scholarly journals SLC19A1 is an importer of the immunotransmitter cGAMP

2019 ◽  
Author(s):  
Anthony F. Cordova ◽  
Christopher Ritchie ◽  
Gaelen T. Hess ◽  
Michael C. Bassik ◽  
Lingyin Li

Abstract2’3’-cyclic-GMP-AMP (cGAMP) is a second messenger that activates the antiviral Stimulator of Interferon Genes (STING) pathway. We recently identified a novel role for cGAMP as a soluble, extracellular immunotransmitter that is produced and secreted by cancer cells. Secreted cGAMP is then sensed by host cells, eliciting an antitumoral immune response. Due to the antitumoral effects of cGAMP, other CDN-based STING agonists are currently under investigation in clinical trials for metastatic solid tumors. However, it is unknown how cGAMP and other CDNs cross the cell membrane to activate intracellular STING. Using a genome-wide CRISPR screen we identified SLC19A1 as the first known importer of cGAMP and other CDNs, including the investigational new drug 2′3′-bisphosphosphothioate-cyclic-di-AMP (2′3′-CDAS). These discoveries will provide insight into cGAMP’s role as an immunotransmitter and aid in the development of more targeted CDN-based cancer therapeutics.

2019 ◽  
Author(s):  
Noori Chai ◽  
Michael S. Haney ◽  
Julien Couthouis ◽  
David W. Morgens ◽  
Alyssa Benjamin ◽  
...  

AbstractMutations in the C9ORF72 gene are the most common cause of amyotrophic lateral sclerosis (ALS). Both toxic gain of function and loss of function pathogenic mechanisms have been proposed. Accruing evidence from mouse knockout studies point to a role for C9ORF72 as a regulator of immune function. To provide further insight into its cellular function, we performed a genome-wide synthetic lethal CRISPR screen in human myeloid cells lacking C9ORF72. We discovered a strong synthetic lethal genetic interaction between C9ORF72 and FIS1, which encodes a mitochondrial membrane protein involved in mitochondrial fission and mitophagy. Mass spectrometry experiments revealed that in C9ORF72 knockout cells, FIS1 strongly bound to a class of immune regulators that activate the receptor for advanced glycation end (RAGE) products and trigger inflammatory cascades. These findings present a novel genetic interactor for C9ORF72 and suggest a compensatory role for FIS1 in suppressing inflammatory signaling in the absence of C9ORF72.


2020 ◽  
Vol 26 (6) ◽  
pp. 459-472
Author(s):  
Laurent Zablocki-Thomas ◽  
Sam A Menzies ◽  
Paul J Lehner ◽  
Nicolas Manel ◽  
Philippe Benaroch

A subset of TLRs is specialised in the detection of incoming pathogens by sampling endosomes for nucleic acid contents. Among them, TLR3 senses the abnormal presence of double-stranded RNA in the endosomes and initiates a potent innate immune response via activation of NF-κB and IRF3. Nevertheless, mechanisms governing TLR3 regulation remain poorly defined. To identify new molecular players involved in the TLR3 pathway, we performed a genome-wide screen using CRISPR/Cas9 technology. We generated TLR3+ reporter cells carrying a NF-κB-responsive promoter that controls GFP expression. Cells were next transduced with a single-guide RNA (sgRNA) library, subjected to sequential rounds of stimulation with poly(I:C) and sorting of the GFP-negative cells. Enrichments in sgRNA estimated by deep sequencing identified genes required for TLR3-induced activation of NF-κB. Among the hits, five genes known to be critically involved in the TLR3 pathway, including TLR3 itself and the chaperone UNC93B1, were identified by the screen, thus validating our strategy. We further studied the top 40 hits and focused on the transcription factor aryl hydrocarbon receptor (AhR). Depletion of AhR had a dual effect on the TLR3 response, abrogating IL-8 production and enhancing IP-10 release. Moreover, in primary human macrophages exposed to poly(I:C), AhR activation enhanced IL-8 and diminished IP-10 release. Overall, these results reveal AhR plays a role in the TLR3 cellular innate immune response.


Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 441
Author(s):  
Fanny Pineau ◽  
Davide Caimmi ◽  
Sylvie Taviaux ◽  
Maurane Reveil ◽  
Laura Brosseau ◽  
...  

Cystic fibrosis (CF) is a chronic genetic disease that mainly affects the respiratory and gastrointestinal systems. No curative treatments are available, but the follow-up in specialized centers has greatly improved the patient life expectancy. Robust biomarkers are required to monitor the disease, guide treatments, stratify patients, and provide outcome measures in clinical trials. In the present study, we outline a strategy to select putative DNA methylation biomarkers of lung disease severity in cystic fibrosis patients. In the discovery step, we selected seven potential biomarkers using a genome-wide DNA methylation dataset that we generated in nasal epithelial samples from the MethylCF cohort. In the replication step, we assessed the same biomarkers using sputum cell samples from the MethylBiomark cohort. Of interest, DNA methylation at the cg11702988 site (ATP11A gene) positively correlated with lung function and BMI, and negatively correlated with lung disease severity, P. aeruginosa chronic infection, and the number of exacerbations. These results were replicated in prospective sputum samples collected at four time points within an 18-month period and longitudinally. To conclude, (i) we identified a DNA methylation biomarker that correlates with CF severity, (ii) we provided a method to easily assess this biomarker, and (iii) we carried out the first longitudinal analysis of DNA methylation in CF patients. This new epigenetic biomarker could be used to stratify CF patients in clinical trials.


Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 675
Author(s):  
Samira Elmanfi ◽  
Mustafa Yilmaz ◽  
Wilson W. S. Ong ◽  
Kofi S. Yeboah ◽  
Herman O. Sintim ◽  
...  

Host cells can recognize cytosolic double-stranded DNAs and endogenous second messengers as cyclic dinucleotides—including c-di-GMP, c-di-AMP, and cGAMP—of invading microbes via the critical and essential innate immune signaling adaptor molecule known as STING. This recognition activates the innate immune system and leads to the production of Type I interferons and proinflammatory cytokines. In this review, we (1) focus on the possible role of bacterial cyclic dinucleotides and the STING/TBK1/IRF3 pathway in the pathogenesis of periodontal disease and the regulation of periodontal immune response, and (2) review and discuss activators and inhibitors of the STING pathway as immune response regulators and their potential utility in the treatment of periodontitis. PubMed/Medline, Scopus, and Web of Science were searched with the terms “STING”, “TBK 1”, “IRF3”, and “cGAS”—alone, or together with “periodontitis”. Current studies produced evidence for using STING-pathway-targeting molecules as part of anticancer therapy, and as vaccine adjuvants against microbial infections; however, the role of the STING/TBK1/IRF3 pathway in periodontal disease pathogenesis is still undiscovered. Understanding the stimulation of the innate immune response by cyclic dinucleotides opens a new approach to host modulation therapies in periodontology.


Cell Reports ◽  
2021 ◽  
Vol 34 (11) ◽  
pp. 108859
Author(s):  
Jessie Kulsuptrakul ◽  
Ruofan Wang ◽  
Nathan L. Meyers ◽  
Melanie Ott ◽  
Andreas S. Puschnik

2016 ◽  
Vol 62 (2) ◽  
pp. 307-313 ◽  
Author(s):  
Sergio Ruiz ◽  
Cristina Mayor-Ruiz ◽  
Vanesa Lafarga ◽  
Matilde Murga ◽  
Maria Vega-Sendino ◽  
...  
Keyword(s):  
A Genome ◽  

Microbiology ◽  
2014 ◽  
Vol 160 (9) ◽  
pp. 1821-1831 ◽  
Author(s):  
Viveshree S. Govender ◽  
Saiyur Ramsugit ◽  
Manormoney Pillay

