Figure 4. Bioassay for IFN production during TCRV and JUNV infection of primary human monocytes.

IFN-α/β activity in monocyte culture supernatants was detected using a biological assay for protection against vesicular stomatitis virus (VSV) infection and its associated cytopathic effects. For this assay, VeroE6 cells cultured in 12-well plates were treated with supernatants from monocytes infected with either JUNV or TCRV, supernatants from mock infected monocytes or dilutions of a commercial recombinant human IFN-β standard (50 ng/ml to 100 pg/ml). After 24 h the cells were washed and infected with VSV at an MOI of 0.001. Cells were then incubated at 37°C for 18 h before being examined for the formation of CPE.