scholarly journals Host Avian Beta-Defensin and Toll-Like Receptor Responses of Pigeons following Infection with Pigeon Paramyxovirus Type 1

2015 ◽  
Vol 81 (18) ◽  
pp. 6415-6424 ◽  
Author(s):  
Yanyan Li ◽  
Qianqian Xu ◽  
Tingting Zhang ◽  
Mengying Gao ◽  
Qiuling Wang ◽  
...  
Keyword(s):  
Bursa Of Fabricius ◽  
Host Responses ◽  
High Morbidity ◽  
Toll Like Receptor ◽  
Host Defense Peptides ◽  
Cecal Tonsil ◽  
Immune Related Genes ◽  
Pigeon Paramyxovirus Type 1

ABSTRACTThe high morbidity and mortality in pigeons caused by pigeon paramyxovirus type 1 (PPMV-1) highlights the need for new insights into the host immune response and novel treatment approaches. Host defense peptides (HDPs) are key components of the innate immune system. In this study, three novel avian β-defensins (AvBDs 2, 7, and 10) were characterized in pigeons and shown to possess direct antiviral activity against PPMV-1in vitro. In addition, we evaluated the mRNA expression of these AvBDs and other immune-related genes in tissues of 2-month-old infected pigeons at 3 and 7 days postinfection. We observed that the expression of AvBD2 in the cecal tonsil, lungs, and proventriculus, as well as the expression of AvBD10 in the spleen, lungs, proventriculus, and kidneys, was upregulated in infected pigeons. Similarly, the expression of both Toll-like receptor 3 (TLR3) and TLR7 was increased in the spleen, trachea, and proventriculus, while TLR15 expression was increased only in the lungs of infected pigeons. In addition, inducible nitric oxide synthase (iNOS) expression was upregulated in the spleen, the bursa of Fabricius, the trachea, and the proventriculus of infected pigeons. Furthermore, we observed a high correlation between the expression of AvBD2 and the expression of either TLR7 or TLR15, as well as between AvBD10 expression and either TLR3 or TLR7 expression in respective tissues. The results suggest that PPMV-1 infection can induce innate host responses characterized by the activation of TLRs, particularly TLR3 and TLR7, AvBDs (2 and 10), and iNOS in pigeons.

Herpes simplex virus type 1 activates murine natural interferon-producing cells through toll-like receptor 9

Blood ◽  
2004 ◽  
Vol 103 (4) ◽  
pp. 1433-1437 ◽  
Author(s):  
Anne Krug ◽  
Gary D. Luker ◽  
Winfried Barchet ◽  
David A. Leib ◽  
Shizuo Akira ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Virus Type ◽  
Herpes Simplex Virus Type ◽  
Interleukin 12 ◽  
Toll Like Receptor ◽  
Simplex Virus ◽  
Hsv 1

Abstract Natural interferon-producing cells (IPCs) specialize in the production of high levels of type 1 interferons (IFNs) in response to encapsulated DNA and RNA viruses. Here we demonstrate that the secretion of type 1 IFN in response to herpes simplex virus type 1 (HSV-1) in vitro is mediated by the toll-like receptor 9 (TLR9)/MyD88 pathway. Moreover, IPCs produce interleukin-12 (IL-12) in response to HSV-1 in vitro, which is also dependent on TLR9/ MyD88 signaling. Remarkably, though TLR9/MyD88-deficiency abrogates IPC responses to HSV-1 in vitro, mice lacking either MyD88 or TLR9 are capable of controlling HSV-1 replication in vivo after local infection, demonstrating that TLR9- and MyD88-independent pathways in cells other than IPCs can effectively compensate for defective IPC responses to HSV-1.

scholarly journals Tissue factor and Toll-like receptor (TLR)4 in hyperglycaemia-hyperinsulinaemia

2015 ◽  
Vol 113 (04) ◽  
pp. 750-758 ◽  
Author(s):  
Anamika Singh ◽  
Guenther Boden ◽  
A. Koneti Rao
Keyword(s):  
Tissue Factor ◽  
Healthy Subjects ◽  
Toll Like Receptor ◽  
Elevated Plasma ◽  
Type 2 Dm ◽  
Type 1 Dm

