scholarly journals Toll-Like Receptor 7 Agonist GS-9620 Induces HIV Expression and HIV-Specific Immunity in Cells from HIV-Infected Individuals on Suppressive Antiretroviral Therapy

2017 ◽  
Vol 91 (8) ◽  
Author(s):  
Angela Tsai ◽  
Alivelu Irrinki ◽  
Jasmine Kaur ◽  
Tomas Cihlar ◽  
George Kukolj ◽  
...  

ABSTRACT Antiretroviral therapy can suppress HIV replication to undetectable levels but does not eliminate latent HIV, thus necessitating lifelong therapy. Recent efforts to target this persistent reservoir have focused on inducing the expression of latent HIV so that infected cells may be recognized and eliminated by the immune system. Toll-like receptor (TLR) activation stimulates antiviral immunity and has been shown to induce HIV from latently infected cells. Activation of TLR7 leads to the production of several stimulatory cytokines, including type I interferons (IFNs). In this study, we show that the selective TLR7 agonist GS-9620 induced HIV in peripheral blood mononuclear cells (PBMCs) from HIV-infected individuals on suppressive antiretroviral therapy. GS-9620 increased extracellular HIV RNA 1.5- to 2-fold through a mechanism that required type I IFN signaling. GS-9620 also activated HIV-specific T cells and enhanced antibody-mediated clearance of HIV-infected cells. Activation by GS-9620 in combination with HIV peptide stimulation increased CD8 T cell degranulation, production of intracellular cytokines, and cytolytic activity. T cell activation was again dependent on type I IFNs produced by plasmacytoid dendritic cells. GS-9620 induced phagocytic cell maturation and improved effector-mediated killing of HIV-infected CD4 T cells by the HIV envelope-specific broadly neutralizing antibody PGT121. Collectively, these data show that GS-9620 can activate HIV production and improve the effector functions that target latently infected cells. GS-9620 may effectively complement orthogonal therapies designed to stimulate antiviral immunity, such as therapeutic vaccines or broadly neutralizing antibodies. Clinical studies are under way to determine if GS-9620 can target HIV reservoirs. IMPORTANCE Though antiretroviral therapies effectively suppress viral replication, they do not eliminate integrated proviral DNA. This stable intermediate of viral infection is persistently maintained in reservoirs of latently infected cells. Consequently, lifelong therapy is required to maintain viral suppression. Ultimately, new therapies that specifically target and eliminate the latent HIV reservoir are needed. Toll-like receptor agonists are potent enhancers of innate antiviral immunity that can also improve the adaptive immune response. Here, we show that a highly selective TLR7 agonist, GS-9620, activated HIV from peripheral blood mononuclear cells isolated from HIV-infected individuals with suppressed infection. GS-9620 also improved immune effector functions that specifically targeted HIV-infected cells. Previously published studies on the compound in other chronic viral infections show that it can effectively induce immune activation at safe and tolerable clinical doses. Together, the results of these studies suggest that GS-9620 may be useful for treating HIV-infected individuals on suppressive antiretroviral therapy.

2019 ◽  
Vol 93 (6) ◽  
Author(s):  
Nina C. Flerin ◽  
Ariola Bardhi ◽  
Jian Hua Zheng ◽  
Maria Korom ◽  
Joy Folkvord ◽  
...  

