Plant & Animal Genome VI Conference

W57

ANALYSES OF DISEASE RESISTANCE IN PIGS

USDA, ARS, LPSI, IDRL, BARC-East, Building 1040, Room 105, Beltsville, MD 20705, USA

Studies in this laboratory have focused on understanding the genetic basis of disease resistance in pigs, with a focus on resistance to parasitic diseases. Responses of genetically defined pigs to deliberate controlled infections of Trichinella spiralis and Toxoplasma gondii have been followed. Analyses of disease responses have been monitored throughout the infection period and assays have included clinical signs of disease, parasite recovery, anti-parasite antibody levels, cytokine responses and immune cell subset levels in different tissues and in blood. Molecular probes have been developed to assess mRNA levels of the important immune cytokines and monoclonal antibodies to quantitate cytokine protein levels unique and immune cell subsets. Clear evidence of genetic control of anti-Trichinella spiralis responses has been documented and mapped both to the SLA region and to a second gene. For Toxoplasma gondii infections, experimental trials are underway; data collected in the first two trials will be discussed. More recently, studies have been initiated to assess the development of mucosal immune responses in neonatal pigs as a measure of their ability to resist early infectious disease stressors. Cytokine modulation of immune maturation and the genetic basis of cytokine responsiveness will be monitored. Overall, these studies will help identify genes which endow natural disease resistance to specific parasitic infections or which enable neonates to more rapidly resist infectious disease.