Development and Characterization of Chicken CD127-Specific Antibodies

Abstract Research in avian immunology has been significantly hampered by lack of effective immunological reagents in birds cross-reactive with mammalian orthologs and lack of sensitive assays for a long time. To better serve the avian immunology community, monoclonal and polyclonal antibodies specific for avian molecules of Clusters of Differentiation (CD) are being developed to promote thorough research on avian infection and immunity. In this study, chicken CD127 antibodies were developed and characterized. CD127, also named interleukin-7 receptor (IL-7R), is expressed on various cell types, including naive and memory T cells as well as many other types of immune cells, and plays a critical role in differentiation and activation of T lymphocytes. An extracellular region of chicken CD127 gene of 678 bp was cloned in pET28a(+) vector and expressed in BL21-AI™ E. coli. The expressed CD127 protein was around 30 kDa and crossed-reacted with monoclonal antibodies specific for human CD127 (Clone G-11). The protein was then immunized in BALB/c mice. After 3 immunizations, murine sera were found to detect a protein of 30 kDa expressed in E. coli, and react to the protein expressed on chicken T cell line (CU205) by flow cytometry as well. Flow cytometric analysis of cells from two-week-old chickens showed that CD127-positive populations were detected in spleen and thymus with such murine sera as polyclonal antibodies, and detected in thymus when using anti-human Clone G-11. Availability of these antibodies for CD127 and other CD molecules will dramatically facilitate the commercialization of poultry immune reagents, greatly benefit the avian immunology community and promote poultry health and production.