Critical Role of the Interleukin-17/Interleukin-17 Receptor Axis in Regulating Host Susceptibility to Respiratory Infection with Chlamydia Species

ABSTRACT The specific contribution of interleukin-17/interleukin-17 receptor (IL-17/IL-17R)-mediated responses in regulating host susceptibility against obligatory intracellular Chlamydia infection was investigated in C57BL/6 and C3H/HeN mice during Chlamydia muridarum respiratory infection. We demonstrated that Chlamydia stimulated IL-17/IL-17R-associated responses in both Chlamydia-resistant C57BL/6 and Chlamydia-susceptible C3H/HeN mice. However, C3H/HeN mice developed a significantly greater IL-17/IL-17R-associated response than C57BL/6 mice did. This was reflected by an increase in IL-17 mRNA expression, a higher recall IL-17 production from splenocytes upon antigen restimulation, and higher production of Th17-related cytokines (IL-23 and IL-6) and chemokines (chemokine [C-X-C motif] ligand 2 [CXCL1]/keratinocyte-derived chemokine [KC] and CXCL2/macrophage inflammatory protein 1 [MIP2]) in C3H/HeN mice than in C57BL/6 mice. Furthermore, C3H/HeN mice displayed a massive accumulation of activated and preactivated neutrophils in the airway and lung parenchyma compared to their C57BL/6 counterparts. We further demonstrated that the skewed IL-17/Th17 profile in C3H/HeN mice was predisposed by a higher basal level of IL-17 receptor C (IL-17RC) expression and then further amplified by a higher inducible IL-17RA expression in lungs. Most importantly, in vivo delivery of IL-17RA antagonist that resulted in a 50% reduction in the neutrophilic infiltration in lungs was able to reverse the susceptible phenotype of C3H/HeN mice to respiratory Chlamydia infection. Thus, our data for the first time have demonstrated a critical role for the IL-17/IL-17R axis in regulating host susceptibility to Chlamydia infection in mice.

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ADF/n-cofilin–dependent actin turnover determines platelet formation and sizing

Blood ◽

10.1182/blood-2010-03-274340 ◽

2010 ◽

Vol 116 (10) ◽

pp. 1767-1775 ◽

Cited By ~ 56

Author(s):

Markus Bender ◽

Anita Eckly ◽

John H. Hartwig ◽

Margitta Elvers ◽

Irina Pleines ◽

...

Keyword(s):

Actin Filament ◽

Molecular Mechanisms ◽

Critical Role ◽

Actin Dynamics ◽

Complex Process ◽

First Time ◽

Late Stages ◽

Platelet Formation

Abstract The cellular and molecular mechanisms orchestrating the complex process by which bone marrow megakaryocytes form and release platelets remain poorly understood. Mature megakaryocytes generate long cytoplasmic extensions, proplatelets, which have the capacity to generate platelets. Although microtubules are the main structural component of proplatelets and microtubule sliding is known to drive proplatelet elongation, the role of actin dynamics in the process of platelet formation has remained elusive. Here, we tailored a mouse model lacking all ADF/n-cofilin–mediated actin dynamics in megakaryocytes to specifically elucidate the role of actin filament turnover in platelet formation. We demonstrate, for the first time, that in vivo actin filament turnover plays a critical role in the late stages of platelet formation from megakaryocytes and the proper sizing of platelets in the periphery. Our results provide the genetic proof that platelet production from megakaryocytes strictly requires dynamic changes in the actin cytoskeleton.

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S100A8/A9 modulates inflammatory collateral tissue damage during intraperitoneal origin systemic candidiasis

10.1101/2020.03.30.017491 ◽

2020 ◽

Author(s):

Madhu Shankar ◽

Nathalie Uwamahoro ◽

Sandra Holmberg ◽

Maria Joanna Niemiec ◽

Johannes Roth ◽

...

