scholarly journals Essential roles of DC-derived IL-15 as a mediator of inflammatory responses in vivo

2006 ◽  
Vol 203 (10) ◽  
pp. 2329-2338 ◽  
Author(s):  
Toshiaki Ohteki ◽  
Hiroyuki Tada ◽  
Kazuto Ishida ◽  
Taku Sato ◽  
Chikako Maki ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Inflammatory Diseases ◽  
Neutralizing Antibody ◽  
Endotoxin Shock ◽  
Granuloma Formation ◽  
Wild Type ◽  
Monocyte Migration ◽  
Ifn Γ ◽  
Sequential Induction

Interleukin (IL)-15 is expressed in a variety of inflammatory diseases. However, the contribution of dendritic cell (DC)–derived IL-15 to the development of diseases is uncertain. Using established models of Propionibacterium acnes (P. acnes)– and zymosan-induced liver inflammation, we observed granuloma formation in the livers of wild-type (WT) and RAG-2−/− mice but not in those of IL-15−/− mice. We demonstrate that this is likely caused by an impaired sequential induction of IL-12, IFN-γ, and chemokines necessary for monocyte migration. Likewise, lethal endotoxin shock was not induced in P. acnes– and zymosan-primed IL-15−/− mice or in WT mice treated with a new IL-15–neutralizing antibody. In both systems, proinflammatory cytokine production was impaired. Surprisingly, neither granuloma formation, lethal endotoxin shock, nor IL-15 production was induced in mice deficient for DCs, and adoptive transfer of WT but not IL-15−/− DCs restored the disease development in IL-15−/− mice. Collectively, these data indicate the importance of DC-derived IL-15 as a mediator of inflammatory responses in vivo.

scholarly journals MyD88-Dependent Signaling Affects the Development of Meningococcal Sepsis by Nonlipooligosaccharide Ligands

2006 ◽  
Vol 74 (6) ◽  
pp. 3538-3546 ◽  
Author(s):  
Laura Plant ◽  
Hong Wan ◽  
Ann-Beth Jonsson
Keyword(s):  
Inflammatory Responses ◽  
Innate Immune ◽  
Meningococcal Sepsis ◽  
Wild Type ◽  
Microbial Infections ◽  
In The Wild ◽  
Myeloid Differentiation Factor ◽  
Dependent Pathway ◽  
Meningococcal Strain

ABSTRACT The Toll-like receptors (TLRs) and the adaptor myeloid differentiation factor 88 (MyD88) are important in the innate immune defenses of the host to microbial infections. Meningococcal ligands signaling via TLRs control inflammatory responses, and stimulation can result in fulminant meningococcal sepsis. In this study, we show that the responses to nonlipooligosaccharide (non-LOS) ligands of meningococci are MyD88 dependent. An isogenic LOS-deficient mutant of the serogroup C meningococcal strain FAM20 caused fatal disease in wild type C57BL/6 mice that was not observed in MyD88−/− mice. Fatality correlated with high proinflammatory cytokine and C5a levels in serum, high neutrophil numbers in blood, and increased bacteremia at 24 h postinfection in the wild-type mice. Infection with the parent strain FAM20 resulted in fatality in 100% of the wild-type mice and 50% of the MyD88−/− mice. We conclude that both LOS and another neisserial ligand cause meningococcal sepsis in an in vivo mouse model and confirm that meningococcal LOS can act via both the MyD88- dependent and -independent pathways, while the non-LOS meningococcal ligand(s) acts only via the MyD88-dependent pathway.

scholarly journals Induction of Host Chemotactic Response by Encephalitozoon spp.

