scholarly journals Extracellular Vesicles From KSHV-Infected Cells Stimulate Antiviral Immune Response Through Mitochondrial DNA

2019 ◽  
Vol 10 ◽  
Author(s):  
Hyungtaek Jeon ◽  
Jisu Lee ◽  
Suhyuk Lee ◽  
Su-Kyung Kang ◽  
Sang June Park ◽  
...  
Keyword(s):  
Immune Response ◽  
Mitochondrial Dna ◽  
Extracellular Vesicles ◽  
Antiviral Immune Response ◽  
Infected Cells

scholarly journals Role of Virally-Encoded Deubiquitinating Enzymes in Regulation of the Virus Life Cycle

2021 ◽  
Vol 22 (9) ◽  
pp. 4438
Author(s):  
Jessica Proulx ◽  
Kathleen Borgmann ◽  
In-Woo Park
Keyword(s):  
Immune Response ◽  
Life Cycle ◽  
Deubiquitinating Enzyme ◽  
Deubiquitinating Enzymes ◽  
Antiviral Immune Response ◽  
Cellular Processes ◽  
Virus Life Cycle ◽  
Infected Cells ◽  
Dependent Processes

The ubiquitin (Ub) proteasome system (UPS) plays a pivotal role in regulation of numerous cellular processes, including innate and adaptive immune responses that are essential for restriction of the virus life cycle in the infected cells. Deubiquitination by the deubiquitinating enzyme, deubiquitinase (DUB), is a reversible molecular process to remove Ub or Ub chains from the target proteins. Deubiquitination is an integral strategy within the UPS in regulating survival and proliferation of the infecting virus and the virus-invaded cells. Many viruses in the infected cells are reported to encode viral DUB, and these vial DUBs actively disrupt cellular Ub-dependent processes to suppress host antiviral immune response, enhancing virus replication and thus proliferation. This review surveys the types of DUBs encoded by different viruses and their molecular processes for how the infecting viruses take advantage of the DUB system to evade the host immune response and expedite their replication.

scholarly journals Deficient Incorporation of Rabies Virus Glycoprotein into Virions Enhances Virus-Induced Immune Evasion and Viral Pathogenicity

Viruses ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 218 ◽  
Author(s):  
Chunfu Li ◽  
Hongliang Zhang ◽  
Lina Ji ◽  
Xiao Wang ◽  
Yongjun Wen ◽  
...  
Keyword(s):  
Immune Response ◽  
Rabies Virus ◽  
Recombinant Virus ◽  
Neutralizing Antibodies ◽  
Single Copy ◽  
Wild Type ◽  
Antiviral Immune Response ◽  
Glycoprotein G ◽  
Lethal Infection ◽  
Infected Cells

Previous studies have shown that wild-type (wt) rabies virus (RABV) evades the host immune response by restricting expression of glycoprotein (G), which blocks activation of dendritic cells (DCs) and induces production of virus-neutralizing antibodies (VNAs). In the present study, wt RABVs not only restricted G expression but also reduced incorporation of G into mature virions compared with laboratory-adapted viruses. A recombinant RABV expressing triple G was used to further determine whether G expression relates to incorporation. The recombinant virus showed higher expression and incorporation of G and activated more DCs than the virus that expressed a single copy of G. Removal of G from viruses using subtilisin or Dithiothreitol (DTT)/ Nonidet P-40 (NP40) almost completely abolishes DC activation and VNA production. Consequently, these G-depleted viruses cause lethal infection in mice. Thus, wt RABVs can subvert DC-induced antiviral immune response and maintain pathogenicity by decreasing G expression in infected cells and G incorporation into virions.

scholarly journals Extracellular vesicles secreted by HBV-infected cells modulate HBV persistence in hydrodynamic HBV transfection mouse model

