Reactivation of latent HIV-1 by a wide variety of butyric acid-producing bacteria

• Published in: Cellular and molecular life sciences : CMLS Vol. 69; no. 15; pp. 2583 - 2592
• Main Authors: Imai, Kenichi, Yamada, Kiyoshi, Tamura, Muneaki, Ochiai, Kuniyasu, Okamoto, Takashi
• Format: Journal Article
• Language: English
• Published: Basel SP Birkhäuser Verlag Basel 01.08.2012
• Subjects: Acetylation - drug effects; Bacteria - metabolism; Bacteria - pathogenicity; Bacterial Infections - complications; Bacterial Infections - virology; Base Sequence; Biochemistry; Biomedical and Life Sciences; Biomedicine; Butyric Acid - metabolism; Butyric Acid - toxicity; Cell Biology; Cell Line; Chromatin Assembly and Disassembly - drug effects; Digestive System - microbiology; DNA, Viral - genetics; Female; Histones - metabolism; HIV Infections - complications; HIV Infections - virology; HIV Long Terminal Repeat; HIV-1 - drug effects; HIV-1 - genetics; HIV-1 - pathogenicity; HIV-1 - physiology; Humans; Life Sciences; Mouth - microbiology; Mucous Membrane - microbiology; Research Article; Vagina - microbiology; Virus Activation - drug effects; Virus Activation - physiology; Virus Latency - drug effects; Virus Latency - physiology; Virus Replication - drug effects; Virus Replication - physiology; HIV-1; Epigenetics; Histone; HDAC; Butyric acid
• ISSN: 1420-682X; 1420-9071
• DOI: 10.1007/s00018-012-0936-2

Latently infected cells harbor human immunodeficiency virus type 1 (HIV-1) proviral DNA copies integrated in heterochromatin, allowing persistence of transcriptionally silent proviruses. It is widely accepted that hypoacetylation of histone proteins by histone deacetylases (HDACs) is involved in maintaining the HIV-1 latency by repressing viral transcription. HIV-1 replication can be induced from latently infected cells by environmental factors, such as inflammation and co-infection with other microbes. It is known that a bacterial metabolite butyric acid inhibits catalytic action of HDAC and induces transcription of silenced genes including HIV-1 provirus. There are a number of such bacteria in gut, vaginal, and oral cavities that produce butyric acid during their anaerobic glycolysis. Since these organs are known to be the major site of HIV-1 transmission and its replication, we explored a possibility that explosive viral replication in these organs could be ascribable to butyric acid produced from anaerobic resident bacteria. In this study, we demonstrate that the culture supernatant of various bacteria producing butyric acid could greatly reactivate the latently-infected HIV-1. These bacteria include Fusobacterium nucleatum (commonly present in oral cavity, and gut), Clostridium cochlearium, Eubacterium multiforme (gut), and Anaerococcus tetradius (vagina). We also clarified that butyric acid in these culture supernatants could induce histone acetylation and HIV-1 replication by inhibiting HDAC. Our observations indicate that butyric acid-producing bacteria could be involved in AIDS progression by reactivating the latent HIV provirus and, subsequently, by eliminating such bacterial infection may contribute to the prevention of the AIDS development and transmission.