SummaryDiabetes mellitus (DM) patients have an increased incidence of cardiovascular events. Blood tissue factor-procoagulant activity (TF-PCA), the initiating mechanism for blood coagulation, is elevated in DM. We have shown that hyperglycaemia (HG), hyperinsulinaemia (HI) and combined HG+HI (induced using 24-hour infusion clamps) increases TF-PCA in healthy and type 2 DM (T2DM) subjects, but not in type 1 DM (T1DM) subjects. The mechanisms for this are unknown. DM patients have elevated plasma lipopolysaccharide (LPS), a toll-like receptor (TLR) 4 ligand. We postulated that TLR4 plays a role in modulating TF levels. We studied the effect of HG+HI on TLR4 and TF-PCA in vivo during 24-hour HG+HI infusion clamps in healthy subjects, and T1DM and T2DM subjects, and in vitro in blood. In vivo, in healthy subjects, 24-hour HG + HI infusion increased TLR4 six-fold, which correlated with TF-PCA (r=0.91, p<0.0001). T2DM patients showed smaller increases in both. In T1DM subjects, TLR4 declined (50%, p<0.05) and correlated with TF-PCA (r=0.55; p<0.05). In vitro, HG (200 mg/dl added glucose) and HI (1-100 nM added insulin) increased TF-PCA in healthy subjects (˜2-fold, 2-4 hours). Insulin inhibited by ~30% LPSinduced increase in TF-PCA and high glucose reversed it. TLR4 levels paralleled TF-PCA (r=0.71, p<0.0001); HG and HI increased TLR4 and insulin inhibited LPS-induced TLR4 increase. This is first evidence that even in healthy subjects, HG of short duration increases TLR4 and TFPCA, key players in inflammation and thrombosis. TLR4-TF interplay is strikingly different in non-diabetic, T1DM and T2DM subjects.

scholarly journals Differential Regulation of DAP12 and Molecules Associated with DAP12 during Host Responses to Mycobacterial Infection

2004 ◽  
Vol 72 (5) ◽  
pp. 2477-2483 ◽  
Author(s):  
Naoko Aoki ◽  
Anna Zganiacz ◽  
Peter Margetts ◽  
Zhou Xing
Keyword(s):  
Mycobacterial Infection ◽  
Host Responses ◽  
Necrosis Factor Alpha ◽  
Lung Macrophage ◽  
Tnf Α ◽  
Kinetic Expression ◽  
Ifn Γ

ABSTRACT DAP12 and its associating molecules MDL-1, TREM-1, and TREM-2 are the recently identified immune regulatory molecules, expressed primarily on myeloid cells including monocytes/macrophages, dendritic cells, NK cells, and neutrophils. However, little is known about the regulation of their expression during host antimicrobial responses. We have investigated the effect of pulmonary mycobacterial infection and type 1 cytokines on the expression of these molecules both in vivo and in vitro. While DAP12 was constitutively expressed at high levels in the lungs, the MDL-1, TREM-1, and TREM-2 molecules were inducible during mycobacterial infection. Their kinetic expression was correlated with that of the type 1 cytokines tumor necrosis factor alpha (TNF-α) and gamma interferon (IFN-γ). In primary lung macrophage cultures, high constitutive levels of DAP12 and TREM-2 were not modulated by mycobacterial or type 1 cytokine exposure. In contrast, expression of both MDL-1 and TREM-1 was markedly induced by mycobacterial infection and such induction was inhibited by concurrent exposure to IFN-γ. On mycobacterial infection of TNF-α−/− and IFN-γ−/− mice in vivo or their lung macrophages in vitro, TNF-α was found to be critical for mycobacterially induced MDL-1, but not TREM-1, expression whereas IFN-γ negatively regulated mycobacterially induced MDL-1 and TREM-1 expression. Our findings thus suggest that DAP12 and its associating molecules are differentially regulated by mycobacterial infection and type 1 cytokines and that MDL-1- and TREM-1-triggered DAP12 signaling may play an important role in antimicrobial type 1 immunity.

scholarly journals NFATC3 promotes IRF7 transcriptional activity in plasmacy­­toid dendritic cells

2016 ◽  
Vol 213 (11) ◽  
pp. 2383-2398 ◽  
Author(s):  
Musheng Bao ◽  
York Wang ◽  
Ying Liu ◽  
Peiqing Shi ◽  
Hongbo Lu ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Transcription Factor ◽  
Nuclear Translocation ◽  
Constitutive Expression ◽  
Toll Like Receptor ◽  
Cpg Dna ◽  
Specialized Function

