Elevated Interferon Alpha in the Serum of Laboratory Strains of Mice and Porcine Serum by ELISA

Abstract We examined Interferon (IFN)-Alpha and -Beta levels in pooled sera and individual bleeds from C57/Bl, Balb/C and CD-1 mice. 20 Individuals from each strain from two independent colonies were evaluated in commercial assays. The IFN-Beta ELISA detected IFN in 1 of the 60 individuals while the IFN-Alpha assay which detects all 14 subtypes measured IFN in 13 of 60. 5 individuals exhibited greater than 4 pg/ml of IFN-Alpha detected. Specificity was demonstrated by knockdown of the signal using non-biotinylated detection antibody. 14 of 54 porcine sera samples from 4 independent sources were positive for IFN alpha by an ELISA under development, and similar knock-down experiments suggest specificity. This is in contrast to human sera/plasma samples where less than 3% of healthy donor samples have quantifiable IFN-Alpha or -Beta above 0.5 pg/ml. This study may raise questions about the regulation of the IFN system in different species and the potential of these differences to affect experimental results in a variety of models.