Thymosin beta4, inhibitor for normal hematopoietic progenitor cells.
Exp Hematol
; 24(7): 776-82, 1996 Jun.
Article
en En
| MEDLINE
| ID: mdl-8647227
ABSTRACT
Thymosin beta4 (Tbeta4), isolated from the calf thymus fraction 5, has a ubiquitous localization and plays a pleiotropic role in both the immune and nonimmune systems. Because it contains at its N-terminal end the sequence of a known inhibitor of hematopoiesis, the acetylated tetrapeptide Ac-N-Ser-Asp-Lys-Pro (AcSDKP, Goralatide), we have assayed Tbeta4 on human hematopoietic cells. We demonstrate that it inhibits normal bone marrow progenitor cell growth; indeed, it decreased the growth of both granulo-macrophagic and erythroid progenitors and reduces their percentage in S phase. Furthermore, we show that Tbeta4 reduces both the clonogenicity and the cell proliferation of purified CD34+ cells induced by a combination of seven growth factors. Although Tbeta4's inhibitory effect is very similar to that of AcSDKP, we demonstrate, using neutralizing antibodies and a truncated form of Tbeta4 devoid of the AcSDKP sequence, that the inhibitory effect of Tbeta4 is not mediated by the sequence AcSDKP. These data indicate that Tbeta4 is a novel inhibitor for human normal hematopoietic progenitors.
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Banco de datos:
MEDLINE
Asunto principal:
Timosina
/
Células Madre Hematopoyéticas
/
Inhibidores de Crecimiento
Límite:
Animals
/
Humans
Idioma:
En
Año:
1996
Tipo del documento:
Article