scholarly journals Crosstalk Between NDP52 and LUBAC in Innate Immune Responses, Cell Death, and Xenophagy

2021 ◽  
Vol 12 ◽  
Author(s):  
Hirohisa Miyashita ◽  
Daisuke Oikawa ◽  
Seigo Terawaki ◽  
Daijiro Kabata ◽  
Ayumi Shintani ◽  
...  
Keyword(s):  
Immune Responses ◽  
Hela Cells ◽  
Nuclear Factor Κb ◽  
Suppressive Effect ◽  
Innate Immune ◽  
Bacterial Invasion ◽  
Innate Immune Responses ◽  
Apoptotic Pathway ◽  
Ubiquitin Chain ◽  
Tnf Α

Nuclear dot protein 52 kDa (NDP52, also known as CALCOCO2) functions as a selective autophagy receptor. The linear ubiquitin chain assembly complex (LUBAC) specifically generates the N-terminal Met1-linked linear ubiquitin chain, and regulates innate immune responses, such as nuclear factor-κB (NF-κB), interferon (IFN) antiviral, and apoptotic pathways. Although NDP52 and LUBAC cooperatively regulate bacterial invasion-induced xenophagy, their functional crosstalk remains enigmatic. Here we show that NDP52 suppresses canonical NF-κB signaling through the broad specificity of ubiquitin-binding at the C-terminal UBZ domain. Upon TNF-α-stimulation, NDP52 associates with LUBAC through the HOIP subunit, but does not disturb its ubiquitin ligase activity, and has a modest suppressive effect on NF-κB activation by functioning as a component of TNF-α receptor signaling complex I. NDP52 also regulates the TNF-α-induced apoptotic pathway, but not doxorubicin-induced intrinsic apoptosis. A chemical inhibitor of LUBAC (HOIPIN-8) cancelled the increased activation of the NF-κB and IFN antiviral pathways, and enhanced apoptosis in NDP52-knockout and -knockdown HeLa cells. Upon Salmonella-infection, colocalization of Salmonella, LC3, and linear ubiquitin was detected in parental HeLa cells to induce xenophagy. Treatment with HOIPIN-8 disturbed the colocalization and facilitated Salmonella expansion. In contrast, HOIPIN-8 showed little effect on the colocalization of LC3 and Salmonella in NDP52-knockout cells, suggesting that NDP52 is a weak regulator in LUBAC-mediated xenophagy. These results indicate that the crosstalk between NDP52 and LUBAC regulates innate immune responses, apoptosis, and xenophagy.

Effect of aerobic exercise on innate immune responses and inflammatory mediators in the spinal cord of diabetic rats

2020 ◽  
Vol 16 (4) ◽  
pp. 293-301
Author(s):  
A. Kaki ◽  
M. Nikbakht ◽  
A.H. Habibi ◽  
H.F. Moghadam
Keyword(s):  
Spinal Cord ◽  
Neuropathic Pain ◽  
Immune Responses ◽  
Diabetic Neuropathy ◽  
Aerobic Exercise ◽  
Inflammatory Mediators ◽  
Innate Immune ◽  
Moderate Intensity ◽  
Innate Immune Responses ◽  
Tnf Α

Neuronal inflammation is one of the pathophysiological causes of diabetes neuropathic pain. The purpose of this research was to determine the effect of aerobic exercise on innate immune responses and inflammatory mediators in the spinal dorsal horn in rats with diabetic neuropathic pain. 40 eight-week-old male Wistar rats (weight range 220±10.2 g) were randomly divided into four groups of (1) sedentary diabetic neuropathy (SDN), (2) training diabetic neuropathy (TDN), (3) training control (TC), and (4) sedentary control (SC). Diabetes was induced by injection of streptozocin (50 mg/kg). Following confirmation of behavioural tests for diabetes neuropathy, the training groups performed 6 weeks of moderate-intensity aerobic exercise on the treadmill. The expression of Toll like receptor (TLR)4, TLR2, tumour necrosis factor (TNF)-α, interleukin (IL)-1β and IL-10 genes in L4-L6 spinal cord sensory neurons was measured by Real Time PCR. Two-way ANOVA and Bonferroni’s post hoc tests were used for statistical analysis. After performing aerobic exercise protocol, the TDN compared to the SDN showed a significant decrease in the mean score of pain in the formalin test and a significant increase in the latency in Tail-Flick test was observed. The expression of TLR4, TLR2, TNF-α and IL-1β genes was significantly higher in the SDN than in the SC group (P<0.05). The expression of the above genes in the TDN was significantly lower than the SDN group (P<0.05). Also, the expression level of IL-10 gene was significantly higher in the TDN than the SDN group (P<0.05). Aerobic exercise improved sensitivity of nociceptors to pain-inducing agents in diabetic neuropathy due to inhibition of inflammatory receptors and increased levels of anti-inflammatory agents in the nervous system. Thus, aerobic exercise should be used as a non-pharmacological intervention for diabetic patients to reduce neuropathic pain.

