scholarly journals HCV-Induced Immunometabolic Crosstalk in a Triple-Cell Co-Culture Model Capable of Simulating Systemic Iron Homeostasis

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2251
Author(s):  
Pelagia Foka ◽  
Alexios Dimitriadis ◽  
Eirini Karamichali ◽  
Emmanouil Kochlios ◽  
Petros Eliadis ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Immune System ◽  
Iron Homeostasis ◽  
Expression Patterns ◽  
Interleukin 10 ◽  
Innate Immune ◽  
Hcv Infection ◽  
Human Pathogens ◽  
Culture Model ◽  
Triple Cell

Iron is crucial to the regulation of the host innate immune system and the outcome of many infections. Hepatitis C virus (HCV), one of the major viral human pathogens that depends on iron to complete its life cycle, is highly skilled in evading the immune system. This study presents the construction and validation of a physiologically relevant triple-cell co-culture model that was used to investigate the input of iron in HCV infection and the interplay between HCV, iron, and determinants of host innate immunity. We recorded the expression patterns of key proteins of iron homeostasis involved in iron import, export and storage and examined their relation to the iron regulatory hormone hepcidin in hepatocytes, enterocytes and macrophages in the presence and absence of HCV. We then assessed the transcriptional profiles of pro-inflammatory cytokines Interleukin-6 (IL-6) and interleukin-15 (IL-15) and anti-inflammatory interleukin-10 (IL-10) under normal or iron-depleted conditions and determined how these were affected by infection. Our data suggest the presence of a link between iron homeostasis and innate immunity unfolding among liver, intestine, and macrophages, which could participate in the deregulation of innate immune responses observed in early HCV infection. Coupled with iron-assisted enhanced viral propagation, such a mechanism may be important for the establishment of viral persistence and the ensuing chronic liver disease.

scholarly journals The neuropeptide receptor NMUR-1 regulates the specificity of C. elegans innate immunity against pathogen infection

2021 ◽  
Author(s):  
Phillip Wibisono ◽  
Shawndra Wibisono ◽  
Jan Watteyne ◽  
Chia-Hui Chen ◽  
Durai Sellegounder ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Immune System ◽  
Immune Responses ◽  
Adaptive Immune System ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Immune Genes ◽  
C Elegans ◽  
Adaptive Immune ◽  
Functional Assays

A key question in current immunology is how the innate immune system generates high levels of specificity. Like most invertebrates, Caenorhabditis elegans does not have an adaptive immune system and relies solely on innate immunity to defend itself against pathogen attacks, yet it can still differentiate different pathogens and launch distinct innate immune responses. Here, we have found that functional loss of NMUR-1, a neuronal GPCR homologous to mammalian receptors for the neuropeptide neuromedin U, has diverse effects on C. elegans survival against various bacterial pathogens. Transcriptomic analyses and functional assays revealed that NMUR-1 modulates C. elegans transcription activity by regulating the expression of transcription factors, which, in turn, controls the expression of distinct immune genes in response to different pathogens. Our study has uncovered a molecular basis for the specificity of C. elegans innate immunity that could provide mechanistic insights into understanding the specificity of vertebrate innate immunity.

scholarly journals Innate immunity and the pneumococcus

Microbiology ◽  
2006 ◽  
Vol 152 (2) ◽  
pp. 285-293 ◽  
Author(s):  
Gavin K. Paterson ◽  
Tim J. Mitchell
Keyword(s):  
Innate Immunity ◽  
Immune System ◽  
Streptococcus Pneumoniae ◽  
Immune Responses ◽  
Innate Immune System ◽  
Innate Immune ◽  
First Line ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Made In

The innate immune system provides a non-specific first line of defence against microbes and is crucial both in the development and effector stages of subsequent adaptive immune responses. Consistent with its importance, study of the innate immune system is a broad and fast-moving field. Here we provide an overview of the recent key advances made in this area with relation to the important pathogen Streptococcus pneumoniae (the pneumococcus).

scholarly journals The Interplay between Host Innate Immunity and Hepatitis E Virus

Viruses ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 541 ◽  
Author(s):  
Yang Li ◽  
Changbo Qu ◽  
Peifa Yu ◽  
Xumin Ou ◽  
Qiuwei Pan ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Immune System ◽  
Hepatitis E Virus ◽  
Inflammatory Responses ◽  
Hepatitis E ◽  
Experimental Models ◽  
Innate Immune ◽  
Host Immune System ◽  
Global Health Issue ◽  
Host Innate Immunity

