Project Number: 8042-32000-107-00-D
Project Type: In-House Appropriated
Start Date: Oct 13, 2016
End Date: Oct 12, 2021
Necrotic enteritis (NE) and coccidiosis are considered the most important enteric diseases impacting poultry production in the U.S. and Europe. With increasing regulation on the use of antibiotics to control infectious diseases and as growth promoters, the incidence of clostridial infections has been rising. This project will focus on developing new poultry immune reagents and immunoassays to promote progress in poultry disease research, and to understand the immunobiology of host-pathogen interactions for developing mitigation strategies for coccidiosis and NE. Specifically, synergistic, non-antibiotic-based strategies will be developed that promote host innate immunity and induce innate effector molecules, thereby decreasing commercial antibiotic usage in the field. In our previous research projects, we developed a unique Clostridium perfringens/Eimeria co-infection model system, and identified a heightened proinflammatory response as a major factor in NE-induced intestinal immunopathology. Furthermore, we identified several plant products and host-derived antimicrobial peptides (AMPs), each of which reduced inflammation-mediated gut damage, activated poultry innate immune responses, and exerted direct cytotoxic activity against C. perfringens and Eimeria. Herein, we propose continued development of critical immune reagents and immunoassays for poultry species and disease research to: use them to better understand the host-pathogen immunobiology of coccidiosis and NE, develop sustainable antibiotic-free alternative strategies to reduce economic losses due to coccidiosis and NE, and enhance the overall gut health of commercial poultry. Objective 1. Develop immunologic tools to evaluate avian immunity including tools to detect host effector molecules associated with immune responses to enteric diseases, and tools to determine the role of host effector molecules in disease resistance to enteric diseases of poultry. [C5, PS5C] We will continue to develop new immunologic tools to evaluate avian immunity, including the next-generation of tools to detect host effector molecules associated with immune responses to enteric diseases, and to determine the role of these effector molecules in avian resistance to enteric diseases. This objective is highly relevant to the current state-of-the-art in poultry research which suffers from a critical shortage of immune reagents and methodologies to evaluate host-pathogen interactions and where traditional vaccines are not effective. Objective 2. Develop alternatives to antibiotics for preventing or treating enteric diseases of poultry including discovering vaccine platforms that could reduce the use of antibiotics in poultry production, and develop non-antibiotic approaches for treating priority enteric diseases of poultry. [C2, PS2B] We will identify additional, non-antibiotic-based immunotherapeutics to 1) reduce the harmful inflammatory response and associated collateral intestinal damage that develop during coccidiosis and NE, 2) activate broad spectrum innate immune responses, and 3) directly target the viability of C. perfringens and Eimeria pathogens.
Develop immune reagents (genes, recombinant cytokines, mAbs) and immunoassays for Th1, Th2, Th17 and Treg immune responses for the investigation of host-pathogen interaction on the gut mucosa in avian coccidiosis and NE. Develop novel strategies to immunomodulate innate host response. Identify potential biomarkers of gut health and assess the levels of gut health biomarkers in vivo. Develop antibiotic alternative strategies including recombinant vaccines and passive immunization methods.