STING-driven interferon signaling triggers metabolic alterations in pancreas cancer cells visualized by [18F]FLT PET imaging

Type I interferons (IFNs) are critical effectors of emerging cancer immunotherapies designed to activate pattern recognition receptors (PRRs). A challenge in the clinical translation of these agents is the lack of noninvasive pharmacodynamic biomarkers that indicate increased intratumoral IFN signaling following PRR activation. Positron emission tomography (PET) imaging enables the visualization of tissue metabolic activity, but whether IFN signaling–induced alterations in tumor cell metabolism can be detected using PET has not been investigated. We found that IFN signaling augments pancreatic ductal adenocarcinoma (PDAC) cell nucleotide metabolism via transcriptional induction of metabolism-associated genes including thymidine phosphorylase (TYMP). TYMP catalyzes the first step in the catabolism of thymidine, which competitively inhibits intratumoral accumulation of the nucleoside analog PET probe 3′-deoxy-3′-[18F]fluorothymidine ([18F]FLT). Accordingly, IFN treatment up-regulates cancer cell [18F]FLT uptake in the presence of thymidine, and this effect is dependent upon TYMP expression. In vivo, genetic activation of stimulator of interferon genes (STING), a PRR highly expressed in PDAC, enhances the [18F]FLT avidity of xenograft tumors. Additionally, small molecule STING agonists trigger IFN signaling–dependent TYMP expression in PDAC cells and increase tumor [18F]FLT uptake in vivo following systemic treatment. These findings indicate that [18F]FLT accumulation in tumors is sensitive to IFN signaling and that [18F]FLT PET may serve as a pharmacodynamic biomarker for STING agonist–based therapies in PDAC and possibly other malignancies characterized by elevated STING expression.

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Development of a blood sample detector for multi-tracer positron emission tomography using gamma spectroscopy

EJNMMI Physics ◽

10.1186/s40658-019-0263-x ◽

2019 ◽

Vol 6 (1) ◽

Cited By ~ 1

Author(s):

Carlos Velasco ◽

Adriana Mota-Cobián ◽

Jesús Mateo ◽

Samuel España

Keyword(s):

Positron Emission Tomography ◽

Blood Sample ◽

Pet Imaging ◽

Spectroscopic Analysis ◽

Gamma Spectroscopy ◽

Emission Tomography ◽

Blood Samples ◽

Positron Emission

Abstract Background Multi-tracer positron emission tomography (PET) imaging can be accomplished by applying multi-tracer compartment modeling. Recently, a method has been proposed in which the arterial input functions (AIFs) of the multi-tracer PET scan are explicitly derived. For that purpose, a gamma spectroscopic analysis is performed on blood samples manually withdrawn from the patient when at least one of the co-injected tracers is based on a non-pure positron emitter. Alternatively, these blood samples required for the spectroscopic analysis may be obtained and analyzed on site by an automated detection device, thus minimizing analysis time and radiation exposure of the operating personnel. In this work, a new automated blood sample detector based on silicon photomultipliers (SiPMs) for single- and multi-tracer PET imaging is presented, characterized, and tested in vitro and in vivo. Results The detector presented in this work stores and analyzes on-the-fly single and coincidence detected events. A sensitivity of 22.6 cps/(kBq/mL) and 1.7 cps/(kBq/mL) was obtained for single and coincidence events respectively. An energy resolution of 35% full-width-half-maximum (FWHM) at 511 keV and a minimum detectable activity of 0.30 ± 0.08 kBq/mL in single mode were obtained. The in vivo AIFs obtained with the detector show an excellent Pearson’s correlation (r = 0.996, p < 0.0001) with the ones obtained from well counter analysis of discrete blood samples. Moreover, in vitro experiments demonstrate the capability of the detector to apply the gamma spectroscopic analysis on a mixture of 68Ga and 18F and separate the individual signal emitted from each one. Conclusions Characterization and in vivo evaluation under realistic experimental conditions showed that the detector proposed in this work offers excellent sensibility and stability. The device also showed to successfully separate individual signals emitted from a mixture of radioisotopes. Therefore, the blood sample detector presented in this study allows fully automatic AIFs measurements during single- and multi-tracer PET studies.

