scholarly journals ADAP1 promotes latent HIV-1 reactivation by selectively tuning a T cell signaling-transcriptional axis

2021 ◽  
Author(s):  
Nora Guadalupe Ramirez ◽  
Jeon Lee ◽  
Yue Zheng ◽  
Lianbo Li ◽  
Bryce Dennis ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Signaling ◽  
Ph Domain ◽  
T Cell Signaling ◽  
Cellular Assays ◽  
Biological Responses ◽  
T Cell Stimulation ◽  
Infected Cells ◽  
Latent Hiv ◽  
Hiv 1

Immune stimulation fuels cell signaling transcriptional programs inducing biological responses to eliminate virus infected cells. Yet, retroviruses that integrate into host cell chromatin, such as HIV1, coopt these programs to switch between latent and reactivated states; however, the regulatory mechanisms are still unfolding. Here, we implemented a functional screen leveraging HIV1 dependence on CD4+ T cell signaling transcriptional programs and discovered ADAP1 is an undescribed modulator of HIV1 proviral fate. Specifically, we report ADAP1 (ArfGAP with dual PH domain containing protein 1), a previously thought neuronal restricted factor, is an amplifier of select T cell signaling programs. Using complementary biochemical and cellular assays, we demonstrate ADAP1 inducibly interacts with the immune signalosome to directly stimulate KRAS GTPase activity thereby augmenting T cell signaling through targeted activation of the ERK/AP1 axis. Single cell transcriptomics analysis revealed loss of ADAP1 function blunts gene programs upon T cell stimulation consequently dampening latent HIV1 reactivation. Our combined experimental approach defines ADAP1 as an unexpected tuner of T cell programs coopted by HIV1 for latency escape.

scholarly journals Strength of T cell signaling regulates HIV-1 replication and establishment of latency

2018 ◽  
Author(s):  
M Gagne ◽  
D Michaels ◽  
GM Schiralli Lester ◽  
WW Wong ◽  
S Gummuluru ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Signaling ◽  
Latent Reservoir ◽  
Binding Affinities ◽  
Antigen Receptors ◽  
T Cell Signaling ◽  
Chimeric Antigen Receptors ◽  
Latently Infected ◽  
Infected Cells ◽  
Hiv 1

AbstractA major barrier to curing HIV is the long-lived latent reservoir that supports re-emergence of HIV upon treatment interruption. Targeting this reservoir will require mechanistic insights into the establishment and maintenance of HIV latency. Whether T cell signaling at the time of HIV-1 infection influences productive replication or latency is not fully understood. We used a panel of chimeric antigen receptors (CARs) with different ligand binding affinities to induce a range of signaling strengths to model differential T cell receptor signaling at the time of HIV-1 infection. Stimulation of T cell lines or primary CD4+ T cells expressing chimeric antigen receptors supported HIV-1 infection regardless of affinity for ligand; however, only signaling by the highest affinity receptor facilitated HIV-1 expression. Activation of chimeric antigen receptors that had intermediate and low binding affinities did not support provirus transcription, suggesting that a minimal signal is required for optimal HIV-1 expression. In addition, strong signaling at the time of infection produced a latent population that was readily inducible, whereas latent cells generated in response to weaker signals were not easily reversed. Chromatin immunoprecipitation showed HIV-1 transcription was limited by transcriptional elongation and that robust signaling decreased the presence of negative elongation factor, a pausing factor, by more than 80%. These studies demonstrate that T cell signaling influences HIV-1 infection and the establishment of different subsets of latently infected cells, which may have implications for targeting the HIV reservoir.Author SummaryActivation of CD4+ T cells facilitates HIV-1 infection; however, whether there are minimal signals required for the establishment of infection, replication, and latency has not been explored. To determine how T cell signaling influences HIV-1 infection and the generation of latently infected cells, we used chimeric antigen receptors to create a tunable model. Stronger signals result in robust HIV-1 expression and an inducible latent population. Minimal signals predispose cells towards latent infections that are refractory to reversal. We discovered that repression of HIV-1 transcription immediately after infection is due to RNA polymerase II pausing and inefficient transcription elongation. These studies demonstrate that signaling events influence the course of HIV-1 infection and have implications for cure strategies. They also provide a mechanistic explanation for why a significant portion of the HIV latent reservoir is not responsive to latency reversing agents which function by modifiying chromatin.

scholarly journals T cell stimulation remodels the latently HIV-1 infected cell population by differential activation of proviral chromatin

2021 ◽  
Author(s):  
Birgitta Lindqvist ◽  
Wlaa Assi ◽  
Julie Roux ◽  
Luca Love ◽  
Bianca B. Jütte ◽  
...  
Keyword(s):  
T Cell ◽  
Infected Cell ◽  
Zinc Finger Protein ◽  
Single Cells ◽  
Continuous Production ◽  
Cell Stimulation ◽  
T Cell Stimulation ◽  
Infected Cells ◽  
Latent Hiv ◽  
Hiv 1