Adhesion to host cells is a precursor to host colonization and evasion of the host immune response. Conversely, it triggers the induction of the immune response, a process vital to the host’s defence against infection. Adhesins are microbial cell surface molecules or structures that mediate the attachment of the microbe to host cells and thus the host–pathogen interaction. They also play a crucial role in bacterial aggregation and biofilm formation. In this review, we discuss the role of adhesins in the pathogenesis of the aetiological agent of tuberculosis, Mycobacterium tuberculosis. We also provide insight into the structure and characteristics of some of the characterized and putative M. tuberculosis adhesins. Finally, we examine the potential of adhesins as targets for the development of tuberculosis control strategies.


eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Rowena DeJesus ◽  
Francesca Moretti ◽  
Gregory McAllister ◽  
Zuncai Wang ◽  
Phil Bergman ◽  
...  

SQSTM1 is an adaptor protein that integrates multiple cellular signaling pathways and whose expression is tightly regulated at the transcriptional and post-translational level. Here, we describe a forward genetic screening paradigm exploiting CRISPR-mediated genome editing coupled to a cell selection step by FACS to identify regulators of SQSTM1. Through systematic comparison of pooled libraries, we show that CRISPR is superior to RNAi in identifying known SQSTM1 modulators. A genome-wide CRISPR screen exposed MTOR signalling and the entire macroautophagy machinery as key regulators of SQSTM1 and identified several novel modulators including HNRNPM, SLC39A14, SRRD, PGK1 and the ufmylation cascade. We show that ufmylation regulates SQSTM1 by eliciting a cell type-specific ER stress response which induces SQSTM1 expression and results in its accumulation in the cytosol. This study validates pooled CRISPR screening as a powerful method to map the repertoire of cellular pathways that regulate the fate of an individual target protein.


2016 ◽  
Author(s):  
Bony De Kumar ◽  
Hugo J. Parker ◽  
Ariel Paulson ◽  
Mark E. Parrish ◽  
Irina Pushel ◽  
...  

AbstractHoxa1 has diverse functional roles in differentiation and development. We have identified and characterized properties of regions bound by Hoxa1 on a genome-wide basis in differentiating mouse ES cells. Hoxa1 bound regions are enriched for clusters of consensus binding motifs for Hox, Pbx and Meis and many display co-occupancy of Pbx and Meis. Pbx and Meis are members of the TALE family and genome-wide analysis of multiple TALE members (Pbx, Meis, TGIF, Prep1 and Prep2) show that nearly all Hoxa1 targets display occupancy of one or more TALE members. The combinatorial binding patterns of TALE proteins defines distinct classes of Hoxa1 targets and indicates a role as cofactors in modulating the specificity of Hox proteins. We also discovered extensive auto- and cross-regulatory interactions among the Hoxa1 and TALE genes. This study provides new insight into a regulatory network involving combinatorial interactions between Hoxa1 and TALE proteins.


Haematologica ◽  
2020 ◽  
Author(s):  
Alisa Damnernsawad ◽  
Daniel Bottomly ◽  
Stephen E. Kurtz ◽  
Christopher A. Eide ◽  
Shannon K. McWeeney ◽  
...  

Drug resistance impedes the long-term effect of targeted therapies in acute myeloid leukemia (AML), necessitating the identification of mechanisms underlying resistance. Approximately 25% of AML patients carry FLT3 mutations and develop post-treatment insensitivity to FLT3 inhibitors, including sorafenib. Using a genome-wide CRISPR screen, we identified LZTR1, NF1, TSC1 or TSC2, negative regulators of the MAPK and MTOR pathways, as mediators of sorafenib resistance. Analyses of ex vivo drug sensitivity assays in FLT3-ITD AML patient samples revealed lower expression of LZTR1, NF1, and TSC2 correlated with sorafenib sensitivity. Importantly, MAPK and/or MTOR complex1 (MTORC1) activity were upregulated in AML cells made resistant to several FLT3 inhibitors, including crenolanib, quizartinib, or sorafenib. These cells were sensitive to MEK inhibitors, and the combination of FLT3 and MEK inhibitors showed enhanced efficacy, suggesting its effectiveness in AML patients with FLT3 mutations and those with resistance to FLT3 inhibitors.


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