scholarly journals Toll-Like Receptor-Initiated Testicular Innate Immune Responses in Mouse Leydig Cells

Endocrinology ◽  
2011 ◽  
Vol 152 (7) ◽  
pp. 2827-2836 ◽  
Author(s):  
Tao Shang ◽  
Xiaoyan Zhang ◽  
Tao Wang ◽  
Bing Sun ◽  
Tingting Deng ◽  
...  
Keyword(s):  
Immune Responses ◽  
Tyrosine Kinases ◽  
Leydig Cells ◽  
Innate Immune ◽  
Inflammatory Factors ◽  
Innate Immune Responses ◽  
Polyinosinic:Polycytidylic Acid ◽  
Tnf Α ◽  
Microbial Infections ◽  
Local Cell

The testis is an immunoprivileged site, where the local cell-initiated testicular innate immune responses play a crucial role in defense against microbial infections. Mechanisms modulating the testicular cell-built defense system remain to be clarified. In this article, we demonstrate that Leydig cells, a major cell population in the testicular interstitium, initiate innate immunity through the activation of Toll-like receptors (TLRs). Several TLRs are expressed in mouse Leydig cells; among these, TLR3 and TLR4 are expressed at relatively high levels compared with other TLR members. Both TLR3 and TLR4 can be activated by their agonists (polyinosinic:polycytidylic acid and lipopolysaccharide) in Leydig cells and subsequently induce the production of inflammatory factors, such as IL-1β, IL-6, TNF-α, and type 1 interferons (IFN) (IFN-α and IFN-β). Notably, the activation of TLR3 and TLR4 suppresses steroidogenesis by Leydig cells. Further, we provide evidence that Axl and Mer receptor tyrosine kinases are expressed in Leydig cells and regulate TLR-mediated innate immune responses negatively. Data presented here describe a novel function of Leydig cells in eliciting testicular innate immune responses that should contribute to the protection of the testis from microbial infections.

scholarly journals Pneumolysin is responsible for differential gene expression and modifications in the epigenetic landscape of primary monocyte derived macrophages

2020 ◽  
Author(s):  
J. Cole ◽  
A. Angyal ◽  
R. D. Emes ◽  
T.J. Mitchell ◽  
M.J. Dickman ◽  
...  
Keyword(s):  
Gene Expression ◽  
Streptococcus Pneumoniae ◽  
Immune Responses ◽  
Epigenetic Modification ◽  
Transcriptional Response ◽  
Innate Immune ◽  
Global Changes ◽  
Innate Immune Responses ◽  
Transcriptional Responses ◽  
Tnf Α

