Effect of XXXX on in vitro @entity1 megakaryocytopoiesis: its interaction with other cytokines.

@entity1 @entity650 @entity12718 @entity568 @entity1307 @entity5301 @entity8885 @entity2533 @entity7422 @entity3646 @entity7421 @entity2841
The effects of @entity1 recombinant @entity650 ( @entity568 ) on in vitro @entity1 megakaryocytopoiesis were studied utilizing a serum-depleted culture system. Recombinant @entity650 increased both the number of megakaryocyte (MK) colonies formed and the number of cells comprising individual MK colonies cloned from normal low-density bone marrow (LDBM) cells. This stimulation of MK colony number and size was significantly less than that observed following the addition of recombinant interleukin 3 ( @entity7422 ) or @entity2841 ( @entity7421 ). The addition of either @entity7422 or @entity7421 , but not @entity568 promoted MK colony formation by nonadherent, low-density, T-cell-depleted (NALDT-) marrow cells. Recombinant interleukin 1 alpha ( @entity8885 ) and @entity3646 ( @entity12718 ) failed either to promote LDBM MK colony formation when added alone or to significantly increase @entity568 -promoted MK colony formation. MK colony formation promoted by optimal doses of @entity568 was, in fact, significantly inhibited by @entity8885 at all concentrations tested. Addition of either recombinant @entity1307 ( @entity5301 ) or purified thrombocytopoiesis-stimulating factor (TSF) to assays containing @entity568 also resulted in significant inhibition of MK colony formation. The effect of suboptimal concentrations of @entity568 on MK colony formation was additive to that of @entity7422 but not @entity7421 . The addition of @entity2533 ( @entity2533 ) resulted in a 58% reduction of @entity568 -promoted MK colony formation by LDBM. These data suggest that @entity568 can promote in vitro megakaryocytopoiesis and that this effect can be either augmented or inhibited by the addition of several other cytokines. Recombinant @entity650 , however, might affect the MK colony-forming unit (CFU-MK) by acting through bone marrow accessory cells or requiring the presence of as yet unidentified additional cytokines.
