Enhancement of reactive oxygen species production from canine blood leukocytes by human recombinant interleukin-12

A novel biological activity of human recombinant interleukin-12 (rhIL-12) on canine peripheral blood mononuclear cells (PBMC) was investigated in vitro. Canine PBMC were cultured in the presence or absence of rhIL-12 for 3 days. The reactive oxygen species (ROS) production induced by opsonized-zymosan (OZ) was then measured by a luminol-dependent chemiluminescense assay and demonstrated that the ROS production was enhanced after culture with rhIL-12. A nitro blue tetrazolium test and flowcytometry analysis revealed that canine lymphocytes, eosinophils, and monocytes were capable of ROS production, but that monocytes had the highest capacity. These results suggest that rhIL-12 enhances ROS production from canine monocytes.