Location: Animal Parasitic Diseases Laboratory
Project Number: 8042-32000-094-00-D
Project Type: Appropriated
Start Date: Nov 17, 2011
End Date: Nov 16, 2016
Objective 1: Determine the immune relationship between parasites and the mucosal immune response concentrating on epigenetic targets and the innate immune system. The goal of the proposed research project is to evaluate the influence of parasitic infection during gestation and in the pre-weaning period on mucosal macrophages and to explore dietary effects that regulate mucosal immune responses in pigs. Objective 2: Evaluate the ability of nutritional supplements and pathogen-associated molecules in modulating the immune response. Macrophages and related dendritic cells at mucosal surfaces provide the first line of defense as they respond to pathogen-associated molecular pattern (PAMP) molecules that bind toll-like receptors (TLRs) and trigger innate immune responses that link them to components of acquired immunity. They also respond to danger-associated molecular pattern (DAMP) molecules that trigger responses to cell injury and inflammation. The inherent potential of molecules from the parasite to modulate immune function to secure the parasitic relationship with the host may be met by nutritional conditions that influence host immunity. This objective will begin to evaluate these features of macrophage biology as they contribute to resistance to parasitic infection and the influence of nutrients on this process.
The approach for Objective 1 is to determine the immune relationship between parasites and the mucosal immune response concentrating on epigenetic targets and the innate immune system. Stimulation of primary pig alveolar macrophages (AM) by all-trans retinoic acid (ATRA), parasites, or parasite-derived products in vitro will provide information on transcriptomic markers and epigenetic sites to evaluate in later in vivo-treatment studies of pigs given ATRA and infected with Ascaris suum. Exposure of sows during gestation and neonates during the first 21 days of life to ATRA or infection with A. suum will polarize pig AM and imprint epigenetic traits that influence functional activity at mucosal surfaces. The approach used for Objective 2 is to evaluate the ability of nutritional supplements and pathogen-associated molecules in modulating the immune response. The aim is to identify parasite-derived nucleotide metabolizing enzymes, and in particular apyrases, that may control local inflammatory responses by modulating ATP levels in surrounding tissues. The AM will be used as a functional readout cell for parasite products and metabolites derived from parasite enzymatic activity. ATRA acting as a supplemental nutrient in the presence of adenosine will modulate adenosine receptor signaling of primary pig AM leading to synergistic effects on macrophage function, cytokine production, and gene expression. The study is designed to determine if ATRA co-stimulation with adenosine alters pig AM function in vitro.