrends
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94143-0414, USA
| | - Gero Knittel
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94143-0414, USA
| | - Rafael Wabl
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94143-0414, USA
| | - Mirjam Metzner
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94143-0414, USA
| | - Dan Eilat
- Department of Medicine, Hadassah University Hospital and The Hebrew University Faculty of Medicine, Jerusalem 91120, Israel
| | - Matthias Wabl
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94143-0414, USA
| |
Collapse
|
4
|
Kozak CA. Origins of the endogenous and infectious laboratory mouse gammaretroviruses. Viruses 2014; 7:1-26. [PMID: 25549291 PMCID: PMC4306825 DOI: 10.3390/v7010001] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 12/18/2014] [Indexed: 01/07/2023] Open
Abstract
The mouse gammaretroviruses associated with leukemogenesis are found in the classical inbred mouse strains and in house mouse subspecies as infectious exogenous viruses (XRVs) and as endogenous retroviruses (ERVs) inserted into their host genomes. There are three major mouse leukemia virus (MuLV) subgroups in laboratory mice: ecotropic, xenotropic, and polytropic. These MuLV subgroups differ in host range, pathogenicity, receptor usage and subspecies of origin. The MuLV ERVs are recent acquisitions in the mouse genome as demonstrated by the presence of many full-length nondefective MuLV ERVs that produce XRVs, the segregation of these MuLV subgroups into different house mouse subspecies, and by the positional polymorphism of these loci among inbred strains and individual wild mice. While some ecotropic and xenotropic ERVs can produce XRVs directly, others, especially the pathogenic polytropic ERVs, do so only after recombinations that can involve all three ERV subgroups. Here, I describe individual MuLV ERVs found in the laboratory mice, their origins and geographic distribution in wild mouse subspecies, their varying ability to produce infectious virus and the biological consequences of this expression.
Collapse
|
5
|
Ito K, Baudino L, Kihara M, Leroy V, Vyse TJ, Evans LH, Izui S. Three Sgp loci act independently as well as synergistically to elevate the expression of specific endogenous retroviruses implicated in murine lupus. J Autoimmun 2013; 43:10-7. [PMID: 23465716 DOI: 10.1016/j.jaut.2013.01.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 01/28/2013] [Accepted: 01/31/2013] [Indexed: 01/06/2023]
Abstract
Endogenous retroviruses are implicated in murine lupus nephritis. They provide a source of nephritogenic retroviral gp70-anti-gp70 immune complexes through the production of serum gp70 protein and anti-gp70 autoantibodies as a result of the activation of TLR7. The Sgp (serum gp70 production) loci identified in lupus-prone mice play distinct roles for the expression of different classes of endogenous retroviruses, as Sgp3 regulates the transcription of xenotropic, polytropic and modified polytropic (mPT) viruses, and Sgp4 the transcription of only xenotropic viruses. In the present study, we extended these analyses to a third locus, Sgp5, using BALB/c mice congenic for the NZW-derived Sgp5 allele and also explored the possible interaction of Sgp3 and Sgp4 loci to promote the expression of endogenous retroviruses and serum gp70. The analysis of Sgp5 BALB/c congenic mice demonstrated that the Sgp5 locus enhanced the expression of xenotropic and mPT viruses, thereby upregulating the production of serum gp70. These data indicate a distinct action of the Sgp5 locus on the expression of endogenous retroviruses, as compared with two other Sgp loci. Moreover, comparative analysis of C57BL/6 double congenic mice for Sgp3 and Sgp4 loci with single congenic mice revealed that Sgp3 and Sgp4 acted synergistically to elevate the transcription of the potentially replication-competent Xmv18 provirus and the production of serum gp70. This indicates that the combined effect of three different Sgp loci markedly enhance the expression of endogenous retroviruses and their gene product, serum gp70, thereby contributing to the formation of nephritogenic gp70-anti-gp70 immune complexes in murine lupus.
