Highly potent, fully recombinant anti-HIV chemokines: Reengineering a low-cost microbicide

doi:10.1073/pnas.0805098105

Highly potent, fully recombinant anti-HIV chemokines: Reengineering a low-cost microbicide

^aDepartment of Structural Biology and Bioinformatics, Faculty of Medicine, University of Geneva, 1 Rue Michel Servet, 1211 Geneva 4, Switzerland;
^cDepartment of Immunology, Scripps Research Institute, La Jolla, CA 92037;
^dImmunologie A, CERVI, Institut National de la Santé et de la Recherche Médicale U543, Hopital Pitié-Salpêtrière, 75013 Paris, France; and
^bMintaka Foundation for Medical Research, 14 Chemin des Aulx, 1228 Plan-les-Ouates, Switzerland

Edited by Gregory A. Petsko, Brandeis University, Waltham, MA, and approved September 24, 2008 (received for review May 29, 2008)

Abstract

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.

Footnotes

²To whom correspondence should be addressed. E-mail: oliver.hartley{at}medecine.unige.ch
Author contributions: R.O., G.G., D.M., and O.H. designed research; H.G., F.C., J.-M.E., G.K., A.M., I.R.-B., R.N., and J.S. performed research; R.O., D.M., and O.H. analyzed data; and R.O., G.G., D.M., and O.H. wrote the paper.
↵¹Present address: Department of Biological Sciences, University of Texas, 500 West University Avenue, El Paso, TX 79968.
Conflict of interest statement: O.H. is the inventor on a patent application covering the new chemokine analogs described in this study, which is held by the Mintaka Medical Research Foundation, a nonprofit foundation registered in Geneva, Switzerland. O.H. and R.O. are cofounders of the Mintaka Foundation, with the roles of Chief Scientific Officer and Chief Executive Officer, respectively.
This article is a PNAS Direct Submission.
This article contains supporting information online at www.pnas.org/cgi/content/full/0805098105/DCSupplemental.