Key Points
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In the past few years, with the availability of near-complete sequences for several vertebrate genomes, the targeting of retroviral DNA integration has been subjected to genomic analysis. These studies have shown that different retroviruses have different integration target-site preferences.
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HIV favours integration in transcription units, particularly into active transcription units. In line with this, HIV integration is disfavoured in human endogenous retrovirus (HERV) elements, which are depleted in gene-rich regions of the genome and, in some studies, HIV integration is favoured in Alu elements, which are abundant in gene-rich chromosomal domains.
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Murine leukaemia virus (MLV) favours integration near the 5′ ends of genes.
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By contrast, avian sarcoma-leukosis virus (ASLV) shows a near-random distribution of integration sites in the human genome, with only a weak favouring of integration in genes.
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The chromosomal environment can influence expression of integrated sequences — for example, integration of HIV into highly expressed cellular genes inhibits HIV transcription. These factors provide explanations for transcriptional latency in cells from HIV-infected patients.
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Several chromosomal and nuclear factors might influence the targeting of retroviral integration. These include the presence of cellular proteins that can tether the integration complex to sites in the host genome, the intranuclear position of chromosomes, the accessibility of chromatin, and the cell-cycle status of the target cell.
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Insertional activation of oncogenes by retroviral integration during human gene therapy has now been seen in three cases, which highlights the need for a further understanding of the mechanisms that direct retroviral integration.
Abstract
Retroviral vectors are often used to introduce therapeutic sequences into patients' cells. In recent years, gene therapy with retroviral vectors has had impressive therapeutic successes, but has also resulted in three cases of leukaemia caused by insertional mutagenesis, which has focused attention on the molecular determinants of retroviral-integration target-site selection. Here, we review retroviral DNA integration, with emphasis on recent genome-wide studies of targeting and on the status of efforts to modulate target-site selection.
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References
Coffin, J. M., Hughes, S. H. & Varmus, H. E. Retroviruses (Cold Spring Harbor Laboratory Press, Cold Spring Harbor, 1997). The 'bible' of retrovirology.
Bushman, F. D. Lateral DNA Transfer: Mechanisms and Consequences (Cold Spring Harbor Laboratory Press, New York, 2001). Describes retroviral replication in the context of the mobile-DNA field.
Brown, P. O., Bowerman, B., Varmus, H. E. & Bishop, J. M. Correct integration of retroviral DNA in vitro. Cell 49, 347–356 (1987). The first demonstration of retroviral integration using preintegration complexes from infected cells.
Craigie, R., Fujiwara, T. & Bushman, F. The IN protein of Moloney murine leukemia virus processes the viral DNA ends and accomplishes their integration in vitro. Cell 62, 829–837 (1990). The first demonstration that MLV integrase could form covalent bonds between model viral DNA and target DNA.
Bor, Y. -C., Miller, M., Bushman, F. & Orgel, L. Target sequence preferences of HIV-1 integration complexes in vitro. Virology 222, 238–242 (1996).
Stevens, S. W. & Griffith, J. D. Sequence analysis of the human DNA flanking sites of human immunodeficiency virus type 1 integration. J. Virol. 70, 6459–6462 (1996).
Carteau, S., Hoffmann, C. & Bushman, F. D. Chromosome structure and HIV-1 cDNA integration: centromeric alphoid repeats are a disfavored target. J. Virol. 72, 4005–4014 (1998).
Yant, S. R. et al. High-resolution genome-wide mapping of transposon integration in mammals. Mol. Cell. Biol. 25, 2085–2094 (2005).
Holman, A. G. & Coffin, J. M. Symmetrical base preferences surrounding HIV-1, avian sarcoma/leukosis virus, and murine leukemia virus integration sites. Proc. Natl Acad. Sci. USA 102, 6103–6107 (2005).
Schroder, A. et al. HIV-1 integration in the human genome favors active genes and local hotspots. Cell 110, 521–529 (2002). The first genome-wide study of HIV integration, which revealed that HIV favours integration in active transcription units.
Wu, X., Li, Y., Crise, B. & Burgess, S. M. Transcription start regions in the human genome are favored targets for MLV integration. Science 300, 1749–1751 (2003). The first genome-wide study of MLV integration, which showed that this virus differed from HIV by favouring integration near transcription start sites.