ABSTRACT Curing HIV infection has been thwarted by the persistent reservoir of latently infected CD4+ T cells, which reinitiate systemic infection after antiretroviral therapy (ART) interruption. To evaluate reservoir depletion strategies, we developed a novel preclinical in vivo model consisting of immunodeficient mice intrasplenically injected with peripheral blood mononuclear cells (PBMC) from long-term ART-suppressed HIV-infected donors. In the absence of ART, these mice developed rebound viremia which, 2 weeks after PBMC injection, was 1,000-fold higher (mean = 9,229,281 HIV copies/ml) in mice injected intrasplenically than in mice injected intraperitoneally (mean = 6,838 HIV copies/ml) or intravenously (mean = 591 HIV copies/ml). One week after intrasplenic PBMC injection, in situ hybridization of the spleen demonstrated extensive disseminated HIV infection, likely initiated from in vivo-reactivated primary latently infected cells. The time to viremia was delayed significantly by treatment with a broadly neutralizing antibody, 10-1074, compared to treatment with 10-1074-FcRnull, suggesting that 10-1074 mobilized Fc-mediated effector mechanisms to deplete the replication-competent reservoir. This was supported by phylogenetic analysis of Env sequences from viral-outgrowth cultures and untreated, 10-1074-treated, or 10-1074-FcRnull-treated mice. The predominant sequence cluster detected in viral-outgrowth cultures and untreated mouse plasma was significantly reduced in the plasma of 10-1074-treated mice, whereas two new clusters emerged that were not detected in viral-outgrowth cultures or plasma from untreated mice. These new clusters lacked mutations associated with 10-1074 resistance. Taken together, these data indicated that 10-1074 treatment depletes the reservoir of latently infected cells harboring replication competent HIV. Furthermore, this mouse model represents a new in vivo approach for the preclinical evaluation of new HIV cure strategies. IMPORTANCE Sustained remission of HIV infection is prevented by a persistent reservoir of latently infected cells capable of reinitiating systemic infection and viremia. To evaluate strategies to reactivate and deplete this reservoir, we developed and characterized a new humanized mouse model consisting of highly immunodeficient mice intrasplenically injected with peripheral blood mononuclear cells from long-term ART-suppressed HIV-infected donors. Reactivation and dissemination of HIV infection was visualized in the mouse spleens in parallel with the onset of viremia. The applicability of this model for evaluating reservoir depletion treatments was demonstrated by establishing, through delayed time to viremia and phylogenetic analysis of plasma virus, that treatment of these humanized mice with a broadly neutralizing antibody, 10-1074, depleted the patient-derived population of latently infected cells. This mouse model represents a new in vivo approach for the preclinical evaluation of new HIV cure strategies.


2002 ◽  
Vol 13 (3) ◽  
pp. 177-183 ◽  
Author(s):  
X Wang ◽  
M Okamoto ◽  
M Kawamura ◽  
S Izumo ◽  
M Baba

EM2487, a Streptomyces-derived substance, has previously been shown to inhibit HIV-1 replication in both acutely and chronically infected cells. In this study, we found that EM2487 was also a selective inhibitor of human T-lymphotropic virus type I (HTLV-I) replication in persistently infected cells. Its 50% effective concentrations for HTLV-I p19 antigen production were 3.6 and 1.2 μM in MT-2 and MT-4 cells, respectively. However, the compound did not reduce cell proliferation and viability at these concentrations. The 50% cytotoxic concentrations of EM2487 were 30.6 and 5.7 μM in MT-2 and MT-4 cells, respectively. The compound also displayed selective inhibition of HTLV-I production in peripheral blood mononuclear cells obtained from patients with HTLV-I-associated myelopathy/tropical spastic paraparesis. Quantitative reverse transcription PCR analysis revealed that EM2487 selectively suppressed HTLV-I mRNA synthesis in MT-2 cells in a dose-dependent fashion. However, the compound did not inhibit endogenous Tax-induced HTLV-I long terminal repeat-driven reporter gene expression. Furthermore, intracellular Tax accumulation was not suppressed in MT-2 cells exposed to EM2487. These results suggest that the inhibition occurred at the viral transcription level, but it cannot be attributed to the inhibition of the Tax function.


2021 ◽  
Author(s):  
Helen Payne ◽  
Man Chan ◽  
Sarah Watters ◽  
Kennedy Otwombe ◽  
Yuan Hsiao ◽  
...  