Collapse
Affiliation(s)
- Kiyoaki Ito
- Department of Pathology and Immunology, University of Geneva, 1211 Geneva 4, Switzerland
| | | | | | | | | | | | | |
Collapse
|
6
|
Kihara M, Leroy V, Baudino L, Evans LH, Izui S. Sgp3 and Sgp4 control expression of distinct and restricted sets of xenotropic retroviruses encoding serum gp70 implicated in murine lupus nephritis. J Autoimmun 2011; 37:311-8. [PMID: 21982749 DOI: 10.1016/j.jaut.2011.09.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Revised: 09/02/2011] [Accepted: 09/05/2011] [Indexed: 12/23/2022]
Abstract
The envelope glycoprotein gp70 of endogenous retroviruses implicated in murine lupus nephritis is secreted by hepatocytes and its expression is controlled by Sgp3 (serum gp70 production 3) and Sgp4 loci derived from lupus-prone mice. Among three different endogenous retroviruses (ecotropic, xenotropic and polytropic), xenotropic viruses are considered to be the major source of serum gp70. Although the abundance of xenotropic viral gp70 RNA in livers was up-regulated by the presence of these two Sgp loci, it has not yet been clear whether Sgp3 and Sgp4 regulate the expression of a fraction or multiple xenotropic viruses present in mouse genome. To address this question, we determined the genetic origin of xenotropic viral sequences expressed in wild-type and two different Sgp congenic C57BL/6 mice. Among 14 xenotropic proviruses present in the C57BL/6 genome, only two proviruses (Xmv10 and Xmv14) were actively transcribed in wild-type C57BL/6 mice. In contrast, Sgp3 enhanced the transcription of Xmv10 and induced the transcription of three additional xenotropic viruses (Xmv15, Xmv17 and Xmv18), while Sgp4 induced the expression of a different xenotropic virus (Xmv13). Notably, stimulation of TLR7 in Sgp3 congenic C57BL/6 mice led to a highly enhanced expression of potentially replication-competent Xmv18. These results indicated that Sgp3 and Sgp4 independently regulated the transcription of distinct and restricted sets of xenotropic viruses in trans, thereby promoting the production of nephritogenic gp70 autoantigens. Furthermore, the induced expression of potentially replication-competent xenotropic viruses by Sgp3 may contribute to the development of autoimmune responses against gp70 through the activation of TLR7.
Collapse
Affiliation(s)
- Masao Kihara
- Department of Pathology and Immunology, University of Geneva, 1211 Geneve 4, Switzerland
| | | | | | | | | |
Collapse
|
7
|
Baudino L, Yoshinobu K, Dunand-Sauthier I, Evans LH, Izui S. TLR-mediated up-regulation of serum retroviral gp70 is controlled by the Sgp loci of lupus-prone mice. J Autoimmun 2010; 35:153-9. [PMID: 20619604 DOI: 10.1016/j.jaut.2010.06.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Revised: 06/08/2010] [Accepted: 06/13/2010] [Indexed: 12/29/2022]
Abstract
The endogenous retroviral envelope glycoprotein, gp70, implicated in murine systemic lupus erythematosus (SLE), has been considered to be a product of xenotropic, polytropic (PT) and modified PT (mPT) endogenous retroviruses. It is secreted by hepatocytes like an acute phase protein, but its response is under a genetic control. Given critical roles of TLR7 and TLR9 in the pathogenesis of SLE, we assessed their contribution to the acute phase expression of serum gp70, and defined a pivotal role of the Sgp3 (serum gp70 production 3) and Sgp4 loci in this response. Our results demonstrated that serum levels of gp70 were up-regulated in lupus-prone NZB mice injected with TLR7 or TLR9 agonist at levels comparable to those induced by injection of IL-1, IL-6 or TNF. In addition, studies of C57BL/6 Sgp3 and/or Sgp4 congenic mice defined the major roles of these two loci in up-regulated production of serum gp70 during acute phase responses. Finally, the analysis of Sgp3 congenic mice strongly suggests the presence of at least two distinct genetic factors in the Sgp3 interval, one of which controlled the basal-level expression of xenotropic, PT and mPT gp70 and the other which controlled the up-regulated production of xenotropic and mPT gp70 during acute phase responses. Our results uncovered an additional pathogenic role of TLR7 and TLR9 in murine lupus nephritis by promoting the expression of nephritogenic gp70 autoantigen. Furthermore, they revealed the involvement of multiple regulatory genes for the expression of gp70 autoantigen under steady-state and inflammatory conditions in lupus-prone mice.
