Search for Low Molecular Weight Compounds that Inhibit Human Immunodeficiency Virus Type 1 Replication

Abstract

Highly active antiretroviral (ARV) therapy has successfully reduced viral transmission, morbidity, and mortality associated with human immunodeficiency virus type 1 (HIV-1) disease; however, the emergence of drug-resistant viruses is a major obstacle associated with ARV therapy. Therefore, the development of a new class of ARV drugs is urgently required. Cyclophilin A (CypA) is a host factor required for HIV-1 replication, and plays a role in viral replication by interacting with the HIV-1 capsid protein (CA). As such, it represents a potential target for novel ARV drugs. We here searched for low molecular weight compounds that inhibited HIV-1 replication by interfering with binding between CypA and HIV-1 CA. A total of 106 compounds were screened in an in silico docking study as candidates that were predicted to interact with the HIV-1 CA binding pocket of CypA. Biological tests were then conducted to evaluate the anti-HIV-1 activities as well as cytotoxicities of these test compounds, and 4 compounds that efficiently inhibited viral replication without exhibiting strong cytotoxicity were subsequently selected. The molecular mechanisms underlying the inhibition of HIV-1 replication by the 4 selected compounds have not been elucidated in the present study; however, we consider that these compounds will become the lead compounds for developing novel ARV drugs once more detailed studies are performed on the molecular mechanisms responsible for their anti-HIV-1 activities.