scholarly journals Coincidental loss of DOCK8 function in NLRP10-deficient and C3H/HeJ mice results in defective dendritic cell migration

2015 ◽  
Vol 112 (10) ◽  
pp. 3056-3061 ◽  
Author(s):  
Jayendra Kumar Krishnaswamy ◽  
Arpita Singh ◽  
Uthaman Gowthaman ◽  
Renee Wu ◽  
Pavane Gorrepati ◽  
...  
Keyword(s):  
T Cells ◽  
Lymph Nodes ◽  
Knockout Mice ◽  
T Cell Response ◽  
Inflammasome Activation ◽  
Nucleotide Exchange ◽  
Loss Of Function ◽  
Pyrin Domain ◽  
Proteomic Approach ◽  
Dendritic Cell Migration

Dendritic cells (DCs) are the primary leukocytes responsible for priming T cells. To find and activate naïve T cells, DCs must migrate to lymph nodes, yet the cellular programs responsible for this key step remain unclear. DC migration to lymph nodes and the subsequent T-cell response are disrupted in a mouse we recently described lacking the NOD-like receptor NLRP10 (NLR family, pyrin domain containing 10); however, the mechanism by which this pattern recognition receptor governs DC migration remained unknown. Using a proteomic approach, we discovered that DCs from Nlrp10 knockout mice lack the guanine nucleotide exchange factor DOCK8 (dedicator of cytokinesis 8), which regulates cytoskeleton dynamics in multiple leukocyte populations; in humans, loss-of-function mutations in Dock8 result in severe immunodeficiency. Surprisingly, Nlrp10 knockout mice crossed to other backgrounds had normal DOCK8 expression. This suggested that the original Nlrp10 knockout strain harbored an unexpected mutation in Dock8, which was confirmed using whole-exome sequencing. Consistent with our original report, NLRP3 inflammasome activation remained unaltered in NLRP10-deficient DCs even after restoring DOCK8 function; however, these DCs recovered the ability to migrate. Isolated loss of DOCK8 via targeted deletion confirmed its absolute requirement for DC migration. Because mutations in Dock genes have been discovered in other mouse lines, we analyzed the diversity of Dock8 across different murine strains and found that C3H/HeJ mice also harbor a Dock8 mutation that partially impairs DC migration. We conclude that DOCK8 is an important regulator of DC migration during an immune response and is prone to mutations that disrupt its crucial function.

Abstract 44: Failure of Protective Autoimmunity in Mouse and Human Atherosclerosis

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Dennis Wolf ◽  
Teresa Gerhardt ◽  
Nathaly Anto Michel ◽  
Bjarke Hansen ◽  
Alessandro Sette ◽  
...  
Keyword(s):  
T Cells ◽  
Lymph Nodes ◽  
Mhc Class Ii ◽  
T Regulatory Cells ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
T Cell Response ◽  
Regulatory Cells ◽  
Protective Autoimmunity