Mitchell, R. et al. Retroviral DNA integration: ASLV, HIV, and MLV show distinct target site preferences. PLoS Biol. 2, E234 (2004). Bioinformatic survey of integration by HIV, MLV and ASLV, and a comparison of integration by HIV in different cell types.
Hacein-Bey-Abina, S. et al. A serious adverse event after successful gene therapy for X-linked severe combined immunodeficiency. N. Engl. J. Med. 348, 255–256 (2003).
Hacein-Bey-Abina, S. et al. LMO2-associated clonal T cell proliferation in two patients after gene therapy for SCID-X1. Science 302, 415–419 (2003). References 13 and 14 characterize the adverse events that occurred during gene therapy for X-SCID.
Panet, A. & Cedar, H. Selective degradation of integrated murine leukemia proviral DNA by deoxyribonucleases. Cell 11, 933–940 (1977).
Rohdewohld, H., Weiher, H., Reik, W., Jaenisch, R. & Breindl, M. Retrovirus integration and chromatin structure: Moloney murine leukemia proviral integration sites map near DNase I-hypersensitive sites. J. Virol. 61, 336 (1987).
Vijaya, S., Steffan, D. L. & Robinson, H. L. Acceptor sites for retroviral integrations map near DNase I-hypersensitive sites in chromatin. J. Virol. 60, 683–692 (1986).
Scherdin, U., Rhodes, K. & Breindl, M. Transcriptionally active genome regions are preferred targets for retrovirus integration. J. Virol. 64, 907 (1990).
Shih, C. -C., Stoye, J. P. & Coffin, J. M. Highly preferred targets for retrovirus integration. Cell 53, 531–537 (1988).
Withers-Ward, E. S., Kitamura, Y., Barnes, J. P. & Coffin, J. M. Distribution of targets for avian retrovirus DNA integration in vivo. Genes Dev. 8, 1473–1487 (1994).
Bushman, F. D., Fujiwara, T. & Craigie, R. Retroviral DNA integration directed by HIV integration protein in vitro. Science 249, 1555–1558 (1990).
Katz, R. A., Merkel, G., Kulkosky, J., Leis, J. & Skalka, A. M. The avian retroviral IN protein is both necessary and sufficient for integrative recombination in vitro. Cell 63, 87–95 (1990).
Bushman, F. D. & Craigie, R. Activities of human immunodeficiency virus (HIV) integration protein in vitro: specific cleavage and integration of HIV DNA. Proc. Natl Acad. Sci. USA 88, 1339–1343 (1991).
Pryciak, P. M., Sil, A. & Varmus, H. E. Retroviral integration into minichromosomes in vitro. EMBO J. 11, 291–303 (1992). An early study of integration into chromatin templates.
Pruss, D., Reeves, R., Bushman, F. D. & Wolffe, A. P. The influence of DNA and nucleosome structure on integration events directed by HIV integrase. J. Biol. Chem. 269, 25031–25041 (1994).
Fitzgerald, M. L. & Grandgenett, D. P. Retroviral integration: in vitro host site selection by avian integrase. J. Virol. 68, 4314–4321 (1994).
Pryciak, P. M. & Varmus, H. E. Nucleosomes, DNA-binding proteins, and DNA sequence modulate retroviral integration target site selection. Cell 69, 769–780 (1992). The first study of integration into chromatin templates.
Bushman, F. D. Tethering human immunodeficiency virus 1 integrase to a DNA site directs integration to nearby sequences. Proc. Natl Acad. Sci. USA 91, 9233–9237 (1994). The first demonstration that fusion of retroviral integrase proteins to sequence-specific DNA-binding domains can direct integration into predetermined target DNA sites in vitro.
Bor, Y. -C., Bushman, F. & Orgel, L. In vitro integration of human immunodeficiency virus type 1 cDNA into targets containing protein-induced bends. Proc. Natl Acad. Sci. USA 92, 10334–10338 (1995).
Weidhaas, J. B., Angelichio, E. L., Fenner, S. & Coffin, J. M. Relationship between retroviral DNA integration and gene expression. J. Virol. 74, 8382–8389 (2000).
Pryciak, P., Muller, H. -P. & Varmus, H. E. Simian virus 40 minichromosomes as targets for retroviral integration in vivo. Proc. Natl Acad. Sci. USA 89, 9237–9241 (1992).
