Cell lines with latent immunodeficiency virus and methods of use thereof

Abstract

The present invention provides isolated cells that comprise, integrated into the genome of the cell, a transcription-competent immunodeficiency virus or a transcription-competent immunodeficiency virus-based retroviral vector. Under basal in vitro culture conditions, the immunodeficiency virus is latent, and the expression of the latent immunodeficiency virus can be reactivated. The invention farther provides methods of making a subject cell. The invention further provides screening methods for identifying agents that activate a latent immunodeficiency virus; and screening method for identifying agents that block reactivation of latent immunodeficiency virus expression in response to T cell activation signals. The invention further provides agents identified in the subject screening assays. The invention further provides methods of treating an immunodeficiency virus infection.

1 . An isolated cell that comprises, integrated into the genome of the cell, a recombinant transcription-competent immunodeficiency virus-based vector, wherein, under basal in vitro culture conditions, the immunodeficiency virus is latent, and wherein expression of the latent immunodeficiency virus can be reactivated. 
     
     
         2 . The cell of  claim 1 , wherein said cell is an immortalized cell line. 
     
     
         3 . The cell of  claim 1 , wherein said cell is a T lymphoid cell. 
     
     
         4 . The cell of  claim 1 , wherein said immunodeficiency virus is human immunodeficiency virus (HAV). 
     
     
         5 . The cell of  claim 4 , wherein said immunodeficiency virus is HIV-1. 
     
     
         6 . A method of making an immortalized cell that comprises, integrated into the genome of the cell, a recombinant, transcription-competent human immunodeficiency virus (HIV) vector, wherein, under basal in vitro culture conditions, the HIV is latent, and wherein expression of the latent HIV can be reactivated, the method comprising
 a) introducing into population of immortalized cells in vitro a recombinant, transcription-competent HIV that comprises a nucleotide sequence encoding a selectable marker operably linked to a promoter; and   b) selecting a cell population that comprises the recombinant HIV integrated into the genome of the cell, and that does not produce the detectable marker.   
     
     
         7 . The method of  claim 6 , further comprising cloning a cell from the selected cell population. 
     
     
         8 . The method of  claim 6 , wherein step (b) results in a first selected cell population, and the method further comprises the steps of:
 c) contacting said first selected cell population with an agent that activates HIV transcription;   d) selecting a second population of cells from the first selected population, which second selected population produces the selectable marker,   
     
     
         9 . The method of  claim 8 , wherein said agent is selected from the group consisting of an activator of NF-κB, an agent that cross-links cell-surface T-cell receptor, and an inhibitor of histone deacetylase. 
     
     
         10 . The method of  claim 9 , wherein said activating agent is selected from the group consisting of phytohemagglutinin, tetradecanoyl phorbol acetate, TNFα, an anti-CD3 antibody, and trichostatin A. 
     
     
         11 . An isolated immortalized cell that comprises, integrated into the genome of the cell, a recombinant transcription-competent human immunodeficiency virus (HIV) vector that comprises a nucleotide sequence encoding a selectable marker operably linked to a promoter, wherein, under basal in vitro culture conditions, the HIV is latent, and wherein expression of the latent HIV can be reactivated. 
     
     
         12 . A method of identifying an agent that activates a latent human immunodeficiency virus (HIV), the method comprising:
 a) contacting the cell according to  claim 11  with a test agent; and   b) determining the effect, if any, of the test agent on production of the detectable marker, wherein production of the detectable marker indicates that the test agent activates a latent HIV   
     
     
         13 . The method of  claim 12 , wherein said detectable marker is a fluorescent protein, and said determining is detection of fluorescence. 
     
     
         14 . A composition comprising an agent identified by the method of  claim 12 ; and
 a pharmaceutically acceptable excipient.   
     
     
         15 . A method of reducing the number of cells containing a latent human immunodeficiency virus in an individual, the method comprising:
 administering to the individual an effective amount of the composition of  claim 14 .   
     
     
         16 . A method of treating a human immunodeficiency virus infection in an individual, the method comprising:
 administering to an individual an effective amount of the composition of  claim 14 ; and   administering to the individual an effective amount of an agent that inhibits-an immunodeficiency virus function selected from the group consisting of viral replication, viral protease activity, viral reverse transcriptase activity, viral entry into a cell, viral integrase activity, viral Rev activity, viral Tat activity, viral Nef activity, viral Vpr activity, viral Vpu activity, and viral Vif activity.