In:
The Journal of Experimental Medicine, Rockefeller University Press, Vol. 190, No. 10 ( 1999-11-15), p. 1493-1504
Abstract:
Hematopoietic stem cell (HSC) self-renewal is a complicated process, and its regulatory mechanisms are poorly understood. Previous studies have identified tumor necrosis factor (TNF)-α as a pleiotropic cytokine, which, among other actions, prevents various hematopoietic progenitor cells from proliferating and differentiating in vitro. However, its role in regulating long-term repopulating HSCs in vivo has not been investigated. In this study, mice deficient for the p55 or the p75 subunit of the TNF receptor were analyzed in a variety of hematopoietic progenitor and stem cell assays. In older p55−/− mice ( & gt;6 mo), we identified significant differences in their hematopoietic system compared with age-matched p75−/− or wild-type counterparts. Increased marrow cellularity and increased numbers of myeloid and erythroid colony-forming progenitor cells (CFCs), paralleled by elevated peripheral blood cell counts, were found in p55-deficient mice. In contrast to the increased myeloid compartment, pre-B CFCs were deficient in older p55−/− mice. In addition, a fourfold decrease in the number of HSCs could be demonstrated in a competitive repopulating assay. Secondary transplantations of marrow cells from primary recipients of p55−/− marrow revealed impaired self-renewal ability of p55-deficient HSCs. These data show that, in vivo, signaling through the p55 subunit of the TNF receptor is essential for regulating hematopoiesis at the stem cell level.
Type of Medium:
Online Resource
ISSN:
0022-1007
,
1540-9538
DOI:
10.1084/jem.190.10.1493
Language:
English
Publisher:
Rockefeller University Press
Publication Date:
1999
detail.hit.zdb_id:
1477240-1
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