Reduce transmission of foodborne pathogens of swine: 1) define cytokine- regulated immune mechanisms that protect pigs against parasites that threaten food safety; 2) study parasite proteases and other secreted products as regulators of host immunity and pathology; 3) identify DNA sequences for diagnosis and for expression of specific and shared antigens for a broad spectrum anti-worm vaccine.
Immunologic studies will define local and systemic type 1 and type 2 immune responses in swine to parasitic organisms through bioassays for cytokines that affect immune and inflammatory processes; measurement of cytokine gene expression; quantitate antibody secreting cells; characterize effector cell populations; screen T-cell lines for parasite reactivity. The role of specific parasite proteases will be examined using purified and recombinant Trichuris suis metalloprotease as an immungen and cell activator in vitro and in vivo. Antigens shared by several economically important worm parasites of swine will be isolated from excretory/secretory products and cryptic sites on parasite intestinal membranes and evaluated as a broad spectrum vaccine against gastrointestinal parasites using novel immunization strategies. Recombinant DNA probes for multicopy gene families or intergenic DNA sequences will detect differences among closely related Trichinella. Beltsville, MD B-1041, B-1180. BL-exempt 3/28/91.