The effect of Sendai virus infection using 2 concentrations on U937 cells

Sendai virus is a potent inducer of type I interferons in human cells. Type I interferons consist of 13 different IFN alpha genes and 1 IFN beta gene. Each of these subtypes have differing functional activites depending on the infecting virus and cell. However, the exact signaling pathways that lead to the induction of individual type I IFN subtypes are not known. We have found that inefction with 2 different concentrations of Sendai virus in the human monocytoid cell line U937 results in 2 distinct profiles of type I IFN subtypes. In other words, inefction with a high concentration of virus results in the induction of a certain subset of subtypes, while infection with a lower concetration results in the induction of a different subset of subtypes We therefore wanted to determine which signaling pathways were activated during infection with these 2 different virus concentrations in order to see which signaling pathways may be involved in the induction of individual type I IFN subtypes. We also wanted to determine if the existence of different type I IFN subtype profiles resulted in different profiles of interferon stimulated genes. We therefore performed microarray analysis on U937 cells that were uninfected or infected with either 150 or 1.5 HA units/mL of SeV for 24 hours. U937 cells were uninfected or infected with either 1.5 or 150 HA u/mL of SeV (corresponding to MOIs of 0.0002 and 0.02, respectively) for 24 h. RNA was isolated and microarray was performed.