2020 ◽  
Vol 295 (35) ◽  
pp. 12449-12460
Author(s):  
Masatoshi Kakizaki ◽  
Yuichiro Yamamoto ◽  
Motoyuki Otsuka ◽  
Kouichi Kitamura ◽  
Masatoshi Ito ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Immune Response ◽  
Hepatitis B ◽  
Extracellular Vesicles ◽  
Liver Cells ◽  
Target Cells ◽  
Multiple Organs ◽  
Life Threatening ◽  
Infected Cells ◽  
Infected Liver

Hepatitis B, a viral infection that affects the liver, is thought to affect over 257 million people worldwide, and long-term infection can lead to life-threatening issues such as cirrhosis or liver cancer. Chronic hepatitis B develops by the interaction between hepatitis B virus (HBV) and host immune response. However, questions of how HBV-infected cells thwart immune system defenses remain unanswered. Extracellular vesicles (EVs) are used for cellular communication, carrying cargoes such as RNAs, proteins, and lipids and delivering them intracellularly after being endocytosed by target cells. HBV-infected liver cells secrete several types of EVs into body fluids such as complete and incomplete virions, and exosomes. We previously demonstrated that monocytes that incorporated EVs moved to immunoregulatory phenotypes via up-regulation of PD-L1, an immunocheckpoint molecule, and down-regulation of CD69, a leukocyte activation molecule. In this study, we transfected mice with HBV using hydrodynamic injection and studied the effects of EVs secreted by HBV-infected liver cells. EVs secreted from cells with HBV replication strongly suppressed the immune response, inhibiting the eradication of HBV-replicating cells in the mice transfected with HBV. EVs were systemically incorporated in multiple organs, including liver, bone marrow (BM), and intestine. Intriguingly, the BM cells that incorporated EVs acquired intestinal tropism and the dendritic cell populations in the intestine increased. These findings suggest that the EVs secreted by HBV-infected liver cells exert immunosuppressive functions, and that an association between the liver, bone marrow, and intestinal tract exists through EVs secreted from HBV-infected cells.

scholarly journals Sending Out Alarms: A Perspective on Intercellular Communications in Insect Antiviral Immune Response

2021 ◽  
Vol 12 ◽  
Author(s):  
Fei Wang
Keyword(s):  
Immune Response ◽  
Viral Infection ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Antiviral Immune Response ◽  
Intracellular Degradation ◽  
Infected Cells ◽  
Insect Immune Response ◽  
Intercellular Communications ◽  
Future Work

Viral infection triggers insect immune response, including RNA interference, apoptosis and autophagy, and profoundly changes the gene expression profiles in infected cells. Although intracellular degradation is crucial for restricting viral infection, intercellular communication is required to mount a robust systemic immune response. This review focuses on recent advances in understanding the intercellular communications in insect antiviral immunity, including protein-based and virus-derived RNA based cell-cell communications, with emphasis on the signaling pathway that induces the production of the potential cytokines. The prospects and challenges of future work are also discussed.

scholarly journals Human plasmacytoid dendritic cells mount a distinct antiviral response to virus-infected cells

2021 ◽  
Vol 6 (58) ◽  
pp. eabc7302
Author(s):  
Tae Jin Yun ◽  
Suzu Igarashi ◽  
Haoquan Zhao ◽  
Oriana A. Perez ◽  
Marcus R. Pereira ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Virus Detection ◽  
Plasmacytoid Dendritic Cells ◽  
Lung Epithelial Cells ◽  
Live Cells ◽  
Type I ◽  
Antiviral Immune Response ◽  
Lung Epithelial ◽  
Functional Consequences ◽  
Infected Cells

