Rational CCL5 mutagenesis integration in a lactobacilli platform generates extremely potent HIV-1 blockers

Abstract

Efforts to improve existing anti-HIV-1 therapies or develop preventatives have identified CCR5 as an important target and CCL5 as an ideal scaffold to sculpt potent HIV-1 entry inhibitors. We created novel human CCL5 variants that exhibit exceptional anti-HIV-1 features using recombinant lactobacilli (exploited for live microbicide development) as a screening platform. Protein design, expression and anti-HIV-1 activity flowed in iterative cycles, with a stepwise integration of successful mutations and refinement of an initial CCL5 mutant battery towards the generation of two ultimate CCL5 derivatives, a CCR5 agonist and a CCR5 antagonist with similar anti-HIV-1 potency. The CCR5 antagonist was tested in human macrophages and against primary R5 HIV-1 strains, exhibiting cross-clade low picomolar IC50 activity. Moreover, its successful combination with several HIV-1 inhibitors provided the ground for conceiving therapeutic and preventative anti-HIV-1 cocktails. Beyond HIV-1 infection, these CCL5 derivatives may now be tested against several inflammation-related pathologies where the CCL5:CCR5 axis plays a relevant role.

Genetic organization and cellular specificity of S. aureus leukocidins

“…LukED mechanism of action satisfies previously proposed models where the S subunit initiates the binding and recruits the F subunit to proceed with pore formation [53,55]. In addition, it was shown that the FDA-approved CCR5 antagonist maraviroc can block the interaction between LukE and CCR5 [53], and recently developed potent CCL5 derivatives are presently being investigated in this context [56,57]. These data confirm the specificity of this interaction and proves that a drug currently used as HIV-1 inhibitor has repositioning potentials as a treatment option for S. aureus infections [53].…”

Filling the Gaps in Antagonist CCR5 Binding, a Retrospective and Perspective Analysis

“…Among the CCL5 derivatives efficiently blocking CCR5, the most potent HIV-1 entry inhibitors reported to date are CCL5 5P12 5M and CCL5 6P4 5M, a CCR5 antagonist and a superagonist, respectively ( 11 ). Five mutated hotspots (5M) were selected to enhance different features related to the CCL5:CCR5 interaction.…”

“…The high-resolution structure of CCR5 in complex with 5P7 CCL5 (a CCR5 antagonist) (PDB ID: 5UIW) ( 16 ) was used as template for the modeling of CCL5 5P12 5M, the most potent CCR5 antagonist reported to date ( 11 ). Six separate 3D models (T7L, F12Y, A13V, Y27W, F28W and E66S), accounting for the differences between 5P7 CCL5 and CCL5 5P12 5M were built using SWISS-MODEL.…”

“…Initially, CCL5 variants retained CCR5 agonist activity, later followed by efforts to attain a switch to antagonism ( 9 ). Last generation CCL5 derivatives acting as CCR5 antagonists could be a valid alternative to MVC, as they present in vitro anti-HIV-1 activity largely superior to MVC ( 10 , 11 ). Monoclonal antibodies (mAbs) acting as CCR5 antagonists have been the subject of intense investigation ( 12 ) leading to promising therapeutic perspectives ( 13 , 14 ).…”

“…In this study, we investigated both retroactively and in perspective the innovative role of selected point mutations inserted in CCL5 regions distal to the classically targeted N-terminus ( 11 ). We also briefly discuss emerging allosteric strategies to block GPCRs alternative to the active site occupancy and that could be of interest to tackle CCR5 in pathology.…”