Background: In atherosclerosis, CD4 + T helper cells recognize auto-antigens including ApoB, the main protein in low-density lipoprotein (LDL). However, atherosclerosis-specific, auto-reactive CD4 + T cells have not been detected in vivo , and their function is unknown. Methods and Results: We have previously identified peptides derived from mouse ApoB that bind with high affinity to the MHC class II molecule of C57BL/6 mice (I-A b ). We designed and validated a new multimer of a recombinant MHC-II molecule fused to one ApoB auto-epitopes, P6 (TGAYSNASSTESASY, P6:I-A b ), that enabled detection of low-affinity, P6-reactive CD4 + T cells. Using this P6:I-A b multimer, we identified ApoB-reactive CD4 + T cells in healthy, young C57BL/6 mice that were predominately differentiated T-regulatory cells (T regs ) and expressed IL-10, a known atheroprotective cytokine. This population was detectable in lymph nodes and already showed a memory phenotype in young animals without atherosclerosis. In Apoe -/- mice, adoptively transferred ApoB P6-specific T regs accumulated in the aorta and draining lymph nodes and gave rise to pathogenic T H 1 and T H 17 cells. This phenotypic switch was caused by enhanced plasticity of antigen-specific T regs as evidenced by multiple clusters of intermediate T reg -T eff phenotypes in single cell RNA sequencing of 4485 antigen-specific CD4 + T cells. In the plaque, many T cells were ex-T regs as identified by a FoxP3 lineage tracker mouse, suggesting that atherosclerosis-specific CD4 + T cells lost their regulatory capacity. Vaccination with P6 maintained a protective phenotype in antigen-specific T regs and protected from atherosclerosis. In humans, ApoB-specific CD4 + T cells from atherosclerotic patients showed the same cytokine patterns found in mouse CD4 + T cells, suggesting that autoimmunity to ApoB is protective first, but later gives rise to a pathogenic CD4 + T cell response that aggravates atherosclerosis. Conclusion: Protective T-regulatory cells recognizing peptide antigens of ApoB exist in naïve mice, protect against atherosclerosis, but convert into pathogenic T H 1 and -17 cells during the natural course of disease in mice and humans. These results call for immunomodulatory therapies to maintain protective autoimmunity.

scholarly journals T cells Mediate Progression of Load-Induced Osteoarthritis

2020 ◽  
Author(s):  
Tibra A. Wheeler ◽  
Adrien Y. Antoinette ◽  
Matthew J. Kim ◽  
Marjolein C. H. van der Meulen ◽  
Ankur Singh
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Lymph Nodes ◽  
Mechanical Loading ◽  
Joint Damage ◽  
Γδ T Cells ◽  
Cartilage Degradation ◽  
T Cell Response ◽  
Lymphoid Tissues

AbstractOsteoarthritis (OA) is a degenerative disease that manifests as joint damage and synovial inflammation. To date, most studies have focused on the decrease in cartilage stiffness, chondrocyte viability, and changes in matrix-degrading enzymes. With the exception of a few inflammatory cytokines and macrophages, the immune response in OA is poorly characterized, and the crosstalk of joint damage with T and B cells in local lymph nodes is unknown. Here, using an in vivo mouse model of mechanical loading of mouse tibia, we demonstrate that CD8+ T cells and subsets of CD4+ T cells, and not B cells, increase in the local lymph nodes and contribute to the progression of load-induced OA pathology. We demonstrate that T cell response is sex- and age-dependent. Mechanical loading of T cell knock-out mice that lack αβ T cell receptor carrying cells resulted in attenuation of both cartilage degradation and osteophyte formation in loaded joints, with a concomitant increase in γδ+ T cells. Restricting the migration of T cells in lymphoid tissues through the systemic treatment using Sphingosine-1-phosphate (S1P) inhibitor, decreased localization of T cells in synovium, and attenuated cartilage degradation. Our results lay the foundation of the role T cells play in the joint damage of load-induced OA and allude to the use of S1P inhibitors and T cell immunotherapies for slowing the progression of OA pathology.

scholarly journals The NLRP3 inflammasome mediates DSS-induced intestinal inflammation in Nod2 knockout mice

2019 ◽  
Vol 25 (2) ◽  
pp. 132-143 ◽  
Author(s):  
Benjamin Umiker ◽  
Hyun-Hee Lee ◽  
Julia Cope ◽  
Nadim J. Ajami ◽  
Jean-Philippe Laine ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Intestinal Inflammation ◽  
Inflammasome Activation ◽  
Intestinal Epithelial ◽  
Loss Of Function ◽  
Pyrin Domain ◽  
Nlrp3 Inflammasome Activation ◽  
Chronic Disorder ◽  
Molecule Inhibitor ◽  
Pathway Inhibition

