EFFECT OF DIET ON IMMUNE AND PHYSIOLOGICAL CHANGES BY INFECTION, INFLAMMATON, AND ALLERGENS
Diet, Genomics and Immunology Lab
2012 Annual Report
1a.Objectives (from AD-416):
ARS is interested in determining the impact of health-promoting components in foods including those containing probiotic bacteria, and how allergens and infections alter intestinal immunity and physiology. Our project plan has two objectives that directly relate to this agreement: Objective 2: To elucidate the mechanisms used by probiotic bacteria to improve respiratory and intestinal mucosal responses to allergens, and correlate intestinal microflora composition of pigs and humans with biomarkers of allergic and intestinal disease, and Objective 3: To elucidate the mechanisms by which micronutrients affect gut physiology and immune competence in response to food-borne illness due to viruses, bacteria, and gastrointestinal parasites. The COOPERATOR directs a laboratory that has supported ARS activities to evaluate mucosal responses to pathogens and allergens. A formal agreement to expand the interaction can facilitate the objectives of the project and support from external funds.
1b.Approach (from AD-416):
Experimental mouse and swine models of viral, bacterial, and parasitic infection as well as exposure to allergens will be evaluated for changes in immune and physiological responses at mucosal surfaces. This information will be used by both ARS and the COOPERATOR to jointly develop new research studies that focus on the evaluation of dietary and probiotic intervention to prevent the onset of inflammation and dysfunction, and enhance healthy mucosal surfaces.
This is a long standing and productive interaction that has been expanded to include two graduate students from the Cooperator that are collaborating on PhD dissertation projects. In one case, a serine protease has been identified, isolated, and sequenced to show unique homology between several different parasitic worms. The functional activity of this protease is similar to trypsin and it activates protease-activated receptor-2 in the small intestine that appears to induce host changes in intestinal physiology and immune induction. In a second project, parasite-induced changes in intestinal smooth muscle hyper-contractility and hypertrophy were blocked in the absence of the IL-13 receptor alpha 1 component of the IL-13 receptor. Mucosal permeability was also blocked although mucosal mast cells were in abundance. This work is important in the understanding of the regulation of intestinal immune and physiological changes both in healthy conditions and in response to infection. Scientific discussion on the project is part of student graduate committee meetings and routine visits to the laboratory of the host and Cooperator.