2006 ◽  
Vol 75 (4) ◽  
pp. 1619-1625 ◽  
Author(s):  
Jeffrey Fischer ◽  
Jeffrey West ◽  
Nnenaya Agochukwu ◽  
Colby Suire ◽  
Hollie Hale-Donze
Keyword(s):  
Inflammatory Responses ◽  
Kinetic Studies ◽  
Protein Profiling ◽  
Diagnostic Tools ◽  
Emerging Pathogens ◽  
Chemokine Production ◽  
Human Macrophages ◽  
Monocyte Migration

ABSTRACT Microsporidians are a group of emerging pathogens typically associated with chronic diarrhea in immunocompromised individuals. The number of reports of infections with these organisms and the disseminated pathology is growing as diagnostic tools become more readily available. However, little is known about the innate immune response induced by and generated against these parasites. Using a coculture chemotaxis system, primary human macrophages were infected with Encephalitozoon cuniculi or Encephalitozoon intestinalis, and the recruitment of naïve monocytes was monitored. Encephalitozoon spp. induced an average threefold increase in migration of naïve cells 48 h postinfection, which corresponded to optimal infection of monocyte-derived-macrophages. A limited microarray analysis of infected macrophages revealed several chemokines involved in the inflammatory responses whose expression was upregulated, including CCL1, CCL2, CCL3, CCL4, CCL7, CCL15, CCL20, CXCL1, CXCL2, CXCL3, CXCL5, and CXCL8. The levels of 6 of 11 chemokines also present in the microarray were confirmed to be elevated by protein profiling. Kinetic studies confirmed that secreted CCL2, CCL3, and CCL4 were expressed as early as 6 h postinfection, with peak expression at 12 to 24 h and expression remaining until 48 h postinfection. Neutralization of these chemokines, specifically CCL4, significantly reduced the number of migrating cells in vitro, indicating their role in the induction of monocyte migration. This mechanism of recruitment not only supports the evidence that in vivo cellular infiltration occurs but also provides new hosts for the parasites, which escape macrophages by rupturing the host cell. To our knowledge, this is the first documentation that chemokine production is induced by microsporidian infections in human macrophages.

scholarly journals Continuous in vivo infusion of interferon-gamma (IFN-γ) enhances engraftment of syngeneic wild-type cells in Fanca–/– and Fancg–/– mice

Blood ◽  
2006 ◽  
Vol 108 (13) ◽  
pp. 4283-4287 ◽  
Author(s):  
Yue Si ◽  
Samantha Ciccone ◽  
Feng-Chun Yang ◽  
Jin Yuan ◽  
Daisy Zeng ◽  
...  
Keyword(s):  
Stem Cells ◽  
Interferon Gamma ◽  
Cancer Susceptibility ◽  
Genetic Disorder ◽  
Wild Type ◽  
Regulatory Cytokine ◽  
Complementation Groups ◽  
Ifn Γ

Abstract Fanconi anemia (FA) is a heterogeneous genetic disorder characterized by bone marrow (BM) failure and cancer susceptibility. Identification of the cDNAs of FA complementation types allows the potential of using gene transfer technology to introduce functional cDNAs as transgenes into autologous stem cells and provide a cure for the BM failure in FA patients. However, strategies to enhance the mobilization, transduction, and engraftment of exogenous stem cells are required to optimize efficacy prior to widespread clinical use. Hypersensitivity of Fancc–/– cells to interferon-gamma (IFN-γ), a nongenotoxic immune-regulatory cytokine, enhances engraftment of syngeneic wild-type (WT) cells in Fancc–/– mice. However, whether this phenotype is of broad relevance in other FA complementation groups is unresolved. Here we show that primitive and mature myeloid progenitors in Fanca–/– and Fancg–/– mice are hypersensitive to IFN-γ and that in vivo infusion of IFN-γ at clinically relevant concentrations was sufficient to allow consistent long-term engraftment of isogenic WT repopulating stem cells. Given that FANCA, FANCC, and FANCG complementation groups account for more than 90% of all FA patients, these data provide evidence that IFN-γ conditioning may be a useful nongenotoxic strategy for myelopreparation in FA patients.