Collapse
Affiliation(s)
- Lucie Baudino
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | | | | | | | | |
Collapse
|
8
|
Yoshinobu K, Baudino L, Santiago-Raber ML, Morito N, Dunand-Sauthier I, Morley BJ, Evans LH, Izui S. Selective up-regulation of intact, but not defective env RNAs of endogenous modified polytropic retrovirus by the Sgp3 locus of lupus-prone mice. THE JOURNAL OF IMMUNOLOGY 2009; 182:8094-103. [PMID: 19494335 DOI: 10.4049/jimmunol.0900263] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Endogenous retroviruses are implicated in the pathogenesis of systemic lupus erythematosus (SLE). Because four different classes of endogenous retroviruses, i.e., ecotropic, xenotropic, polytropic, or modified polytropic (mPT), are expressed in mice, we investigated the possibility that a particular class of endogenous retroviruses is associated with the development of murine SLE. We observed >15-fold increased expression of mPT env (envelope) RNA in livers of all four lupus-prone mice, as compared with those of nine nonautoimmune strains of mice. This was not the case for the three other classes of retroviruses. Furthermore, we found that in addition to intact mPT transcripts, many strains of mice expressed two defective mPT env transcripts which carry a deletion in the env sequence of the 3' portion of the gp70 surface protein and the 5' portion of the p15E transmembrane protein, respectively. Remarkably, in contrast to nonautoimmune strains of mice, all four lupus-prone mice expressed abundant levels of intact mPT env transcripts, but only low or nondetectable levels of the mutant env transcripts. The Sgp3 (serum gp70 production 3) locus derived from lupus-prone mice was responsible for the selective up-regulation of the intact mPT env RNA. Finally, we observed that single-stranded RNA-specific TLR7 played a critical role in the production of anti-gp70 autoantibodies. These data suggest that lupus-prone mice may possess a unique genetic mechanism responsible for the expression of mPT retroviruses, which could act as a triggering factor through activating TLR7 for the development of autoimmune responses in mice predisposed to SLE.
Collapse
Affiliation(s)
- Kumiko Yoshinobu
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Baudino L, Yoshinobu K, Morito N, Kikuchi S, Fossati-Jimack L, Morley BJ, Vyse TJ, Hirose S, Jørgensen TN, Tucker RM, Roark CL, Kotzin BL, Evans LH, Izui S. Dissection of genetic mechanisms governing the expression of serum retroviral gp70 implicated in murine lupus nephritis. THE JOURNAL OF IMMUNOLOGY 2008; 181:2846-54. [PMID: 18684976 DOI: 10.4049/jimmunol.181.4.2846] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The endogenous retroviral envelope glycoprotein, gp70, implicated in murine lupus nephritis is secreted by hepatocytes as an acute phase protein, and it has been thought to be a product of an endogenous xenotropic virus, NZB-X1. However, since endogenous polytropic (PT) and modified polytropic (mPT) viruses encode gp70s that are closely related to xenotropic gp70, these viruses can be additional sources of serum gp70. To better understand the genetic basis of the expression of serum gp70, we analyzed the abundance of xenotropic, PT, or mPT gp70 RNAs in livers and the genomic composition of corresponding proviruses in various strains of mice, including two different Sgp (serum gp70 production) congenic mice. Our results demonstrated that the expression of different viral gp70 RNAs was remarkably heterogeneous among various mouse strains and that the level of serum gp70 production was regulated by multiple structural and regulatory genes. Additionally, a significant contribution of PT and mPT gp70s to serum gp70 was revealed by the detection of PT and mPT, but not xenotropic transcripts in 129 mice, and by a closer correlation of serum levels of gp70 with the abundance of PT and mPT gp70 RNAs than with that of xenotropic gp70 RNA in Sgp3 congenic mice. Furthermore, the injection of lipopolysaccharides selectively up-regulated the expression of xenotropic and mPT gp70 RNAs, but not PT gp70 RNA. Our data indicate that the genetic origin of serum gp70 is more heterogeneous than previously thought, and that distinct retroviral gp70s are differentially regulated in physiological vs inflammatory conditions.