Keyword(s):

Tissue Damage ◽

Critical Role ◽

Specific Inhibitor ◽

Surgical Intensive Care ◽

Inflammatory Protein ◽

Systemic Level ◽

Combating Infection ◽

Deficient Mice

AbstractPeritonitis is a leading cause of severe sepsis in surgical intensive care units, as over 70% of patients diagnosed with peritonitis develop septic shock. A critical role of the immune system is to return to homeostasis after combating infection. S100A8/A9 (calprotectin) is an antimicrobial, pro-inflammatory protein complex often used as a biomarker for diagnosis of disease activities in many inflammatory disorders. Here we describe the role of S100A8/A9 on inflammatory collateral tissue damage (ICTD).We performed an in vivo Candida albicans disseminated peritonitis mouse model using WT and S100A9-deficient mice and stimulated primary macrophages with recombinant S100A8/A9 in the presence or absence of the compound paquinimod, a specific inhibitor of S100A9. In addition, the effects on ICTD and fungal clearance were investigated. S100A9-deficient mice developed less ICTD than wildtype mice. Restoration of S100A8/A9 in S100A9 knockout mice resulted in increased ICTD and fungal clearance comparable to wildtype levels. Treatment with paquinimod abolished ICTD.The data indicated that S100A8/A9 controls ICTD levels and host antimicrobial modulation at a systemic level during intra-abdominal candidiasis (IAC).

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Siderophore-Mediated Iron Acquisition Plays a Critical Role in Biofilm Formation and Survival of Staphylococcus epidermidis Within the Host

Frontiers in Medicine ◽

10.3389/fmed.2021.799227 ◽

2021 ◽

Vol 8 ◽

Author(s):

Fernando Oliveira ◽

Tânia Lima ◽

Alexandra Correia ◽

Ana Margarida Silva ◽

Cristina Soares ◽

...

Keyword(s):

Staphylococcus Epidermidis ◽

Iron Acquisition ◽

Critical Role ◽

Siderophore Production ◽

Restricted Environment ◽

Underlying Mechanisms ◽

First Time ◽

Comprehensive Study

Iron acquisition through siderophores, a class of small, potent iron-chelating organic molecules, is a widely spread strategy among pathogens to survive in the iron-restricted environment found in the host. Although these molecules have been implicated in the pathogenesis of several species, there is currently no comprehensive study addressing siderophore production in Staphylococcus epidermidis. Staphylococcus epidermidis is an innocuous skin commensal bacterium. The species, though, has emerged as a leading cause of implant-associated infections, significantly supported by an inherent ability to form biofilms. The process of adaptation from skin niche environments to the hostile conditions during invasion is yet not fully understood. Herein, we addressed the possible role of siderophore production in S. epidermidis virulence. We first identified and deleted a siderophore homolog locus, sfaABCD, and provided evidence for its involvement in iron acquisition. Our findings further suggested the involvement of siderophores in the protection against oxidative stress-induced damage and demonstrated the in vivo relevance of a siderophore-mediated iron acquisition during S. epidermidis infections. Conclusively, this study addressed, for the first time in this species, the underlying mechanisms of siderophore production, highlighting the importance of a siderophore-mediated iron acquisition under host relevant conditions and, most importantly, its contribution to survival within the host.

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T cells expressing specific V beta elements regulate immunoglobulin E production and airways responsiveness in vivo.

Journal of Experimental Medicine ◽

10.1084/jem.177.4.1175 ◽

1993 ◽

Vol 177 (4) ◽

pp. 1175-1180 ◽

Cited By ~ 60

Author(s):

H Renz ◽

K Bradley ◽

J Saloga ◽

J Loader ◽

G L Larsen ◽

...

Keyword(s):

T Cells ◽

Immunoglobulin E ◽

Critical Role ◽

Specific Ige ◽

Specific Immunoglobulin ◽

Cutaneous Hypersensitivity ◽

First Time ◽

Draining Lymph Nodes

The role of T cells expressing specific V beta elements was examined in the regulation of allergen-specific immunoglobulin (Ig)E production and airways responsiveness (AR). In BALB/c mice, inhalation of the allergen ovalbumin (OVA) induced an IgE anti-OVA response, immediate cutaneous reactivity, and increased AR. These results were associated with an expansion of V beta 8.1/8.2 T cells in local draining lymph nodes of the airways and the lung. Transfer of V beta 8.1/8.2 T cells from sensitized mice stimulated an IgE anti-OVA response, immediate cutaneous hypersensitivity, and increased AR in naive syngeneic recipients. In contrast, OVA-reactive V beta 2 T cells inhibited these effects. These data demonstrate for the first time that T cells with different V beta specificities play a critical role in the in vivo regulation of allergen-specific IgE production and AR.