AbstractEpigenetic modifications regulate gene expression in the host response to a diverse range of pathogens. The extent and consequences of epigenetic modification during macrophage responses to Streptococcus pneumoniae, and the role of pneumolysin, a key Streptococcus pneumoniae virulence factor, in influencing these responses, are currently unknown. To investigate this, we infected human monocyte derived macrophages (MDMs) with Streptococcus pneumoniae and addressed whether pneumolysin altered the epigenetic landscape and the associated acute macrophage transcriptional response using a combined transcriptomic and proteomic approach. Transcriptomic analysis identified 503 genes that were differentially expressed in a pneumolysin-dependent manner in these samples. Pathway analysis highlighted the involvement of transcriptional responses to core innate responses to pneumococci including modules associated with metabolic pathways activated in response to infection, oxidative stress responses and NFκB, NOD-like receptor and TNF signalling pathways. Quantitative proteomic analysis confirmed pneumolysin-regulated protein expression, early after bacterial challenge, in representative transcriptional modules associated with innate immune responses. In parallel, quantitative mass spectrometry identified global changes in the relative abundance of histone post translational modifications (PTMs) upon pneumococcal challenge. We identified an increase in the relative abundance of H3K4me1, H4K16ac and a decrease in H3K9me2 and H3K79me2 in a PLY-dependent fashion. We confirmed that pneumolysin blunted early transcriptional responses involving TNF-α and IL-6 expression. Vorinostat, a histone deacetylase inhibitor, similarly downregulated TNF production, reprising the pattern observed with pneumolysin. In conclusion, widespread changes in the macrophage transcriptional response are regulated by pneumolysin and are associated with global changes in histone PTMs. Modulating histone PTMs can reverse pneumolysin-associated transcriptional changes influencing innate immune responses, suggesting that epigenetic modification by pneumolysin plays a role in dampening the innate responses to pneumococci.Author summaryPneumolysin is a toxin that contributes to how Streptococcus pneumoniae, the leading cause of pneumonia, causes disease. In this study, the toxin alters gene expression in immune cells called macrophages, one of the first lines of defence against bacteria at sites of infection. Modulation involved multiple immune responses, including generation of chemical signals coordinating responses in immune cells termed cytokines. In addition, changes were observed in histone proteins that are involved in controlling gene expression in the cell. Pneumolysin reduced early production of the cytokine TNF-α and a medicine vorinostat that modifies these ‘epigenetic’ histone modifications had a similar affect, suggesting epigenetic mechanisms contribute to the ability of pneumolysin to reduce immune responses.

scholarly journals Meta-analysis of immune induced gene expression changes in diverse Drosophila melanogaster innate immune responses

2021 ◽  
Author(s):  
Ashley L Waring ◽  
Joshua Hill ◽  
Brooke M Allen ◽  
Nicholas M Bretz ◽  
Nguyen Le ◽  
...  
Keyword(s):  
Gene Expression ◽  
Drosophila Melanogaster ◽  
Immune Responses ◽  
Meta Analysis ◽  
Nuclear Factor Κb ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Response Factors ◽  
Induced Genes ◽  
Conserved Gene

Background: Organisms are commonly infected by a diverse array of pathogen types including bacteria, fungi, viruses, and parasites, and mount functionally distinct responses to each of these varied immune challenges. Host immune responses are characterized by the induction of gene expression in response to infection. However, the extent to which expression changes are shared among responses to distinct pathogens is largely unknown. Results: We performed meta-analysis of gene expression data collected from Drosophila melanogaster following infection with a wide array of pathogens. We identified 62 genes that are significantly induced by infection. While many of these infection-induced genes encode known immune response factors, we also identified 21 genes that have not been previously associated with host immunity. Examination of the upstream flanking sequences of the infection-induced genes lead to the identification of two conserved enhancer sites. These sites correspond to conserved binding sites for GATA and nuclear factor κB (NFκB) family transcription factors and are associated with higher levels of transcript induction. We further identified 31 genes with predicted functions in metabolism and organismal development that are significantly downregulated following infection by diverse pathogens. Conclusions: Our study identifies conserved gene expression changes in Drosophila melanogaster following infection with varied pathogens, and transcription factor families that may regulate this immune induction. These findings provide new insight into transcriptional changes that accompany Drosophila immunity. They may suggest possible roles for the differentially regulated genes in innate immune responses to diverse classes of pathogens, and serve to identify candidate genes for further empirical study of these processes.

scholarly journals CD1d-Associated Expression of NF-κB and Cardiac Dysfunction in Diabetic and Obese Mice

2013 ◽  
Vol 26 (1) ◽  
pp. 59-73 ◽  
Author(s):  
R. Madonna ◽  
H. Wu ◽  
H. Shelat ◽  
Y-J. Geng
Keyword(s):  
Immune Responses ◽  
Knockout Mice ◽  
Cardiac Dysfunction ◽  
Splenic Tissue ◽  
Innate Immune ◽  
Inflammatory Factors ◽  
Innate Immune Responses ◽  
Obesity And Diabetes ◽  
Tnf Α ◽  
The Impact

