An Assessment of the Mechanistic Differences Between Two Integrin α<sub>4</sub>β<sub>1</sub>Inhibitors, the Monoclonal Antibody TA-2 and the Small Molecule BIO5192, in Rat Experimental Autoimmune Encephalomyelitis
作者:D. R. Leone、K. Giza、A. Gill、B. M. Dolinski、W. Yang、S. Perper、D. M. Scott、W.-C. Lee、M. Cornebise、K. Wortham、C. Nickerson-Nutter、L. L. Chen、D. LePage、J. C. Spell、E. T. Whalley、R. C. Petter、S. P. Adams、R. R. Lobb、R. B. Pepinsky
DOI:10.1124/jpet.102.047332
日期:2003.6
Integrin α4β1 plays an important role in inflammatory processes by regulating the migration of lymphocytes into inflamed tissues. Here we evaluated the biochemical, pharmacological, and pharmacodynamic properties and efficacy in experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis, of two types of α4β1 inhibitors, the anti-rat α4 monoclonal antibody TA-2 and the small molecule inhibitor BIO5192 [2( S )-[1-(3,5-dichloro-benzenesulfonyl)-pyrrolidine-2( S )-carbonyl]-amino}-4-[4-methyl-2( S )-(methyl-2-[4-(3- o -tolyl-ureido)-phenyl]-acetyl}-amino)-pentanoylamino]-butyric acid]. TA-2 has been extensively studied in rats and provides a benchmark for assessing function. BIO5192 is a highly selective and potent ( K D of <10 pM) inhibitor of α4β1. Dosing regimens were identified for both inhibitors, which provided full receptor occupancy during the duration of the study. Both inhibitors induced leukocytosis, an effect that was used as a pharmacodynamic marker of activity, and both were efficacious in the EAE model. Treatment with TA-2 caused a decrease in α4 integrin expression on the cell surface, which resulted from internalization of α4 integrin/TA-2 complexes. In contrast, BIO5192 did not modulate cell surface α4β1. Our results with BIO5192 indicate that α4β7 does not play a role in this model and that blockade of α4β1/ligand interactions without down-modulation is sufficient for efficacy in rat EAE. BIO5192 is highly selective and binds with high affinity to α4β1 from four of four species tested. These studies demonstrate that BIO5192, a novel, potent, and selective inhibitor of α4β1 integrin, will be a valuable reagent for assessing α4β1 biology and may provide a new therapeutic for treatment of human inflammatory diseases.
整合素α4β1通过调节淋巴细胞向炎症组织的迁移,在炎症过程中发挥着重要作用。在这里,我们评估了两种α4β1抑制剂的生化、药理和药效学特性,以及它们在多发性硬化症模型--实验性自身免疫性脑脊髓炎(EAE)中的疗效、抗大鼠 α4 单克隆抗体 TA-2 和小分子抑制剂 BIO5192 [2( S )-[1-(3,5- 二氯苯磺酰基)-吡咯烷-2( S )- 甲酰基]-氨基}-4-[4-甲基-2( S )-(甲基-2-[4-(3-邻甲苯基脲基)-苯基]-乙酰基}-氨基)-戊酰氨基]-丁酸]。TA-2 已在大鼠体内进行了广泛研究,为评估功能提供了基准。BIO5192 是一种高选择性、强效(K D <10 pM)的 α4β1 抑制剂。两种抑制剂的给药方案均已确定,可在研究期间提供充分的受体占用。两种抑制剂都能诱导白细胞增多,这种效应被用作活性的药效学标志,而且在EAE模型中都有疗效。用TA-2治疗会导致细胞表面的α4整合素表达减少,这是α4整合素/TA-2复合物内化的结果。相比之下,BIO5192 对细胞表面的 α4β1 没有调节作用。我们对 BIO5192 的研究结果表明,α4β7 在该模型中不起作用,阻断α4β1/配体之间的相互作用而不进行下调足以对大鼠 EAE 产生疗效。BIO5192 具有高度选择性,能与四种受试物种中四种的 α4β1 高度亲和地结合。这些研究表明,BIO5192 是一种新型、强效、选择性的 α4β1 整合素抑制剂,它将成为评估 α4β1 生物学特性的重要试剂,并可能为治疗人类炎症性疾病提供一种新疗法。