Abstract BACKGROUND: Reduction of the reservoir of latent HIV-infected cells might increase the possibility of long-term remission in individuals living with HIV. We investigated factors associated with HIV-1 proviral DNA levels in children receiving different antiretroviral therapy (ART) strategies in the Children with HIV Early Antiretroviral Therapy (CHER) trial. METHODS: Infants with HIV <12 weeks old with CD4% ≥25% were randomized in the CHER trial to early limited ART for 40 or 96 weeks (ART-40W, ART-96W), or deferred ART (ART-Def). For ART-Def infants or following ART interruption in ART-40W/ART-96W, ART was started/re-started for clinical progression or CD4% <25%. In 229 participants, HIV-1 proviral DNA was quantified by PCR from stored peripheral blood mononuclear cells from children who had received ≥24 weeks ART and two consecutive undetectable HIV-1 RNA 12-24 weeks apart. HIV-1 proviral DNA was compared between ART-Def and ART-96W at week 96, and in all arms at week 248. Factors associated with HIV-1 proviral DNA levels were evaluated using linear regression.FINDINGS: Longer duration of ART was significantly associated with lower HIV-1 proviral DNA at both 96 (p=0.0003) and 248 weeks (p=0.0011). Higher total CD8 count at ART initiation was associated with lower HIV-1 proviral DNA at both 96 (p=0.0225) and 248 weeks (p=0.0398). Week 248 HIV-1 proviral DNA was significantly higher in those with positive HIV-1 serology at week 84 than those with negative serology (p=0.0042).INTEPRETATION: Longer ART duration is key to HIV-1 proviral DNA reduction. Further understanding is needed of the effects of “immune-attenuation” through early HIV-1 exposure.FUNDING: Wellcome Trust, National Institutes of Health, Medical Research Council.


Viruses ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 401 ◽  
Author(s):  
Anirban Sanyal ◽  
Nina Wallaschek ◽  
Mandy Glass ◽  
Louis Flamand ◽  
Darren Wight ◽  
...  

Human herpesvirus 6A (HHV-6A) replicates in peripheral blood mononuclear cells (PBMCs) and various T-cell lines in vitro. Intriguingly, the virus can also establish latency in these cells, but it remains unknown what influences the decision between lytic replication and the latency of the virus. Incoming virus genomes are confronted with the nuclear domain 10 (ND10) complex as part of an intrinsic antiviral response. Most herpesviruses can efficiently subvert ND10, but its role in HHV-6A infection remains poorly understood. In this study, we investigated if the ND10 complex affects HHV-6A replication and contributes to the silencing of the virus genome during latency. We could demonstrate that ND10 complex was not dissociated upon infection, while the number of ND10 bodies was reduced in lytically infected cells. Virus replication was significantly enhanced upon knock down of the ND10 complex using shRNAs against its major constituents promyelocytic leukemia protein (PML), hDaxx, and Sp100. In addition, we could demonstrate that viral genes are more efficiently silenced in the presence of a functional ND10 complex. Our data thereby provides the first evidence that the cellular ND10 complex plays an important role in suppressing HHV-6A lytic replication and the silencing of the virus genome in latently infected cells.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Helen Payne ◽  
Man K. Chan ◽  
Sarah A. Watters ◽  
Kennedy Otwombe ◽  
Nei-Yuan Hsiao ◽  
...  

Abstract Background Reduction of the reservoir of latent HIV-infected cells might increase the possibility of long-term remission in individuals living with HIV. We investigated factors associated with HIV-1 proviral DNA levels in children receiving different antiretroviral therapy (ART) strategies in the children with HIV early antiretroviral therapy (CHER) trial. Methods Infants with HIV  <  12 weeks old with CD4%  ≥  25% were randomized in the CHER trial to early limited ART for 40 or 96 weeks (ART-40 W, ART-96 W), or deferred ART (ART-Def). For ART-Def infants or following ART interruption in ART-40 W/ART-96 W, ART was started/re-started for clinical progression or CD4%  <  25%. In 229 participants, HIV-1 proviral DNA was quantified by PCR from stored peripheral blood mononuclear cells from children who had received  ≥  24 weeks ART and two consecutive undetectable HIV-1 RNA 12–24 weeks apart. HIV-1 proviral DNA was compared between ART-Def and ART-96 W at week 96, and in all arms at week 248. Factors associated with HIV-1 proviral DNA levels were evaluated using linear regression. Findings Longer duration of ART was significantly associated with lower HIV-1 proviral DNA at both 96 (p  =  0.0003) and 248 weeks (p  =  0.0011). Higher total CD8 count at ART initiation was associated with lower HIV-1 proviral DNA at both 96 (p  =  0.0225) and 248 weeks (p  =  0.0398). Week 248 HIV-1 proviral DNA was significantly higher in those with positive HIV-1 serology at week 84 than those with negative serology (p  =  0.0042). Intepretation Longer ART duration is key to HIV-1 proviral DNA reduction. Further understanding is needed of the effects of “immune-attenuation” through early HIV-1 exposure. Funding Wellcome Trust, National Institutes of Health, Medical Research Council.