Crohn’s disease (CD) is a chronic disorder of the gastrointestinal tract characterized by inflammation and intestinal epithelial injury. Loss of function mutations in the intracellular bacterial sensor NOD2 are major risk factors for the development of CD. In the absence of robust bacterial recognition by NOD2 an inflammatory cascade is initiated through alternative PRRs leading to CD. In the present study, MCC950, a specific small molecule inhibitor of NLR pyrin domain-containing protein 3 (NLRP3), abrogated dextran sodium sulfate (DSS)-induced intestinal inflammation in Nod2−/− mice. NLRP3 inflammasome formation was observed at a higher rate in NOD2-deficient small intestinal lamina propria cells after insult by DSS. NLRP3 complex formation led to an increase in IL-1β secretion in both the small intestine and colon of Nod2ko mice. This increase in IL-1β secretion in the intestine was attenuated by MCC950 leading to decreased disease severity in Nod2ko mice. Our work suggests that NLRP3 inflammasome activation may be a key driver of intestinal inflammation in the absence of functional NOD2. NLRP3 pathway inhibition can prevent intestinal inflammation in the absence of robust NOD2 signaling.

scholarly journals Quantitative Analysis of the Acute and Long-Term CD4+ T-Cell Response to a Persistent Gammaherpesvirus

1999 ◽  
Vol 73 (5) ◽  
pp. 4279-4283 ◽  
Author(s):  
Jan P. Christensen ◽  
Peter C. Doherty
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
Cell Response ◽  
Peak Frequency ◽  
T Cell Response ◽  
Compensatory Response ◽  
Cervical Lymph Nodes ◽  
Murine Gammaherpesvirus

ABSTRACT The murine gammaherpesvirus 68 (MHV-68) replicates in respiratory epithelial cells, where it establishes a persistent, latent infection limited predominantly to B lymphocytes. The virus-specific CD4+ T-cell response in C57BL/6 mice challenged intranasally with MHV-68 is detected first in the mediastinal lymph nodes and then in the cervical lymph nodes and the spleen. The numbers of MHV-68-specific CD4+ T cells generated in congenic mice homozygous for disruption of the β2-microglobulin gene tended to be higher, indicating that the absence of the CD8+ set in this group resulted in a compensatory response. The peak frequency within the splenic CD4+ T-cell population may reach 1:50 in the acute response; it then drops to 1:400 to 1:500 within 4 months and stays at that level in the very long term. Sorting for L-selectin (CD62L) expression established that all virus-specific CD4+ T cells were initially CD62Llow, with >80% maintaining that phenotype for the next 14 months. The overall conclusion is that MHV-68-specific CD4+ T cells remain activated (CD62Llow) and at a stable frequency in the face of persistent infection.

Abstract 458: Fcgamma Receptor IV Expressed on Inflammatory Cells Drive Diet-induced Atherosclerosis in Hyperlipidemic Mouse Model

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Branimir Popovic ◽  
Doug Feck ◽  
Shanmugam Nagarajan
Keyword(s):  
T Cells ◽  
Mouse Model ◽  
Knockout Mice ◽  
Inflammatory Responses ◽  
Inflammasome Activation ◽  
Double Knockout ◽  
Arterial Lesions ◽  
Apoe Ko Mice ◽  
Progression Of Atherosclerosis ◽  
Apoe Ko