Plasmacytoid dendritic cells (pDCs) can rapidly produce interferons and other soluble factors in response to extracellular viruses or virus mimics such as CpG-containing DNA. pDCs can also recognize live cells infected with certain RNA viruses, but the relevance and functional consequences of such recognition remain unclear. We studied the response of primary DCs to the prototypical persistent DNA virus, human cytomegalovirus (CMV). Human pDCs produced high amounts of type I interferon (IFN-I) when incubated with live CMV-infected fibroblasts but not with free CMV; the response involved integrin-mediated adhesion, transfer of DNA-containing virions to pDCs, and the recognition of DNA through TLR9. Compared with transient polyfunctional responses to CpG or free influenza virus, pDC response to CMV-infected cells was long-lasting, dominated by the production of IFN-I and IFN-III, and lacked diversification into functionally distinct populations. Similarly, pDC activation by influenza-infected lung epithelial cells was highly efficient, prolonged, and dominated by interferon production. Prolonged pDC activation by CMV-infected cells facilitated the activation of natural killer cells critical for CMV control. Last, patients with CMV viremia harbored phenotypically activated pDCs and increased circulating IFN-I and IFN-III. Thus, recognition of live infected cells is a mechanism of virus detection by pDCs that elicits a unique antiviral immune response.

scholarly journals Protective Effects of Lactoferrin against SARS-CoV-2 Infection In Vitro

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 328 ◽  
Author(s):  
Claudio Salaris ◽  
Melania Scarpa ◽  
Marina Elli ◽  
Alice Bertolini ◽  
Simone Guglielmetti ◽  
...  
Keyword(s):  
Immune Response ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Plaque Assay ◽  
Immune Response Gene ◽  
Intestinal Epithelial ◽  
Antiviral Immune Response ◽  
Qrt Pcr ◽  
Anti Inflammatory

SARS-CoV-2 is a newly emerging virus that currently lacks curative treatments. Lactoferrin (LF) is a naturally occurring non-toxic glycoprotein with broad-spectrum antiviral, immunomodulatory and anti-inflammatory effects. In this study, we assessed the potential of LF in the prevention of SARS-CoV-2 infection in vitro. Antiviral immune response gene expression was analyzed by qRT-PCR in uninfected Caco-2 intestinal epithelial cells treated with LF. An infection assay for SARS-CoV-2 was performed in Caco-2 cells treated or not with LF. SARS-CoV-2 titer was determined by qRT-PCR, plaque assay and immunostaining. Inflammatory and anti-inflammatory cytokine production was determined by qRT-PCR. LF significantly induced the expression of IFNA1, IFNB1, TLR3, TLR7, IRF3, IRF7 and MAVS genes. Furthermore, LF partially inhibited SARS-CoV-2 infection and replication in Caco-2 intestinal epithelial cells. Our in vitro data support LF as an immune modulator of the antiviral immune response with moderate effects against SARS-CoV-2 infection.

scholarly journals Helicobacter pylori Outer Membrane Vesicles and Extracellular Vesicles from Helicobacter pylori-Infected Cells in Gastric Disease Development

2021 ◽  
Vol 22 (9) ◽  
pp. 4823
Author(s):  
María Fernanda González ◽  
Paula Díaz ◽  
Alejandra Sandoval-Bórquez ◽  
Daniela Herrera ◽  
Andrew F. G. Quest
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Outer Membrane ◽  
Extracellular Vesicles ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Host Cells ◽  
Gastric Epithelium ◽  
Infected Cells ◽  
H Pylori

Extracellular vesicles (EVs) are cell-derived vesicles important in intercellular communication that play an essential role in host-pathogen interactions, spreading pathogen-derived as well as host-derived molecules during infection. Pathogens can induce changes in the composition of EVs derived from the infected cells and use them to manipulate their microenvironment and, for instance, modulate innate and adaptive inflammatory immune responses, both in a stimulatory or suppressive manner. Gastric cancer is one of the leading causes of cancer-related deaths worldwide and infection with Helicobacter pylori (H. pylori) is considered the main risk factor for developing this disease, which is characterized by a strong inflammatory component. EVs released by host cells infected with H. pylori contribute significantly to inflammation, and in doing so promote the development of disease. Additionally, H. pylori liberates vesicles, called outer membrane vesicles (H. pylori-OMVs), which contribute to atrophia and cell transformation in the gastric epithelium. In this review, the participation of both EVs from cells infected with H. pylori and H. pylori-OMVs associated with the development of gastric cancer will be discussed. By deciphering which functions of these external vesicles during H. pylori infection benefit the host or the pathogen, novel treatment strategies may become available to prevent disease.

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