scholarly journals Human Cytomegalovirus UL138 Protein Inhibits the STING Pathway and Reduces Interferon Beta mRNA Accumulation during Lytic and Latent Infections

mBio ◽  
2021 ◽  
Author(s):  
Emily R. Albright ◽  
Clayton K. Mickelson ◽  
Robert F. Kalejta

While a cellular restriction versus viral countermeasure arms race between innate immunity and viral latency is expected, few examples have been documented. Our identification of the first HCMV latency protein that inactivates the cGAS/STING/TBK1 innate immune pathway opens the door to understanding how innate immunity, or its neutralization, impacts long-term persistence by HCMV and other latent viruses.

Cancers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 83
Author(s):  
Benoit R. Gauthier ◽  
Petra I. Lorenzo ◽  
Valentine Comaills

During metastasis, invading tumor cells and circulating tumor cells (CTC) face multiple mechanical challenges during migration through narrow pores and cell squeezing. However, little is known on the importance and consequences of mechanical stress for tumor progression and success in invading a new organ. Recently, several studies have shown that cell constriction can lead to nuclear envelope rupture (NER) during interphase. This loss of proper nuclear compartmentalization has a profound effect on the genome, being a key driver for the genome evolution needed for tumor progression. More than just being a source of genomic alterations, the transient nuclear envelope collapse can also support metastatic growth by several mechanisms involving the innate immune response cGAS/STING pathway. In this review we will describe the importance of the underestimated role of cellular squeezing in the progression of tumorigenesis. We will describe the complexity and difficulty for tumor cells to reach the metastatic site, detail the genomic aberration diversity due to NER, and highlight the importance of the activation of the innate immune pathway on cell survival. Cellular adaptation and nuclear deformation can be the key to the metastasis success in many unsuspected aspects.


2011 ◽  
Vol 11 ◽  
pp. 2037-2050 ◽  
Author(s):  
Manoranjan Sahoo ◽  
Ivonne Ceballos-Olvera ◽  
Laura del Barrio ◽  
Fabio Re

The inflammasome is an important innate immune pathway that regulates at least two host responses protective against infections: (1) secretion of the proinflammatory cytokines IL-1βand IL-18 and (2) induction of pyroptosis, a form of cell death. Inflammasomes, of which different types have been identified, are multiprotein complexes containing pattern recognition receptors belonging to the Nod-like receptor family or the PYHIN family and the protease caspase-1. The molecular aspects involved in the activation of different inflammasomes by various pathogens are being rapidly elucidated, and their role during infections is being characterized. Production of IL-1βand IL-18 and induction of pyroptosis of the infected cell have been shown to be protective against many infectious agents. Here, we review the recent literature concerning inflammasome activation in the context of bacterial infections and identify important questions to be answered in the future.


2018 ◽  
Vol 8 (12) ◽  
pp. 2627
Author(s):  
Hui Xie ◽  
Yonghua Zhan ◽  
Xueli Chen ◽  
Qi Zeng ◽  
Dan Chen ◽  
...  

The issue of Staphylococcus aureus (MRSA) developing a resistance to drugs such as methicillin has long been the focus for new drug development. In recent years, antimicrobial peptides, such as small molecular peptides with broad-spectrum antibacterial activity and special antibacterial mechanism, have shown a strong medicinal potential. In particular, the Brevinin-2 family has been shown to have a significant inhibitory effect against gram-positive bacteria (G+). In this study, we researched the influence of MRSA on the behavior and survival rate of nematodes. We established an assay of Caenorhabditis elegans–MRSA antimicrobial peptides to screen for new potent anti-infective peptides against MRSA. From the Brevinin-2 family, 13 peptides that had shown strong effects on G+ were screened for their ability to prolong the lifespan of infected worms. Real-time Polymerase Chain Reaction (PCR) tests were used to evaluate the effect on the innate immune pathway dauer formation defective (DAF)-2/DAF-16 of C. elegans. The assay successfully screened and filtered out four of the 13 peptides that significantly improved the survival rate of MRSA-infected worms. The result of real-time PCR indicated that the mRNA and protein expression levels of lys-7 were consistently upregulated by being treated with four of the Brevinin-2 family. The Brevinin-2 family peptides, including Brevinin-2, Brevinin-2-OA3, Brevinin-2ISb, and Brevinin-2TSa, also played an active role in the DAF-2/DAF-16 pathway in C. elegans. We successfully demonstrated the utility of anti-infective peptides that prolong the survival rate of the MRSA-infected host and discovered the relationship between antibacterial peptides and the innate immune system of C. elegans. We demonstrated the antimicrobial effects of Brevinin-2 family peptides, indicating their potential for use as new drug candidates against MRSA infections.


2017 ◽  
Vol 47 (10) ◽  
pp. 1025-1035
Author(s):  
XiangLong WU ◽  
HongYan GUO ◽  
RenYong JIA

Immunity ◽  
2013 ◽  
Vol 39 (6) ◽  
pp. 1000-1002 ◽  
Author(s):  
Stephane Lajoie ◽  
Marsha Wills-Karp

2009 ◽  
Vol 285 (4) ◽  
pp. 2227-2231 ◽  
Author(s):  
Tian-Tian Wang ◽  
Basel Dabbas ◽  
David Laperriere ◽  
Ari J. Bitton ◽  
Hafid Soualhine ◽  
...  

2021 ◽  
Author(s):  
Vy N. Nguyen ◽  
Salomé Brunon ◽  
Maria N. Pavlova ◽  
Pavlo Lazarchuk ◽  
Roya D. Sharifian ◽  
...  

The cGAS/STING pathway, part of the innate immune response to foreign DNA, is known to be activated by cell's own DNA arising from the processing of the genome, including the excision of nascent DNA at arrested replication forks. We found STING activation to affect nascent DNA processing, suggesting a novel, unexpected feedback connection between the two events. Depletion of STING suppressed and re-expression of the protein in STING-deficient cells upregulated degradation of nascent DNA. Fork arrest was accompanied by the STING pathway activation, and a STING mutant that does not activate the pathway failed to upregulate nascent strand degradation. Consistent with this, cells expressing the STING mutant had a reduced level of RPA on parental and nascent DNA of arrested forks as well as a reduced CHK1 activation compared to the cells with wild type STING. Together our findings reveal a novel connection between replication stress and innate immunity.


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