Collapse
Affiliation(s)
- Lucie Baudino
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Sutton CA, Gordnier PM, Avery RJ, Casey JW. Comparative replication kinetics of two cytopathic feline lentiviruses ex vivo. Virology 2005; 332:519-28. [PMID: 15680417 DOI: 10.1016/j.virol.2004.11.042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2004] [Revised: 09/23/2004] [Accepted: 11/30/2004] [Indexed: 10/26/2022]
Abstract
Feline immunodeficiency virus infection of cats provides a model to elucidate mechanisms of lentiviral pathogenesis. We isolated a non-domestic FIV from a Pallas' cat, FIV-Oma, which replicates in feline PBMCs and CRFK cells. To gain insights into FIV pathogenesis, we compared rates of viral replication and apoptosis of FIV-Oma with FIV-PPR in the MYA-1 T-cell line. To minimize heterogeneity of virus, infections were initiated with virus derived from molecular clones. Viral DNA and RNA levels, assessed by qPCR and qRT-PCR, apoptosis, and supernatant reverse transcriptase were slower in FIV-Oma infections. Immunostaining for cellular Gag showed that few cells were productively infected. The majority of cells infected with either virus instead became apoptotic. Apoptosis was detectable within 6 h PI, suggesting activation of a signaling pathway. We propose that apoptosis is due to interaction of virus with cells, and is the usual outcome of infection by cytopathic FIVs in these cells.
Collapse
Affiliation(s)
- Claudia A Sutton
- Department of Microbiology and Immunology, Veterinary Medical Center, College of Veterinary Medicine, Cornell University, C5-153 Ithaca, NY 14853, USA
| | | | | | | |
Collapse
|
11
|
van der Laan LJ, Lockey C, Griffeth BC, Frasier FS, Wilson CA, Onions DE, Hering BJ, Long Z, Otto E, Torbett BE, Salomon DR. Infection by porcine endogenous retrovirus after islet xenotransplantation in SCID mice. Nature 2000; 407:90-4. [PMID: 10993079 DOI: 10.1038/35024089] [Citation(s) in RCA: 304] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Animal donors such as pigs could provide an alternative source of organs for transplantation. However, the promise of xenotransplantation is offset by the possible public health risk of a cross-species infection. All pigs contain several copies of porcine endogenous retroviruses (PERV), and at least three variants of PERV can infect human cell lines in vitro in co-culture, infectivity and pseudotyping experiments. Thus, if xenotransplantation of pig tissues results in PERV viral replication, there is a risk of spreading and adaptation of this retrovirus to the human host. C-type retroviruses related to PERV are associated with malignancies of haematopoietic lineage cells in their natural hosts. Here we show that pig pancreatic islets produce PERV and can infect human cells in culture. After transplantation into NOD/SCID (non-obese diabetic, severe combined immunodeficiency) mice, we detect ongoing viral expression and several tissue compartments become infected. This is the first evidence that PERV is transcriptionally active and infectious cross-species in vivo after transplantation of pig tissues. These results show that a concern for PERV infection risk associated with pig islet xenotransplantation in immunosuppressed human patients may be justified.