scholarly journals Transcription modulation by CDK9 regulates inflammatory genes and RIPK3-MLKL-mediated necroptosis in periodontitis progression

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jiao Li ◽  
Jiahong Shi ◽  
Yue Pan ◽  
Yunhe Zhao ◽  
Fuhua Yan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Survival ◽  
Inflammatory Responses ◽  
Inflammatory Diseases ◽  
Acute Infection ◽  
Infection Process ◽  
Inhibitory Protein ◽  
Inflammatory Gene ◽  
Knock Down

AbstractCyclin-dependent kinase 9 (CDK9), one crucial molecule in promoting the transition from transcription pausing to elongation, is a critical modulator of cell survival and death. However, the pathological function of CDK9 in bacterial inflammatory diseases has never been explored. CDK9 inhibition or knock-down attenuated Porphyromonas gingivalis-triggered inflammatory gene expression. Gene-expression microarray analysis of monocytes revealed that knock-down of CDK9 not only affected inflammatory responses, but also impacted cell death network, especially the receptor-interacting protein kinase 3 (RIPK3)-mixed lineage kinase domain-like (MLKL)-mediated necroptosis after P. gingivalis infection. Inhibition of CDK9 significantly decreased necroptosis with downregulation of both MLKL and phosphorylated MLKL. By regulating caspase-8 and cellular FLICE inhibitory protein (cFLIP), key molecules in regulating cell survival and death, CDK9 affected not only the classic RIPK1-RIPK3-mediated necroptosis, but also the alternate TIR-domain-containing adapter-inducing interferon-β-RIPK3-mediated necroptosis. CDK9 inhibition dampened pro-inflammatory gene production in the acute infection process in the subcutaneous chamber model in vivo. Moreover, CDK9 inhibition contributed to the decreased periodontal bone loss and inflammatory response induced by P. gingivalis in the periodontal micro-environment. In conclusion, by modulating the RIPK3-MLKL-mediated necroptosis, CDK9 inhibition provided a novel mechanism to impact the progress of bacterial infection in the periodontal milieu.

scholarly journals TMIC-02. JUNCTIONAL ADHESION MOLECULE-A (JAM-A) DEFICIENCY DRIVES SEX-SPECIFIC DIFFERENCES IN GLIOBLASTOMA PROGRESSION VIA DIFFERENTIAL MICROGLIA RESPONSES IN THE TUMOR MICROENVIRONMENT

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi247-vi247
Author(s):  
Soumya Turaga ◽  
Daniel Silver ◽  
Evi Paouri ◽  
Defne Bayik ◽  
Sen Peng ◽  
...  
Keyword(s):  
Overall Survival ◽  
Tumor Microenvironment ◽  
Inflammatory Diseases ◽  
Therapy Response ◽  
Clinical Variable ◽  
Specific Gene ◽  
Wild Type ◽  
Male And Female ◽  
Junction Protein

Abstract Despite the male preponderance for developing glioblastoma (GBM) and better survival outcomes in females, current treatment paradigms do not account for biological sex as a biological or clinical variable. Sex-specific molecular alterations that drive tumor cell growth and therapy response have been documented, however, sex-specific extrinsic differences in the tumor microenvironment have yet to be identified. Based on well-established sex-specific gene signatures and functional differences in microglia, we interrogated influences of male and female microglia in driving GBM growth. Specifically, manipulation of JAM-A expression, a tight junction protein on microglia, was exploited as a paradigm for determining effects on in vivo syngeneic GBM mouse models. Male and female JAM-A KO mice that received orthotopic injection of syngeneic GBM cells presented differential overall survival distinct from their wildtype counterparts. Wild-type male mice phenocopied human males, presenting shorter overall survival than females, this trend was reversed in JAM-A KO mice. Compared to the other genotypes, female JAM-A KO mice presented the greatest number of phagocytic, tumor-promoting, activated microglia. RNA-sequencing of tumors from JAM-A KO and WT mice revealed that female JAM-A KO mice had increased expression of Ifi202b (interferon activated gene 202b), a member of the Activity-regulated Inhibitor of Death (AID) gene family that contributes to mitochondrial resistance to cellular stress. Ifi202b has a role in sex-specific inflammatory diseases, which is consistent with our observation. Female KO microglia had enhanced Ifi202b expression, along with the secretion of Ifi202b associated cytokines, including interleukin-6. Treatment of wild-type female microglia with a JAM-A function blocking antibody demonstrated an increase in Ifi202b levels, confirming direct regulation of Ifi202b expression by neutralizing JAM-A. While cell intrinsic, sex-specific differences have been reported in GBM, our findings demonstrate that differences in the GBM tumor microenvironment also drive sexually dimorphic tumor growth.

