Megakaryocytes derived from CD34-positive cord blood cells produce interleukin-8.
In a serum-free liquid culture, thrombopoietin (TPO) selectively stimulated the growth of megakaryocytic cells from CD34-positive cord blood cells. Using these cultured cells, we investigated cytokine production by human megakaryocytes. Day 10 megakaryocytes (2 x 10(5)) secreted > 1000 pg/ml of interleukin (IL)-8, in contrast to small amounts of IL-1beta and IL-6. A time-course study showed that the IL-8 production of megakaryocytes occurred at the late phase of the culture period. The megakaryocyte-conditioned medium had the chemotactic potential of polymorphonuclear leucocytes, which was abrogated by the addition of anti-IL-8 antibody, suggesting the secretion of biologically active IL-8. The combination of TPO and IL-1alpha was required for a significant augmentation of the IL-8 secretion. Direct evidence for IL-8 synthesis in megakaryocytes was provided by reverse transcription-polymerase chain reaction on purified CD41b+ cells and by the detection of intracellular IL-8 in CD41b+ cells. These results suggest that TPO stimulates not only the proliferation and differentiation of the progenitors capable of megakaryocytic lineage expression but also IL-8 release by the megakaryocytic cells with the aid of IL-1.
Higuchi
T
T
Department of Paediatrics, Shinshu University School of Medicine, Matsumoto, Japan.
Koike
K
K
Sawai
N
N
Mwamtemi
H H
HH
Takeuchi
K
K
Shiohara
M
M
Kikuchi
T
T
Yasui
K
K
Ito
S
S
Yamagami
O
O
Sasaki
Y
Y
Okumura
N
N
Kato
T
T
Miyazaki
H
H
Ikeda
M
M
Yamada
M
M
Komiyama
A
A
D002478:Cells, Cultured; D002633:Chemotaxis; D016895:Culture Media, Serum-Free; D005312:Fetal Blood / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D016209:Interleukin-8 / Q000096:biosynthesis*; D008533:Megakaryocytes / Q000378:metabolism*; D009504:Neutrophils / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D013926:Thrombopoietin / Q000494:pharmacology
D016895:Culture Media, Serum-Free; D007375:Interleukin-1; D016209:Interleukin-8; D012333:RNA, Messenger; D013926:Thrombopoietin