Enhancing effects of IL-2 on M-CSF production by human peripheral blood monocytes.
Monocytes have the capacity to produce granulopoietic factors such as M-CSF and G-CSF. Our findings here showed that interleukin-2 (IL-2), at a concentration of more than 0.05 ng/ml, led to a 12-fold increase in the production of M-CSF in the human peripheral blood mononuclear cells after 72 h incubation compared to the control culture. Even in purified monocyte cultures with added IL-2, a 3-fold increase in M-CSF production was observed at an IL-2 concentration of 50 ng/ml. The enhancing effect of IL-2 on M-CSF secretion was also observed when IL-2-stimulated non-phagocytic cell-conditioned medium was added to monocyte cultures. These results indicated that IL-2, both directly and indirectly, activated monocytes to enhance the production of M-CSF. In addition, the expression of IL-2 receptor (CD25) on monocytes was more enhanced in cultures containing IL-2 than in cultures without IL-2. On the other hand, IL-2 did not induce G-CSF production in purified monocytes. These in vitro results suggest that when IL-2 is used clinically, the various biological activities of M-CSF should also be taken into consideration.
Misago
M
M
First Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
Tsukada
J
J
Ogawa
R
R
Kikuchi
M
M
Hanamura
T
T
Chiba
S
S
Oda
S
S
Morimoto
I
I
Eto
S
S
D002478:Cells, Cultured; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology*; D016173:Macrophage Colony-Stimulating Factor / Q000096:biosynthesis*; D009000:Monocytes / Q000378:metabolism*; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology
D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins; D016173:Macrophage Colony-Stimulating Factor