title: Highly potent, fully recombinant anti-HIV chemokines: reengineering a low-cost microbicide.
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.
authors.affiliation: Department of Structural Biology and Bioinformatics, Faculty of Medicine, University of Geneva, 1 Rue Michel Servet, 1211 Geneva 4, Switzerland.
authors.forename: Hubert
authors.initials: H
authors.lastname: Gaertner
authors.forename: Fabrice
authors.initials: F
authors.lastname: Cerini
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Escola
authors.forename: Gabriel
authors.initials: G
authors.lastname: Kuenzi
authors.forename: Astrid
authors.initials: A
authors.lastname: Melotti
authors.forename: Robin
authors.initials: R
authors.lastname: Offord
authors.forename: Irène
authors.initials: I
authors.lastname: Rossitto-Borlat
authors.forename: Rebecca
authors.initials: R
authors.lastname: Nedellec
authors.forename: Janelle
authors.initials: J
authors.lastname: Salkowitz
authors.forename: Guy
authors.initials: G
authors.lastname: Gorochov
authors.forename: Donald
authors.initials: D
authors.lastname: Mosier
authors.forename: Oliver
authors.initials: O
authors.lastname: Hartley
mesh_terms: D000890:Anti-Infective Agents / Q000191:economics* / Q000494:pharmacology*; D000998:Antiviral Agents / Q000494:pharmacology*; D018946:Chemokine CCL5 / Q000737:chemistry; D018925:Chemokines / Q000494:pharmacology*; D004705:Endocytosis / Q000187:drug effects; D006678:HIV / Q000187:drug effects*; D006367:HeLa Cells; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000821:virology; D015202:Protein Engineering; D019713:Receptors, CCR5 / Q000378:metabolism; D011991:Receptors, Virus / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology*; D015203:Reproducibility of Results; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000890:Anti-Infective Agents; D000998:Antiviral Agents; D018946:Chemokine CCL5; D018925:Chemokines; D019713:Receptors, CCR5; D011991:Receptors, Virus; D011994:Recombinant Proteins