Pruss, D., Bushman, F. D. & Wolffe, A. P. Human immunodeficiency virus integrase directs integration to sites of severe DNA distortion within the nucleosome core. Proc. Natl Acad. Sci. USA 91, 5913–5917 (1994). A study of integration in nucleosomes, which revealed that integration at 'kinked' DNA sites is favoured.
Muller, H. -P. & Varmus, H. E. DNA bending creates favored sites for retroviral integration: an explanation for preferred insertion sites in nucleosomes. EMBO J. 13, 4704–4714 (1994).
Bushman, F. D. & Craigie, R. Integration of human immunodeficiency virus DNA: adduct interference analysis of required DNA sites. Proc. Natl Acad. Sci. USA 89, 3458–3462 (1992).
Scottoline, B. P., Chow, S., Ellison, V. & Brown, P. O. Disruption of the terminal base pairs of retroviral DNA during integration. Genes Dev. 11, 371–382 (1997).
Lander, E. et al. Initial sequencing and analysis of the human genome. Nature 409, 860–921 (2001). The first draft of the human genome sequence from the public consortium.
Venter, J. C. The sequence of the human genome. Science 291, 1304–1351 (2001). The first draft of the human genome sequence from Celera.
Caron, H. et al. The human transcriptome map: clustering of highly expressed genes in chromosomal domains. Science 291, 1289–1292 (2001).
Versteeg, R. et al. The human transcriptome map reveals extremes in gene density, intron length, GC content, and repeat pattern for domains of highly and weakly expressed genes. Genome Res. 13, 1998–2004 (2003).
Mungall, A. J. & et al. The DNA sequence and analysis of human chromosome 6. Nature 425, 805–811 (2003).
Lewinski, M. et al. Genome-wide analysis of chromosomal features repressing HIV transcription. J. Virol. 79, 6610–6619 (2005).
van't Wout, A. B. et al. Cellular gene expression upon human immunodeficiency virus type 1 infection of CD4+-T-cell lines. J. Virol. 77, 1392–1402 (2003).
Corbeil, J. et al. Temporal gene regulation during HIV-1 infection of human CD4+ T cells. Genome Res. 11, 1198–204. (2001).
Mitchell, R., Chiang, C., Berry, C. & Bushman, F. D. Global effects on cellular transcription following infection with an HIV-based vector. Mol. Ther. 8, 674–687 (2003).
Chubb, J. R. & Bickmore, W. A. Considering nuclear compartmentalization in light of nuclear dynamics. Cell 112, 403–406 (2003).
Laufs, S. et al. Retroviral vector integration occurs in preferred genomic targets in human bone marrow-repopulating cells. Blood 101, 2191–2198 (2003).
Laufs, S. et al. Insertion of retroviral vectors in NOD/SCID repopulating human peripheral blood progenitor cells occurs preferentially in the vicinity of transcription start regions and in introns. Mol. Ther. 10, 874–881 (2004).
Fischer, A., Abina, S. H., Thrasher, A., von Kalle, C. & Cavazzana-Calvo, M. LMO2 and gene therapy for severe combined immunodeficiency. N. Engl. J. Med. 350, 2526–2527 (2004).
Narezkina, A. et al. Genome-wide analyses of avian sarcoma virus integration sites. J. Virol. 78, 11656–11663 (2004).
Maxfield, L. F., Fraize, C. D. & Coffin, J. M. Relationship between retroviral DNA-integration-site selection and host cell transcription. Proc. Natl Acad. Sci. USA 102, 1436–1441 (2005).
Hematti, P. et al. Distinct genomic integration of MLV and SIV vectors in primate hematopoietic stem and progenitor cells. PLoS Biol. 2, e423 (2004).
Nakai, H. et al. AAV serotype 2 vectors preferentially integrate into active genes in mice. Nature Genet. 34, 297–302 (2003).
Sandmeyer, S. Integration by design. Proc. Natl Acad. Sci. USA 100, 5586–5588 (2003).
Zhu, Y., Dai, J., Fuerst, P. G. & Voytas, D. F. Controlling integration specificity of yeast retrotransposon. Proc. Natl Acad. Sci. USA 100, 5891–5895 (2003). The demonstration of controlling integration target-site specificity in vivo by engineering a yeast retrotransposon.
