Colony promoting activity: differences from interleukin-3 and similarities to interleukin-6.
The supernatant of long-term bone marrow culture contains colony promoting activity (CPA) which does not have granulocyte-macrophage colony stimulating activity (CSF) but which enhances granulocyte-macrophage (GM) colony formation in the presence of CSF. CPA might consist of IL-3 or IL-3-like activity, since CPA stimulates proliferation and differentiation of more immature cells to CSF-responding granulocytes-macrophage progenitors (GM-CFC), and since IL-3 also stimulates immature hemopoietic cells to proliferate and differentiate to functional blood cells. IL-1 and IL-6 are also known to enhance GM colony formation. One or both of these molecules can accordingly be another candidate for CPA. In the present study, GM-CSF activity of IL-3 was dependent on the batch of serum: it was negative in the presence of fetal calf serum, but positive in the presence of horse serum. In contrast, GM-CSF and CPA showed no such dependence on the batch of serum. The addition of IL-3 to GM colony assay system did not enhance but rather suppressed GM colony formation. The supernatant of long-term bone marrow culture which contains substantial levels of CPA did not stimulate proliferation of IL-3 dependent DA-1 cells, but facilitated the proliferation of IL-6 dependent, MH60.BSF2 cells. No detectable level of IL-1 activity was found in the supernatant. These results indicate that CPA is different from IL-1, IL-3 or GM-CSF, but similar to or the same as IL-6.
Sugimoto
K
K
Department of Biology, Faculty of Science, Niigata University, Japan.
Shirata
K
K
Kadowaki
S
S
Tsuboi
I
I
Morimoto
K
K
Sawada
S
S
Mori
K J
KJ
D000818:Animals; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D003115:Colony-Stimulating Factors / Q000494:pharmacology; D006098:Granulocytes / Q000187:drug effects; D006801:Humans; D007377:Interleukin-3 / Q000494:pharmacology*; D015850:Interleukin-6 / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects
D003115:Colony-Stimulating Factors; D007377:Interleukin-3; D015850:Interleukin-6