Granulocyte colony-stimulating factor stimulates human mature neutrophilic granulocytes to produce interferon-alpha.
Granulocyte colony-stimulating factor (G-CSF) is a glycoprotein hormone that specifically stimulates both production and functional activation of neutrophils, while interferon-alpha (IFN-alpha) is known to suppress myelopoiesis, including neutrophil production in vivo and in vitro. On a possibility that IFN-alpha may operate as one of the inhibitory feedback factors in neutropoiesis, we examined whether neutrophils produce IFN-alpha in response to G-CSF. Northern blot analysis showed that messenger RNA (mRNA) for human IFN-alpha 1 became detectable time-dependently in highly purified human neutrophils incubated with purified recombinant human G-CSF (rhG-CSF). But such transcription was not observed either in neutrophils incubated with other neutrophil activators, such as formyl-methionyl-leucyl-phenylalanine (fMLP) or lipopolysaccharides (LPS), or in blood mononuclear cells incubated with rhG-CSF. In addition, radioimmunoassay for human IFN-alpha showed that its levels in culture medium of the rhG-CSF-treated neutrophils rose markedly (up to approximately 100 IU/mL/1 x 10(7) cells) in a time-dependent way, compared with those of nonstimulated neutrophils. These findings suggest that the G-CSF/IFN-alpha system may participate in the feedback regulatory loop of neutropoiesis.
Shirafuji
N
N
Department of Hematology-Oncology, University of Tokyo, Japan.
Matsuda
S
S
Ogura
H
H
Tani
K
K
Kodo
H
H
Ozawa
K
K
Nagata
S
S
Asano
S
S
Takaku
F
F
D015152:Blotting, Northern; D003115:Colony-Stimulating Factors / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D016179:Granulocyte Colony-Stimulating Factor; D006801:Humans; D066298:In Vitro Techniques; D007370:Interferon Type I / Q000096:biosynthesis*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects
D003115:Colony-Stimulating Factors; D007370:Interferon Type I; D012333:RNA, Messenger; D011994:Recombinant Proteins; D016179:Granulocyte Colony-Stimulating Factor; D009240:N-Formylmethionine Leucyl-Phenylalanine