Hepatitis E virus (HEV) infection represents an emerging global health issue, whereas the clinical outcomes vary dramatically among different populations. The host innate immune system provides a first-line defense against the infection, but dysregulation may partially contribute to severe pathogenesis. A growing body of evidence has indicated the active response of the host innate immunity to HEV infection both in experimental models and in patients. In turn, HEV has developed sophisticated strategies to counteract the host immune system. In this review, we aim to comprehensively decipher the processes of pathogen recognition, interferon, and inflammatory responses, and the involvement of innate immune cells in HEV infection. We further discuss their implications in understanding the pathogenic mechanisms and developing antiviral therapies.

scholarly journals Toll-like receptor-mediated innate immunity against herpesviridae infection: a current perspective on viral infection signaling pathways

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Wenjin Zheng ◽  
Qing Xu ◽  
Yiyuan Zhang ◽  
Xiaofei E ◽  
Wei Gao ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Immune System ◽  
Signaling Pathways ◽  
Critical Role ◽  
Innate Immune ◽  
Host Cells ◽  
Main Body ◽  
Current Perspective ◽  
Viral Components

Abstract Background In the past decades, researchers have demonstrated the critical role of Toll-like receptors (TLRs) in the innate immune system. They recognize viral components and trigger immune signal cascades to subsequently promote the activation of the immune system. Main body Herpesviridae family members trigger TLRs to elicit cytokines in the process of infection to activate antiviral innate immune responses in host cells. This review aims to clarify the role of TLRs in the innate immunity defense against herpesviridae, and systematically describes the processes of TLR actions and herpesviridae recognition as well as the signal transduction pathways involved. Conclusions Future studies of the interactions between TLRs and herpesviridae infections, especially the subsequent signaling pathways, will not only contribute to the planning of effective antiviral therapies but also provide new molecular targets for the development of antiviral drugs.

scholarly journals P0022INNATE IMMUNE RESPONSES ELICITED BY TOLL-LIKE RECEPTORS ARE POSSIBLY INVOLVED IN THE PATHOGENESIS OF NEPHROTIC SYNDROME

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Eriko Tanaka ◽  
Ichiro Hada ◽  
Naoaki Mikami ◽  
Kunimasa Yan
Keyword(s):  
Innate Immunity ◽  
Nephrotic Syndrome ◽  
Immune System ◽  
Innate Immune System ◽  
Expression Profiles ◽  
Kidney Tissue ◽  
Innate Immune ◽  
Rna Expression ◽  
Toll Like Receptors ◽  
Tissue Samples

Abstract Background and Aims Pathogenesis of idiopathic nephrotic syndrome (INS) is yet to be fully elucidated. Immunological disorders are reported to be involved in the etiology of INS. Due to the efficacy of immunosuppressant agents such as calcineurin inhibitor and rituximab in treating nephrotic syndrome, aberrant activation of the acquired immune system through T and B cells are considered to be the underlying pathogenic mechanisms of INS. Nevertheless, there is a possibility that the innate immune system plays a key role in INS pathogenesis. This study aims to investigate the involvement of innate immunity in INS pathogenesis by examining the expressions of toll-like receptors (TLRs). Method Kidney tissue samples from two INS patients were collected at two points of time: the first biopsy was performed during nephrosis and the second during remission. Total RNA was extracted from the kidney tissue samples, and RNA-sequencing was performed to investigate RNA expression profiles. The differences between RNA expression profiles of TLRs and molecules related to TLR pathways in the tissue samples collected during nephrosis and remission were analyzed. Results There was a significant decrease in RNA expression of TLR9 and TLR10 during remission compared to nephrosis: fold change in each patient was -2.12 and -2.12 for TLR9, and -2.51 and -2.09 for TLR10. RNA expression of TLR8 also decreased: fold change in each patient was -1.19 and -1.75. There were no significant changes in the RNA expression profiles of TLR1, 2, 3, 4, 5, 6, and 7. In addition, there were no differences in the RNA expression profiles of MYD88, IRAK family, and TRAF family molecules that are associated with TLR pathways. However, RNA expressions of IL6, IL1B, IL12B, and TNF, as well as the cytokines controlled by TLR8 and TLR9 pathways, which were activated during nephrosis, disappeared or decreased during remission. Conclusion The involvement of the innate immune system in the pathogenesis of nephrotic syndrome has been suggested in some reports. Based on the fact that the onset or recurrence of nephrosis is triggered by non-specific viral infection, it is highly possible that innate immunity is involved in the pathogenesis of nephrotic syndrome. TLRs play a key role in innate immunity as they elicit the innate immune system after detecting pathogens, induce inflammatory cytokine production, and trigger signaling pathways that activate lymphocytes via maturation of dendritic cells. Specifically, TLR8, 9, and 10 mediate pathways of the first immune response to viral infections. Our study reveals that TLRs play a pivotal role in innate immunity associated with renal tissue during the onset of nephrosis.

