Tiyamanee Wisa, Konnai Satoru, Okagawa Tomohiro, Nojima Yutaro, Ganbaatar Otgontuya, Maekawa Naoya, Hasebe Rie, Kagawa Yumiko, Kato Yukinari, Suzuki Yasuhiko, Murata Shiro, Ohashi Kazuhiko
Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan; Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan; Institute for Vaccine Research and Development (HU-IVReD), Hokkaido University, Sapporo, Japan.
Vet Immunol Immunopathol. 2023 Jul;261:110609. doi: 10.1016/j.vetimm.2023.110609. Epub 2023 May 11.
Sheep have been used as a large animal experimental model for studying infectious diseases. However, due to a lack of staining antibodies and reagents, immunological studies on sheep have not progressed. The immunoinhibitory receptor programmed death-1 (PD-1) is expressed on T lymphocytes. The interaction of PD-1 with its ligand PD-ligand 1 (PD-L1) delivers inhibitory signals and impairs proliferation, cytokine production, and cytotoxicity of T cells. We previously reported that the PD-1/PD-L1 pathway was closely associated with T-cell exhaustion and disease progression in bovine chronic infections using anti-bovine PD-L1 monoclonal antibodies (mAbs). Furthermore, we found that blocking antibodies against PD-1 and PD-L1 restore T-cell functions and could be used in immunotherapy of cattle. However, the immunological role of the PD-1/PD-L1 pathway in chronic diseases of sheep remains unknown. In this study, we identified cDNA sequences of ovine PD-1 and PD-L1 and examined the cross-activity of anti-bovine PD-L1 mAbs against ovine PD-L1 as well as the expression of PD-L1 in ovine listeriosis. The amino acid sequences of ovine PD-1 and PD-L1 share a high degree of identity and similarity with homologs from ruminants and other mammalian species. Anti-bovine PD-L1 mAb recognized ovine PD-L1 on lymphocytes in the flow cytometric assay. Furthermore, an immunohistochemical staining confirmed the PD-L1 expression on macrophages in the brain lesions of ovine listeriosis. These findings indicated that our anti-PD-L1 mAb would be useful for analyzing the ovine PD-1/PD-L1 pathway. Further research is needed to determine the immunological role of PD-1/PD-L1 in chronic diseases such as BLV infection through experimental infection of sheep.
绵羊已被用作研究传染病的大型动物实验模型。然而，由于缺乏染色抗体和试剂，对绵羊的免疫学研究尚未取得进展。免疫抑制受体程序性死亡-1（PD-1）在T淋巴细胞上表达。PD-1与其配体程序性死亡配体1（PD-L1）的相互作用传递抑制信号，并损害T细胞的增殖、细胞因子产生和细胞毒性。我们之前报道过，使用抗牛PD-L1单克隆抗体（mAb），PD-1/PD-L1通路与牛慢性感染中的T细胞耗竭和疾病进展密切相关。此外，我们发现抗PD-1和PD-L1阻断抗体可恢复T细胞功能，并可用于牛的免疫治疗。然而，PD-1/PD-L1通路在绵羊慢性疾病中的免疫作用仍不清楚。在本研究中，我们鉴定了绵羊PD-1和PD-L1的cDNA序列，检测了抗牛PD-L1 mAb对绵羊PD-L1的交叉活性以及PD-L1在绵羊李斯特菌病中的表达。绵羊PD-1和PD-L1的氨基酸序列与反刍动物和其他哺乳动物物种的同源物具有高度的同一性和相似性。在流式细胞术检测中，抗牛PD-L1 mAb识别淋巴细胞上的绵羊PD-L1。此外，免疫组织化学染色证实了PD-L1在绵羊李斯特菌病脑损伤巨噬细胞上的表达。这些发现表明，我们的抗PD-L1 mAb将有助于分析绵羊的PD-1/PD-L1通路。需要通过绵羊实验感染进一步研究来确定PD-1/PD-L1在慢性疾病如BLV感染中的免疫作用。
