{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T18:12:34Z","timestamp":1791223954850,"version":"4.1.0"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"7","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1994,3,29]]},"abstract":"<jats:p>We describe studies of gene transfer and expression of the human glucocerebrosidase cDNA by a Moloney murine leukemia virus (MoMuLV)-based retroviral vector in a murine gene transfer\/bone marrow transplant (BMT) model. Pluripotent hematopoietic stem cells (HSCs) were assayed as the colony-forming units, spleen (CFU-S) generated after serial transplantation. Transcriptional expression from the MoMuLV long-terminal repeat (LTR) was detected at a high level in the primary (1 degree) CFU-S and tissues of reconstituted BMT recipients. However, we observed transcriptional inactivity of the proviral MoMuLV-LTR in &gt; 90% of the secondary (2 degrees) CFU-S and in 100% of the tertiary (3 degrees) CFU-S examined. We have compared the methylation status of the provirus in the 1 degree CFU-S, which show strong vector expression, to that of the transcriptionally inactive provirus in the 2 degrees and 3 degrees CFU-S by Southern blot analysis using the methylation-sensitive restriction enzyme Sma I. The studies demonstrated a 3- to 4-fold increase in methylation of the Sma I site in the proviral LTR of 2 degrees and 3 degrees CFU-S compared to the transcriptionally active 1 degree CFU-S. These observations may have important implications for future clinical applications of retroviral-mediated gene transfer into HSCs, where persistent gene expression would be needed for an enduring therapeutic effect.<\/jats:p>","DOI":"10.1073\/pnas.91.7.2567","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T09:06:33Z","timestamp":1149066393000},"page":"2567-2571","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":330,"title":["Lack of expression from a retroviral vector after transduction of murine hematopoietic stem cells is associated with methylation in vivo."],"prefix":"10.1073","volume":"91","author":[{"given":"P M","family":"Challita","sequence":"first","affiliation":[{"name":"Department of Microbiology, University of Southern California School of Medicine, Los Angeles."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D B","family":"Kohn","sequence":"additional","affiliation":[{"name":"Department of Microbiology, University of Southern California School of Medicine, Los Angeles."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1994,3,29]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.91.7.2567","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T13:51:16Z","timestamp":1649857876000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.91.7.2567"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1994,3,29]]},"references-count":0,"journal-issue":{"issue":"7","published-print":{"date-parts":[[1994,3,29]]}},"alternative-id":["10.1073\/pnas.91.7.2567"],"URL":"https:\/\/doi.org\/10.1073\/pnas.91.7.2567","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1994,3,29]]},"assertion":[{"value":"1994-03-29","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}