Gladue Ronald P, Cole Susan H, Roach Marsha L, Tylaska Laurie A, Nelson Robin T, Shepard Richard M, McNeish John D, Ogborne Kevin T, Neote Kuldeep S
Pfizer Global Research and Development, Department of Immunology, Groton, CT 06340, USA.
J Immunol. 2006 Mar 1;176(5):3141-8. doi: 10.4049/jimmunol.176.5.3141.
We previously described the in vitro characteristics of the potent and selective CCR1 antagonist, CP-481,715. In addition to being selective for CCR1 vs other chemokine receptors, CP-481,715 is also specific for human CCR1 (hCCR1), preventing its evaluation in classical animal models. To address this, we generated mice whereby murine CCR1 was replaced by hCCR1 (knockin) and used these animals to assess the anti-inflammatory properties of CP-481,715. Cells isolated from hCCR1 knockin mice were shown to express hCCR1 and migrate in response to both murine CCR1 and hCCR1 ligands. Furthermore, this migration is inhibited by CP-481,715 at dose levels comparable to those obtained with human cells. In animal models of cell infiltration, CP-481,715 inhibited CCL3-induced neutrophil infiltration into skin or into an air pouch with an ED50 of 0.2 mg/kg. CP-481,715 did not inhibit cell infiltration in wild-type animals expressing murine CCR1. In a more generalized model of inflammation, delayed-type hypersensitivity, CP-481,715 significantly inhibited footpad swelling and decreased the amount of IFN-gamma and IL-2 produced by isolated spleen cells from sensitized animals. It did not, however, induce tolerance to a subsequent challenge. These studies illustrate the utility of hCCR1 knockin animals to assess the activity of human specific CCR1 antagonists; demonstrate the ability of the CCR1 antagonist CP-481,715 to inhibit cell infiltration, inflammation, and Th1 cytokine responses in these animals; and suggest that CP-481,715 may be useful to modulate inflammatory responses in human disease.
我们之前描述了强效选择性CCR1拮抗剂CP-481,715的体外特性。除了对CCR1相对于其他趋化因子受体具有选择性外，CP-481,715对人CCR1（hCCR1）也具有特异性，这使得其无法在经典动物模型中进行评估。为了解决这个问题，我们培育出了将小鼠CCR1替换为人CCR1的小鼠（基因敲入小鼠），并利用这些动物评估CP-481,715的抗炎特性。从hCCR1基因敲入小鼠分离出的细胞显示表达hCCR1，并对小鼠CCR1和hCCR1配体均有迁移反应。此外，CP-481,715在与用人细胞获得的剂量水平相当的情况下可抑制这种迁移。在细胞浸润的动物模型中，CP-481,715抑制CCL3诱导的中性粒细胞浸润到皮肤或气袋中，半数有效剂量（ED50）为0.2mg/kg。CP-481,715在表达小鼠CCR1的野生型动物中不抑制细胞浸润。在更广泛的炎症模型即迟发型超敏反应中，CP-481,715显著抑制足垫肿胀，并减少致敏动物分离的脾细胞产生的IFN-γ和IL-2量。然而，它并未诱导对后续攻击的耐受性。这些研究说明了hCCR1基因敲入动物在评估人特异性CCR1拮抗剂活性方面的实用性；证明了CCR1拮抗剂CP-481,715在这些动物中抑制细胞浸润、炎症和Th1细胞因子反应的能力；并表明CP-481,715可能有助于调节人类疾病中的炎症反应。
