{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T18:07:17Z","timestamp":1791223637596,"version":"4.1.0"},"reference-count":41,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2011,11,2]],"date-time":"2011-11-02T00:00:00Z","timestamp":1320192000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Viruses"],"abstract":"<jats:p>Human endogenous retroviruses (HERVs) represent approximately 8% of our genome. HERVs influence cellular gene expression and contribute to normal physiological processes such as cellular differentiation and morphogenesis. HERVs have also been associated with certain pathological conditions, including cancer and neurodegenerative diseases. As HTLV-1 causes adult T-cell leukemia and HTLV-1-associated myelopathy\/tropical spastic paraparesis (HAM\/TSP) and has been shown to modulate host gene expression mainly through the expression of the powerful Tax transactivator, herein we were interested in looking at the potential modulation capacity of HTLV-1 Tax on HERV expression. In order to evaluate the promoter activity of different HERV LTRs, pHERV-LTR-luc constructs were co-transfected in Jurkat T-cells with a Tax expression vector. Tax expression potently increased the LTR activity of HERV-W8 and HERV-H (MC16). In parallel, Jurkat cells were also stimulated with different T-cell-activating agents and HERV LTRs were observed to respond to different combination of Forskolin, bpV[pic] a protein tyrosine phosphatase inhibitor, and PMA. Transfection of expression vectors for different Tax mutants in Jurkat cells showed that several transcription factors including CREB appeared to be important for HERV-W8 LTR activation. Deletion mutants were derived from the HERV-W8 LTR and the region from \u2212137 to \u2212123 was found to be important for LTR response following Tax expression in Jurkat cells, while a different region was shown to be required in cells treated with activators. Our results thus demonstrated that HTLV-1 Tax activates several HERV LTRs. This raises the possibility that upregulated HERV expression could be involved in diseases associated with HTLV-1 infection.<\/jats:p>","DOI":"10.3390\/v3112146","type":"journal-article","created":{"date-parts":[[2011,11,2]],"date-time":"2011-11-02T12:58:41Z","timestamp":1320238721000},"page":"2146-2159","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":68,"title":["Activation of LTRs from Different Human Endogenous Retrovirus (HERV) Families by the HTLV-1 Tax Protein and T-Cell Activators"],"prefix":"10.3390","volume":"3","author":[{"given":"Chirine","family":"Toufaily","sequence":"first","affiliation":[{"name":"D\u00e9partement des sciences biologiques, Universit\u00e9 du Qu\u00e9bec \u00e0 Montr\u00e9al, SB-R860, 2080 St-Urbain, Montr\u00e9al, Qu\u00e9bec, H2X 3X8, Canada"},{"name":"Centre de recherche BioMed, Universit\u00e9 du Qu\u00e9bec \u00e0 Montr\u00e9al, SB-R860, 2080 St-Urbain, Montr\u00e9al, Qu\u00e9bec, H2X 3X8, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sebastien","family":"Landry","sequence":"additional","affiliation":[{"name":"Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christine","family":"Leib-Mosch","sequence":"additional","affiliation":[{"name":"Institute of Virology, Helmholtz Zentrum M\u00fcnchen, German Research Center for Environmental Health, Institute of Virology, 85764 Neuherberg, Germany"},{"name":"III. Medizinische Klinik, UMM-Universit\u00e4tsmedizin Mannheim, University of Heidelberg, 68305 Mannheim, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eric","family":"Rassart","sequence":"additional","affiliation":[{"name":"D\u00e9partement des sciences biologiques, Universit\u00e9 du Qu\u00e9bec \u00e0 Montr\u00e9al, SB-R860, 2080 St-Urbain, Montr\u00e9al, Qu\u00e9bec, H2X 3X8, Canada"},{"name":"Centre de recherche BioMed, Universit\u00e9 du Qu\u00e9bec \u00e0 Montr\u00e9al, SB-R860, 2080 St-Urbain, Montr\u00e9al, Qu\u00e9bec, H2X 3X8, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Benoit","family":"Barbeau","sequence":"additional","affiliation":[{"name":"D\u00e9partement des sciences biologiques, Universit\u00e9 du Qu\u00e9bec \u00e0 Montr\u00e9al, SB-R860, 2080 St-Urbain, Montr\u00e9al, Qu\u00e9bec, H2X 3X8, Canada"},{"name":"Centre de recherche BioMed, Universit\u00e9 du Qu\u00e9bec \u00e0 Montr\u00e9al, SB-R860, 2080 St-Urbain, Montr\u00e9al, Qu\u00e9bec, H2X 3X8, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2011,11,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1017","DOI":"10.1186\/gb-2001-2-6-reviews1017","article-title":"Endogenous retroviruses in the human genome sequence","volume":"2","author":"Griffiths","year":"2001","journal-title":"Genome Biol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"437","DOI":"10.1006\/bbrc.2001.4814","article-title":"Molecular analysis of endogenous retrovirus hres-1: Identification of frameshift mutations in region encoding putative 28-kda autoantigen","volume":"283","author":"Lefranc","year":"2001","journal-title":"Biochem. 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