2015 ◽  
Vol 112 (10) ◽  
pp. E1126-E1134 ◽  
Author(s):  
Meghan K. Rothenberger ◽  
Brandon F. Keele ◽  
Stephen W. Wietgrefe ◽  
Courtney V. Fletcher ◽  
Gregory J. Beilman ◽  
...  

Antiretroviral therapy (ART) suppresses HIV replication in most individuals but cannot eradicate latently infected cells established before ART was initiated. Thus, infection rebounds when treatment is interrupted by reactivation of virus production from this reservoir. Currently, one or a few latently infected resting memory CD4 T cells are thought be the principal source of recrudescent infection, but this estimate is based on peripheral blood rather than lymphoid tissues (LTs), the principal sites of virus production and persistence before initiating ART. We, therefore, examined lymph node (LN) and gut-associated lymphoid tissue (GALT) biopsies from fully suppressed subjects, interrupted therapy, monitored plasma viral load (pVL), and repeated biopsies on 12 individuals as soon as pVL became detectable. Isolated HIV RNA-positive (vRNA+) cells were detected by in situ hybridization in LTs obtained before interruption in several patients. After interruption, multiple foci of vRNA+ cells were detected in 6 of 12 individuals as soon as pVL was measureable and in some subjects, in more than one anatomic site. Minimal estimates of the number of rebounding/founder (R/F) variants were determined by single-gene amplification and sequencing of viral RNA or DNA from peripheral blood mononuclear cells and plasma obtained at or just before viral recrudescence. Sequence analysis revealed a large number of R/F viruses representing recrudescent viremia from multiple sources. Together, these findings are consistent with the origins of recrudescent infection by reactivation from many latently infected cells at multiple sites. The inferred large pool of cells and sites to rekindle recrudescent infection highlights the challenges in eradicating HIV.


2005 ◽  
Vol 16 (5) ◽  
pp. 303-313
Author(s):  
Yu Zhong ◽  
Yuji Matsuya ◽  
Hideo Nemoto ◽  
Masao Mori ◽  
Haruo Saito ◽  
...  

Two new phorbol esters, NPB-11 (12- O-methoxymethylphorbol-13-decanoate) and NPB-15 (12- O-benzyloxymethylphorbol-13-decanoate) were synthesized. The compounds exhibited potent anti-HIV-1 activity and low cytotoxicity in MT-4 cells by MTT assay even at a high concentration [50% cytotoxic concentrations (CC50) were 8.32 and 4.39 μg/ml, respectively]. Two inhibitors strongly suppressed HIV-1 (IIIB strain) replication in MT-4 cells with a 50% effective concentration (EC50) of 1.3 and 0.27 ng/ml, respectively. NPB-11 efficiently blocked replication of both X4 and R5 HIV-1 in PHA-activated peripheral blood mononuclear cells and MT-4 cells as revealed by p24 assay. The antiviral activity appeared to be mediated, at least partially, by the down-regulation of the expression of CD4 and the HIV-1 co-receptors, CXCR4 and CCR5. The compounds were also capable of selectively up-regulating HIV-1 expression in a variety of latently infected cell lines and inducing cell death in HIV-1 infected cells. The effect of NPBs on the induction of HIV-1 was specifically blocked by nontoxic doses of a protein kinase C blocker, staurosporine. NPB-11 blocked the spread of HIV-1 released from latently infected ACH-2 cells to MT-4 cells in a co-culture system. When combined with AZT, NPB-11 synergistically inhibited HIV-1 replication in MTT assay using MT-4 cells. These data suggest that these agents might be useful in reducing persistent viral reservoirs in patients and as adjuvant therapy in patients treated with HAART.


