title: Prime, Shock, and Kill: Priming CD4 T Cells from HIV Patients with a BCL-2 Antagonist before HIV Reactivation Reduces HIV Reservoir Size.
abstract: Understanding how some HIV-infected cells resist the cytotoxicity of HIV replication is crucial to enabling HIV cure efforts. HIV killing of CD4 T cells that replicate HIV can involve HIV protease-mediated cleavage of procaspase 8 to generate a fragment (Casp8p41) that directly binds and activates the mitochondrial proapoptotic protein BAK. Here, we demonstrate that Casp8p41 also binds with nanomolar affinity to the antiapoptotic protein Bcl-2, which sequesters Casp8p41 and prevents apoptosis. Further, we show that central memory CD4 T cells (TCM) from HIV-infected individuals have heightened expression of BCL-2 relative to procaspase 8, possibly explaining the persistence of HIV-infected TCMdespite generation of Casp8p41. Consistent with this hypothesis, the selective BCL-2 antagonist venetoclax induced minimal killing of uninfected CD4 T cells but markedly increased the death of CD4 T cells and diminished cell-associated HIV DNA when CD4 T cells from antiretroviral therapy (ART)-suppressed HIV patients were induced with αCD3/αCD28 to reactivate HIVex vivo Thus, priming CD4 T cells from ART suppressed HIV patients with a BCL-2 antagonist, followed by HIV reactivation, achieves reductions in cell-associated HIV DNA, whereas HIV reactivation alone does not.
  
  
  OBJECTIVE
  HIV infection is incurable due to a long-lived reservoir of HIV(+)memory CD4 T cells, and no clinically relevant interventions have been identified that reduce the number of these HIV DNA-containing cells. Since postintegration HIV replication can result in HIV protease generation of Casp8p41, which activates BAK, causing infected CD4 T cell death, we sought to determine whether this occurs in memory CD4 T cells. Here, we demonstrate that memory CD4 T cells can generate Casp8p41 and yet are intrinsically resistant to death induced by diverse stimuli, including Casp8p41. Furthermore, BCL-2 expression is relatively increased in these cells and directly binds and inhibits Casp8p41's proapoptotic effects. Antagonizing BCL-2 with venetoclax derepresses this antagonism, resulting in death, preferentially in HIV DNA containing cells, since only these cells generate Casp8p41. Thus, BCL-2 antagonism is a clinically relevant intervention with the potential to reduce HIV reservoir size in patients.
authors: Division of Infectious Diseases, Mayo Clinic, Rochester, Minnesota, USA.
authors: Nathan W
authors: NW
authors: Cummins
authors: Department of Pharmacology, Mayo Clinic, Rochester, Minnesota, USA.
authors: Amy M
authors: AM
authors: Sainski
authors: Department of Pharmacology, Mayo Clinic, Rochester, Minnesota, USA.|Division of Oncology Research, Mayo Clinic, Rochester, Minnesota, USA.
authors: Haiming
authors: H
authors: Dai
authors: Division of Infectious Diseases, Mayo Clinic, Rochester, Minnesota, USA.
authors: Sekar
authors: S
authors: Natesampillai
authors: Department of Pharmacology, Mayo Clinic, Rochester, Minnesota, USA.
authors: Yuan-Ping
authors: YP
authors: Pang
authors: Division of Infectious Diseases, Mayo Clinic, Rochester, Minnesota, USA.
authors: Gary D
authors: GD
authors: Bren
authors: Department of Pharmacology, Mayo Clinic, Rochester, Minnesota, USA.|Division of Oncology Research, Mayo Clinic, Rochester, Minnesota, USA.
authors: Maria Cristina Miranda
authors: MCM
authors: de Araujo Correia
authors: Division of Infectious Diseases, Mayo Clinic, Rochester, Minnesota, USA.
authors: Rahul
authors: R
authors: Sampath
authors: Division of Infectious Diseases, Mayo Clinic, Rochester, Minnesota, USA.
authors: Stacey A
authors: SA
authors: Rizza
authors: Department of Biostatistics, Mayo Clinic, Rochester, Minnesota, USA.
authors: Daniel
authors: D
authors: O'Brien
authors: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA.
authors: Joseph D
authors: JD
authors: Yao
authors: Department of Pharmacology, Mayo Clinic, Rochester, Minnesota, USA andrew@mayo.edu kaufmann.scott@mayo.edu.|Division of Oncology Research, Mayo Clinic, Rochester, Minnesota, USA.
authors: Scott H
authors: SH
authors: Kaufmann
authors: Division of Infectious Diseases, Mayo Clinic, Rochester, Minnesota, USA andrew@mayo.edu kaufmann.scott@mayo.edu.|Department of Molecular Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors: Andrew D
authors: AD
authors: Badley
mesh_terms: D017209:Apoptosis; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D053181:Caspase 8 / Q000378:metabolism*; D061945:Caspase Inhibitors / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D057809:HEK293 Cells; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000187:drug effects / Q000276:immunology* / Q000502:physiology; D006801:Humans; D007156:Immunologic Memory; D019169:Jurkat Cells; D010446:Peptide Fragments / Q000037:antagonists & inhibitors / Q000276:immunology; D011485:Protein Binding; D013449:Sulfonamides / Q000494:pharmacology; D019562:Viral Load; D014775:Virus Activation / Q000187:drug effects; D050998:bcl-2 Homologous Antagonist-Killer Protein / Q000037:antagonists & inhibitors*
chemical_list: C494772:BAK1 protein, human; D019086:Bridged Bicyclo Compounds, Heterocyclic; D061945:Caspase Inhibitors; D010446:Peptide Fragments; D013449:Sulfonamides; D050998:bcl-2 Homologous Antagonist-Killer Protein; D053181:Caspase 8; C579720:venetoclax