scholarly journals Granulocyte CEACAM3 Is a Phagocytic Receptor of the Innate Immune System that Mediates Recognition and Elimination of Human-specific Pathogens

2004 ◽  
Vol 199 (1) ◽  
pp. 35-46 ◽  
Author(s):  
Tim Schmitter ◽  
Franziska Agerer ◽  
Lisa Peterson ◽  
Petra Münzner ◽  
Christof R. Hauck
Keyword(s):  
Immune System ◽  
Tyrosine Kinases ◽  
Innate Immune System ◽  
Small Gtpase ◽  
Innate Immune ◽  
Dominant Negative ◽  
Host Cells ◽  
Human Pathogens ◽  
Human Granulocytes ◽  
Human Specific

Carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) are used by several human pathogens to anchor themselves to or invade host cells. Interestingly, human granulocytes express a specific isoform, CEACAM3, that participates together with CEACAM1 and CEACAM6 in the recognition of CEACAM-binding microorganisms. Here we show that CEACAM3 can direct efficient, opsonin-independent phagocytosis of CEACAM-binding Neisseria, Moraxella, and Haemophilus species. CEACAM3- but not CEACAM6-mediated uptake is blocked by dominant-negative versions of the small GTPase Rac. Moreover, CEACAM3 engagement triggers membrane recruitment and increased GTP loading of Rac that are not observed upon bacterial binding to CEACAM6. Internalization and Rac stimulation are also inhibited by compromising the integrity of an immunoreceptor tyrosine-based activation motif (ITAM)–like sequence in the cytoplasmic tail of CEACAM3 or by interference with Src family protein tyrosine kinases that phosphorylate CEACAM3. In contrast to interfering with CEACAM6, blockage of CEACAM3-mediated events reduces the ability of primary human granulocytes to internalize and eliminate CEACAM-binding bacteria, indicating an important role of CEACAM3 in the control of human-specific pathogens by the innate immune system.

scholarly journals Still Enigmatic: Innate Immunity in the Ctenophore Mnemiopsis leidyi

2019 ◽  
Vol 59 (4) ◽  
pp. 811-818 ◽  
Author(s):  
Nikki Traylor-Knowles ◽  
Lauren E Vandepas ◽  
William E Browne
Keyword(s):  
Innate Immunity ◽  
Immune System ◽  
Innate Immune System ◽  
Defense Mechanism ◽  
Innate Immune ◽  
Phylogenetic Position ◽  
Mnemiopsis Leidyi ◽  
Immunity Genes ◽  
Review Current

Abstract Innate immunity is an ancient physiological response critical for protecting metazoans from invading pathogens. It is the primary pathogen defense mechanism among invertebrates. While innate immunity has been studied extensively in diverse invertebrate taxa, including mollusks, crustaceans, and cnidarians, this system has not been well characterized in ctenophores. The ctenophores comprise an exclusively marine, non-bilaterian lineage that diverged early during metazoan diversification. The phylogenetic position of ctenophore lineage suggests that characterization of the ctenophore innate immune system will reveal important features associated with the early evolution of the metazoan innate immune system. Here, we review current understanding of the ctenophore immune repertoire and identify innate immunity genes recovered from three ctenophore species. We also isolate and characterize Mnemiopsis leidyi cells that display macrophage-like behavior when challenged with bacteria. Our results indicate that ctenophores possess cells capable of phagocytosing microbes and that two distantly related ctenophores, M. leidyi and Hormiphora californiensis, possess many candidate innate immunity proteins.