Plasmacytoid dendritic cells (pDCs) rapidly produce large amounts of type 1 interferon (IFN) after Toll-like receptor 7 and 9 engagements. This specialized function of type 1 IFN production is directly linked to the constitutive expression of IRF7, the master transcription factor for type 1 IFN production. However, the IRF7 regulatory network in pDCs remains largely unknown. In this study, we identify that the transcription factor NFATC3 specifically binds to IRF7 and enhances IRF7-mediated IFN production. Furthermore, knockout of NFATC3 greatly reduced the CpG DNA–induced nuclear translocation of IRF7, which resulted in impaired type 1 IFN production in vitro and in vivo. In addition, we found that NFATC3 and IRF7 both bound to type 1 IFN promoters and that the NFAT binding site in IFN promoters was required for IRF7-mediated IFN expression. Collectively, our study shows that the transcription factor NFATC3 binds to IRF7 and functions synergistically to enhance IRF7-mediated IFN expression in pDCs.

scholarly journals Evolutionary Dynamics and Age-Dependent Pathogenesis of Sub-Genotype VI.2.1.1.2.2 PPMV-1 in Pigeons

Viruses ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 433 ◽  
Author(s):  
Peng Xie ◽  
Libin Chen ◽  
Yifan Zhang ◽  
Qiuyan Lin ◽  
Chan Ding ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
South China ◽  
Evolutionary Dynamics ◽  
Guangdong Province ◽  
High Morbidity ◽  
Age Dependent ◽  
Significant Burden ◽  
Pigeon Paramyxovirus Type 1 ◽  
Effect Of Age

Pigeon paramyxovirus type 1 (PPMV-1) infection causes high morbidity in pigeons, resulting in a significant burden to the poultry industry. In this study, we isolated three PPMV-1 strains from diseased pigeons collected in Guangdong Province, South China, from June 2017 to April 2019. Genetic analysis revealed that these three PPMV-1 strains and most of the PPMV-1 strains isolated from China after 2011 were clustered into sub-genotype VI.2.1.1.2.2. Our Bayesian analysis revealed that the VI.2.1.1.2.2 viruses might have originated in Europe. Phylogeographic analyses revealed that East and South China might have played a key role in seeding the VI.2.1.1.2.2 PPMV-1 epidemic in China. To characterize the effect of age at infection on the outcome of PPMV-1 infection in pigeons, we investigated the pathogenesis and transmission of the pigeon/Guangdong/GZ08/2017 (GZ08) virus in 3-, 6-, and 12-week-old pigeons. Two of six 12-week-old pigeons inoculated with GZ08 survived, and all of the 3- and 6-week-pigeons inoculated with GZ08 died. Moreover, the GZ08 virus could be transmitted to 3-, 6-, and 12-week-old naïve contact pigeons. The lethality of the GZ08 virus through contact with 3-, 6-, and 12-week-old pigeons was 100%, 66.7%, and 0%, respectively, suggesting that the transmissibility of the GZ08 virus was stronger in young pigeons. These findings demonstrated that East and South China was the epicenter for dissemination of VI.2.1.1.2.2 PPMV-1, and age at infection has an impact on the outcome of PPMV-1 infection in pigeons.

scholarly journals Losartan promotes cell survival following SARS-CoV-2 infection in vitro

2020 ◽  
Author(s):  
Reza Nejat ◽  
Ahmad Shahir Sadr ◽  
Brendan T. Freitas ◽  
Jackelyn Crabtree ◽  
Scott D. Pegan ◽  
...  
Keyword(s):  
Cell Culture ◽  
Angiotensin Ii ◽  
Post Infection ◽  
Inhibitory Effect ◽  
High Morbidity ◽  
Type I ◽  
Infection Group ◽  
Shift Analysis