In patients with obesity and diabetes mellitus, abnormal production of inflammatory factors may result in cardiovascular dysfunction. In the current study, we tested the impact of CD1d-mediated innate immune responses on the expression and activation of NFκB in the hearts of adipose diabetic ( db/db) mice. Splenocytes from adult db/db and CD1d-knockout mice of both genders and their wild-type, C57BL/6 and Balb/C counterparts were examined for tumor necrosis factor (TNF)-α and TNF-α receptor type 1. The percentage of natural killer T (NKT) cells in CD3+ T cells was compared with that in nondiabetic control mice. Despite the absence of inflammatory infiltrates, the hearts of db/db mice showed alterations in TNF-α receptor-1 and NFκB activity, including increased expression of both the NFκB p52 and p65 subunits. In the hearts of CD1d-knockout mice, p52 expression was reduced, while p65 expression remained largely unchanged. On echocardiography, the ratio of E to A transmitral flow velocities (an indicator of diastolic function) was significantly decreased in db/db mice after they swam for 30 minutes. These results provide evidence for CD1d-mediated NFκB activation and diastolic dysfunction in the hearts of db/db mice. Therefore, CD1d-associated abnormalities of innate immune responses and TNF-α production in splenic tissue may contribute to NFκB activation and cardiac dysfunction in type 2 diabetes.

LIR9, an immunoglobulin-superfamily–activating receptor, is expressed as a transmembrane and as a secreted molecule

Blood ◽  
2003 ◽  
Vol 101 (4) ◽  
pp. 1484-1486 ◽  
Author(s):  
Luis Borges ◽  
Marek Kubin ◽  
Tracy Kuhlman
Keyword(s):  
Immune Responses ◽  
Innate Immune ◽  
Calcium Flux ◽  
Immunoglobulin Superfamily ◽  
Innate Immune Responses ◽  
Transmembrane Region ◽  
Tnf Α ◽  
Membrane Bound ◽  
Factor Α ◽  
Necrosis Factor

LIRs are immunoglobulinlike receptors that have activating and inhibitory functions in leukocytes. Here we report the identification of the first LIR family member, LIR9, expressed as a membrane-bound receptor and as a secreted molecule. We identified 4 different forms of LIR9, 2 of which encode transmembrane molecules and 2 encode secreted molecules. The transmembrane forms of LIR9 contain a short cytoplasmic domain and a charged arginine residue within the transmembrane region that is likely to mediate its association with another coreceptor. LIR9 is mostly expressed in myeloid cells, including monocytes and neutrophils. Cross-linking of LIR9 on the surfaces of monocytes induces calcium flux and secretion of the proinflammatory cytokines interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and IL-6, indicating that LIR9 could play a role in triggering innate immune responses.

scholarly journals Unique and complementary suppression of cGAS-STING and RNA sensing- triggered innate immune responses by SARS-CoV-2 proteins

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Yajuan Rui ◽  
Jiaming Su ◽  
Si Shen ◽  
Ying Hu ◽  
Dingbo Huang ◽  
...  
Keyword(s):  
Immune Responses ◽  
Nuclear Factor Κb ◽  
Innate Immune ◽  
Nuclear Accumulation ◽  
Innate Immune Responses ◽  
Structural Protein ◽  
Viral Protease ◽  
Downstream Signaling ◽  
Efficient Replication

AbstractThe emergence of SARS-CoV-2 has resulted in the COVID-19 pandemic, leading to millions of infections and hundreds of thousands of human deaths. The efficient replication and population spread of SARS-CoV-2 indicates an effective evasion of human innate immune responses, although the viral proteins responsible for this immune evasion are not clear. In this study, we identified SARS-CoV-2 structural proteins, accessory proteins, and the main viral protease as potent inhibitors of host innate immune responses of distinct pathways. In particular, the main viral protease was a potent inhibitor of both the RLR and cGAS-STING pathways. Viral accessory protein ORF3a had the unique ability to inhibit STING, but not the RLR response. On the other hand, structural protein N was a unique RLR inhibitor. ORF3a bound STING in a unique fashion and blocked the nuclear accumulation of p65 to inhibit nuclear factor-κB signaling. 3CL of SARS-CoV-2 inhibited K63-ubiquitin modification of STING to disrupt the assembly of the STING functional complex and downstream signaling. Diverse vertebrate STINGs, including those from humans, mice, and chickens, could be inhibited by ORF3a and 3CL of SARS-CoV-2. The existence of more effective innate immune suppressors in pathogenic coronaviruses may allow them to replicate more efficiently in vivo. Since evasion of host innate immune responses is essential for the survival of all viruses, our study provides insights into the design of therapeutic agents against SARS-CoV-2.

