Gaertner Hubert, Cerini Fabrice, Escola Jean-Michel, Kuenzi Gabriel, Melotti Astrid, Offord Robin, Rossitto-Borlat Irène, Nedellec Rebecca, Salkowitz Janelle, Gorochov Guy, Mosier Donald, Hartley Oliver
Department of Structural Biology and Bioinformatics, Faculty of Medicine, University of Geneva, 1 Rue Michel Servet, 1211 Geneva 4, Switzerland.
Proc Natl Acad Sci U S A. 2008 Nov 18;105(46):17706-11. doi: 10.1073/pnas.0805098105. Epub 2008 Nov 12.
New prevention strategies for use in developing countries are urgently needed to curb the worldwide HIV/AIDS epidemic. The N-terminally modified chemokine PSC-RANTES is a highly potent entry inhibitor against R5-tropic HIV-1 strains, with an inhibitory mechanism involving long-term intracellular sequestration of the HIV coreceptor, CCR5. PSC-RANTES is fully protective when applied topically in a macaque model of vaginal HIV transmission, but it has 2 potential disadvantages related to further development: the requirement for chemical synthesis adds to production costs, and its strong CCR5 agonist activity might induce local inflammation. It would thus be preferable to find a recombinant analogue that retained the high potency of PSC-RANTES but lacked its agonist activity. Using a strategy based on phage display, we set out to discover PSC-RANTES analogs that contain only natural amino acids. We sought molecules that retain the potency and inhibitory mechanism of PSC-RANTES, while trying to reduce CCR5 signaling to as low a level as possible. We identified 3 analogues, all of which exhibit in vitro potency against HIV-1 comparable to that of PSC-RANTES. The first, 6P4-RANTES, resembles PSC-RANTES in that it is a strong agonist that induces prolonged intracellular sequestration of CCR5. The second, 5P12-RANTES, has no detectable G protein-linked signaling activity and does not bring about receptor sequestration. The third, 5P14-RANTES, induces significant levels of CCR5 internalization without detectable G protein-linked signaling activity. These 3 molecules represent promising candidates for further development as topical HIV prevention strategies.
迫切需要新的预防策略用于发展中国家，以遏制全球范围内的艾滋病毒/艾滋病流行。N端修饰的趋化因子PSC-RANTES是一种针对R5嗜性HIV-1毒株的高效进入抑制剂，其抑制机制涉及HIV共受体CCR5的长期细胞内隔离。在阴道HIV传播的猕猴模型中局部应用时，PSC-RANTES具有完全的保护作用，但在进一步开发方面有两个潜在缺点：化学合成的要求增加了生产成本，且其强大的CCR5激动剂活性可能会诱发局部炎症。因此，找到一种保留PSC-RANTES高效性但缺乏其激动剂活性的重组类似物会更好。我们采用基于噬菌体展示的策略，着手发现仅包含天然氨基酸的PSC-RANTES类似物。我们寻找保留PSC-RANTES效力和抑制机制的分子，同时试图将CCR5信号传导降低到尽可能低的水平。我们鉴定出3种类似物，它们在体外对HIV-1的效力均与PSC-RANTES相当。第一种，6P4-RANTES，与PSC-RANTES相似，是一种强激动剂，可诱导CCR5长期细胞内隔离。第二种，5P12-RANTES，没有可检测到的G蛋白偶联信号活性，也不会导致受体隔离。第三种，5P14-RANTES，可诱导显著水平的CCR5内化，但没有可检测到的G蛋白偶联信号活性。这3种分子是作为局部HIV预防策略进一步开发的有希望的候选物。
