HUMORAL AND CELLULAR IMMUNE-RESPONSES TO EXPERIMENTAL FASCIOLA-HEPATICA INFECTIONS IN GOATS

Humoral and cellular immune responses to Fasciola hepatica excretory-s ecretory products (ESPs) in primary and secondary experimental infecti ons in goats were studied. Primary infection induced the development o f chronic subclinical fascioliasis that did not affect the establishme nt of flukes coming from the secondary infection, as the same percenta ges of recovered flukes were found in both groups. The specific IgG re sponse to F. hepatica ESPs was similar in primary and secondary infect ions: challenge flukes did not induce ally modification in the Ige res ponse, The specific lymphocyte response to F. hepatica ESPs was absent in most of the infected goats. both primarily and secondarily infecte d. A modulation of the nonspecific cellular responses to mitogens was also observed. All infected goats showed a reduced proliferative respo nse to concanavalin A and phytohemagglutinin. According to our results , humoral and cellular responses to F. hepatica ESPs in gents have no protective effect on the establishment of flukes and the development o f disease in either primary or secondary infections.