scholarly journals Relationship between the Size of the Human Immunodeficiency Virus Type 1 (HIV‐1) Reservoir in Peripheral Blood CD4+T Cells and CD4+:CD8+T Cell Ratios in Aviremic HIV‐1–Infected Individuals Receiving Long‐Term Highly Active Antiretroviral Therapy

2002 ◽  
Vol 185 (11) ◽  
pp. 1672-1676 ◽  
Author(s):  
Tae‐Wook Chun ◽  
J. Shawn Justement ◽  
Punita Pandya ◽  
Claire W. Hallahan ◽  
Mary McLaughlin ◽  
...  
2004 ◽  
Vol 78 (17) ◽  
pp. 9105-9114 ◽  
Author(s):  
Kara G. Lassen ◽  
Justin R. Bailey ◽  
Robert F. Siliciano

ABSTRACT A stable latent reservoir for human immunodeficiency virus type 1 (HIV-1) in resting memory CD4+ T cells presents a barrier to eradication of the infection even in patients on highly active antiretroviral therapy. Potential mechanisms for latency include inaccessibility of the integrated viral genome, absence of key host transcription factors, premature termination of HIV-1 RNAs, and abnormal splicing patterns. To differentiate among these mechanisms, we isolated extremely pure populations of resting CD4+ T cells from patients on highly active antiretroviral therapy. These cells did not produce virus but retained the capacity to do so if appropriately stimulated. Products of HIV-1 transcription were examined in purified resting CD4+ T cells. Although short, prematurely terminated HIV-1 transcripts have been suggested as a marker for latently infected cells, the production of short transcripts had not been previously demonstrated in purified populations of resting CD4+ T cells. By separating RNA into polyadenylated and nonpolyadenylated fractions, we showed that resting CD4+ T cells from patients on highly active antiretroviral therapy produce abortive transcripts that lack a poly(A) tail and that terminate prior to nucleotide 181. Short transcripts dominated the pool of total HIV-1 transcripts in resting CD4+ T cells. Processive, polyadenylated HIV-1 mRNAs were also present at a low level. Both unspliced and multiply spliced forms were found. Taken together, these results show that the nonproductive nature of the infection in resting CD4+ T cells from patients on highly active antiretroviral therapy is not due to absolute blocks at the level of either transcriptional initiation or elongation but rather relative inefficiencies at multiple steps.


2002 ◽  
Vol 76 (2) ◽  
pp. 707-716 ◽  
Author(s):  
Tuofu Zhu ◽  
David Muthui ◽  
Sarah Holte ◽  
David Nickle ◽  
Feng Feng ◽  
...  

ABSTRACT In vitro studies show that human immunodeficiency virus type 1 (HIV-1) does not replicate in freshly isolated monocytes unless monocytes differentiate to monocyte-derived macrophages. Similarly, HIV-1 may replicate in macrophages in vivo, whereas it is unclear whether blood monocytes are permissive to productive infection with HIV-1. We investigated HIV-1 replication in CD14+ monocytes and resting and activated CD4+ T cells by measuring the levels of cell-associated viral DNA and mRNA and the genetic evolution of HIV-1 in seven acutely infected patients whose plasma viremia had been <100 copies/ml for 803 to 1,544 days during highly active antiretroviral therapy (HAART). HIV-1 DNA was detected in CD14+ monocytes as well as in activated and resting CD4+ T cells throughout the course of study. While significant variation in the decay slopes of HIV-1 DNA was seen among individual patients, viral decay in CD14+ monocytes was on average slower than that in activated and resting CD4+ T cells. Measurements of HIV-1 sequence evolution and the concentrations of unspliced and multiply spliced mRNA provided evidence of ongoing HIV-1 replication, more pronounced in CD14+ monocytes than in resting CD4+ T cells. Phylogenetic analyses of HIV-1 sequences indicated that after prolonged HAART, viral populations related or identical to those found only in CD14+ monocytes were seen in plasma from three of the seven patients. In the other four patients, HIV-1 sequences in plasma and the three cell populations were identical. CD14+ monocytes appear to be one of the potential in vivo sources of HIV-1 in patients receiving HAART.