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TRIM41 is required to innate antiviral response by polyubiquitinating BCL10 and recruiting NEMO

Signal Transduction and Targeted Therapy ◽

10.1038/s41392-021-00477-8 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Zhou Yu ◽

Xuelian Li ◽

Mingjin Yang ◽

Jiaying Huang ◽

Qian Fang ◽

...

Keyword(s):

Nucleic Acids ◽

Ubiquitin Ligase ◽

E3 Ubiquitin Ligase ◽

B Cell Lymphoma ◽

Antiviral Response ◽

Type I Interferons ◽

Type I ◽

Innate Response ◽

Innate Antiviral Response

AbstractSensing of pathogenic nucleic acids by pattern recognition receptors (PRR) not only initiates anti-microbe defense but causes inflammatory and autoimmune diseases. E3 ubiquitin ligase(s) critical in innate response need to be further identified. Here we report that the tripartite motif-containing E3 ubiquitin ligase TRIM41 is required to innate antiviral response through facilitating pathogenic nucleic acids-triggered signaling pathway. TRIM41 deficiency impairs the production of inflammatory cytokines and type I interferons in macrophages after transfection with nucleic acid-mimics and infection with both DNA and RNA viruses. In vivo, TRIM41 deficiency leads to impaired innate response against viruses. Mechanistically, TRIM41 directly interacts with BCL10 (B cell lymphoma 10), a core component of CARD proteins−BCL10 − MALT1 (CBM) complex, and modifies the Lys63-linked polyubiquitylation of BCL10, which, in turn, hubs NEMO for activation of NF-κB and TANK-binding kinase 1 (TBK1) − interferon regulatory factor 3 (IRF3) pathways. Our study suggests that TRIM41 is the potential universal E3 ubiquitin ligase responsible for Lys63 linkage of BCL10 during innate antiviral response, adding new insight into the molecular mechanism for the control of innate antiviral response.

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11C- and 18F-Radiotracers for In Vivo Imaging of the Dopamine System: Past, Present and Future

Biomedicines ◽

10.3390/biomedicines9020108 ◽

2021 ◽

Vol 9 (2) ◽

pp. 108

Author(s):

Michael R. Kilbourn

Keyword(s):

Pet Imaging ◽

In Vivo Imaging ◽

Dopamine Synthesis ◽

Dopamine System ◽

Synaptic Release ◽

Positron Emission ◽

The Central Nervous System ◽

Pet Radiotracers ◽

Selection Of

The applications of positron emission tomography (PET) imaging to study brain biochemistry, and in particular the aspects of dopamine neurotransmission, have grown significantly over the 40 years since the first successful in vivo imaging studies in humans. In vivo PET imaging of dopaminergic functions of the central nervous system (CNS) including dopamine synthesis, vesicular storage, synaptic release and receptor binding, and reuptake processes, are now routinely used for studies in neurology, psychiatry, drug abuse and addiction, and drug development. Underlying these advances in PET imaging has been the development of the unique radiotracers labeled with positron-emitting radionuclides such as carbon-11 and fluorine-18. This review focuses on a selection of the more accepted and utilized PET radiotracers currently available, with a look at their past, present and future.

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HIV-Infected Macrophages Are Infected and Killed by the Interferon-Sensitive Rhabdovirus MG1

Journal of Virology ◽

10.1128/jvi.01953-20 ◽

2021 ◽

Vol 95 (9) ◽

Author(s):

Teslin S. Sandstrom ◽

Nischal Ranganath ◽

Stephanie C. Burke Schinkel ◽

Syim Salahuddin ◽

Oussama Meziane ◽

...

