High-mobility group box 1 protein induces HIV-1 expression from persistently infected cells.
BACKGROUND
Necrosis is a frequent condition during AIDS, notably in organs targetted by opportunistic infections. Soluble factors released by necrotic cells are important for signalling cell damage, but little is known concerning their effect on HIV-1 replication. We focused on HMGB1, an abundant component of the chromatin that is released from necrotic cells and can act as a pro-inflammatory mediator.


METHODS
A native form of HMGB1 was obtained from necrotic Hela cells, whereas a purified recombinant HMGB1 was generated in Escherichia coli. ACH-2 and U1 cells were used as models of persistent HIV-1 infection in lymphocytes and monocytes. Reactivation from latency was also investigated ex vivo using peripheral blood mononuclear cells (PBMC) collected from HIV-1-infected patients controlled by HAART. HIV-1 expression was quantified by enzyme-linked immunosorbent assay, real-time reverse transcription-polymerase chain reaction and branched DNA techniques. Flow cytometry and blocking experiments were used to identify the receptor used by HMGB1. Chromatin immunoprecipitation was used to investigate long-terminal repeat activation upon stimulation by HMGB1.


RESULTS
HMGB1 increased HIV-1 transcription in chronically infected cells, a process that did not require de-novo protein synthesis. HIV-1 induction relied on HMGB1 interaction with the receptor for advanced glycation end-products. The activation pathway involved p38 and extracellular signal-related kinase as well as nuclear factor kappa B binding to the HIV-1 promoter. Finally, HMGB1 reactivated HIV-1 from latently infected PBMC collected in aviraemic HIV-infected patients.


CONCLUSIONS
This work establishes for the first time a link between necrosis and HIV-1 replication, which involves HMGB1, a soluble mediator released by damaged cells.
Thierry
Sylvain
S
UMR 7079, Université Pierre et Marie Curie, Paris, France.
Gozlan
Joël
J
Jaulmes
Amandine
A
Boniface
Rachel
R
Nasreddine
Nadine
N
Strauss
François
F
Maréchal
Vincent
V
D023241:Antiretroviral Therapy, Highly Active; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D048049:Extracellular Signal-Regulated MAP Kinases / Q000502:physiology; D015658:HIV Infections / Q000188:drug therapy / Q000473:pathology / Q000821:virology*; D015497:HIV-1 / Q000187:drug effects* / Q000502:physiology; D024243:HMGB1 Protein / Q000494:pharmacology* / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D016328:NF-kappa B / Q000502:physiology; D009336:Necrosis; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic / Q000502:physiology; D011994:Recombinant Proteins / Q000494:pharmacology; D015533:Transcriptional Activation / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D014775:Virus Activation / Q000187:drug effects* / Q000502:physiology; D017735:Virus Latency; D048051:p38 Mitogen-Activated Protein Kinases / Q000502:physiology
D016207:Cytokines; D024243:HMGB1 Protein; D016328:NF-kappa B; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D048049:Extracellular Signal-Regulated MAP Kinases; D048051:p38 Mitogen-Activated Protein Kinases