Artificial peptides conjugated with cholesterol and pocket-specific small molecules potently inhibit infection by laboratory-adapted and primary HIV-1 isolates and enfuvirtide-resistant HIV-1 strains.
OBJECTIVE
To develop new HIV-1 fusion inhibitors with improved antiviral activities and resistance profiles, we designed two categories of artificial peptides, each containing four heptad repeats (m4HR) conjugated with a pocket-specific small molecule (pssm) or pssm and cholesterol (chol), designated pssm-m4HR or pssm-m4HR-chol, respectively, and tested their anti-HIV-1 activity.


METHODS
We synthesized the artificial peptides and conjugated these peptides with pssm and chol using a standard solid-phase Fmoc protocol and a chemoselective thioether conjugation method, respectively. We tested the inhibitory activities of the peptide conjugates against HIV-1 Env-mediated cell-cell fusion and infection by laboratory-adapted and primary HIV-1 isolates, and enfuvirtide-resistant HIV-1 strains using cell-cell fusion and p24 production assays, respectively. We assessed their cytotoxicity towards MT-2 cells using the XTT assay.


RESULTS
We found that pssm-m4HR conjugates exhibited promising inhibitory activity against HIV-1 Env-mediated cell-cell fusion and laboratory-adapted HIV-1 replication with IC50 values at the low micromolar level, whereas the pssm-m4HR-chol conjugates exhibited dramatically increased anti-HIV-1 activities with IC50 values at the low nanomolar level. Some of the pssm-m4HR-chol conjugates (e.g. 5a and 5b) showed highly potent antiviral activity against infection by primary HIV-1 isolates and enfuvirtide-resistant HIV-1 strains. All the conjugates displayed no or low cytotoxicity towards MT-2 cells. The result of a prime/wash assay indicated pssm-m4HR-chol conjugates were strongly anchored to the membrane and sustained a potent inhibitory effect after washing.


CONCLUSIONS
These results suggest this scaffold design is a promising strategy for developing novel peptide conjugates with improved antiviral activity against a broad spectrum of HIV-1 strains, including those highly resistant to enfuvirtide.
Beijing Institute of Pharmacology & Toxicology, 27 Tai-Ping Road, Beijing 100850, China.
Chao
C
Wang
Beijing Institute of Pharmacology & Toxicology, 27 Tai-Ping Road, Beijing 100850, China.
Weiguo
W
Shi
Beijing Institute of Pharmacology & Toxicology, 27 Tai-Ping Road, Beijing 100850, China.
Lifeng
L
Cai
Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Shanghai Medical College and Institute of Medical Microbiology, Fudan University, Shanghai 200032, China.
Lu
L
Lu
Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY 10065, USA.
Fei
F
Yu
Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Shanghai Medical College and Institute of Medical Microbiology, Fudan University, Shanghai 200032, China.
Qian
Q
Wang
Beijing Institute of Pharmacology & Toxicology, 27 Tai-Ping Road, Beijing 100850, China.
Xifeng
X
Jiang
Beijing Institute of Pharmacology & Toxicology, 27 Tai-Ping Road, Beijing 100850, China.
Xiaoyu
X
Xu
Beijing Institute of Pharmacology & Toxicology, 27 Tai-Ping Road, Beijing 100850, China.
Kun
K
Wang
Beijing Institute of Pharmacology & Toxicology, 27 Tai-Ping Road, Beijing 100850, China.
Liang
L
Xu
Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Shanghai Medical College and Institute of Medical Microbiology, Fudan University, Shanghai 200032, China Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY 10065, USA.
Shibo
S
Jiang
Beijing Institute of Pharmacology & Toxicology, 27 Tai-Ping Road, Beijing 100850, China keliangliu55@126.com.
Keliang
K
Liu
D000595:Amino Acid Sequence; D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line; D002784:Cholesterol / Q000737:chemistry; D015195:Drug Design; D024882:Drug Resistance, Viral; D000077560:Enfuvirtide; D015700:HIV Envelope Protein gp41 / Q000494:pharmacology; D023581:HIV Fusion Inhibitors / Q000494:pharmacology; D015658:HIV Infections / Q000821:virology; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D008561:Membrane Fusion; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000494:pharmacology; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D011487:Protein Conformation
D000998:Antiviral Agents; D015700:HIV Envelope Protein gp41; D023581:HIV Fusion Inhibitors; D010446:Peptide Fragments; D010455:Peptides; D000077560:Enfuvirtide; D002784:Cholesterol
HIV; conjugate; fusion inhibitors