Hyperactivable NFAT1 Ameliorates Autoimmune Encephalitis In Vivo.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 711-711
Author(s):  
Srimoyee Ghosh ◽  
Sergei B Koralov ◽  
Irena Stevanovic ◽  
Mark S Sundrud ◽  
Yoshiteru Sasaki ◽  
...  
Keyword(s):  
T Cells ◽  
Transgenic Mice ◽  
Cd4 T Cells ◽  
Th17 Cells ◽  
Autoimmune Encephalitis ◽  
Cell Types ◽  
Wild Type ◽  
Ifn Γ

Abstract Abstract 711 Naïve CD4 T cells differentiate into diverse effector and regulatory subsets to coordinate the adaptive immune response. TH1 and TH2 effector subsets produce IFN-γ and IL-4, respectively, whereas proinflammatory TH17 cells are key regulators of autoimmune inflammation, characteristically produce IL-17 and IL-22 and differentiate in the presence of inflammatory cytokines like IL-6 and IL-21 together with TGF-β. Naive T cells can also differentiate into tissue-protective induced T regulatory (iTreg) cells. NFAT proteins are highly phosphorylated and reside in the cytoplasm of resting cells. Upon dephosphorylation by the Ca2+/calmodulin-dependent serine phosphatase calcineurin, NFAT proteins translocate to the nucleus, where they orchestrate developmental and activation programs in diverse cell types. In this study, we investigated the role of the Ca/NFAT signaling pathway in regulating T cell differentiation and the development of autoimmune diseases. We generated transgenic mice conditionally expressing a hyperactivable version of NFAT1 (AV-NFAT1) from the ROSA26 locus. To restrict AV-NFAT1 expression to the T cell compartment, ROSA26-AV-NFAT1 transgenic mice were bred to CD4-Cre transgenic mice. Naïve CD4 T cells freshly isolated from AV mice produced significantly less IL-2 but increased amounts of the inhibitory cytokine IL-10. To investigate the role of NFAT1 in the generation of TH1, TH2, Tregand TH17 cells, the respective cell types were generated from CD4 T cells of AV mice by in vitro differentiation. T cells from AV-NFAT1 mice exhibited a dysregulation of cytokine expression, producing more IFN-γ and less IL-4. While the numbers of CD4+CD25+ “natural” Treg cells in peripheral lymphoid organs and their in vitro suppressive functions were slightly decreased in AV mice, iTreg generation from CD4+CD25- T cells of AV mice as compared to wild type cells was markedly enhanced. Moreover, TH17 cells generated in vitro from CD4 T cells of AV mice in the presence of IL-6, IL-21 and TGF-β exhibited dramatically increased expression of both IL-10 and IL-17 as compared to wild type controls. To investigate putative NFAT binding sites in the IL-10 and IL-17 gene loci, we performed chromatin immunoprecipitation experiments. We show that NFAT1 can bind at the IL-17 locus at 3 out of 9 CNS regions which are accessible specifically during TH17 but not during TH1 and TH2 differentiation. Furthermore, we provide evidence that NFAT1 binds one CNS region in the IL10-locus in TH17 cells. To verify our observations in vivo, we induced experimental autoimmune encephalitis (EAE) in AV mice and wild type controls with the immunodominant myelin antigen MOG33-55 emulsified in complete Freund‘s adjuvant. While wild type animals showed a normal course of disease with development of tail and hind limb paralysis after approximately 10 days, AV mice showed a markedly weaker disease phenotype with less severe degrees of paralysis and accelerated kinetics of remission. Moreover at the peak of the response, there were fewer CD4+CD25- but more CD4+CD25+ T cells in the CNS of AV animals compared to wild type controls. Surprisingly, these cells produced significantly more IL-2, IL-17 and IFN-γ upon restimulation, even though they displayed decreased disease. In summary, our data provide strong evidence that NFAT1 contributes to the regulation of IL-10 and IL-17 expression in TH17 cells and show that increasing NFAT1 activity can ameliorate autoimmune encephalitis. This could occur in part through upregulation of IL-10 expression as observed in vitro, but is also likely to reflect increased infiltration of regulatory T cells into the CNS as well as increased conversion of conventional T cells into Foxp3+ regulatory T cells within the CNS. Disclosures: No relevant conflicts of interest to declare.