Keyword(s):

Cancer Cells ◽

Oncolytic Viruses ◽

Type I Interferons ◽

Viral Reservoir ◽

Type I ◽

Antiviral Signaling ◽

Infected Cells ◽

Hiv 1

ABSTRACT The use of unique cell surface markers to target and eradicate HIV-infected cells has been a longstanding objective of HIV-1 cure research. This approach, however, overlooks the possibility that intracellular changes present within HIV-infected cells may serve as valuable therapeutic targets. For example, the identification of dysregulated antiviral signaling in cancer has led to the characterization of oncolytic viruses capable of preferentially killing cancer cells. Since impairment of cellular antiviral machinery has been proposed as a mechanism by which HIV-1 evades immune clearance, we hypothesized that HIV-infected macrophages (an important viral reservoir in vivo) would be preferentially killed by the interferon-sensitive oncolytic Maraba virus MG1. We first showed that HIV-infected monocyte-derived macrophages (MDM) were more susceptible to MG1 infection and killing than HIV-uninfected cells. As MG1 is highly sensitive to type I interferons (IFN-I), we then investigated whether we could identify IFN-I signaling differences between HIV-infected and uninfected MDM and found evidence of impaired IFN-α responsiveness within HIV-infected cells. Finally, to assess whether MG1 could target a relevant, primary cell reservoir of HIV-1, we investigated its effects in alveolar macrophages (AM) obtained from effectively treated individuals living with HIV-1. As observed with in vitro-infected MDM, we found that HIV-infected AM were preferentially eliminated by MG1. In summary, the oncolytic rhabdovirus MG1 appears to preferentially target and kill HIV-infected cells via impairment of antiviral signaling pathways and may therefore provide a novel approach to an HIV-1 cure. IMPORTANCE Human immunodeficiency virus type 1 (HIV-1) remains a treatable, but incurable, viral infection. The establishment of viral reservoirs containing latently infected cells remains the main obstacle in the search for a cure. Cure research has also focused on only one cellular target of HIV-1 (the CD4+ T cell) while largely overlooking others (such as macrophages) that contribute to HIV-1 persistence. In this study, we address these challenges by describing a potential strategy for the eradication of HIV-infected macrophages. Specifically, we show that an engineered rhabdovirus—initially developed as a cancer therapy—is capable of preferential infection and killing of HIV-infected macrophages, possibly via the same altered antiviral signaling seen in cancer cells. As this rhabdovirus is currently being explored in phase I/II clinical trials, there is potential for this approach to be readily adapted for use within the HIV-1 cure field.

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Abstract 2876: Early Retention and Subsequent Engraftment of Transplanted Progenitor Cells is Improved by Delivery within Collagen Matrix

Circulation ◽

10.1161/circ.118.suppl_18.s_790-b ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Yan Zhang ◽

Marc Lamoureux ◽

Stephanie Thorn ◽

Vincent Chan ◽

Joel Price ◽

...

Keyword(s):

