Inhibiting early-stage events in HIV-1 replication by small-molecule targeting of the HIV-1 capsid.
The HIV-1 capsid (CA) protein plays essential roles in both early and late stages of virl replication and has emerged as a novel drug target. We report hybrid structure-based virtual screening to identify small molecules with the potential to interact with the N-terminal domain (NTD) of HIV-1 CA and disrupt early, preintegration steps of the HIV-1 replication cycle. The small molecule 4,4'-[dibenzo[b,d]furan-2,8-diylbis(5-phenyl-1H-imidazole-4,2-diyl)]dibenzoic acid (CK026), which had anti-HIV-1 activity in single- and multiple-round infections but failed to inhibit viral replication in peripheral blood mononuclear cells (PBMCs), was identified. Three analogues of CK026 with reduced size and better drug-like properties were synthesized and assessed. Compound I-XW-053 (4-(4,5-diphenyl-1H-imidazol-2-yl)benzoic acid) retained all of the antiviral activity of the parental compound and inhibited the replication of a diverse panel of primary HIV-1 isolates in PBMCs, while displaying no appreciable cytotoxicity. This antiviral activity was specific to HIV-1, as I-XW-053 displayed no effect on the replication of SIV or against a panel of nonretroviruses. Direct interaction of I-XW-053 was quantified with wild-type and mutant CA protein using surface plasmon resonance and isothermal titration calorimetry. Mutation of Ile37 and Arg173, which are required for interaction with compound I-XW-053, crippled the virus at an early, preintegration step. Using quantitative PCR, we demonstrated that treatment with I-XW-053 inhibited HIV-1 reverse transcription in multiple cell types, indirectly pointing to dysfunction in the uncoating process. In summary, we have identified a CA-specific compound that targets and inhibits a novel region in the NTD-NTD interface, affects uncoating, and possesses broad-spectrum anti-HIV-1 activity.
Department of Microbiology & Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA.
Sandhya
S
Kortagere
Navid
N
Madani
Marie K
MK
Mankowski
Arne
A
Schön
Isaac
I
Zentner
Gokul
G
Swaminathan
Amy
A
Princiotto
Kevin
K
Anthony
Apara
A
Oza
Luz-Jeannette
LJ
Sierra
Shendra R
SR
Passic
Xiaozhao
X
Wang
David M
DM
Jones
Eric
E
Stavale
Fred C
FC
Krebs
Julio
J
Martín-García
Ernesto
E
Freire
Roger G
RG
Ptak
Joseph
J
Sodroski
Simon
S
Cocklin
Amos B
AB
Smith
D019380:Anti-HIV Agents / Q000138:chemical synthesis / Q000494:pharmacology* / Q000633:toxicity; D002151:Calorimetry; D036022:Capsid Proteins / Q000037:antagonists & inhibitors*; D002460:Cell Line; D015497:HIV-1 / Q000187:drug effects* / Q000502:physiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D011485:Protein Binding; D060888:Real-Time Polymerase Chain Reaction; D048348:Reverse Transcription / Q000187:drug effects; D015302:Simian Immunodeficiency Virus / Q000187:drug effects; D020349:Surface Plasmon Resonance; D053586:Virus Internalization / Q000187:drug effects; D014779:Virus Replication / Q000187:drug effects; D057646:Virus Uncoating / Q000187:drug effects*
D019380:Anti-HIV Agents; D036022:Capsid Proteins