AbstractThe reservoir of latently HIV-1 infected cells is heterogeneous. To achieve an HIV-1 cure, the reservoir of activatable proviruses should be eliminated while permanently silenced proviruses may be tolerated. We have developed a method to assess the proviral nuclear microenvironment in single cells. In latently HIV-1 infected cells, a zinc finger protein tethered to the HIV-1 promoter produced a fluorescent signal as a protein of interest came in its proximity, such as the viral transactivator Tat when recruited to the nascent RNA. Tat is essential for viral replication. In these cells we assessed the proviral activation and chromatin composition. By linking Tat recruitment to proviral activity, we dissected the mechanisms of HIV-1 latency reversal and the consequences of HIV-1 production. A pulse of promoter-associated Tat was identified that contrasted to the continuous production of viral proteins. As expected, promoter H3K4me3 led to substantial expression of the provirus following T cell stimulation. However, the activation-induced cell cycle arrest and death led to a surviving cell fraction with proviruses encapsulated in repressive chromatin. Further, this cellular model was used to reveal mechanisms of action of small molecules. In a proof-of-concept study we determined the effect of an enhancer specific CBP/P300-inhibitor on HIV-1 latency reversal. Only proviruses resembling active enhancers, associated with H3K4me1 and H3K27ac, efficiently recruited Tat. Tat-independent HIV-1 latency reversal of unknown significance still occurred. We present a method for single cell assessment of the microenvironment of the latent HIV-1 proviruses, used here to reveal how T cell stimulation modulates the proviral activity and how the subsequent fate of the infected cell depends on the chromatin context.

scholarly journals BTLA and PD-1 employ distinct phosphatases to differentially repress T cell signaling

2019 ◽  
Author(s):  
Xiaozheng Xu ◽  
Amitkumar Fulzele ◽  
Yunlong Zhao ◽  
Zijun Wu ◽  
Yanyan Hu ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Signaling ◽  
Cell Activity ◽  
Immune Checkpoints ◽  
Clinical Activity ◽  
T Cell Signaling ◽  
Tcr Signaling ◽  
Durable Response ◽  
Infected Cells ◽  
Cell Death Protein

ABSTRACTT cell-mediated destruction of tumors and virus-infected cells is restricted by co-inhibitory receptors such as programmed cell death protein 1 (PD-1). Monoclonal antibodies blocking PD-1 have produced impressive clinical activity against human cancers, but durable response is limited to a minority of patients. Previous results suggest that B and T lymphocyte attenuator (BTLA), a co-inhibitory receptor structurally related to PD-1, may contribute to the resistance to PD-1 targeted therapy and co-blockade of BTLA can enhance the efficacy of anti-PD-1 immunotherapy. However, the biochemical mechanism by which BTLA represses T cell activity and to what extent the mechanism differs from that of PD-1 is unknown. Here we examine differences in the ability of BTLA and PD-1 to recruit effector molecules and regulate T cell signaling. We show that PD-1 and BTLA recruit different tyrosine phosphatases to regulate either CD28 or T cell antigen receptor (TCR)-signaling cascades. Our data reveal unexpected disparities between two structurally related immune checkpoints and two phosphatase paralogs.

scholarly journals Strength of T cell signaling regulates HIV-1 replication and establishment of latency

2019 ◽  
Vol 15 (5) ◽  
pp. e1007802 ◽  
Author(s):  
Matthew Gagne ◽  
Daniel Michaels ◽  
Gillian M. Schiralli Lester ◽  
Suryaram Gummuluru ◽  
Wilson W. Wong ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Signaling ◽  
T Cell Signaling ◽  
Hiv 1

scholarly journals T-Cell Signaling in HIV-1 Infection

2013 ◽  
Vol 7 (1) ◽  
pp. 57-71 ◽  
Author(s):  
Wasim Abbas ◽  
Georges Herbein
Keyword(s):  
T Cell ◽  
Cell Signaling ◽  
Viral Proteins ◽  
Special Focus ◽  
T Cell Signaling ◽  
T Cell Apoptosis ◽  
Cellular Components ◽  
Hiv 1 ◽  
Gain Access

HIV exploits the T-cell signaling network to gain access to downstream cellular components, which serves as effective tools to break the cellular barriers. Multiple host factors and their interaction with viral proteins contribute to the complexity of HIV-1 pathogenesis and disease progression. HIV-1 proteins gp120, Nef, Tat and Vpr alter the T-cell signaling pathways by activating multiple transcription factors including NF-ĸB, Sp1 and AP-1. HIV-1 evades the immune system by developing a multi-pronged strategy. Additionally, HIV-1 encoded proteins influence the apoptosis in the host cell favoring or blocking T-cell apoptosis. Thus, T-cell signaling hijacked by viral proteins accounts for both viral persistence and immune suppression during HIV-1 infection. Here, we summarize past and present studies on HIV-1 T-cell signaling with special focus on the possible role of T cells in facilitating viral infection and pathogenesis

scholarly journals TRIM24 controls induction of latent HIV-1 by stimulating transcriptional elongation