scholarly journals Malaria Modifies Neonatal and Early-Life Toll-Like Receptor Cytokine Responses

2013 ◽  
Vol 81 (8) ◽  
pp. 2686-2696 ◽  
Author(s):  
Komi Gbédandé ◽  
Stefania Varani ◽  
Samad Ibitokou ◽  
Parfait Houngbegnon ◽  
Sophie Borgella ◽  
...  
Keyword(s):  
Immune Responses ◽  
Early Life ◽  
In Utero ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Toll Like Receptor ◽  
Content Type ◽  
Cytokine Responses ◽  
Increased Risk ◽  
Tnf Α

ABSTRACTProtection from infections in early life relies extensively on innate immunity, but it is unknown whether and how maternal infections modulate infants' innate immune responses, thereby altering susceptibility to infections.Plasmodium falciparumcauses pregnancy-associated malaria (PAM), and epidemiological studies have shown that PAM enhances infants' susceptibility to infection withP. falciparum. We investigated how PAM-mediated exposuresin uteroaffect innate immune responses and their relationship with infection in infancy. In a prospective study of mothers and their babies in Benin, we investigated changes in Toll-like receptor (TLR)-mediated cytokine responses related toP. falciparuminfections. Whole-blood samples from 134 infants at birth and at 3, 6, and 12 months of age were stimulated with agonists specific for TLR3, TLR4, TLR7/8, and TLR9. TLR-mediated interleukin 6 (IL-6) and IL-10 production was robust at birth and then stabilized, whereas tumor necrosis factor alpha (TNF-α) and gamma interferon (IFN-γ) responses were weak at birth and then increased. In multivariate analyses, maternalP. falciparuminfections at delivery were associated with significantly higher TLR3-mediated IL-6 and IL-10 responses in the first 3 months of life (P< 0.05) and with significantly higher TLR3-, TLR7/8-, and TLR9-mediated TNF-α responses between 6 and 12 months of age (P< 0.05). Prospective analyses showed that higher TLR3- and TLR7/8-mediated IL-10 responses at birth were associated with a significantly higher risk ofP. falciparuminfection in infancy (P< 0.05). Neonatal and infant intracellular TLR-mediated cytokine responses are conditioned byin uteroexposure through PAM late in pregnancy. Enhanced TLR-mediated IL-10 responses at birth are associated with an increased risk ofP. falciparuminfection, suggesting a compromised ability to combat infection in early life.

scholarly journals Mce1C and Mce1D facilitate N. farcinica invasion of host cells and suppress immune responses by inhibiting innate signaling pathways

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Xingzhao Ji ◽  
Xiujuan Zhang ◽  
Lina Sun ◽  
Xuexin Hou ◽  
Jingdong Song ◽  
...  
Keyword(s):  
Immune Responses ◽  
Signaling Pathways ◽  
Hela Cells ◽  
Mapk Signaling ◽  
Host Cells ◽  
Innate Immune Responses ◽  
Latex Beads ◽  
Tnf Α ◽  
Associated Proteins ◽  
Mapk Signaling Pathways

Abstract The mammalian cell entry (Mce) family of proteins consists of invasin-like membrane-associated proteins. The roles of Mce1C and Mce1D proteins in host–pathogen interactions have not been investigated. In this study, we demonstrate that Mce1C and Mce1D protein is localized in the cell wall fraction of N. farcinica. Both N. farcinica Mce1C and Mce1D proteins are expressed at the level of protein and mRNA and elicit antibody responses during infection. Mce1C and Mce1D facilitate the internalization of Escherichia coli expressing Mce1C protein or latex beads coated with Mce1D protein by HeLa cells, respectively. We further demonstrate that Mce1C and Mce1D can suppress the secretion of the proinflammatory factors TNF-α and IL-6 in macrophages infected with Mycobacterium smegmatis expressing Mce1C or Mce1D and promote the survival of M. smegmatis expressing Mce1C or Mce1D in macrophages. In addition, Mce1C and Mce1D supress the activation of the NF-κB and MAPK signaling pathways by blocking the phosphorylation of AKT, P65, ERK1/2, JNK, or P38 in macrophages. These findings suggest that Mce1C and Mce1D proteins facilitate N. farcinica invasion of HeLa cells and suppress host innate immune responses by manipulating NF-κB and MAPK signaling pathways, which may provide a target for N. farcinica treatment.

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