title: Selective killing of HIV-1-positive macrophages and T cells by the Rev-dependent lentivirus carrying anthrolysin O from Bacillus anthracis.
abstract: BACKGROUND
  The ability of Human Immunodeficiency Virus (HIV) to persist in the body has proven to be a long-standing challenge to virus eradication. Current antiretroviral therapy cannot selectively destroy infected cells; it only halts active viral replication. With therapeutic cessation or interruption, viral rebound occurs, and invariably, viral loads return to pre-treatment levels. The natural reservoirs harboring replication-competent HIV-1 include CD4 T cells and macrophages. In particular, cells from the macrophage lineage resist HIV-1-mediated killing and support sustained viral production. To develop a complementary strategy to target persistently infected cells, this proof-of-concept study explores an HIV-1 Rev-dependent lentiviral vector carrying a bacterial hemolysin, anthrolysin O (anlO) from Bacillus anthracis, to achieve selective killing of HIV-1- infected cells.
  
  
  RESULTS
  We demonstrate that in the Rev-dependent lentiviral vector, anlO expression is exclusively dependent on Rev, a unique HIV-1 protein present only in infected cells. Intracellular expression and oligomerization of AnlO result in membrane pore formation and cytolysis. We have further overcome a technical hurdle in producing a Revdependent AnlO lentivirus, through the use of beta-cyclodextrin derivatives to inhibit direct killing of producer cells by AnlO. Using HIV-1-infected macrophages and T cells as a model, we demonstrate that this Rev-dependent AnlO lentivirus diminishes HIV-1- positive cells.
  
  
  CONCLUSIONS
  The Rev-dependent lentiviral vector has demonstrated its specificity in targeting persistently infected cells. The choice of anlO as the first suicidal gene tested in this vector is based on its cytolytic activity in macrophages and T cells. We conclude that Rev-regulated expression of suicidal genes in HIV-1-positive cells is possible, although future in vivo delivery of this system needs to address numerous safety issues.
authors.affiliation: Department of Molecular and Microbiology, George Mason University, Manassas, VA 20110, USA. jyoung4@gmu.edu
authors.forename: Jessica
authors.initials: J
authors.lastname: Young
authors.forename: Zhongwei
authors.initials: Z
authors.lastname: Tang
authors.forename: Quan
authors.initials: Q
authors.lastname: Yu
authors.forename: Dongyang
authors.initials: D
authors.lastname: Yu
authors.forename: Yuntao
authors.initials: Y
authors.lastname: Wu
mesh_terms: D001408:Bacillus anthracis / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D004279:DNA, Viral / Q000235:genetics; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000235:genetics; D015497:HIV-1 / Q000235:genetics / Q000502:physiology*; D006801:Humans; D016086:Lentivirus / Q000235:genetics / Q000502:physiology*; D008264:Macrophages / Q000166:cytology* / Q000821:virology*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology* / Q000821:virology*; D047392:beta-Cyclodextrins / Q000494:pharmacology; D054321:rev Gene Products, Human Immunodeficiency Virus / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004279:DNA, Viral; D008562:Membrane Glycoproteins; C498000:anthrolysin O, Bacillus anthracis; D047392:beta-Cyclodextrins; D054321:rev Gene Products, Human Immunodeficiency Virus; D049452:Green Fluorescent Proteins