Szymczak Klaudia, Pelletier Margery G H, Mackay James M, Reid DeAnne, Gaines Peter C W
Department of Biological Sciences, Biomedical Engineering and Biotechnology Program, University of Massachusetts Lowell, Lowell, MA 01854, USA.
Aristea Therapeutics, 12770 High Bluff Drive, #380, San Diego, CA 92130, USA.
Biomedicines. 2023 Feb 7;11(2):479. doi: 10.3390/biomedicines11020479.
Neutrophils act as critical mediators of innate immunity, which depends on their rapid responses to chemokines followed by their migration towards sites of infection during chemotaxis. Chemokine receptors expressed on the surface of neutrophils mediate chemotaxis by activating contractile machinery as the cells escape from capillary beds and then attack pathogens. Neutrophils also contribute to inflammatory responses, which support pathogen destruction but can lead to acute and chronic inflammatory disorders. CXCR2, a G-protein-coupled chemokine receptor expressed on both myeloid and epithelial cells, is well-characterized for its capacities to bind multiple chemokines, including interleukin-8 and growth-related oncogene alpha in humans or keratinocyte chemokine (KC) in mice. Here we show that a small molecule CXCR2 antagonist termed RIST4721 can effectively inhibit KC-stimulated chemotaxis by neutrophils derived from ex vivo-cultured mouse bone marrow in a potent and dose-dependent manner. Antagonistic properties of RIST4721 are thoroughly characterized, including the maximal, half-maximal and minimum concentrations required to inhibit chemotaxis. Importantly, RIST4721-treated neutrophils exhibit robust phagocytosis and reactive oxygen species production, confirming drug specificity to chemotaxis inhibition. Together our data indicate that RIST4721 acts to inhibit inflammation mediated and potentiated by neutrophils and therefore promises to facilitate treatment of a host of inflammatory conditions.
中性粒细胞是先天性免疫的关键介质，先天性免疫依赖于它们对趋化因子的快速反应，随后在趋化作用期间向感染部位迁移。中性粒细胞表面表达的趋化因子受体通过激活收缩机制介导趋化作用，使细胞从毛细血管床逸出，然后攻击病原体。中性粒细胞也参与炎症反应，炎症反应有助于病原体的破坏，但可导致急性和慢性炎症性疾病。CXCR2是一种在髓样细胞和上皮细胞上均有表达的G蛋白偶联趋化因子受体，因其能够结合多种趋化因子而被充分表征，这些趋化因子包括人类的白细胞介素-8和生长相关癌基因α或小鼠的角质形成细胞趋化因子（KC）。在此，我们表明一种名为RIST4721的小分子CXCR2拮抗剂能够以有效且剂量依赖性的方式，有效抑制体外培养的小鼠骨髓来源的中性粒细胞对KC刺激的趋化作用。RIST4721的拮抗特性得到了充分表征，包括抑制趋化作用所需的最大、半最大和最小浓度。重要的是，用RIST4721处理的中性粒细胞表现出强大的吞噬作用和活性氧生成，证实了该药物对趋化作用抑制的特异性。我们的数据共同表明，RIST4721的作用是抑制由中性粒细胞介导和增强的炎症，因此有望促进一系列炎症性疾病的治疗。
