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The aim of the study was to investigate lipopolysaccharide (LPS)-induced short and long term changes in capacity for intracellular cytokine-production of bovine circulating peripheral blood mononuclear cells (PBMCs). Eight dairy cows each received three intravenous injections of Escherichia coli LPS (10, 100 and 1000 ng/kg, consecutively) at 3 week intervals. Intracellular cytokine production was determined by flow cytometry in PBMCs obtained 0, 2, 6 and 24 h after each LPS challenge. After LPS administration, proportions of monocytes producing tumour necrosis factor (TNF)α, interleukin (IL)-11β and IL-8, as well as proportions of circulating lymphocytes producing interferon (IFN) γ, decreased significantly. Within 24 h, proportions had returned to or increased above pre-injection levels. Proportions of lymphocytes producing IL-4 and IL-10 increased significantly after injection of 1000 ng LPS/kg. This study demonstrated that cytokine profiles shift quickly, but temporarily, to favour the anti-inflammatory response immediately after LPS exposure. The long term response to LPS Was opposite to the immediate response, as cytokine profiles shifted in the 3 weeks between challenges towards a pro-inflammatory response. Proportions of monocytes producing IL-1β and TNFα determined immediately before the second and/or third LPS injection were higher than proportions determined before the first injection, whereas pre-injection proportions of lymphocytes producing IL-4 decreased with each challenge. These changes may result in a quicker host response to invading pathogens. [ABSTRACT FROM AUTHOR]

Eleven monoclonal antibodies specific for ovine, bovine and human cytokines were investigated by flow cytometry for cross-reactivities with cytokines produced by peripheral blood mononuclear cells (PBMCs) from sheep, cattle, goat, swine, horse, dog, mink, rabbit and human. Four antibodies specific for IL-4, IL-8, IFN-γ and TNF-α cross-reacted with cytokines from a majority of the species investigated. These antibodies can be applied to flow cytometric studies of cytokine production by PBMCs from several veterinary species. Another five antibodies specific for IL-2, IL-6, GM-CSF and IFN-γ (two antibodies) cross-reacted weakly and with a variable number of animal species. These antibodies could in certain situations be useful in flow cytometry. In a number of cases the immunological cross-reactivities were confirmed by Western blot analyses. Overall, the results of this study will remedy some of the lack of species-specific anti-cytokine antibodies in veterinary research. [Copyright &y& Elsevier]