1a. Objectives (from AD-416):
Develop immune reagents for veterinary animals of economic importance including cattle, swine, poultry, horses, and aquaculture species.
1b. Approach (from AD-416):
Immune reagents will be developed for basic and applied studies in veterinary animal species. They will be developed into multiplex assays to measure cytokine and chemokine production during infections and host immune responses. As a member of a large consortium grant to develop immunological reagents for five different animal species, we will identify major cytokines and cell surface markers of poultry, express them in suitable expression vectors and validate their function using in vivo and in vitro assay systems.
3. Progress Report:
This agreement was established as a 4-year consortium grant to advance veterinary immunology. The main mission is to develop immunological reagents specific for poultry, ruminants, swine, equine, and aquaculture species. During this reporting period, we have characterized chicken receptor, which binds to interleukin-2 (IL-2). Interleukin-2 is synthesized and secreted mainly by activated T-type lymphocytes and plays a pivotal role in the growth and differentiation of T- and B-type lymphocytes, monocytes, and natural killer cells. Three IL-2 receptor subunits form a trimeric complex consisting of alpha (CD25), beta (CD122), and gamma (CD132) chains. In chickens, limited information exists for CD25, a transmembrane glycoprotein that binds to IL-2 with high affinity and modulates T-cell proliferation. In this reporting period, ARS scientists developed a recombinant plasmid (chCD25/horse immunoglobulin G4) as an immunogen to induce mouse hybridomas to produce monoclonal antibodies against chicken CD25. These monoclonal antibodies detected CD25 cells in chicken tissues such as spleen, bursa, and duodenum, as well as several chicken cell lines, and a 55 kilodalton protein of chicken spleen blast cell. These results show that chCD25 is an important immunological tool for investigating biological functions of chicken regulatory T cells.