IFN gamma and IL-10 production by hepatic lymph node and peripheral blood lymphocytes in Fasciola hepatica infected sheep

The present study was designed to determine whether IFN gamma and IL-10 wer e secreted by peripheral blood mononuclear cells (PBMC) and hepatic lymph n ode mononuclear cells (HLNMC) from 17 Fasciola hepatica infected sheep afte r in vitro stimulation by Fasciola hepatica excretory-secretory products (F hESP) during the first six weeks of two different infections. The IFN gamma concentration in mononuclear cells (MC) culture supernatants was determine d by sandwich ELISA. The presence of IL-10 in MC culture supernatants was d etermined by the capacity of these to inhibit, with or without monoclonal a ntibodies to IL-10, the NO production of recombinant bovine IFN gamma (rBoI FN gamma) activated monocytes. FhESP stimulated PBMC and HLNMC produced IFN gamma in culture supernatants from DPI 7 (day post-infestation 7) to DPI 1 4. (Culture supernatants of PBMC stimulated with FhESP first induced an inc rease in the NO production of rBoIFN gamma activated monocytes. After 2 or 3 weeks of infection, MC culture supernatant reduced the NO production of r BoIFN gamma activated monocytes. From DPI 35, anti-IL-10 antibodies additio n restored or enhanced NO production. During sheep fasciolosis, IFN gamma p roduction increased only until the first two weeks post infection. IL-10 co uld be secreted throughout the first six weeks of infection and could inhib it monocytes from DPI 35.