The ability to detect the presence of and quantify the inflammatory response in marine mammal species would be diagnostically useful in captive, rehabilitation and field situations. This report describes two assays currently under development to measure the acute phase response in marine mammals using specific reagents generated for interleukin 6 (IL-6) and C-reactive protein (C-RP).

IL-6, described in a number of mammalian species, is a multi-functional soluble cytokine (hormone of the immune system) exhibiting pivotal activities controlling the inflammatory and associated acute phase protein response. Unlike many other cytokines that exert their influence at the local cellular level, IL-6 has systemic activity. Elevated serum concentrations of IL-6 can be detected using bioassay, in harbor seal and killer whale serum, from animals exhibiting various inflammatory conditions. Initial work focusing on the genetic cloning of harbor seal (Phoca vitulina), killer whale (Orcinus orca) and sea otter (Enhydra lutris nereis) cDNA sequences suggests that IL-6 is a well conserved molecule between mammalian species. Expression of these cloned genes is currently underway for the production of species-specific antibodies, reagents, and development of immunoassays.

C-reactive protein (C-RP) is an important liver-derived acute-phase protein found in serum. Rapid increases in serum concentrations (ranging from 5-200 mg/L) can be correlated with a variety of inflammatory conditions in many different mammalian species. Harbor seal C-RP has been purified from acute phase serum by phosphoryl-choline and protein A affinity chromatography. Sequencing of an internal amino acid peptide of this purified protein demonstrates a high homology with human and murine C­RP. Using a panel of specific monoclonal antibodies against this protein work is currently underway to establish a sensitive capture immuno-assay for serum C-RP for routine diagnostic use.