Objective: Functionally, Fcgamma receptors (FcgRs) can be classified as activating (FcgRI, III, and IV) and inhibitory (FcgRII) receptors. We have reported that combined deficiency of all three activating FcgRs in apoE knockout mice decreased atherosclerosis. In this report, we investigated the independent role of FcgRI and FcgRIV in the progression of atherosclerosis. We investigated the hypothesis that the deficiency of FcgRIV, one of the activating FcgRs, inhibits atherosclerosis in a hypercholesterolemic mouse model. We tested the hypothesis that FcgRI and FcgRIV exacerbate atherosclerosis using apoE-FcgRI dKO and apoE-FcgRIV deficient mice. Approach and Results: ApoE-FcgRI and apoE-FcgRIV double knockout mice (dKO) congenic to the C57BL/6 were generated and atherosclerotic lesions were assessed. Our results show that arterial lesions were not different between apoE-FcgRI dKO and apoE knockout (apoE KO) mice. Interestingly, arterial lesions were significantly decreased in a regular chow or a high-fat diet fed apoE-FcgRIV dKO male and female mice, relative to apoE KO mice. Bone marrow chimeras were used to address the relative contribution of FcgRIV expressed on hematopoietic cells including macrophages and dendritic cell. ApoE KO mice transplanted with apoE-FcgRIV dKO marrow showed significantly reduced arterial lesions relative to recipient mice transplanted with apoE KO marrow. Next, we investigated whether pro-inflammatory response contributed to the pro-atherogenic effect of FcgRIV. Activated CD4+ T cells of apoE-FcgRIV dKO mice showed increased secretion of IL-10, whereas IFN-gamma and IL-17 by T cells were decreased. Interestingly, dendritic cells at the lesion-prone vascular site from apoE-FcgRIV dKO mice induced increased IL-10 secretion by LDL-specific T cells. Moreover, FcgRIV KO and apoE-FcgRIV dKO macrophages showed decreased inflammasome activation as evidenced by decreased IL-1 beta response. Conclusions: Our findings demonstrate that the pro-inflammatory responses initiated by FcgRIV, one of the activating FcgRs, contribute to the progression of atherosclerosis.

scholarly journals Prevention of CD8 T Cell Deletion during Chronic Viral Infection

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1189
Author(s):  
David G. Brooks ◽  
Antoinette Tishon ◽  
Michael B. A. Oldstone ◽  
Dorian B. McGavern
Keyword(s):  
T Cells ◽  
T Cell ◽  
Viral Replication ◽  
Viral Infection ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Chronic Viral Infection ◽  
Loss Of Function ◽  
Cell Deletion

During chronic viral infections, CD8 T cells rapidly lose antiviral and immune-stimulatory functions in a sustained program termed exhaustion. In addition to this loss of function, CD8 T cells with the highest affinity for viral antigen can be physically deleted. Consequently, treatments designed to restore function to exhausted cells and control chronic viral replication are limited from the onset by the decreased breadth of the antiviral T cell response. Yet, it remains unclear why certain populations of CD8 T cells are deleted while others are preserved in an exhausted state. We report that CD8 T cell deletion during chronic viral infection can be prevented by therapeutically lowering viral replication early after infection. The initial resistance to deletion enabled long-term maintenance of antiviral cytolytic activity of the otherwise deleted high-affinity CD8 T cells. In combination with decreased virus titers, CD4 T cell help and prolonged interactions with costimulatory molecules B7-1/B7-2 were required to prevent CD8 T cell deletion. Thus, therapeutic strategies to decrease early virus replication could enhance virus-specific CD8 T cell diversity and function during chronic infection.

scholarly journals Vaccination and Infection of Swine With Salmonella Typhimurium Induces a Systemic and Local Multifunctional CD4+ T-Cell Response

2021 ◽  
Vol 11 ◽  
Author(s):  
Selma Schmidt ◽  
Elena L. Sassu ◽  
Eleni Vatzia ◽  
Alix Pierron ◽  
Julia Lagler ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
T Cell Response ◽  
Effector Memory ◽  
Cell Immune Response ◽  
Control Group ◽  
Tnf Α ◽  
Ifn Γ