scholarly journals The macrophage IRF8/IRF1 regulome is required for protection against infections and is associated with chronic inflammation

2016 ◽  
Vol 213 (4) ◽  
pp. 585-603 ◽  
Author(s):  
David Langlais ◽  
Luis B. Barreiro ◽  
Philippe Gros
Keyword(s):  
Pulmonary Tuberculosis ◽  
Mouse Models ◽  
Chromatin Immunoprecipitation ◽  
Inflammatory Diseases ◽  
Transcriptional Regulators ◽  
Interferon Γ ◽  
Wild Type ◽  
Chromatin Immunoprecipitation Sequencing ◽  
Ifn Γ ◽  
And Function

IRF8 and IRF1 are transcriptional regulators that play critical roles in the development and function of myeloid cells, including activation of macrophages by proinflammatory signals such as interferon-γ (IFN-γ). Loss of IRF8 or IRF1 function causes severe susceptibility to infections in mice and in humans. We used chromatin immunoprecipitation sequencing and RNA sequencing in wild type and in IRF8 and IRF1 mutant primary macrophages to systematically catalog all of the genes bound by (cistromes) and transcriptionally activated by (regulomes) IRF8, IRF1, PU.1, and STAT1, including modulation of epigenetic histone marks. Of the seven binding combinations identified, two (cluster 1 [IRF8/IRF1/STAT1/PU.1] and cluster 5 [IRF1/STAT1/PU.1]) were found to have a major role in controlling macrophage transcriptional programs both at the basal level and after IFN-γ activation. They direct the expression of a set of genes, the IRF8/IRF1 regulome, that play critical roles in host inflammatory and antimicrobial defenses in mouse models of neuroinflammation and of pulmonary tuberculosis, respectively. In addition, this IRF8/IRF1 regulome is enriched for genes mutated in human primary immunodeficiencies and with loci associated with several inflammatory diseases in humans.

scholarly journals GITR-GITRL System, A Novel Player in Shock and Inflammation

2007 ◽  
Vol 7 ◽  
pp. 533-566 ◽  
Author(s):  
Ludovic Tibor Krausz ◽  
Rodolfo Bianchini ◽  
Simona Ronchetti ◽  
Katia Fettucciari ◽  
Giuseppe Nocentini ◽  
...  
Keyword(s):  
Innate Immunity ◽  
T Cells ◽  
Inflammatory Responses ◽  
Inflammatory Diseases ◽  
Tumor Necrosis Factor Receptor ◽  
Early Response ◽  
System A ◽  
Antigen Presenting

