Identification and characterization of bovine programmed death‐ligand 2 |
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Authors: | Asami Nishimori Satoru Konnai Ryoyo Ikebuchi Tomohiro Okagawa Chie Nakajima Yasuhiko Suzuki Claro N. Mingala Shiro Murata Kazuhiko Ohashi |
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Affiliation: | 1. Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, , Sapporo 060‐0818;2. Research Center for Zoonosis Control, Hokkaido University, , Sapporo 001‐0020, Japan;3. Philippine Carabao Center National Headquarters and Gene Pool, Science City of Munoz, , 3120 Nueva Ecija, Philippines |
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Abstract: | Previous reports from this group have indicated that the immunoinhibitory programmed death (PD)‐1 receptor and its ligand, PD‐L1, are involved in the mechanism of immune evasion of bovine chronic infection. However, no functional analysis of bovine PD‐L2 in cattle has been reported. Thus, in this study, the molecular function of bovine PD‐L2 was analyzed in vitro. Recombinant PD‐L2 (PD‐L2‐Ig), which comprises an extracellular domain of bovine PD‐L2 fused to the Fc portion of rabbit IgG1, was prepared based on the cloned cDNA sequence for bovine PD‐L2. Bovine PD‐L2‐Ig bound to bovine PD‐1‐expressing cells and addition of soluble bovine PD‐1‐Ig clearly inhibited the binding of PD‐L2‐Ig to membrane PD‐1 in a dose‐dependent manner. Cell proliferation and IFN‐γ production were significantly enhanced in the presence of PD‐L2‐Ig in peripheral blood mononuclear cells (PBMCs) from cattle. Moreover, PD‐L2‐Ig significantly enhanced IFN‐γ production from virus envelope peptides‐stimulated PBMCs derived from bovine leukemia virus‐infected cattle. Interestingly, PD‐L2‐Ig‐induced IFN‐γ production was further enhanced by treatment with anti‐bovine PD‐1 antibody. These data suggest potential applications of bovine PD‐L2‐Ig as a therapy for bovine diseases. |
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Keywords: | bovine leukemia virus gamma‐interferon programmed death‐ligand 2 programmed death‐1 |
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