scholarly journals Roles of Host Immunity in Viral Myocarditis and Dilated Cardiomyopathy

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Lifang Zhao ◽  
Zhaoying Fu
Keyword(s):  
Innate Immunity ◽  
T Cell ◽  
Immune Responses ◽  
Viral Infection ◽  
Dilated Cardiomyopathy ◽  
Viral Myocarditis ◽  
Host Immunity ◽  
Host Immune Responses ◽  
Direct Damage ◽  
Working Together

The pathogenesis of viral myocarditis includes both the direct damage mediated by viral infection and the indirect lesion resulted from host immune responses. Myocarditis can progress into dilated cardiomyopathy that is also associated with immunopathogenesis. T cell-mediated autoimmunity, antibody-mediated autoimmunity (autoantibodies), and innate immunity, working together, contribute to the development of myocarditis and dilated cardiomyopathy.

scholarly journals Role of Alternative Splicing in Regulating Host Response to Viral Infection

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1720
Author(s):  
Kuo-Chieh Liao ◽  
Mariano A. Garcia-Blanco
Keyword(s):  
Innate Immunity ◽  
Alternative Splicing ◽  
Immune Responses ◽  
Viral Infection ◽  
Rna Splicing ◽  
Type I ◽  
Host Immune Responses ◽  
Transcriptional Regulatory Mechanisms ◽  
Host Virus Interactions

The importance of transcriptional regulation of host genes in innate immunity against viral infection has been widely recognized. More recently, post-transcriptional regulatory mechanisms have gained appreciation as an additional and important layer of regulation to fine-tune host immune responses. Here, we review the functional significance of alternative splicing in innate immune responses to viral infection. We describe how several central components of the Type I and III interferon pathways encode spliced isoforms to regulate IFN activation and function. Additionally, the functional roles of splicing factors and modulators in antiviral immunity are discussed. Lastly, we discuss how cell death pathways are regulated by alternative splicing as well as the potential role of this regulation on host immunity and viral infection. Altogether, these studies highlight the importance of RNA splicing in regulating host–virus interactions and suggest a role in downregulating antiviral innate immunity; this may be critical to prevent pathological inflammation.

scholarly journals β-Catenin Is Required for the cGAS/STING Signaling Pathway but Antagonized by the Herpes Simplex Virus 1 US3 Protein

2019 ◽  
Vol 94 (5) ◽  
Author(s):  
Hongjuan You ◽  
Yingying Lin ◽  
Feng Lin ◽  
Mingyue Yang ◽  
Jiahui Li ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Herpes Simplex ◽  
Immune Responses ◽  
Signaling Pathway ◽  
Kinase Activity ◽  
Dna Virus ◽  
Host Immune Responses ◽  
Simplex Virus ◽  
Antiviral Innate Immunity ◽  
Hsv 1

ABSTRACT The cGAS/STING-mediated DNA-sensing signaling pathway is crucial for interferon (IFN) production and host antiviral responses. Herpes simplex virus I (HSV-1) is a DNA virus that has evolved multiple strategies to evade host immune responses. Here, we demonstrate that the highly conserved β-catenin protein in the Wnt signaling pathway is an important factor to enhance the transcription of type I interferon (IFN-I) in the cGAS/STING signaling pathway, and the production of IFN-I mediated by β-catenin was antagonized by HSV-1 US3 protein via its kinase activity. Infection by US3-deficienct HSV-1 and its kinase-dead variants failed to downregulate IFN-I and IFN-stimulated gene (ISG) production induced by β-catenin. Consistent with this, absence of β-catenin enhanced the replication of US3-deficienct HSV-1, but not wild-type HSV-1. The underlying mechanism was the interaction of US3 with β-catenin and its hyperphosphorylation of β-catenin at Thr556 to block its nuclear translocation. For the first time, HSV-1 US3 has been shown to inhibit IFN-I production through hyperphosphorylation of β-catenin and to subvert host antiviral innate immunity. IMPORTANCE Although increasing evidence has demonstrated that HSV-1 subverts host immune responses and establishes lifelong latent infection, the molecular mechanisms by which HSV-1 interrupts antiviral innate immunity, especially the cGAS/STING-mediated cellular DNA-sensing signaling pathway, have not been fully explored. Here, we show that β-catenin promotes cGAS/STING-mediated activation of the IFN pathway, which is important for cellular innate immune responses and intrinsic resistance to DNA virus infection. The protein kinase US3 antagonizes the production of IFN by targeting β-catenin via its kinase activity. The findings in this study reveal a novel mechanism for HSV-1 to evade host antiviral immunity and add new knowledge to help in understanding the interaction between the host and HSV-1 infection.