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Plasmid CDS5 Influences Infectivity and Virulence in a Mouse Model of Chlamydia trachomatis Urogenital Infection

Infection and Immunity ◽

10.1128/iai.01795-14 ◽

2014 ◽

Vol 82 (8) ◽

pp. 3341-3349 ◽

Cited By ~ 21

Author(s):

K. H. Ramsey ◽

J. H. Schripsema ◽

B. J. Smith ◽

Y. Wang ◽

B. C. Jham ◽

...

Keyword(s):

Chlamydia Trachomatis ◽

Inflammatory Responses ◽

Shuttle Vector ◽

Critical Role ◽

Content Type ◽

Chlamydia Muridarum ◽

Urogenital Infection ◽

Parental Isolate ◽

First Time

ABSTRACTThe native plasmid of bothChlamydia muridarumandChlamydia trachomatishas been shown to control virulence and infectivity in mice and in lower primates. We recently described the development of a plasmid-based genetic transformation protocol forChlamydia trachomatisthat for the first time provides a platform for the molecular dissection of the function of the chlamydial plasmid and its individual genes or coding sequences (CDS). In the present study, we transformed a plasmid-free lymphogranuloma venereum isolate ofC. trachomatis, serovar L2, with either the original shuttle vector (pGFP::SW2) or a derivative of pGFP::SW2 carrying a deletion of the plasmid CDS5 gene (pCDS5KO). Female mice were inoculated with these strains either intravaginally or transcervically. We found that transformation of the plasmid-free isolate with the intact pGFP::SW2 vector significantly enhanced infectivity and induction of host inflammatory responses compared to the plasmid-free parental isolate. Transformation with pCDS5KO resulted in infection courses and inflammatory responses not significantly different from those observed in mice infected with the plasmid-free isolate. These results indicate a critical role of plasmid CDS5 inin vivofitness and in induction of inflammatory responses. To our knowledge, these are the firstin vivoobservations ascribing infectivity and virulence to a specific plasmid gene.

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In vivo evidence for the role of GM-CSF as a mediator in acute pancreatitis-associated lung injury

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00413.2001 ◽

2002 ◽

Vol 283 (3) ◽

pp. L541-L548 ◽

Cited By ~ 30

Author(s):

Jean Louis Frossard ◽

Ashok K. Saluja ◽

Nicolas Mach ◽

Hong Sik Lee ◽

Lakshmi Bhagat ◽

...

Keyword(s):

Lung Injury ◽

Critical Role ◽

Membrane Thickness ◽

Myeloperoxidase Activity ◽

Neutrophil Sequestration ◽

Gm Csf ◽

Inflammatory Protein ◽

Macrophage Colony

Severe pancreatitis is frequently associated with acute lung injury (ALI) and the respiratory distress syndrome. The role of granulocyte-macrophage colony-stimulating factor (GM-CSF) in mediating the ALI associated with secretagogue-induced experimental pancreatitis was evaluated with GM-CSF knockout mice (GM-CSF −/−). Pancreatitis was induced by hourly (12×) intraperitoneal injection of a supramaximally stimulating dose of the cholecystokinin analog caerulein. The resulting pancreatitis was similar in GM-CSF-sufficient (GM-CSF +/+) control animals and GM-CSF −/− mice. Lung injury, quantitated by measuring lung myeloperoxidase activity (an indicator of neutrophil sequestration), alveolar-capillary permeability, and alveolar membrane thickness was less severe in GM-CSF −/− than in GM-CSF +/+ mice. In GM-CSF +/+ mice, pancreas, lung and serum GM-CSF levels increase during pancreatitis. Lung levels of macrophage inflammatory protein (MIP)-2 are also increased during pancreatitis, but, in this case, the rise is less profound in GM-CSF −/− mice than in GM-CSF +/+ controls. Administration of anti-MIP-2 antibodies was found to reduce the severity of pancreatitis-associated ALI. Our findings indicate that GM-CSF plays a critical role in coupling pancreatitis to ALI and suggest that GM-CSF may act indirectly by regulating the release of other proinflammatory factors including MIP-2.