2021 ◽  
Author(s):  
Riley Horvath ◽  
Tom Malcolm ◽  
Matthew Dahabieh ◽  
Ivan Sadowski
Keyword(s):  
T Cell ◽  
Cell Signaling ◽  
T Cell Activation ◽  
Cell Activation ◽  
Elongation Factor ◽  
Transcriptional Elongation ◽  
T Cell Signaling ◽  
Rna Pol Ii ◽  
Pol Ii ◽  
Hiv 1

The conserved HIV-1 LTR cis elements RBE1/3 bind the factor RBF2, consisting of USF1/2 and TFII-I, and are essential for reactivation of HIV-1 by T cell signaling. We determined that TFII-I recruits the tripartite motif protein TRIM24 to the LTR, and this interaction is required for efficient reactivation of HIV-1 expression in response to T cell signaling, similar to the effect of TFII-I depletion. Knockout of TRIM24 did not affect recruitment of RNA Pol II to the LTR promoter, but inhibited transcriptional elongation, an effect that was associated with decreased RNA Pol II CTD S2 phosphorylation and impaired recruitment of CDK9 to the LTR. These results demonstrate that TFII-I promotes transcriptional elongation in response to T cell activation through recruitment of the co-factor TRIM24, which is necessary for efficient recruitment of the elongation factor P-TEFb.

scholarly journals Identification of T cell-signaling pathways that stimulate latent HIV in primary cells

2003 ◽  
Vol 100 (22) ◽  
pp. 12955-12960 ◽  
Author(s):  
D. G. Brooks ◽  
P. A. Arlen ◽  
L. Gao ◽  
C. M. R. Kitchen ◽  
J. A. Zack
Keyword(s):  
T Cell ◽  
Cell Signaling ◽  
Signaling Pathways ◽  
Primary Cells ◽  
T Cell Signaling ◽  
Latent Hiv ◽  
Cell Signaling Pathways

scholarly journals COP9 Signalosome Component JAB1/CSN5 Is Necessary for T Cell Signaling through LFA-1 and HIV-1 Replication

PLoS ONE ◽  
2012 ◽  
Vol 7 (7) ◽  
pp. e41725 ◽  
Author(s):  
Shigemi M. Kinoshita ◽  
Peter O. Krutzik ◽  
Garry P. Nolan
Keyword(s):  
T Cell ◽  
Cell Signaling ◽  
Cop9 Signalosome ◽  
T Cell Signaling ◽  
Hiv 1

scholarly journals CAGE-seq reveals that HIV-1 latent infection does not trigger unique cellular responses in a Jurkat T cell model.

2021 ◽  
Author(s):  
Hiroyuki Matsui ◽  
Kotaro Shirakawa ◽  
Yoshinobu Konishi ◽  
Shigeki Hirabayashi ◽  
Anamaria Daniela Sarca ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Mtor Pathway ◽  
Differentially Expressed ◽  
Transcriptional Responses ◽  
Latently Infected ◽  
Infected Cells ◽  
Latent Hiv ◽  
Hiv 1

The cure for HIV-1 is currently stalled by our inability to specifically identify and target latently infected cells. HIV-1 viral RNA/DNA or viral proteins are recognized by cellular mechanisms and induce interferon responses in virus producing cells, but changes in latently infected cells remain unknown. HIVGKO contains a GFP reporter under the HIV-1 promoter and an mKO2 reporter under the internal EF1α promoter. This viral construct enables direct identification of HIV-1 both productively and latently infected cells. In this study we aim to identify specific cellular transcriptional responses triggered by HIV-1 entry and integration using Cap Analysis of Gene Expression (CAGE). We deep sequenced CAGE tags in uninfected, latently and productively infected cells and compared their differentially expressed transcription start site (TSS) profiles. Virus producing cells had differentially expressed TSSs related to T-cell activation and apoptosis when compared to uninfected cells or latently infected cells. Surprisingly, latently infected cells had only 33 differentially expressed TSSs compared to uninfected cells. Among these, SPP1 and APOE were down-regulated in latently infected cells. SPP1 or APOE knockdown in Jurkat T cells increased susceptibility to HIVGKO infection, suggesting that they have anti-viral properties. Components of the PI3K/mTOR pathway, MLST8, 4EBP and RPS6, were significant TSSs in productively infected cells, and S6K phosphorylation was increased compared to latently infected cells, suggesting that mTOR pathway activity plays a role in establishing the latent reservoir. These findings indicate that HIV-1 entry and integration do not trigger unique transcriptional responses when infection becomes latent. Importance: Latent HIV-1 infection is established as early as the first viral exposure and remains the most important barrier in obtaining the cure for HIV-1 infection. Here, we used CAGE to compare the transcriptional landscape of latently infected cells with that of non-infected or productively infected cells. We found that latently infected cells and non-infected cells show quite similar transcriptional profiles. Our data suggest that T-cells cannot recognize incoming viral components nor the integrated HIV-1 genome when infection remains latent. These findings should guide future research into widening our approaches to identify and target latent HIV-1 infected cells.

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