Cell Therapy ◽

Progenitor Cells ◽

Pet Imaging ◽

Ex Vivo ◽

Collagen Matrix ◽

Cell Labeling ◽

Type I ◽

The Matrix ◽

Early Retention

Background: To investigate the mechanisms involved in the potentiation of cell therapy by delivery matrices, we evaluated the retention and engraftment of transplanted human circulating progenitor cells (CPCs) injected in a collagen matrix by using in vivo positron emission tomography (PET) imaging, ex vivo biodistribution, and immunohistochemistry. Methods: CPCs were labeled with 18 F-FDG and injected with or without a collagen type I-based matrix in the ischemic hindlimb muscle (IM) of rats (2x10 6 cells; n=15/group). Localization of cells was acquired by PET imaging (15 min) at 150 min post-injection. In addition, radionuclide biodistribution, immunofluorescence, and immunohistochemical examination of transplanted CPCs were performed at up to 14 days. Results: Cell labeling efficiency was CPC-concentration dependent (r=0.61, p <0.001), but not 18 F-FDG-dose dependent. Labeled CPCs exhibited excellent short-term stability and viability. Persistence of 18 F-FDG radioactivity in cells was markedly greater than non-specific retention in the matrix. Wholebody (WB) PET images revealed better CPC retention in the IM and less non-specific leakage to other tissues when CPCs were delivered within the matrix (IM/WB retention ratio of 43.9±8.2%), compared to cells injected alone (22.3±10.4%; p =0.040) and to 18 F-FDG injected with or without the matrix (9.7±5.5% and 11.0±5.5%, respectively; p <0.005). Radioactivity biodistribution confirmed that accumulation was increased (by 92.5%; p =0.024) in the IM and reduced (by 1.1 to 23.8%; p <0.05) in non-specific tissues when cells were injected within the matrix, compared to cells injected alone. Anti-human mitochondria staining showed increased cell retention in the IM with use of matrices (3.0±2.1%) versus cells only (1.9±0.8%; p =0.048). At 14 days the number of CD31 + transplanted human cells was greater (1.6±0.1%) when injected within the matrix than injected alone (0.7±0.1%; p =0.004). Conclusions: Collagen-based delivery matrices improve the early retention of transplanted CPCs, which in turn favors subsequent cell engraftment in the ischemic tissue. This mechanism conferred by the matrix has potential implications for the optimization of cell therapy at the early stages after cell delivery.

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Thioredoxin 2 Negatively Regulates Innate Immunity to RNA Viruses by Disrupting the Assembly of the Virus-Induced Signaling Adaptor Complex

Journal of Virology ◽

10.1128/jvi.01756-19 ◽

2020 ◽

Vol 94 (7) ◽

Cited By ~ 1

Author(s):

Dan Li ◽

Wenping Yang ◽

Yi Ru ◽

Jingjing Ren ◽

Xiangtao Liu ◽

...

Keyword(s):

Complex Formation ◽

Rna Viruses ◽

Critical Role ◽

Type I Interferons ◽

Type I ◽

Host Proteins ◽

Innate Antiviral Response ◽

Thioredoxin 2

ABSTRACT The virus-induced signaling adaptor (VISA) complex plays a critical role in the innate immune response to RNA viruses. However, the mechanism of VISA complex formation remains unclear. Here, we demonstrate that thioredoxin 2 (TRX2) interacts with VISA at mitochondria both in vivo and in vitro. Knockdown and knockout of TRX2 enhanced the formation of the VISA-associated complex, as well as virus-triggered activation of interferon regulatory factor 3 (IRF3) and transcription of the interferon beta 1 (IFNB1) gene. TRX2 inhibits the formation of VISA aggregates by repressing reactive oxygen species (ROS) production, thereby disrupting the assembly of the VISA complex. Furthermore, our data suggest that the C93 residue of TRX2 is essential for inhibition of VISA aggregation, whereas the C283 residue of VISA is required for VISA aggregation. Collectively, these findings uncover a novel mechanism of TRX2 that negatively regulates VISA complex formation. IMPORTANCE The VISA-associated complex plays pivotal roles in inducing type I interferons (IFNs) and eliciting the innate antiviral response. Many host proteins are identified as VISA-associated-complex proteins, but how VISA complex formation is regulated by host proteins remains enigmatic. We identified the TRX2 protein as an important regulator of VISA complex formation. Knockout of TRX2 increases virus- or poly(I·C)-triggered induction of type I IFNs at the VISA level. Mechanistically, TRX2 inhibits the production of ROS at its C93 site, which impairs VISA aggregates at its C283 site, and subsequently impedes the assembly of the VISA complex. Our findings suggest that TRX2 plays an important role in the regulation of VISA complex assembly.

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Imaging Cardiovascular and Lung Macrophages With the Positron Emission Tomography Sensor 64 Cu-Macrin in Mice, Rabbits, and Pigs

Circulation Cardiovascular Imaging ◽

10.1161/circimaging.120.010586 ◽

2020 ◽

Vol 13 (10) ◽

Cited By ~ 1

Author(s):

Matthias Nahrendorf ◽

Friedrich Felix Hoyer ◽

Anu E. Meerwaldt ◽

Mandy M.T. van Leent ◽

Max L. Senders ◽

...

