Signalling lymphocyte activation molecule family member 9 (SLAMF9) is an orphan receptor of the CD2/SLAM family of leucocyte surface proteins. Examination of SLAMF9 expression and function indicates that SLAMF9 promotes inflammation by specialized subsets of antigen‐presenting cells. Within healthy liver and circulating mouse peripheral blood mononuclear cells, SLAMF9 is expressed on CD11b⁺, Ly6C⁻, CD11c^low, F4/80^low, MHC‐II⁺, CX₃CR1⁺ mononuclear phagocytes as well as plasmacytoid dendritic cells. In addition, SLAMF9 can be found on peritoneal B1 cells and small (F4/80^low), but not large (F4/80^high), peritoneal macrophages. Upon systemic challenge with Salmonella enterica Typhimurium, Slamf9^−/− mice were impaired in their ability to clear the infection from the liver. In humans, SLAMF9 is up‐regulated upon differentiation of monocytes into macrophages, and lipopolysaccharide stimulation of PMA‐differentiated, SLAMF9 knockdown THP‐1 cells showed an essential role of SLAMF9 in production of granulocyte–macrophage colony‐stimulating factor, tumour necrosis factor‐α, and interleukin‐1β. Taken together, these data implicate SLAMF9 in the initiation of inflammation and clearance of bacterial infection.

中文翻译：

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信号淋巴细胞活化分子家族成员 9 存在于抗原呈递细胞的选定亚群中，可促进对沙门氏菌感染的抵抗力。

信号淋巴细胞活化分子家族成员 9 (SLAMF9) 是白细胞表面蛋白 CD2/SLAM 家族的孤儿受体。对 SLAMF9 表达和功能的检查表明，SLAMF9 通过专门的抗原呈递细胞亚群促进炎症。在健康的肝脏和循环的小鼠外周血单核细胞中，SLAMF9 在 CD11b ⁺、Ly6C ^-、CD11c^低、F4/80^低、MHC-II ⁺、CX ₃ CR1 ⁺单核吞噬细胞以及浆细胞样树突状细胞上表达。此外，SLAMF9 可以在腹膜 B1 细胞上发现并且很小（F4​​/80^低），但不大（F4/80^高)、腹腔巨噬细胞。在用鼠伤寒沙门氏菌进行全身性攻击后，Slamf9 ^-/-小鼠清除肝脏感染的能力受损。在人类中，SLAMF9 在单核细胞分化为巨噬细胞时上调，脂多糖刺激 PMA 分化的 SLAMF9 敲低 THP-1 细胞显示 SLAMF9 在粒细胞-巨噬细胞集落刺激因子、肿瘤坏死因子- α和白细胞介素-1 β。总之，这些数据表明 SLAMF9 与炎症的起始和细菌感染的清除有关。