| Research Abstract |
The experiments have been mainly undertaken to examine the effects of IFN and TNF on proliferation and differentiation of leukemia cell lines, and the effects of these cytokines on the activation of human peripheral neutrophils. Results obtained are as follows :
1. The effects of IFN and TNE on proliferation of human leukemia cell lines.
(1) Proliferation of human leukemia cell lines (ML-1, U-937) was inhibited by IFN and TNF.
(2) IFN and TNF induced differentiation of human leukemia cell lines, respectively.
(3) Differentiation of human leukemia cell lines was additively or synergistically induced by combination of TNF and TGF-beta. However, change of TNF receptors was not observed.
(4) In U-937 cells, either TNF and TGF-beta alone decreased myc mRNA expression within one hour. When combined with TGF-beta, TNF additively or synergistically decreased myc mRNA expression.
2. The effects of IFN, IL-1, and TNF on peripheral neutrophil functions. The effects of cytokines (IFN-betaandgamma, IL-1alphaandbeta, IL-2, TNF, G-CSF) on the generation of superoxide (O^-_) of human neutrophils stimulated by PMA or opsonized zymosan were investigated to examine the activation activities of these cytokines.
(1) IFN-gamma, IL-1, TNF and G-CSF enhanced the production of O^-_ form human peripheral neutrophils and INF-gamma was most effective. However, IFN-rho and IL-2 showed no effect.
(2) The mechanism of enhancement of neutrophil functions was investigated by using IFN-gamma as a cytokine and it is suggested that influx of Ca^<++> into cytoplasma may be important to activate neutrophil functions.
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