Detecting wildlife orthologues for tumor necrosis factor (TNF) and interleukin-6 (IL-6)

Detection and quantification of cytokines is important to better understand disease processes in populations. This study assessed the feasibility of quantifying wildlife orthologues for tumor necrosis factor (TNF) and interleukin-6 (IL-6) using two bioassays combined with an in vitro model for immune stimulation. For all species, heparinized blood (1 ml) was exposed to lipopolysaccharide (LPS; 10 pg to 50 mug) for 6 hr (37 degreesC) after which plasma was collected. Neutralizing antibodies were used to demonstrate that grizzly bear (Ursus arctos) TNF can be quantified with a WEHI-164 bioassay, and expression of TNF in the LPS stimulated model is dose-dependent. A B9 bioassay demonstrated LPS-dose-dependent production of IL-6 for grizzly bears, although neutralizing antibodies were not available to confirm that IL-6 was responsible for these results. The B9 assay may have detected IL-6 orthologues for bighorn sheep (Ovis canadensis canadensis), elk (Cervus elaphus) and bison (Bison bison). These assays combined with the LPS stimulated blood model could provide a rapid means for assessing immunological effects of pathogens and toxicants.