Quantification of HIV-1 latency reversal in resting CD4+ T cells from patients on suppressive antiretroviral therapy.
Reversal of proviral latency is being pursued as a curative strategy for HIV-1 infection. Recent clinical studies of in vivo administration of the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA; vorinostat) show increases in unspliced cellular HIV-1 RNA levels in resting CD4(+) T cells. A critical unknown, however, is the proportion of latent proviruses that can be transcriptionally reactivated by SAHA or T-cell activation. In this study, we quantified the fraction of HIV-1 proviruses in resting CD4(+) T cells from patients on suppressive antiretroviral therapy that were reactivated ex vivo with SAHA or antibodies to CD3/CD28. At concentrations of SAHA achieved clinically, only 0.079% of proviruses in resting CD4(+) T cells were reactivated to produce virions, compared with 1.5% of proviruses in cells treated with anti-CD3/CD28 antibodies after correcting for spontaneous virion production in the medium control. A significant positive correlation (ρ = 0.67, P < 0.001) was found between levels of virions in the supernatant and unspliced cellular HIV-1 RNA following anti-CD3/CD28 treatment, but not following SAHA treatment (ρ = 0.21, P = 0.99). These results reveal that the majority of HIV-1 proviruses are not reactivated by current therapeutic approaches and that more effective means of reversing proviral latency will likely be required to deplete HIV-1 reservoirs.
Division of Infectious Diseases, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261;
Anthony R
AR
Cillo
Division of Infectious Diseases, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261;
Michele D
MD
Sobolewski
Department of Biostatistics, School of Public Health, Harvard University, Boston, MA 02115;
Ronald J
RJ
Bosch
Division of Infectious Diseases, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261;
Elizabeth
E
Fyne
AIDS and Cancer Virus Program, SAIC-Frederic, Inc., National Cancer Institute, Frederick, MD 21702; and.
Michael
M
Piatak
Department of Molecular Biology and Microbiology, School of Medicine, Tufts University, Boston, MA 02111 jwm1@pitt.edu john.coffin@tufts.edu.
John M
JM
Coffin
Division of Infectious Diseases, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261; jwm1@pitt.edu john.coffin@tufts.edu.
John W
JW
Mellors
D000328:Adult; D000368:Aged; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000821:virology*; D005260:Female; D015967:Gene Expression Regulation, Viral / Q000187:drug effects; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D015497:HIV-1 / Q000235:genetics / Q000254:growth & development*; D056572:Histone Deacetylase Inhibitors / Q000627:therapeutic use; D006801:Humans; D006877:Hydroxamic Acids / Q000627:therapeutic use*; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011533:Proviruses / Q000235:genetics / Q000254:growth & development; D012367:RNA, Viral / Q000235:genetics; D014766:Viremia / Q000188:drug therapy / Q000276:immunology / Q000821:virology; D017735:Virus Latency / Q000187:drug effects* / Q000276:immunology; D000077337:Vorinostat
D044966:Anti-Retroviral Agents; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D012367:RNA, Viral; D000077337:Vorinostat
HIV-1 cure; HIV-1 eradication; HIV-1 persistence; fractional provirus expression