scholarly journals Determination of the Role and Active Sites of PKC-Delta-Like from Lamprey in Innate Immunity

2019 ◽  
Vol 20 (13) ◽  
pp. 3357
Author(s):  
Yang Xu ◽  
Huan Zhao ◽  
Yang Tian ◽  
Kaixia Ren ◽  
Nan Zheng ◽  
...  
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Immune System ◽  
Innate Immune Response ◽  
Active Sites ◽  
Innate Immune ◽  
Pkc Delta ◽  
Kinase C ◽  
Catalytic Fragment

Protein kinase C-δ (PKC-δ) is an important protein in the immune system of higher vertebrates. Lampreys, as the most primitive vertebrates, have a uniquevariable lymphocyte receptor (VLR) immune system. PKC-δ-like is a crucial functional gene in lampreys and is highly expressed in their immune organs. In this study, lampreys were stimulated with different immunogens, and lipopolysaccharide (LPS) was found to increase the expression of PKC-δ-like. Overexpression of PKC-δ-like could also effectively activate the innate immune response. We further demonstrated that PKC-δ-like-CF, a catalytic fragment of PKC-δ-like, is responsible for activating the innate immune response, and Thr-211, which is Thr-419 of PKC-δ-like, was confirmed to be the key site affecting PKC-δ-like-CF activity. These results indicated that PKC-δ-like from lamprey may have an important role in the innate immune response.

A Critical Role for Innate Immunity In Allogeneic Hematopoietic Cell Rejection Via the TLR4/TRIF Pathway

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 77-77
Author(s):  
Hong Xu ◽  
Jun Yan ◽  
Ziqiang Zhu ◽  
Yiming Huang ◽  
Yujie Wen ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Innate Immunity ◽  
T Cells ◽  
Immune System ◽  
T Cell ◽  
Innate Immune System ◽  
Critical Role ◽  
Innate Immune ◽  
Wild Type

Abstract Abstract 77 Adaptive immunity, especially T cells, has long been believed to be the dominant immune barrier in allogeneic transplantation. Targeting host T cells significantly reduces conditioning for bone marrow cell (BMC) engraftment. Innate immunity has been recently shown to pose a significant barrier in solid organ transplantation, but has not been addressed in bone marrow transplantation (BMT). Using T cell deficient (TCR-β/δ−/−) or T and B cell deficient (Rag−/−) mice, we found that allogeneic BMC rejection occurred early before the time required for T cell activation and was T- and B-cell independent, suggesting an effector role for innate immune cells in BMC rejection. Therefore, we hypothesized that by controlling both innate and adaptive immunity, the donor BMC would have a window of advantage to engraft. Survival of BMC in vivo was significantly improved by depleting recipient macrophages and/or NK cells, but not neutrophils. Moreover, depletion of macrophages and NK cells in combination with co-stimulatory blockade with anti-CD154 and rapamycin as a novel form of conditioning resulted in 100% allogeneic engraftment without any irradiation and T cell depletion. Donor chimerism remained stable and durable up to 6 months. Moreover, specific Vβ5½ and Vβ11 clonal deletion was detected in host CD4+ T cells in chimeras, indicating central tolerance to donor alloantigens. Whether and how the innate immune system recognizes or responds to allogeneic BMCs remains unknown. Toll-like receptors (TLRs) are a class of proteins that play a key role in the innate immune system. The signaling function of TLR depends on intracellular adaptors. The adaptor MyD88 transmits signals emanating from all TLR, except TLR3 while TRIF specifically mediates TLR3 and TLR4 signaling via type 1 IFN. To further determine the innate signaling pathways in allogeneic BMC rejection, B6 background (H2b) MyD88−/− and TRIF−/− mice were conditioned with anti-CD154/rapamycin plus 100 cGy total body irradiation and transplanted with 15 × 106 BALB/c (H2d) BMC. Only 33.3% of MyD88−/− recipients engrafted at 1 month, resembling outcomes for wild-type B6 mice. In contrast, 100% of TRIF−/− mice engrafted. The level of donor chimerism in TRIF−/− mice was 5.1 ± 0.6% at one month, significantly higher than in MyD88−/− and wild-type B6 controls (P < 0.005). To determine the mechanism of innate signaling in BMC rejection, we examined whether TRIF linked TLR3 or TLR4 is the key pattern recognition receptor involved in BMC recognition. To this end, TLR3−/− and TLR4−/− mice were transplanted with BALB/c BMC with same conditioning. None of the TLR3−/− mice engrafted. In contrast, engraftment was achieved in 100% of TLR4−/− mice up to 6 months follow up. Taken together, these results suggest that rejection of allogeneic BMC is uniquely dependent on the TLR4/TRIF signaling pathway. Thus, our results clearly demonstrate a previously unappreciated role for innate immunity in allogeneic BMC rejection. Our current findings are distinct from prior reports demonstrating a critical role of MyD88 in rejection of allogeneic skin grafts and lung, and may reflect unique features related to BMC. The findings of the role of innate immunity in BMC rejection would lead to revolutionary changes in our understanding and management of BMT. This would be informative in design of more specific innate immune targeted conditioning proposals in BMT to avoid the toxicity. Disclosures: Bozulic: Regenerex LLC: Employment. Ildstad:Regenerex LLC: Equity Ownership.

