ATI-2341, pepducin targeting the C-X-C chemokine receptor type 4 (CXCR4), is an allosteric agonist activating the inhibitory heterotrimeric G protein (Gi) to promote inhibition of cAMP production and induce calcium mobilization.

CXCR4:194 nM(EC50)

ATI-2341能够在表达CXCR4的细胞中引发与CXCR4及G蛋白依赖的信号传导、受体内化和趋化性。它是亲和力较高的激动剂，具有194 ± 16 nM的EC50值和81 ± 4%的内在活性。ATI-2341是一种高效的骨髓PMNs（多形核白细胞）和HSPCs（造血干细胞和前体细胞）动员剂，为HSPCs招募至ABMT（自体骨髓移植）前的治疗方法提供了新的策略。同时，ATI-2341能引起CCRF-CEM细胞的趋化性，产生典型的趋化剂所观察到的钟形曲线[1]。

腹腔内给予BALB/c小鼠ATI-2341（i.p.注射）会引起剂量依赖性的PMNs向腹膜的招募，最大效应出现在405 nmol/kg时。ATI-2341的更高浓度会导致招募减少，这种现象与化学趋化剂通常见到的钟形曲线相似。ATI-2341通过静脉（i.v.）给药后，小鼠外周血液中PMNs的数量呈剂量依赖性增加，在给药后90分钟测量达到最大效应，此时ATI-2341的浓度为0.66 μMol/kg。在所有测试剂量下，ATI-2341对淋巴细胞的动员均无影响[1]。

Receptors(CXCR4-eGFP) are transiently transfected into HEK-293 cells and are plated 24 h after transfection on glass coverslips coated with poly-D-lysine. The next day, cells are treated with either vehicle alone or with varying concentrations of ATI-2341 for 30 min at 37 °C followed by fixation with methanol for 5 min at −20 °C. GFP fluorescence is visualized directly using a Zeiss Axiovert inverted microscope. Images are processed using Adobe Photoshop and Adobe Illustrator. (Only for Reference)