although biologically active interferon was not detected in the nutrient medium of macrophage cultures , freshly harvested peritoneal cells could confer an antiviral state on monolayer cultures of mouse cells ( aged macrophages , embryonic fibroblasts , and l cells ) but not on heterologous chicken embryo , rabbit kidney , or human cells infected with vesicular stomatitis virus or encephalomyocarditis virus .
C0007634
cells
C0016030
fibroblasts