Keyword(s):

Positron Emission Tomography ◽

Flow Cytometry ◽

Confocal Microscopy ◽

Pet Imaging ◽

Near Infrared ◽

Emission Tomography ◽

Imaging Biomarker ◽

Positron Emission ◽

Pulmonary Macrophages

Background: Macrophages, innate immune cells that reside in all organs, defend the host against infection and injury. In the heart and vasculature, inflammatory macrophages also enhance tissue damage and propel cardiovascular diseases. Methods: We here use in vivo positron emission tomography (PET) imaging, flow cytometry, and confocal microscopy to evaluate quantitative noninvasive assessment of cardiac, arterial, and pulmonary macrophages using the nanotracer 64 Cu-Macrin—a 20-nm spherical dextran nanoparticle assembled from nontoxic polyglucose. Results: PET imaging using 64 Cu-Macrin faithfully reported accumulation of macrophages in the heart and lung of mice with myocardial infarction, sepsis, or pneumonia. Flow cytometry and confocal microscopy detected the near-infrared fluorescent version of the nanoparticle ( VT680 Macrin) primarily in tissue macrophages. In 5-day-old mice, 64 Cu-Macrin PET imaging quantified physiologically more numerous cardiac macrophages. Upon intravenous administration of 64 Cu-Macrin in rabbits and pigs, we detected heightened macrophage numbers in the infarcted myocardium, inflamed lung regions, and atherosclerotic plaques using a clinical PET/magnetic resonance imaging scanner. Toxicity studies in rats and human dosimetry estimates suggest that 64 Cu-Macrin is safe for use in humans. Conclusions: Taken together, these results indicate 64 Cu-Macrin could serve as a facile PET nanotracer to survey spatiotemporal macrophage dynamics during various physiological and pathological conditions. 64 Cu-Macrin PET imaging could stage inflammatory cardiovascular disease activity, assist disease management, and serve as an imaging biomarker for emerging macrophage-targeted therapeutics.

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PET Imaging of [11C]MPC-6827, a Microtubule-Based Radiotracer in Non-Human Primate Brains

Molecules ◽

10.3390/molecules25102289 ◽

2020 ◽

Vol 25 (10) ◽

pp. 2289

Author(s):

Naresh Damuka ◽

Paul Czoty ◽

Ashley Davis ◽

Michael Nader ◽

Susan Nader ◽

...

Keyword(s):

Pet Imaging ◽

Neurological Disorders ◽

Healthy Male ◽

Time Activity ◽

Positron Emission ◽

Pet Ct ◽

Scan Data ◽

The Brain ◽

Human Primate

Dysregulation of microtubules is commonly associated with several psychiatric and neurological disorders, including addiction and Alzheimer’s disease. Imaging of microtubules in vivo using positron emission tomography (PET) could provide valuable information on their role in the development of disease pathogenesis and aid in improving therapeutic regimens. We developed [11C]MPC-6827, the first brain-penetrating PET radiotracer to image microtubules in vivo in the mouse brain. The aim of the present study was to assess the reproducibility of [11C]MPC-6827 PET imaging in non-human primate brains. Two dynamic 0–120 min PET/CT imaging scans were performed in each of four healthy male cynomolgus monkeys approximately one week apart. Time activity curves (TACs) and standard uptake values (SUVs) were determined for whole brains and specific regions of the brains and compared between the “test” and “retest” data. [11C]MPC-6827 showed excellent brain uptake with good pharmacokinetics in non-human primate brains, with significant correlation between the test and retest scan data (r = 0.77, p = 0.023). These initial evaluations demonstrate the high translational potential of [11C]MPC-6827 to image microtubules in the brain in vivo in monkey models of neurological and psychiatric diseases.

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Targeting JAK/STAT pathway in Takayasu’s arteritis

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2019-216900 ◽

2020 ◽

Vol 79 (7) ◽

pp. 951-959 ◽

Cited By ~ 5

Author(s):

Paul Régnier ◽

Alexandre Le Joncour ◽

Anna Maciejewski-Duval ◽

Anne-Claire Desbois ◽

Cloé Comarmond ◽

...