Collapse
Affiliation(s)
- L J van der Laan
- The Scripps Research Institute, Department of Molecular and Experimental Medicine, La Jolla, California 92037, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Tomonaga K, Coffin JM. Structures of endogenous nonecotropic murine leukemia virus (MLV) long terminal repeats in wild mice: implication for evolution of MLVs. J Virol 1999; 73:4327-40. [PMID: 10196331 PMCID: PMC104214 DOI: 10.1128/jvi.73.5.4327-4340.1999] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
To develop a better understanding of the interaction between retroviruses and their hosts, we have investigated the polymorphism in endogenous murine leukemia proviruses (MLVs). We used genomic libraries of wild mouse DNAs and PCR to analyze genetic variation in the proviruses found in wild mouse species, including Mus musculus (M. m. castaneus, M. m. musculus, M. m. molossinus, and M. m. domesticus), Mus spretus, and Mus spicelegus, as well as some inbred laboratory strains. In this analysis, we detected several unique forms of sequence organization in the U3 regions of the long terminal repeats of these proviruses. The distribution of the proviruses with unique U3 structures demonstrated that xenotropic MLV-related proviruses were present only in M. musculus subspecies, while polytropic MLV-related proviruses were found in both M. musculus and M. spretus. Furthermore, one unique provirus from M. spicelegus was found to be equidistant from ecotropic provirus and nonecotropic provirus by phylogenetic analysis. This provirus, termed HEMV, was thus likely to be related to the common ancestor of these MLVs. Moreover, an ancestral type of polytropic MLV-related provirus was detected in M. spretus species. Despite their "ancestral" phylogenetic position, proviruses of these types are not widespread in mice, implying more-recent spread by infection rather than inheritance. These results imply that recent evolution of these proviruses involved alternating periods of replication as virus and residence in the germ line.
Collapse
Affiliation(s)
- K Tomonaga
- Department of Molecular Biology and Microbiology, Tufts University, School of Medicine, Boston, Massachusetts 02111, USA
| | | |
Collapse
|
13
|
Tomonaga K, Coffin JM. Structure and distribution of endogenous nonecotropic murine leukemia viruses in wild mice. J Virol 1998; 72:8289-300. [PMID: 9733873 PMCID: PMC110191 DOI: 10.1128/jvi.72.10.8289-8300.1998] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Virtually all of our present understanding of endogenous murine leukemia viruses (MLVs) is based on studies with inbred mice. To develop a better understanding of the interaction between endogenous retroviruses and their hosts, we have carried out a systematic investigation of endogenous nonecotropic MLVs in wild mice. Species studied included four major subspecies of Mus musculus (M. m. castaneus, M. m. musculus, M. m. molossinus, and M. m. domesticus) as well as four common inbred laboratory strains (AKR/J, HRS/J, C3H/HeJ, and C57BL/6J). We determined the detailed distribution of nonecotropic proviruses in the mice by using both env- and long terminal repeat (LTR)-derived oligonucleotide probes specific for the three different groups of endogenous MLVs. The analysis indicated that proviruses that react with all of the specific probes are present in most wild mouse DNAs tested, in numbers varying from 1 or 2 to more than 50. Although in common inbred laboratory strains the linkage of group-specific sequences in env and the LTR of the proviruses is strict, proviruses which combine env and the LTR sequences from different groups were commonly observed in the wild-mouse subspecies. The "recombinant" nonecotropic proviruses in the mouse genomes were amplified by PCR, and their genetic and recombinant natures were determined. These proviruses showed extended genetic variation and provide a valuable probe for study of the evolutionary relationship between MLVs and the murine hosts.
Collapse
Affiliation(s)
- K Tomonaga
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| | | |
Collapse
|
14
|
Abstract
Endogenous retroviruses (ERVs) are estimated to comprise up to 1% of human DNA. While the genome of many ERVs is interrupted by termination codons, deletions or frame shift mutations, some ERVs are transcriptionally active and recent studies reveal protein expression or particle formation by human ERVs. ERVs have been implicated as aetiological agents of autoimmune disease, because of their structural and sequence similarities to exogenous retroviruses associated with immune dysregulation and their tissue-specific or differentiation-dependent expression. In fact, retrovirus-like particles distinct from those of known exogenous retroviruses and immune responses to ERV proteins have been observed in autoimmune disease. Quantitatively or structurally aberrant expression of normally cryptic ERVs, induced by environmental or endogenous factors, could initiate autoimmunity through direct or indirect mechanisms. ERVs may lead to immune dysregulation as insertional mutagens or cis-regulatory elements of cellular genes involved in immune function. ERVs may also encode elements like tax in human T-lymphotrophic virus type I (HTLV-I) or tat in human immunodeficiency virus-I (HIV-I) that are capable of transactivating cellular genes. More directly, human ERV gene products themselves may be immunologically active, by analogy with the superantigen activity in the long terminal repeat (LTR) of mouse mammary tumour viruses (MMTV) and the non-specific immunosuppressive activity in mammalian type C retrovirus env protein. Alternatively, increased expression of an ERV protein, or expression of a novel ERV protein not expressed in the thymus during acquisition of immune tolerance, may lead to its perception as a neoantigen. Paraneoplastic syndromes raise the possibility that novel ERV-encoded epitopes expressed by a tumour elicit immunity to cross-reactive epitopes in normal tissues. Recombination events between different but related ERVs, to whose products the host is immunologically tolerant, may also generate new antigenic determinants. Frequently reported humoral immunity to exogenous retrovirus proteins in autoimmune disease could be elicited by cross-reactive ERV proteins. A review of the evidence implicating ERVs in immune dysfunction leads to the conclusion that direct molecular studies are likely to establish a pathogenic role for ERVs in autoimmune disease.