Boeke, J. D. & Devine, S. E. Yeast retrotransposons: finding a nice quiet neighborhood. Cell 93, 1087–1089 (1998).
Bushman, F. D. Targeting survival: integration site selection by retroviruses and LTR-retrotransposons. Cell 115, 135–138 (2003).
Li, L. et al. Role of the non-homologous DNA end joining pathway in retroviral infection. EMBO J. 20, 3272–3281 (2001).
Farnet, C. & Bushman, F. D. HIV-1 cDNA integration: requirement of HMG I(Y) protein for function of preintegration complexes in vitro. Cell 88, 483–492 (1997).
Suzuki, Y. & Craigie, R. Regulatory mechanisms by which barrier-to-autointegration factor blocks autointegration and stimulates intermolecular integration of Moloney murine leukemia virus preintegration complexes. J. Virol. 76, 12376–12380 (2002).
Llano, M. et al. LEDGF/p75 determines cellular trafficking of diverse lentiviral but not murine oncoretroviral integrase proteins and is a component of functional lentiviral preintegration complexes. J. Virol. 78, 9524–9537 (2004).
Kalpana, G. V., Marmon, S., Wang, W., Crabtree, G. R. & Goff, S. P. Binding and stimulation of HIV-1 integrase by a human homolog of yeast transcription factor SNF5. Science 266, 2002–2006 (1994).
Cherepanov, P. et al. HIV-1 integrase forms stable tetramers and associates with LEDGF/p75 protein in human cells. J. Biol. Chem. 278, 372–381 (2003).
Maertens, G. et al. LEDGF/p75 is essential for nuclear and chromosomal targeting of HIV-1 integrase in human cells. J. Biol. Chem. 278, 33528–33539 (2003).
Turlure, F., Devroe, E., Silver, P. A. & Engelman, A. Human cell proteins and human immunodeficiency virus DNA integration. Front. Biosci. 9, 3187–3208 (2004).
Bushman, F. D. Targeting retroviral integration. Science 267, 1443–1444 (1995).
Bushman, F. & Miller, M. D. Tethering human immunodeficiency virus type 1 preintegration complexes to target DNA promotes integration at nearby sites. J. Virol. 71, 458–464 (1997).
Bushman, F. D. Targeting retroviral integration? Mol. Therapy 6, 570–571 (2002).
Goulaouic, H. & Chow, S. A. Directed integration of viral DNA mediated by fusion proteins consisting of human immunodeficiency virus type 1 integrase and Escherichia coli LexA protein. J. Virol. 70, 37–46 (1996).
Katz, R. A., Merkel, G. & Skalka, A. M. Targeting of retroviral integrase by fusion to a heterologous DNA binding domain: in vitro activities and incorporation of a fusion protein into viral particles. Virology 217, 178–190 (1996).
Shiramizu, B., Herndier, B. G. & McGrath, M. S. Identification of a common clonal human immunodeficiency virus integration site in human immunodeficiency virus-associated lymphomas. Cancer Res. 54, 2069–2072 (1994).
Mack, K. D. et al. HIV insertions within and proximal to host cell genes are a common finding in tissues containing high levels of HIV DNA and macrophage-associated p24 antigen expression. J. Acquir. Immune Defic. Syndr. 33, 308–320 (2003).
Wong, J. K. et al. Recovery of replication-competent HIV despite prolonged suppression of plasma viremia. Science 278, 1291–1295 (1997).
Finzi, D. et al. Identification of a reservoir for HIV-1 in patients on highly active antiretroviral therapy. Science 278, 1295–1300 (1997).
Han, Y. et al. Resting CD4+ T cells from human immunodeficiency virus type 1 (HIV-1)-infected individuals carry integrated HIV-1 genomes within actively transcribed host genes. J. Virol. 78, 6122–6133 (2004).
Jordan, A., Defechereux, P. & Verdin, E. The site of HIV-1 integration in the human genome determines basal transcriptional activity and response to Tat transactivation. EMBO J. 20, 1726–1738 (2001).
Jordan, A., Bisgrove, D. & Verdin, E. HIV reproducibly establishes a latent infection after acute infection of T cells in vitro. EMBO J. 22, 1868–1877 (2003).
Cullen, B. R., Lomedico, P. T. & Ju, G. Transcriptional interference in avian retroviruses —implications for the promoter insertion model of leukaemogenesis. Nature 307, 241–245 (1984).
