Human interleukin 6 is a direct promoter of maturation of megakaryocytes in vitro.
The response of cells of the murine megakaryocytic lineage to human interleukin 6 (IL-6) was assessed in serum-depleted cultures using a variety of biological assays. IL-6 alone had no influence on megakaryocytic colony formation but augmented the numbers of these colonies induced by the multipotent colony-stimulating factor interleukin 3. However, in liquid marrow cultures, IL-6 alone promoted marked increments in megakaryocytic size and the activity of acetyl-cholinesterase, a marker enzyme of the lineage. Moreover, IL-6 induced a significant shift toward higher ploidy classes when megakaryocytic DNA was quantitated by flow cytometry. To determine whether the influence of IL-6 on megakaryocytic maturation was direct, the factor was added to cultures of single megakaryocytes isolated from megakaryocytic colonies. Fifty-four percent of these cells increased in size compared with 19% of those grown without IL-6. The data show that human IL-6 is a potent direct-acting growth factor for murine megakaryocytes with activity promoting maturation of that lineage.
Ishibashi
T
T
First Department of Internal Medicine, Fukushima Medical College, Japan.
Kimura
H
H
Uchida
T
T
Kariyone
S
S
Friese
P
P
Burstein
S A
SA
D000818:Animals; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D003115:Colony-Stimulating Factors / Q000494:pharmacology; D046508:Culture Techniques / Q000379:methods; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D015850:Interleukin-6; D007378:Interleukins / Q000494:pharmacology*; D007700:Kinetics; D008264:Macrophages / Q000502:physiology*; D008533:Megakaryocytes / Q000166:cytology* / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL
D003115:Colony-Stimulating Factors; D015850:Interleukin-6; D007378:Interleukins