2004 ◽  
Vol 78 (19) ◽  
pp. 10566-10573 ◽  
Author(s):  
Michele Di Mascio ◽  
Martin Markowitz ◽  
Michael Louie ◽  
Arlene Hurley ◽  
Christine Hogan ◽  
...  

ABSTRACT The meaning of viral blips in human immunodeficiency virus type 1 (HIV-1)-infected patients treated with seemingly effective highly active antiretroviral therapy (HAART) is still controversial and under investigation. Blips might represent low-level ongoing viral replication in the presence of drug or simply release of virions from the latent reservoir. Patients treated early during HIV-1 infection are more likely to have a lower total body viral burden, a homogenous viral population, and preserved HIV-1-specific immune responses. Consequently, viral blips may be less frequent in them than in patients treated during chronic infection. To test this hypothesis, we compared the occurrence of viral blips in 76 acutely infected patients (primary HIV infection [PHI] group) who started therapy within 6 months of the onset of symptoms with that in 47 patients who started HAART therapy during chronic infection (chronic HIV infection [CHI] group). Viral blip frequency was approximately twofold higher in CHI patients (0.122 ± 0.12/viral load [VL] sample, mean ± standard deviation) than in PHI patients (0.066 ± 0.09/VL sample). However, in both groups, viral blip frequency did not increase with longer periods of observation. Also, no difference in viral blip frequency was observed between treatment subgroups, and the occurrence of a blip was not associated with a recent change in CD4+ T-cell count. Finally, in PHI patients the VL set point was a significant predictor of blip frequency during treatment.


2005 ◽  
Vol 79 (12) ◽  
pp. 7349-7354 ◽  
Author(s):  
Thomas W. North ◽  
Koen K. A. Van Rompay ◽  
Joanne Higgins ◽  
Timothy B. Matthews ◽  
Debra A. Wadford ◽  
...  

ABSTRACT We have modeled highly active antiretroviral therapy (HAART) for AIDS in rhesus macaques infected with a chimera (RT-SHIV) of simian immunodeficiency virus containing reverse transcriptase from human immunodeficiency virus type-1 (HIV-1). Seven RT-SHIV-infected macaques were treated with a combination of efavirenz (200 mg orally once daily), lamivudine (8 mg/kg subcutaneously once daily), and tenofovir (30 mg/kg subcutaneously once daily). Plasma viral RNA levels in all animals were reduced by more than 1,000-fold after 4 weeks and, in six of the seven animals, were reduced to undetectable levels after 10 weeks. Virus loads increased slightly between 12 and 16 weeks of treatment, associated with problems with the administration of efavirenz. After a change in the method of efavirenz administration, virus loads declined again and remained undetectable in the majority of animals for the duration of therapy. Treatment was stopped for three animals after 36 weeks of therapy, and virus loads increased rapidly. Posttreatment RT-SHIV isolates had no mutations associated with resistance to any of the three drugs. Efavirenz treatment was stopped, but lamivudine and tenofovir treatment for two other macaques was continued. The virus load in one of these two animals rebounded; virus from this animal was initially free of drug-resistance mutations but acquired the K65R mutation in reverse transcriptase at 11 weeks after efavirenz treatment was withdrawn. These results mimic HAART of HIV-1-infected humans. The RT-SHIV/rhesus macaque model should be useful for studies of tissue reservoirs and sites of residual replication that are not possible or practical with humans.


2006 ◽  
Vol 80 (20) ◽  
pp. 10229-10236 ◽  
Author(s):  
Pierre Delobel ◽  
Marie-Thérèse Nugeyre ◽  
Michelle Cazabat ◽  
Karine Sandres-Sauné ◽  
Christophe Pasquier ◽  
...  