AbstractIntroductionCoronavirus disease 2019 (COVID-19) can be associated with mortality and high morbidity worldwide. There is an extensive effort to control infection and disease caused by SARS-CoV-2. This study addressed the hypothesis that angiotensin II type I receptor blocker, Losartan, may restrict pathogenesis caused by SARS-CoV-2 by decreasing viral-induced cytopathological changes by blocking angiotensin II type 1 receptor (AT1R), thus reducing the affinity of the virus for ACE2, and inhibiting papain-like protease of the virus.MethodLosartan inhibitory effect on deubiquitination and deISGylation properties of papain-like protease was investigated using a fluorescence method and gel shift analysis determining its inhibitory effects.The inhibitory effect of Losartan on SARS-CoV-2 cell replication was investigated both when losartan was added to the cell culture 1 hour before (pre-infection group) and 1 hour after (post-infection group) SARS-CoV-2 infection of Vero E6 cells.ResultsLosartan treatment of Vero E6 cells prior to and after SARS-CoV-2 infection reduced SARS-CoV-2 replication by 80% and 70% respectively. Losartan was not a strong deubiquitinase and deISGylase inhibitor of PLpro.ConclusionLosartan added pre- and post-infection to the Vero E6 cell culture significantly prevents cell destruction and replication by SARS-CoV2. Losartan has low side-effects, is readily available, and can be produced at high levels globally, all features of a promising drug in treatment of COVID-19 if validated by clinical trials.

scholarly journals Preformed Membrane-Associated Stores of Interleukin (Il)-12 Are a Previously Unrecognized Source of Bioactive IL-12 That Is Mobilized within Minutes of Contact with an Intracellular Parasite

2000 ◽  
Vol 192 (4) ◽  
pp. 507-516 ◽  
Author(s):  
Marlon Quinones ◽  
Sunil K. Ahuja ◽  
Peter C. Melby ◽  
Lyle Pate ◽  
Robert L. Reddick ◽  
...  
Keyword(s):  
Leishmania Donovani ◽  
Leishmania Species ◽  
Interferon Γ ◽  
Host Responses ◽  
Prevailing Paradigm ◽  
Helper Cell Type ◽  
Experimental Approaches

The prevailing paradigm is that production of the interleukin (IL)-12 p70 heterodimer, a critical T helper cell type 1 (Th1)–inducing cytokine, depends on the induced transcription of the p40 subunit. Concordant with this paradigm, we found that dendritic cells (DCs) produced IL-12 p70 only after at least 2–4 h of stimulation with lipopolysaccharide plus interferon γ. However, using several complementary experimental approaches, including electron and confocal microscopy, we now show that resting murine and human myeloid cells, including macrophages/DCs and DC-rich tissues, contain a novel source of bioactive IL-12 that is preformed and membrane associated. These preformed, membrane-associated IL-12 p70 stores are released within minutes after in vitro or in vivo contact with Leishmania donovani, an intracellular pathogen. Our findings highlight a novel source of bioactive IL-12 that is readily available for the rapid initiation of Th1 host responses to pathogens such as Leishmania species.

Characterization of host responses induced by Toll-like receptor ligands in chicken cecal tonsil cells

2016 ◽  
Vol 174 ◽  
pp. 19-25 ◽  
Author(s):  
Khaled Taha-abdelaziz ◽  
Tamiru Negash Alkie ◽  
Douglas C. Hodgins ◽  
Bahram Shojadoost ◽  
Shayan Sharif
Keyword(s):  
Host Responses ◽  
Toll Like Receptor ◽  
Receptor Ligands ◽  
Cecal Tonsil

scholarly journals Cathelicidins: Immunomodulatory Antimicrobials

Vaccines ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 63 ◽  
Author(s):  
Roel van Harten ◽  
Esther van Woudenbergh ◽  
Albert van Dijk ◽  
Henk Haagsman
Keyword(s):  
Cell Differentiation ◽  
Immune Responses ◽  
Positive Charge ◽  
Physicochemical Characteristics ◽  
Innate Immune ◽  
Antimicrobial Drugs ◽  
Host Defense Peptides

Cathelicidins are host defense peptides with antimicrobial and immunomodulatory functions. These effector molecules of the innate immune system of many vertebrates are diverse in their amino acid sequence but share physicochemical characteristics like positive charge and amphipathicity. Besides being antimicrobial, cathelicidins have a wide variety in immunomodulatory functions, both boosting and inhibiting inflammation, directing chemotaxis, and effecting cell differentiation, primarily towards type 1 immune responses. In this review, we will examine the biology and various functions of cathelicidins, focusing on putting in vitro results in the context of in vivo situations. The pro-inflammatory and anti-inflammatory functions are highlighted, as well both direct and indirect effects on chemotaxis and cell differentiation. Additionally, we will discuss the potential and limitations of using cathelicidins as immunomodulatory or antimicrobial drugs.

Sign in / Sign up

Export Citation Format

Share Document