2006 ◽  
Vol 81 (3) ◽  
pp. 1305-1312 ◽  
Author(s):  
Milena Iacobelli-Martinez ◽  
Glen R. Nemerow

ABSTRACT Adenoviruses (Ads) are responsible for respiratory, ocular, and gastrointestinal illnesses in humans. While the majority of serotypes utilize coxsackievirus-adenovirus receptor (CAR) as their primary attachment receptor, subgroup B and subgroup D Ad37 serotypes use CD46. Given the propensity of Ad vectors to activate host immune responses, we sought to investigate their potential for type I interferon induction. We found that CD46 Ads were capable of alpha interferon (IFN-α) induction by peripheral blood mononuclear cells and that plasmacytoid dendritic cells (pDCs) were the principal producers of this cytokine. IFN-α induction correlated with the permissivity of pDCs to CD46- but not CAR-utilizing Ad serotypes. A role for Toll-like receptor 9 (TLR9) recognition of Ad was supported by the requirement for viral DNA and efficient endosomal acidification and by the ability of a TLR9-inhibitory oligonucleotide to attenuate IFN-α induction. Cell lines expressing TLR9 that are permissive to infection by both CAR- and CD46-utilizing serotypes showed a preferential induction of TLR9-mediated events by CD46-utilizing Ads. Specifically, the latter virus types induced higher levels of cytokine expression and NF-κB activation in HeLa cells than CAR-dependent Ad types, despite equivalent infection rates. Therefore, infectivity alone is not sufficient for TLR9 activation, but this activation instead is regulated by a specific receptor entry pathway. These data reveal a novel mode of host immune recognition of Ad with implications for Ad pathogenesis and for the use of unconventional Ad vectors for gene delivery and vaccine development.


Blood ◽  
2000 ◽  
Vol 96 (5) ◽  
pp. 1994-1995 ◽  
Author(s):  
Masako Moriuchi ◽  
Hiroyuki Moriuchi

Abstract Although it is widely believed that viral clearance is mediated principally by the destruction of infected cells by cytotoxic T cells, noncytolytic antiviral activity of CD8+ T cells may play a role in preventing the progression to disease in infections with immunodeficiency viruses and hepatitis B virus. We demonstrate here that (1) replication of human T-lymphotropic virus type I (HTLV-I) is more readily detected from CD8+ T-cell–depleted (CD8−) peripheral blood mononuclear cells (PBMCs) of healthy HTLV-I carriers than from unfractionated PBMCs, (2) cocultures of CD8− PBMCs with autologous or allogeneic CD8+ T cells suppressed HTLV-I replication, and (3) CD8+ T-cell anti-HTLV-I activity is not abrogated intrans-well cultures in which CD8+ cells are separated from CD8− PBMCs by a permeable membrane filter. These results suggest that class I-unrestricted noncytolytic anti–HTLV-I activity is mediated, at least in part by a soluble factor(s), and may play a role in the pathogenesis of HTLV-I infection.


Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1798
Author(s):  
Grant R. Campbell ◽  
Stephen A. Spector

Effective antiretroviral therapy has led to significant human immunodeficiency virus type 1 (HIV-1) suppression and improvement in immune function. However, the persistence of integrated proviral DNA in latently infected reservoir cells, which drive viral rebound post-interruption of antiretroviral therapy, remains the major roadblock to a cure. Therefore, the targeted elimination or permanent silencing of this latently infected reservoir is a major focus of HIV-1 research. The most studied approach in the development of a cure is the activation of HIV-1 expression to expose latently infected cells for immune clearance while inducing HIV-1 cytotoxicity—the “kick and kill” approach. However, the complex and highly heterogeneous nature of the latent reservoir, combined with the failure of clinical trials to reduce the reservoir size casts doubt on the feasibility of this approach. This concern that total elimination of HIV-1 from the body may not be possible has led to increased emphasis on a “functional cure” where the virus remains but is unable to reactivate which presents the challenge of permanently silencing transcription of HIV-1 for prolonged drug-free remission—a “block and lock” approach. In this review, we discuss the interaction of HIV-1 and autophagy, and the exploitation of autophagy to kill selectively HIV-1 latently infected cells as part of a cure strategy. The cure strategy proposed has the advantage of significantly decreasing the size of the HIV-1 reservoir that can contribute to a functional cure and when optimised has the potential to eradicate completely HIV-1.


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