ABSTRACT The reasons for poor CD4+ T-cell recovery in some human immunodeficiency virus (HIV)-infected subjects despite effective highly active antiretroviral therapy (HAART) remain unclear. We recently reported that CXCR4-using (X4) HIV-1 could be gradually selected in cellular reservoirs during sustained HAART. Because of the differential expression of HIV-1 coreceptors CCR5 and CXCR4 on distinct T-cell subsets, the residual replication of R5 and X4 viruses could have different impacts on T-cell homeostasis during immune reconstitution on HAART. We examined this hypothesis and the mechanisms of CD4+ T-cell restoration by comparing the virological and immunological features of 15 poor and 15 good immunological responders to HAART. We found a high frequency of X4 viruses in the poor immunological responders. But the levels of intrathymic proliferation of the two groups were similar regardless of whether they were infected by R5 or X4 virus. The frequency of recent thymic emigrants in the poor immunological responders was also similar to that found in the good immunological responders, despite their reduced numbers of naïve CD4+ T cells. Our data, rather, suggest that the naïve T-cell compartment is drained by a high rate of mature naïve cell loss in the periphery due to bystander apoptosis or activation-induced differentiation. X4 viruses could play a role in the depletion of naïve T cells in poor immunological responders to HAART by triggering persistent T-cell activation and bystander apoptosis via gp120-CXCR4 interactions.


2002 ◽  
Vol 76 (5) ◽  
pp. 2206-2216 ◽  
Author(s):  
Xia Jin ◽  
Murugappan Ramanathan, ◽  
Shady Barsoum ◽  
Geoffrey R. Deschenes ◽  
Lei Ba ◽  
...  

ABSTRACT In order to boost immune responses in persons in whom highly active antiretroviral therapy (HAART) was initiated within 120 days of the onset of symptoms of newly acquired human immunodeficiency virus type 1 (HIV-1) infection, we administered vaccines containing a canarypox virus vector, vCP1452, with HIV-1 genes encoding multiple HIV-1 proteins, and recombinant gp160. Fifteen HIV-1-infected subjects who achieved sustained suppression of plasma viremia for at least 2 years were enrolled. While continuing antiretroviral therapy, each subject received at least four intramuscular injections of the vaccines on days 0, 30, 90, and 180. Adverse events were mild, with the most common being transient tenderness at the vCP1452 injection site. Of the 14 patients who completed vaccination, 13 had significant increases in anti-gp120 or anti-p24 antibody titers, and 9 had transient augmentation of their T-cell proliferation responses to gp160 and/or p24. HIV-1-specific CD8+ T cells were quantified using an intracellular gamma interferon staining assay. Among 11 patients who had increased CD8+ T-cell responses, seven had responses to more than one HIV-1 antigen. In summary, vaccination with vCP1452 and recombinant gp160 appears safe and immunogenic in newly HIV-1-infected patients on HAART.


2006 ◽  
Vol 80 (6) ◽  
pp. 2665-2674 ◽  
Author(s):  
Michele Di Mascio ◽  
Irini Sereti ◽  
Lynn T. Matthews ◽  
Ven Natarajan ◽  
Joseph Adelsberger ◽  
...  

ABSTRACT Both naïve CD4+ and naïve CD8+ T cells are depleted in individuals with human immunodeficiency virus type 1 (HIV-1) infection by unknown mechanisms. Analysis of their dynamics prior to and after highly active antiretroviral therapy (HAART) could reveal possible mechanisms of depletion. Twenty patients were evaluated with immunophenotyping, intracellular Ki67 staining, T-cell receptor excision circle (TREC) quantitation in sorted CD4 and CD8 cells, and thymic computed tomography scans prior to and ∼6 and ∼18 months after initiation of HAART. Naïve T-cell proliferation decreased significantly during the first 6 months of therapy (P < 0.01) followed by a slower decline. Thymic indices did not change significantly over time. At baseline, naïve CD4+ T-cell numbers were lower than naive CD8+ T-cell numbers; after HAART, a greater increase in naïve CD4+ T cells than naïve CD8+ T cells was observed. A greater relative change (n-fold) in the number of TREC+ T cells/μl than in naïve T-cell counts was observed at 6 months for both CD4+ (median relative change [n-fold] of 2.2 and 1.7, respectively; P < 0.01) and CD8+ T cell pools (1.4 and 1.2; P < 0.01). A more pronounced decrease in the proliferation than the disappearance rate of naïve T cells after HAART was observed in a second group of six HIV-1-infected patients studied by in vivo pulse labeling with bromodeoxyuridine. These observations are consistent with a mathematical model where the HIV-1-induced increase in proliferation of naïve T cells is mostly explained by a faster recruitment into memory cells.


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