scholarly journals The DBL-1/TGF-β signaling pathway regulates pathogen-specific innate immune responses in C. elegans

2021 ◽  
Author(s):  
Bhoomi Madhu ◽  
Tina L. Gumienny
Keyword(s):  
Innate Immunity ◽  
Immune Responses ◽  
Signaling Pathway ◽  
Defense Responses ◽  
C Elegans ◽  
Host Immune Responses ◽  
Wide Range ◽  
Independent Functions ◽  
Multiple Cell

Innate immunity in animals is orchestrated by multiple cell signaling pathways, including the TGF-β; superfamily pathway. While the role of TGF-β signaling in innate immunity has been clearly identified, the requirement for this pathway in generating specific, robust responses to different bacterial challenges has not been characterized. Here, we address the role of DBL-1/TGF-β in regulating signature host defense responses to a wide range of bacteria in C. elegans. This work reveals a role of DBL-1/TGF-β in animal survival, organismal behaviors, and molecular responses in different environments. Additionally, we identify a novel role for SMA-4/Smad that suggests both DBL-1/TGF-β-dependent and -independent functions in host avoidance responses. RNA-seq analyses and immunity reporter studies indicate DBL-1/TGF-β differentially regulates target gene expression upon exposure to different bacteria. Furthermore, the DBL-1/TGF-β pathway is itself differentially affected by the bacteria exposure. Collectively, these findings demonstrate bacteria-specific host immune responses regulated by the DBL-1/TGF-β signaling pathway.

scholarly journals IL-2 immunotoxin denileukin diftitox reduces regulatory T cells and enhances vaccine-mediated T-cell immunity

Blood ◽  
2007 ◽  
Vol 110 (9) ◽  
pp. 3192-3201 ◽  
Author(s):  
Mary T. Litzinger ◽  
Romaine Fernando ◽  
Tyler J. Curiel ◽  
Douglas W. Grosenbach ◽  
Jeffrey Schlom ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Viral Vector ◽  
Interleukin 2 ◽  
Treg Cells ◽  
Denileukin Diftitox ◽  
Host Immune Responses ◽  
Cell Immunity ◽  
T Cell Immune Responses ◽  
Cellular Compartments

AbstractCD4+CD25+Foxp3+ regulatory T (Treg) cells have been implicated in the lack of effective antitumor immunity. Denileukin diftitox (DAB389IL-2), a fusion protein of interleukin 2 (IL-2) and diphtheria toxin, provides a means of targeting Treg cells. In this study, we examined (1) the effect of denileukin diftitox on the deletion of Treg cells in various lymphoid compartments and (2) the dose scheduling of denileukin diftitox in combination with a recombinant poxviral vaccine to enhance antigen-specific immune responses. Treg cells in spleen, peripheral blood, and bone marrow of normal C57BL/6 mice were variously reduced after a single intraperitoneal injection of denileukin diftitox; the reduction was evident within 24 hours and lasted approximately 10 days. Injection of denileukin diftitox 1 day before vaccination enhanced antigen-specific T-cell responses above levels induced by vaccination alone. These studies show for the first time in a murine model (1) the differential effects of denileukin diftitox on Treg cells in different cellular compartments, (2) the advantage of combining denileukin diftitox with a vaccine to enhance antigen-specific T-cell immune responses, (3) the lack of inhibition by denileukin diftitox of host immune responses directed against a live viral vector, and (4) the importance of dose scheduling of denileukin diftitox when used in combination with a vaccine.

