Calcium and the Production of Interferon by Human Peripheral Blood Mononuclear Cells

We have studied the ability of human peripheral blood mononuclear cells (PBMC) to produce interferon-α (IFN-α) and IFN-γ in the presence of pharmacologic agents known to influence calcium transport or calcium-dependent processes. We have found that the production of human (Hu) IFN-γ is affected significantly by alterations in calcium flux; however, this influence is dependent upon the nature of the compound used to induce IFN. Inhibitors of protein kinase C decreased yields of IFN-7 but inhibition of calmodulin did not. The presence of vitamin D3 reduced IFN-7 titers when PHA and IL-2 were used to induce IFN, but not when ionomycin was used as the inducer. The production of IFN-γ by PBMC was reduced by diminished concentrations in extracellular calcium but not extracellular magnesium. In contrast, neither the presence of any of the pharmacological agents tested above nor the reduction of the calcium concentration influenced the production of HuIFN-γ by PBMC.