In the combat of infectious diseases of livestock success is critically dependent on in-depth knowledge of the factors influencing the host-pathogen relationship.

In the proposed collaborative study a team of 6 research groups (Clinic for Swine, Clinical Immunology, Histology, Medical Chemistry, Parasitology, and Pathology) investigates the host-pathogen interactions in three infection models for pathogens in pigs, i.e. the Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), the intestinal protozoan Isospora suis and the mange mite Sarcoptes scabiei. The aim of this study is to elicit and to compare the immune responses to various pathogens which enter the host via different routes and inhabit different organs, and to characterise mechanisms of defence and tolerance in the host-pathogen interplay.

Pigs are experimentally infected with the respective pathogens and sampled for tissue and organs; parasite and virus material are simultaneously collected and serve as indicators for the infection and as antigen for various immunoassays. Parasite material will be furthermore fractionated and characterised by protein biochemical techniques. Changes of immune cells and their subsets are examined using in situ techniques and flow cytometry (FCM). Changes in cytokine expression patterns are analysed by FCM, ELISA, ELISPOT and RT-PCR. Putative pathogen-specific candidate proteins for immunogenicity or immunomodulation are characterised on molecular level. The study will provide insights in mechanisms of host immunity and pathogen persistence in swine, an animal of many purposes – food, experimental model for humans - but also bearer of zoonotic pathogens that are still a threat to human health.