Abstract
Adenosine is a well described anti-inflammatory modulator of immune responses. The aim of the present study was to describe the role of common adenosine agonist 5'-N-ethylcarboxamidoadenosine (NECA) in cytokine production by main porcine T cell subpopulations.
TNF-alpha, IFN-gamma, IL-2 and IL-10 were detected by multicolor flow cytometry together with cell surface markers CD3, CD4 and CD8. It was found that NECA inhibits (in a dose-dependent manner) production of pro-inflammatory TNF-alpha and Th1-associated cytokines IFN-gamma, IL-2 in all concanavalin A-stimulated T cell subpopulations.
Moreover, production of IL-10 was potentiated in all T cell subpopulations tested. These corresponded well with the fact that all T cell subsets expressed mRNA for adenosine receptor (AR) subtypes to comparable extents.
Contrary to concanavalin A-stimulated cells, NECA had a moderate effect on PMA-stimulated T cells, suggesting that AR in pigs acts via signaling pathways not associated with protein-kinase C. Non-selective antagonist CGS15943 as well as allosteric modulator SCH202676 failed to reverse the effect of NECA in pigs.
In conclusion, NECA has an anti-inflammatory effect on porcine T cell subpopulations.