Keyword(s):

T Cells ◽

Cd8 T Cells ◽

Takayasu’S Arteritis ◽

Signalling Pathway ◽

Janus Kinase ◽

Type I Interferons ◽

Type I ◽

Takayasu's Arteritis

ObjectiveTakayasu’s arteritis (TAK) is a large vessel vasculitis with important infiltration of proinflammatory T cells in the aorta and its main branches, but its aetiology is still unknown. Our work aims to explore the involvement of Janus Kinase/Signal Transducers and Activators of Transcription (JAK/STAT) signalling pathway in proinflammatory T cells differentiation and disease activity of TAK.MethodsWe analysed transcriptome and interferons gene signatures of fluorescence-activated cell sorting (FACS-sorted) CD4+ and CD8+ T cells from healthy donors (HD) and in 25 TAK (median age of 37.6 years including 21 active TAK with National Institutes of Health (NIH) score >1). Then we tested, in vitro and in vivo, the effects of JAK inhibitors (JAKinibs) in TAK.ResultsTranscriptome analysis showed 248 and 432 significantly dysregulated genes for CD4+ and CD8+ samples between HD and TAK, respectively. Among dysregulated genes, we highlighted a great enrichment for pathways linked to type I and type II interferons, JAK/STAT and cytokines/chemokines-related signalling in TAK. We confirmed by Real Time Reverse Transcription Polymerase Chain Reaction (RT-qPCR) the upregulation of type I interferons gene signature in TAK as compared with HD. JAKinibs induced both in vitro and in vivo a significant reduction of CD25 expression by CD4+ and CD8+ T cells, a significant decrease of type 1 helper T cells (Th1) and Th17 cells and an increase of Tregs cells in TAK. JAKinibs also decreased C reactive protein level, NIH score and corticosteroid dose in TAK patients.ConclusionsJAK/STAT signalling pathway is critical in the pathogenesis of TAK and JAKinibs may be a promising therapy.

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pDC Activation by TLR7/8 Ligand CL097 Compared to TLR7 Ligand IMQ or TLR9 Ligand CpG

Journal of Immunology Research ◽

10.1155/2019/1749803 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10

Author(s):

Jing Wu ◽

Shuang Li ◽

Tete Li ◽

Xinping Lv ◽

Mingyou Zhang ◽

...

Keyword(s):

Type I Interferons ◽

Phenotypic Change ◽

Type I ◽

Antitumor Effects ◽

Tlr9 Ligand ◽

New Strategy ◽

Cytotoxic Molecules ◽

Tlr7 Ligand

Plasmacytoid dendritic cells (pDCs) express high levels of the toll-like receptors (TLRs) TLR7 and TLR9. In response to TLR7 and TLR9 ligands, pDCs are primary producers of type I interferons. Our previous study demonstrated that pDCs activated by the TLR7 ligand imiquimod (IMQ) and the TLR9 ligand CpG A can kill breast cancer cells in vitro and inhibit tumor growth in vivo. Moreover, we observed a distinctive morphological, phenotypic change in pDCs after activation by IMQ and CpG A. However, the effect of other TLR7 and TLR9 ligands on pDCs remains less understood. In this study, we treat pDCs with the TLR7 ligand IMQ, TLR7/8 ligands (CL097 and CL075), and three TLR9 ligands (different types of CpGs). The size of pDCs increased significantly after activation by TLR7, or TLR7/8 ligands. TLR7, TLR7/8, and TLR9 ligands similarly modulated cytokine release, as well as protein expression of pDC markers, costimulatory molecules, and cytotoxic molecules. Interestingly, TLR7/8 ligands, especially CL097, induced stronger responses. These results are relevant to the further study of the role and mechanism of pDC-induced antitumor effects and may aid in the development of a new strategy for future tumor immunotherapy.

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