scholarly journals Infection, Inflammation and Immunity in Covid-19 Infection

2021 ◽  
Vol 48 (3) ◽  
pp. 77-82
Author(s):  
R. Cherneva ◽  
Z. Cherneva
Keyword(s):  
Immune Response ◽  
Virus Infection ◽  
Immune Responses ◽  
Systemic Inflammation ◽  
Multiple Organ ◽  
Host Immunity ◽  
Effective Prevention ◽  
Systemic Complications ◽  
Host Immune Responses ◽  
Prevention And Treatment

Abstract The COVID-19 pandemic caused by the SARS-CoV-2 has increased the burden on healthcare system. Despite some progress in its diagnostics has been made, effective prevention and treatment are still insufficient. Since SARS-CoV-2 infections often cause systemic inflammation and multiple organ failure, the therapeutic options aimed at modulating the host immune responses to prevent subsequent systemic complications are demanding. The review provides a summary of the SARS-CoV-2 virus infection and underlines the current perception of pulmonary host’s immune response and its contributions to disease severity and systemic inflammation. Signaling pathways which have the potential to manipulate host immunity and improve clinical outcomes are also presented.

scholarly journals Withaferin A inhibits LFA-1-stimulated ZAP70 activity and T-cell motility

2021 ◽  
Author(s):  
Fazil Mobashar Hussain Urf Turabe ◽  
Chandra Sekhar Chirumamilla ◽  
Claudina Perez-Novo ◽  
Sunil Kumar ◽  
Siu Kwan Sze ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Cell Motility ◽  
Peptide Mapping ◽  
Covalent Binding ◽  
In Silico Analysis ◽  
Withaferin A ◽  
Lymphocyte Function ◽  
Host Immune Responses ◽  
Binding Interface

Here we report that a steroidal lactone withaferin A (WFA) can inhibit T-cell motility, which is crucial for adaptive immune responses as well as autoimmune reactions. Tandem mass spectrometry identified WFA-interactome in human T-cells that were stimulated to migrate via cross-linking of the lymphocyte function-associated antigen-1 (LFA-1) integrin with the ligand intercellular adhesion receptor 1 (ICAM-1). Data revealed significant enrichment of the zeta-chain-associated protein kinase 70 (ZAP70) and cytoskeletal actin protein interaction networks. Phospho-peptide mapping and kinome analysis substantiated kinase signaling downstream of ZAP70 and cytoskeletal kinase pathways as key WFA targets, which was further confirmed by in silico analysis and molecular assays. The WFA-ZAP70 complex was disrupted by a redox agent dithiothreitol, suggesting a covalent binding interface. Moreover, WFA ablated the phosphorylation of the myosin light chain, further constraining T-cell motility. These studies identify a mechanism whereby WFA can impact T-cell motility. WFA can therefore be exploited to pharmacologically controlling host immune responses and preventing autoimmune-mediated pathologies.

scholarly journals Early dysregulation of the memory CD8+ T cell repertoire leads to compromised immune responses to secondary viral infection in the aged

2012 ◽  
Vol 9 (1) ◽  
pp. 28 ◽  
Author(s):  
Lisa M Connor ◽  
Jacob E Kohlmeier ◽  
Lynn Ryan ◽  
Alan D Roberts ◽  
Tres Cookenham ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Viral Infection ◽  
Cd8 T Cell ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
Memory Cd8 T Cell

scholarly journals Activating receptors promote NK cell expansion for maintenance, IL-10 production, and CD8 T cell regulation during viral infection

2009 ◽  
Vol 206 (10) ◽  
pp. 2235-2251 ◽  
Author(s):  
Seung-Hwan Lee ◽  
Kwang-Sin Kim ◽  
Nassima Fodil-Cornu ◽  
Silvia M. Vidal ◽  
Christine A. Biron
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Viral Infection ◽  
Nk Cells ◽  
Cell Expansion ◽  
Nk Cell ◽  
Cd8 T Cell ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Activating Receptors