scholarly journals Interaction of Antibiotics with Innate Host Defense Factors against Salmonella enterica Serotype Newport

mSphere ◽  
2017 ◽  
Vol 2 (6) ◽  
Author(s):  
George Sakoulas ◽  
Monika Kumaraswamy ◽  
Armin Kousha ◽  
Victor Nizet
Keyword(s):  
Innate Immunity ◽  
Immune System ◽  
Innate Immune System ◽  
Salmonella Enterica ◽  
Clinical Performance ◽  
Innate Immune ◽  
Content Type ◽  
Antimicrobial Assay

ABSTRACT It is becoming increasingly understood that the current paradigms of in vitro antimicrobial susceptibility testing may have significant shortcomings in predicting activity in vivo. This study evaluated the activity of several antibiotics alone and in combination against clinical isolates of Salmonella enterica serotype Newport (meningitis case) utilizing both conventional and physiological media. In addition, the interactions of these antibiotics with components of the innate immune system were evaluated. Azithromycin, which has performed quite well clinically despite high MICs in conventional media, was shown to be more active in physiological media and to enhance innate immune system killing. Alternatively, chloramphenicol did not show enhanced immune system killing, paralleling its inferior clinical performance to other antibiotics that have been used to treat Salmonella meningitis. These findings are important additions to the building understanding of current in vitro antimicrobial assay limitations that hopefully will amount to future improvements in these assays to better predict clinical efficacy and activity in vivo. This study examines the pharmacodynamics of antimicrobials that are used to treat Salmonella with each other and with key components of the innate immune system. Antimicrobial synergy was assessed using time-kill and checkerboard assays. Antimicrobial interactions with innate immunity were studied by employing cathelicidin LL-37, whole-blood, and neutrophil killing assays. Ceftriaxone and ciprofloxacin were found to be synergistic in vitro against Salmonella enterica serotype Newport. Ceftriaxone, ciprofloxacin, and azithromycin each demonstrated synergy with the human cathelicidin defense peptide LL-37 in killing Salmonella. Exposure of Salmonella to sub-MICs of ceftriaxone resulted in enhanced susceptibility to LL-37, whole blood, and neutrophil killing. The activity of antibiotics in vivo against Salmonella may be underestimated in bacteriologic media lacking components of innate immunity. The pharmacodynamic interactions of antibiotics used to treat Salmonella with each other and with components of innate immunity warrant further study in light of recent findings showing in vivo selection of antimicrobial resistance by single agents in this pathogen. IMPORTANCE It is becoming increasingly understood that the current paradigms of in vitro antimicrobial susceptibility testing may have significant shortcomings in predicting activity in vivo. This study evaluated the activity of several antibiotics alone and in combination against clinical isolates of Salmonella enterica serotype Newport (meningitis case) utilizing both conventional and physiological media. In addition, the interactions of these antibiotics with components of the innate immune system were evaluated. Azithromycin, which has performed quite well clinically despite high MICs in conventional media, was shown to be more active in physiological media and to enhance innate immune system killing. Alternatively, chloramphenicol did not show enhanced immune system killing, paralleling its inferior clinical performance to other antibiotics that have been used to treat Salmonella meningitis. These findings are important additions to the building understanding of current in vitro antimicrobial assay limitations that hopefully will amount to future improvements in these assays to better predict clinical efficacy and activity in vivo.

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