Greger, I. H., Demarchi, F., Giacca, M. & Proudfoot, N. J. Transcriptional interference perturbs the binding of Sp1 to the HIV-1 promoter. Nucleic Acids Res. 26, 1294–1301 (1998).
Craig, N. L., Craigie, R., Gellert, M. & Lambowitz, A. M. Mobile DNA II (ASM Press, Washington DC, 2002).
Ho, D. D. et al. Rapid turnover of plasma virions and CD4 lymphocytes in HIV-1 infection. Nature 373, 123–126 (1995).
Wei, X. et al. Viral dynamics in human immunodeficiency virus type 1 infection. Nature 373, 117–122 (1995).
Coffin, J. M. HIV population dynamics in vivo: implications for genetic variation, pathogenesis, and therapy. Science 267, 483–486 (1995).
De Palma, M. et al. Promoter trapping reveals significant differences in integration site selection between MLV and HIV vectors in primary hematopoietic cells. Blood 105, 2307–2315 (2005).
Barr, S., Leipzig, J., Shinn, P., Ecker, J. & Bushman, F. Integration targeting by ASLV and HIV in the chicken genome. J. Virol. (in the press).
Roe, T., Reynolds, T. C., Yu, G. & Brown, P. O. Integration of murine leukemia virus DNA depends on mitosis. EMBO J. 12, 2099–2108 (1993).
Naldini, L. et al. In vivo gene delivery and stable transduction of nondividing cells by a lentiviral vector. Science 272, 263–267 (1996).
Lin, S. -Y. & Riggs, A. D. The general affinity of lac repressor for E. coli DNA: implications for gene regulation in prokaryotes and eukaryotes. Cell 4, 107–111 (1975). The classic physicochemical study of the role of non-specific DNA binding in the in vivo association of the lac repressor with its operator.
Lund, A. H. et al. Genome-wide retroviral insertional tagging of genes involved in cancer in Cdkn2a-deficient mice. Nature Genet. 32, 160–165 (2002).
Suzuki, T. et al. New genes involved in cancer identified by retroviral tagging. Nature Genet. 32, 166–174 (2002).
Kim, R. et al. Genome-based identification of cancer genes by proviral tagging in mouse retrovirus-induced T-cell lymphomas. J. Virol. 77, 2056–62 (2003).
Ellerman, V. & Bang, O. Experimentelle Leukamie bei Huhnern. Zentralbl. Bakteriol. Parasitenkd. Infectionskr. Hyg. Abt. Orig. 46, 595–609 (1908). The first paper on retroviruses.
Rous, P. A sarcoma of the fowl transmissible by an agent separable from the tumor cells. J. Exp. Med. 13, 397–411 (1911). Describes the discovery and characterization of Rous sarcoma virus.
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This work was supported by grants from the National Institutes of Health.
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Glossary
- DNase I HYPERSENSITIVE SITES
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DNA sites in chromosomes that show increased sensitivity to digestion by DNase I. These sites probably represent regions of the chromosome that are nucleosome-free, and often correspond to gene-control regions.
- CPG ISLANDS
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Regions in chromosomes that are enriched in the rare CpG dinucleotide. They often correspond to gene-control regions.
- HUMAN ENDOGENOUS RETROVIRUSES
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(HERVs). Sequences in human DNA that are derived from infection of the human germ line by retroviruses. They account for about 8% of the human genome sequence.
- LONG INTERSPERSED NUCLEAR ELEMENTS
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(LINEs). Non-long-terminal-repeat retrotransposons. These comprise the only known type of active transposon in the human genome.
- ALU ELEMENTS
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Repeated DNA sequences that contain recognition sites for the Alu restriction enzyme.
- CENTROMERIC HETEROCHROMATIN
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The distinctive type of protein–DNA complexes that are found at centromeres.
- GIEMSA-LIGHT BANDING
-
Staining of the human chromosomes by the Giemsa procedure results in a pattern of light and dark bands, which roughly corresponds with the relative GC content and gene density.
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Bushman, F., Lewinski, M., Ciuffi, A. et al. Genome-wide analysis of retroviral DNA integration. Nat Rev Microbiol 3, 848–858 (2005). https://doi.org/10.1038/nrmicro1263
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DOI: https://doi.org/10.1038/nrmicro1263