Abstract
Carboxyethylgermanium sesquioxide, Ge-132 was investigated for its effect on the expression of HLA-DR ant·pens or IgG-Fc receptors (FcRl) on human peripheral blood monocytes and a human myelogenous leukemia cell line U937 in culture. Ge-132, when added in the cultures of either purified peripheral monocytes or U937 cells, did not produce any significant effect on expression of either HLA-DR antigens or FcRl on the cell. The peripheral blood mononuclear cells (PBMC) when being incubated with Ge-132 (800μg/ml), however, produced a factor inducing augmentation of HLA-DR and FcR expression on the monocytes or U937. Pretreatment of this PBMC culture fluid with pH2.0 or specific antiserum against human interferon γ (IFNγ) resulted in a marked reduction of both HLA-DR and FcR-inducing activities, suggesting that a major factor induced by Ge-132 in the PBMC may be IFNγ. These results indicate that Ge-132 stimulates PBMC to produce a soluble factor (IFNγ), which in turn augments the expression of HLA-DR antigens and FcRl on the cell of myelogenous or macrophage series.