Glucocorticoid-induced TNFR-Related (GITR) protein is a member of the tumor necrosis factor receptor superfamily that modulates acquired and natural immune response. It is expressed in several cells and tissues, including T cells, natural killer cells, and, at lower levels, in cells of innate immunity. GITR is activated by its ligand, GITRL, mainly expressed on antigen presenting and endothelial cells. Recent evidence suggests that the GITR/GITRL system participates in the development of inflammatory responses, including shock, either due to early response of neutrophils and macrophages, or together with autoimmune/allergic pathogenesis. The pro-inflammatory role of the GITR/GITRL system is due to: 1) modulation of the extravasation process, 2) activation of innate immunity cells, 3) activation of effector T cells also favored by partial inhibition of suppressor T cells and modulation of dendritic function. This review summarizes thein vivorole of the GITR/GITRL system in inflammation and shock, explaining the mechanisms responsible for their effects, considering the interplay among the different cells of the immune system and transduction pathways activated by GITR and GITRL triggering. The hidden aspects about GITR/GITRL function, crucial for treatment planning of inflammatory diseases and shock by modulation of this system is stressed.

scholarly journals In Vivo Targeting of CXCR4—New Horizons

Cancers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 5920
Author(s):  
Margret Schottelius ◽  
Ken Herrmann ◽  
Constantin Lapa
Keyword(s):  
Immune Cells ◽  
Immune Cell ◽  
Inflammatory Responses ◽  
Inflammatory Diseases ◽  
Clinical Status ◽  
Inflammatory Stimuli ◽  
Imaging Probes ◽  
Recent Developments ◽  
Chemokine Receptor 4

Given its pre-eminent role in the context of tumor cell growth as well as metastasis, the C-X-C motif chemokine receptor 4 (CXCR4) has attracted a lot of interest in the field of nuclear oncology, and clinical evidence on the high potential of CXCR4-targeted theranostics is constantly accumulating. Additionally, since CXCR4 also represents a key player in the orchestration of inflammatory responses to inflammatory stimuli, based on its expression on a variety of pro- and anti-inflammatory immune cells (e.g., macrophages and T-cells), CXCR4-targeted inflammation imaging has recently gained considerable attention. Therefore, after briefly summarizing the current clinical status quo of CXCR4-targeted theranostics in cancer, this review primarily focuses on imaging of a broad spectrum of inflammatory diseases via the quantification of tissue infiltration with CXCR4-expressing immune cells. An up-to-date overview of the ongoing preclinical and clinical efforts to visualize inflammation and its resolution over time is provided, and the predictive value of the CXCR4-associated imaging signal for disease outcome is discussed. Since the sensitivity and specificity of CXCR4-targeted immune cell imaging greatly relies on the availability of suitable, tailored imaging probes, recent developments in the field of CXCR4-targeted imaging agents for various applications are also addressed.

scholarly journals Revisiting an IgG Fc Loss-of-Function Experiment: the Role of Complement in HIV Broadly Neutralizing Antibody b12 Activity

mBio ◽  
2021 ◽  
Author(s):  
Benjamin S. Goldberg ◽  
Chengzi I. Kaku ◽  
Jérémy Dufloo ◽  
Timothée Bruel ◽  
Olivier Schwartz ◽  
...  
Keyword(s):  
Neutralizing Antibody ◽  
Loss Of Function ◽  
Wild Type ◽  
Suboptimal Outcome ◽  
Antiviral Activities ◽  
Broadly Neutralizing Antibody ◽  
Hiv 1 ◽  
Prevention Of Hiv

Given the suboptimal outcome of VRC01 antibody-mediated prevention of HIV-1 infection in its first field trial, means to improve diverse antiviral activities in vivo have renewed importance. This work revisits a loss-of-function experiment that investigated the mechanism of action of b12, a similar antibody, and finds that the reason why complement-mediated antiviral activities were not observed to contribute to protection may be the inherent lack of activity of wild-type b12, raising the prospect that this mechanism may contribute in the context of other HIV-specific antibodies.

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