Natural killer (NK) cells have the potential to deliver both direct antimicrobial effects and regulate adaptive immune responses, but NK cell yields have been reported to vary greatly during different viral infections. Activating receptors, including the Ly49H molecule recognizing mouse cytomegalovirus (MCMV), can stimulate NK cell expansion. To define Ly49H's role in supporting NK cell proliferation and maintenance under conditions of uncontrolled viral infection, experiments were performed in Ly49h−/−, perforin 1 (Prf1)−/−, and wild-type (wt) B6 mice. NK cell numbers were similar in uninfected mice, but relative to responses in MCMV-infected wt mice, NK cell yields declined in the absence of Ly49h and increased in the absence of Prf1, with high rates of proliferation and Ly49H expression on nearly all cells. The expansion was abolished in mice deficient for both Ly49h and Prf1 (Ly49h−/−Prf1−/−), and negative consequences for survival were revealed. The Ly49H-dependent protection mechanism delivered in the absence of Prf1 was a result of interleukin 10 production, by the sustained NK cells, to regulate the magnitude of CD8 T cell responses. Thus, the studies demonstrate a previously unappreciated critical role for activating receptors in keeping NK cells present during viral infection to regulate adaptive immune responses.

scholarly journals Viral and Cellular Determinants of the Hepatitis C Virus Envelope-Heparan SulfateInteraction

2006 ◽  
Vol 80 (21) ◽  
pp. 10579-10590 ◽  
Author(s):  
Heidi Barth ◽  
Eva K. Schnober ◽  
Fuming Zhang ◽  
Robert J. Linhardt ◽  
Erik Depla ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Immune Responses ◽  
Viral Infection ◽  
Viral Envelope ◽  
Model Systems ◽  
Target Cells ◽  
Virus Envelope ◽  
Viral Attachment ◽  
Host Immune Responses

ABSTRACT Cellular binding and entry of hepatitis C virus (HCV) are the first steps of viral infection and represent a major target for antiviral antibodies and novel therapeutic strategies. We have recently demonstrated that heparan sulfate (HS) plays a key role in the binding of HCV envelope glycoprotein E2 to target cells (Barth et al., J. Biol. Chem. 278:41003-41012, 2003). In this study, we characterized the HCV-HS interaction and analyzed its inhibition by antiviral host immune responses. Using recombinant envelope glycoproteins, virus-like particles, and HCV pseudoparticles as model systems for the early steps of viral infection, we mapped viral and cellular determinants of HCV-HS interaction. HCV-HS binding required a specific HS structure that included N-sulfo groups and a minimum of 10 to 14 saccharide subunits. HCV envelope binding to HS was mediated by four viral epitopes overlapping the E2 hypervariable region 1 and E2-CD81 binding domains. In functional studies using HCV pseudoparticles, we demonstrate that HCV binding and entry are specifically inhibited by highly sulfated HS. Finally, HCV-HS binding was markedly inhibited by antiviral antibodies derived from HCV-infected individuals. In conclusion, our results demonstrate that binding of the viral envelope to a specific HS configuration represents an important step for the initiation of viral infection and is a target of antiviral host immune responses in vivo. Mapping of viral and cellular determinants of HCV-HS interaction sets the stage for the development of novel HS-based antiviral strategies targeting viral attachment and entry.

scholarly journals Immunopathology of Schistosoma mansoni infection.

1989 ◽  
Vol 2 (3) ◽  
pp. 250-269 ◽  
Author(s):  
D L Boros
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Fatal Outcome ◽  
Severe Morbidity ◽  
Experimental Animals ◽  
Host Immune Responses ◽  
Schistosomiasis Mansoni ◽  
Intestinal Symptoms ◽  
The Tropics ◽  
Immunoregulatory Mechanisms

Schistosomiasis mansoni is a chronic helminthic disease that affects about 100 million people in the tropics. The worms have a life span of 5 to 10 years, and they live in the mesenteric veins of the host. Lightly infected individuals are asymptomatic or manifest mild intestinal symptoms. Heavily infected individuals often develop severe morbidity with hepatosplenomegaly, sometimes with a fatal outcome. Morbidity is attributed to the strong humoral and T-cell-mediated host immune responses developed to a variety of parasite antigens and expressed as tissue inflammations. The immunopathology includes dermatitis, immune complex-mediated kidney disease, and, chiefly, T-cell-mediated granuloma formation and fibrosis around disseminated parasite eggs. This review describes the mechanisms of induction and expression of immunopathology in infected persons and experimental animals. Immunoregulatory mechanisms that modulate the enhanced immune responses and may ameliorate excessive morbidity are discussed.

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