The gram-negative facultative intracellular bacteria Salmonella Typhimurium (STM) often leads to subclinical infections in pigs, but can also cause severe enterocolitis in this species. Due to its high zoonotic potential, the pathogen is likewise dangerous for humans. Vaccination with a live attenuated STM strain (Salmoporc) is regarded as an effective method to control STM infections in affected pig herds. However, information on the cellular immune response of swine against STM is still scarce. In this study, we investigated the T-cell immune response in pigs that were vaccinated twice with Salmoporc followed by a challenge infection with a virulent STM strain. Blood- and organ-derived lymphocytes (spleen, tonsils, jejunal and ileocolic lymph nodes, jejunum, ileum) were stimulated in vitro with heat-inactivated STM. Subsequently, CD4+ T cells present in these cell preparations were analyzed for the production of IFN-γ, TNF-α, and IL-17A by flow cytometry and Boolean gating. Highest frequencies of STM-specific cytokine-producing CD4+ T cells were found in lamina propria lymphocytes of jejunum and ileum. Significant differences of the relative abundance of cytokine-producing phenotypes between control group and vaccinated + infected animals were detected in most organs, but dominated in gut and lymph node-residing CD4+ T cells. IL-17A producing CD4+ T cells dominated in gut and gut-draining lymph nodes, whereas IFN-γ/TNF-α co-producing CD4+ T cells were present in all locations. Additionally, the majority of cytokine-producing CD4+ T cells had a CD8α+CD27- phenotype, indicative of a late effector or effector memory stage of differentiation. In summary, we show that Salmonella-specific multifunctional CD4+ T cells exist in vaccinated and infected pigs, dominate in the gut and most likely contribute to protective immunity against STM in the pig.

scholarly journals SIRT1 Alleviates Aldosterone-Induced Podocyte Injury by Suppressing Mitochondrial Dysfunction and NLRP3 Inflammasome Activation

2021 ◽  
pp. 1-13
Author(s):  
Mingzhu Jiang ◽  
Min Zhao ◽  
Mi Bai ◽  
Juan Lei ◽  
Yanggang Yuan ◽  
...  
Keyword(s):  
Mitochondrial Dysfunction ◽  
Knockout Mice ◽  
Nlrp3 Inflammasome ◽  
Inflammasome Activation ◽  
Glomerular Injury ◽  
Glomerular Diseases ◽  
Podocyte Injury ◽  
Pyrin Domain ◽  
Nlrp3 Inflammasome Activation

Background: Podocyte injury contributes to progressive glomerulosclerosis. Previously, we demonstrated the important role of the NLR family pyrin domain containing 3 (NLRP3) inflammasome in mediating the podocyte injury induced by aldosterone. Silent mating type information regulation 2 homolog 1 (SIRT1) is an NAD+-dependent deacetylase that is associated with the regulation of cellular inflammation. However, whether the activation of the NLRP3 inflammasome in podocytes is regulated by SIRT1, and the mechanism involved, remains unknown. Methods: In this study, we detected SIRT1 expression in patients with podocyte disease and performed an aldosterone infusion model in podocyte-specific Sirt1 knockout mice. In cultured podocytes, we used plasmids to overexpress SIRT1 and treated the podocyte with aldosterone. Results: SIRT1 was significantly decreased in the glomeruli of patients with podocyte disease. Sirt1-deficient mice showed significant urinary albumin excretion after aldosterone infusion, and the severity of the glomerular injury was significantly greater in podocyte-specific Sirt1 knockout mice than in the wild-type mice. Moreover, podocyte conditional Sirt1 knockout aggravated NLRP3 inflammasome activation and mitochondrial dysfunction (MtD). In vitro, overexpression of SIRT1 inhibited NLRP3 activation, protected against MtD and podocyte injury. Conclusion: Taken together, these findings revealed a novel regulatory mechanism of the NLRP3 inflammasome by SIRT1 by promoting mitochondrial function, which provides some potential targets for the treatment of glomerular diseases.

scholarly journals Haploinsufficiency of A20 impairs protein-protein interactome and leads into caspase-8-dependent enhancement of NLRP3 inflammasome activation

2018 ◽  
Author(s):  
Kristiina Rajamäki ◽  
Salla Keskitalo ◽  
Mikko Seppänen ◽  
Outi Kuismin ◽  
Paula Vähäsalo ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Immune Cells ◽  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Luciferase Reporter ◽  
Caspase 8 ◽  
Inflammasome Activation ◽  
Loss Of Function ◽  
Pyrin Domain ◽  
Protein Interactome