Collapse
Affiliation(s)
- K Nakagawa
- Burnet Clinical Research Unit, Walter and Eliza Hall Institute of Medical Research, Royal Melbourne Hospital, Parkville, Australia
| | | |
Collapse
|
15
|
Frankel WN, Coffin JM. Endogenous nonecotropic proviruses mapped with oligonucleotide probes from the long terminal repeat region. Mamm Genome 1994; 5:275-81. [PMID: 8075500 DOI: 10.1007/bf00389541] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We characterized endogenous proviruses in C57BL/6J, DBA/2J, and C3H/HeJ mouse strains with oligonucleotide probes derived from long terminal repeat (LTR) sequences of three classes of nonecotropic murine leukemia virus. The segregation of proviral-host DNA junction fragments was followed in BXH and BXD recombinant inbred (RI) strain sets, and most fragments mapped readily to defined chromosomal regions. Most of the LTR fragments appear to correspond to proviruses mapped previously with oligonucleotide env region probes of the same viral class. At least 22 elements represent new proviral loci, no more than half of which may be solo LTRs, and an additional six may correspond to proviruses identified previously with less specific hybridization probes. Together with proviruses identified previously with env probes, the LTR probe-reactive elements represent the majority of endogenous murine leukemia proviruses in the mouse genome.
Collapse
MESH Headings
- Animals
- Base Sequence
- DNA, Viral/genetics
- Genes, env
- Leukemia Virus, Murine/genetics
- Mice
- Mice, Inbred C3H/genetics
- Mice, Inbred C3H/microbiology
- Mice, Inbred C57BL/genetics
- Mice, Inbred C57BL/microbiology
- Mice, Inbred DBA/genetics
- Mice, Inbred DBA/microbiology
- Molecular Sequence Data
- Oligonucleotide Probes
- Proviruses/genetics
- Repetitive Sequences, Nucleic Acid
Collapse
|
16
|
Bowes C, Li T, Frankel WN, Danciger M, Coffin JM, Applebury ML, Farber DB. Localization of a retroviral element within the rd gene coding for the beta subunit of cGMP phosphodiesterase. Proc Natl Acad Sci U S A 1993; 90:2955-9. [PMID: 8385352 PMCID: PMC46215 DOI: 10.1073/pnas.90.7.2955] [Citation(s) in RCA: 157] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Retinal degeneration in the rd mouse is inherited as an autosomal recessive trait and is caused by a defect in the gene encoding the beta subunit of cGMP phosphodiesterase. Recently, a close genetic association of the rd gene with an endogenous xenotropic murine leukemia virus (Xmv-28) was established by linkage analysis using recombinant inbred strains of mice. In this study, genomic DNA mapping and sequence analyses clarify the position of the proviral sequences in relation to the rd gene. We find that the Xmv-28 provirus is integrated into intron I of the rd gene 1511 bp downstream of the exon-intron boundary. The transcriptional orientation of the provirus is opposite to that of the gene for the beta subunit of cGMP phosphodiesterase. Reverse transcription-PCR demonstrates that the integrated Xmv-28 sequences are transcribed in the retina. The provirus is present in every strain of rd mouse tested.
Collapse
Affiliation(s)
- C Bowes
- Jules Stein Eye Institute, University of California School of Medicine, Los Angeles 90024
| | | | | | | | | | | | | |
Collapse
|