Napier Carolyn, Sale Harriet, Mosley Michael, Rickett Graham, Dorr Pat, Mansfield Roy, Holbrook Mark
Discovery Biology, Pfizer Global Research and Development, Sandwich Laboratories, Sandwich, Kent. CT13 9NJ UK.
Biochem Pharmacol. 2005 Dec 19;71(1-2):163-72. doi: 10.1016/j.bcp.2005.10.024. Epub 2005 Nov 18.
The aim of this study was to determine if macaque represents a suitable species for the pre-clinical evaluation of novel CCR5 antagonists, such as maraviroc (UK-427,857). To do this we cloned and expressed CCR5 from rhesus macaque and compared the binding properties of [125I]-MIP-1beta and [3H]-maraviroc with human recombinant CCR5. [125I]-MIP-1beta bound with similar high affinity to CCR5 from macaque (K(d) = 0.24 +/- 0.05 nM) and human (K(d) = 0.23 +/- 0.05 nM) and with similar kinetic properties. In competition binding studies the affinity of a range of human chemokines for macaque CCR5 was also similar to human CCR5. Maraviroc inhibited binding of [125I]-MIP-1beta to CCR5 from macaque and human with similar potency (IC50 = 17.50 +/- 1.24 nM and 7.18 +/- 0.93 nM, respectively) and antagonised MIP-1beta induced intracellular calcium release mediated through CCR5 from macaque and human with similar potency (IC50 = 17.50 +/- 3.30 nM and 12.07 +/- 1.89, respectively). [3H]-maraviroc bound with high affinity to CCR5 from macaque (K(d) = 1.36+/-0.07 nM) and human (K(d) = 0.86 +/- 0.08 nM), but was found to dissociate approximately 10-fold more quickly from macaque CCR5. However, as with the human receptor, maraviroc was shown to be a high affinity, potent functional antagonist of macaque CCR5 thereby indicating that the macaque should be a suitable species in which to evaluate the pharmacology, safety and potential mechanism-related toxicology of novel CCR5 antagonists.
本研究的目的是确定猕猴是否是新型CCR5拮抗剂（如马拉维若（UK-427,857））临床前评估的合适物种。为此，我们克隆并表达了恒河猴的CCR5，并比较了[125I]-MIP-1β和[3H]-马拉维若与人重组CCR5的结合特性。[125I]-MIP-1β与猕猴CCR5（K(d)=0.24±0.05 nM）和人CCR5（K(d)=0.23±0.05 nM）以相似的高亲和力结合，且动力学特性相似。在竞争结合研究中，一系列人类趋化因子对猕猴CCR5的亲和力也与人CCR5相似。马拉维若抑制[125I]-MIP-1β与猕猴和人CCR5结合的效力相似（IC50分别为17.50±1.24 nM和7.18±0.93 nM），并以相似的效力拮抗MIP-1β诱导的通过猕猴和人CCR5介导的细胞内钙释放（IC50分别为17.50±3.30 nM和12.07±1.89）。[3H]-马拉维若与猕猴CCR5（K(d)=1.36±0.07 nM）和人CCR5（K(d)=0.86±0.08 nM）以高亲和力结合，但发现其从猕猴CCR5上解离的速度约快10倍。然而，与人类受体一样，马拉维若被证明是猕猴CCR5的高亲和力、强效功能性拮抗剂，从而表明猕猴应该是评估新型CCR5拮抗剂的药理学、安全性和潜在机制相关毒理学的合适物种。