ABSTRACTObjectivesTNFAIP3 encodes A20 that negatively regulates nuclear factor kappa light chain enhancer of activated B cells (NF-κB), the major transcription factor coordinating inflammatory gene expression. TNFAIP3 polymorphisms have been linked with a spectrum of inflammatory and autoimmune diseases and recently, loss-of-function mutations in A20 were found to cause a novel inflammatory disease ‘haploinsufficiency of A20’ (HA20). Here we describe a family with HA20 caused by a novel TNFAIP3 loss-of-function mutation and elucidate the upstream molecular mechanisms linking HA20 to dysregulation of NF-κB and the related inflammasome pathway.MethodsNF-κB activation was studied in a mutation-expressing cell line using luciferase reporter assay. Physical and close-proximity protein-protein interactions of wild-type and TNFAIP3 p.(Lys91*) mutant A20 were analyzed using mass spectrometry. NF-κB –dependent transcription, cytokine secretion, and inflammasome activation were compared in immune cells of the HA20 patients and control subjects.ResultsThe protein-protein interactome of p.(Lys91*) mutant A20 was severely impaired, including inter-actions with proteins regulating NF-κB activation, DNA repair responses, and the NLR family pyrin domain containing 3 (NLRP3) inflammasome. The p.(Lys91*) mutant A20 failed to suppress NF-κB signaling, which led to increased NF-κB –dependent proinflammatory cytokine transcription. Functional experiments in the HA20 patients’ immune cells uncovered a novel caspase-8-dependent mechanism of NLRP3 inflammasome hyperresponsiveness that mediated the excessive secretion of interleukin-1β and -18.ConclusionsThe current findings significantly deepen our understanding of the molecular mechanisms underlying HA20 and other diseases associated with reduced A20 expression or function, paving the way for future therapeutic targeting of the pathway.

scholarly journals Precursor abundance influences divergent antigen specific CD8+ T cell responses after Yersinia pseudotuberculosis foodborne infection

2021 ◽  
Author(s):  
Yue Zhang ◽  
Zhijuan Qiu ◽  
Brian Sheridan ◽  
James B. Bliska
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
Post Infection ◽  
Yersinia Pseudotuberculosis ◽  
Bacterial Pathogen ◽  
T Cell Response ◽  
Mesenteric Lymph Nodes ◽  
Cell Responses ◽  
Foodborne Infection

Primary infection of C57BL/6 mice with the bacterial pathogen Yersinia pseudotuberculosis elicits an unusually large H-2Kb-restricted CD8+ T cell response to the endogenous and protective bacterial epitope YopE69-77. To better understand the basis for this large response, the model OVA257-264 epitope was inserted into YopE in Y. pseudotuberculosis and antigen specific CD8+ T cells in mice were characterized after foodborne infection with the resulting strain. The epitope YopE69-77 elicited significantly larger CD8+ T cell populations in the small intestine, mesenteric lymph nodes (MLNs), spleen and liver between 7- and 30-days post infection, despite residing in the same protein and having a similar affinity for H-2Kb as OVA257-264. YopE-specific CD8+ T cell precursors were ~4.6 times as abundant as OVA-specific precursors in the MLNs, spleen and other lymph nodes of naïve mice, explaining the dominance of YopE69-77 over OVA257-264 at early infection times. However, other factors contributed to this dominance as the ratio of YopE-specific to OVA-specific CD8+ T cells increased between 7- and 30-days post infection. We also compared the YopE-specific and OVA-specific CD8+ T cells generated during infection for effector and memory phenotypes. Significantly higher percentages of YopE-specific cells were characterized as short short-lived effectors while higher percentages of OVA-specific cells were memory precursor effectors at day 30 post infection in spleen and liver. Our results suggest that a large precursor number contributes to the dominance and effector and memory functions of CD8+ T cells generated to the protective YopE69-77 epitope during Y. pseudotuberculosis infection of C57BL/6 mice.

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