Recombinant human interleukin-4 inhibits the production of granulocyte-macrophage colony stimulating factor by blood mononuclear cells.
The effect of recombinant human (rh) interleukin-4 (rIL-4) on human blood BFU-E was investigated using two populations of cells: platelet-depleted low-density mononuclear cells (FH,Pl- cells), as unpurified cells, and highly purified BFU-E. When FH,Pl- cells were cultured with rh-erythropoietin (rEp), rIL-4 inhibited BFU-E growth in a dose-dependent manner. However, the addition of rIL-4 did not affect rh-interleukin-3 (rIL-3) supported BFU-E growth. Limiting dilution analysis (LDA) of FH,Pl- cells showed that rIL-4 suppressed endogenous production of burst-promoting activity (BPA) by accessory cells. Highly purified BFU-E were used as target cells to measure BPA in the conditioned medium (CM) that was prepared by FH,Pl- cells. When 100 purified BFU-E were cultured in 0.5 ml clots with 20% (vol/vol) of the CM, the number of BFU-E colonies was increased by the CM. The increase was significantly reduced by the addition of the CM prepared in the presence of rIL-4, but anti-IL-4 blocked the effect of rIL-4. The concentration of IL-3 and granulocyte-macrophage colony-stimulating factor (GM-CSF) in CM was determined by an enzyme-linked immunoadsorbent assay (ELISA). The spontaneous production of GM-CSF but not IL-3 was detected, and this was significantly decreased in the presence of rIL-4. Anti-GM-CSF but not anti-IL-3 inhibited CM supported BFU-E growth, indicating that the main BPA in the CM is GM-CSF and that rIL-4 suppresses the spontaneous production of GM-CSF by accessory cells. From these studies, we conclude that rIL-4 has a unique mechanism as a negative regulator on erythropoiesis through the inhibition of BPA production by blood mononuclear accessory cells.
Sato
N
N
Department of Internal Medicine II, Hokkaido University School of Medicine, Japan.
Sawada
K
K
Tarumi
T
T
Koizumi
K
K
Yasukouchi
T
T
Takahashi
T A
TA
Sekiguchi
S
S
Koike
T
T
D000328:Adult; D002455:Cell Division / Q000187:drug effects; D002469:Cell Separation; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D017077:Culture Media, Conditioned; D004305:Dose-Response Relationship, Drug; D015672:Erythroid Precursor Cells / Q000166:cytology / Q000187:drug effects*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis* / Q000097:blood / Q000494:pharmacology; D006801:Humans; D007377:Interleukin-3 / Q000096:biosynthesis / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology*; D007963:Leukocytes, Mononuclear / Q000187:drug effects; D011994:Recombinant Proteins / Q000494:pharmacology
D017077:Culture Media, Conditioned; D007377:Interleukin-3; D011994:Recombinant Proteins; D015847:Interleukin-4; D016178:Granulocyte-Macrophage Colony-Stimulating Factor