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Cathepsin L plays a key role in SARS-CoV-2 infection in humans and humanized mice and is a promising target for new drug development

Signal Transduction and Targeted Therapy ◽

10.1038/s41392-021-00558-8 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Miao-Miao Zhao ◽

Wei-Li Yang ◽

Fang-Yuan Yang ◽

Li Zhang ◽

Wei-Jin Huang ◽

...

Keyword(s):

Drug Development ◽

Cathepsin L ◽

Human Cells ◽

New Drugs ◽

Disease Course ◽

Promising Target ◽

First Time

AbstractTo discover new drugs to combat COVID-19, an understanding of the molecular basis of SARS-CoV-2 infection is urgently needed. Here, for the first time, we report the crucial role of cathepsin L (CTSL) in patients with COVID-19. The circulating level of CTSL was elevated after SARS-CoV-2 infection and was positively correlated with disease course and severity. Correspondingly, SARS-CoV-2 pseudovirus infection increased CTSL expression in human cells in vitro and human ACE2 transgenic mice in vivo, while CTSL overexpression, in turn, enhanced pseudovirus infection in human cells. CTSL functionally cleaved the SARS-CoV-2 spike protein and enhanced virus entry, as evidenced by CTSL overexpression and knockdown in vitro and application of CTSL inhibitor drugs in vivo. Furthermore, amantadine, a licensed anti-influenza drug, significantly inhibited CTSL activity after SARS-CoV-2 pseudovirus infection and prevented infection both in vitro and in vivo. Therefore, CTSL is a promising target for new anti-COVID-19 drug development.

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The role of the PZP domain of AF10 in acute leukemia driven by AF10 translocations

Nature Communications ◽

10.1038/s41467-021-24418-9 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Brianna J. Klein ◽

Anagha Deshpande ◽

Khan L. Cox ◽

Fan Xuan ◽

Mohamad Zandian ◽

...

Keyword(s):

Critical Role ◽

Cellular Transformation ◽

Acute Leukemias ◽

Hematopoietic Stem ◽

Nucleosome Core ◽

Stem And Progenitor Cells ◽

Transforming Activity

AbstractChromosomal translocations of the AF10 (or MLLT10) gene are frequently found in acute leukemias. Here, we show that the PZP domain of AF10 (AF10PZP), which is consistently impaired or deleted in leukemogenic AF10 translocations, plays a critical role in blocking malignant transformation. Incorporation of functional AF10PZP into the leukemogenic CALM-AF10 fusion prevents the transforming activity of the fusion in bone marrow-derived hematopoietic stem and progenitor cells in vitro and in vivo and abrogates CALM-AF10-mediated leukemogenesis in vivo. Crystallographic, biochemical and mutagenesis studies reveal that AF10PZP binds to the nucleosome core particle through multivalent contacts with the histone H3 tail and DNA and associates with chromatin in cells, colocalizing with active methylation marks and discriminating against the repressive H3K27me3 mark. AF10PZP promotes nuclear localization of CALM-AF10 and is required for association with chromatin. Our data indicate that the disruption of AF10PZP function in the CALM-AF10 fusion directly leads to transformation, whereas the inclusion of AF10PZP downregulates Hoxa genes and reverses cellular transformation. Our findings highlight the molecular mechanism by which AF10 targets chromatin and suggest a model for the AF10PZP-dependent CALM-AF10-mediated leukemogenesis.

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Secreted KIAA1199 promotes the progression of rheumatoid arthritis by mediating hyaluronic acid degradation in an ANXA1-dependent manner

Cell Death and Disease ◽

10.1038/s41419-021-03393-5 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Wei Zhang ◽

Guoyu Yin ◽

Heping Zhao ◽

Hanzhi Ling ◽

Zhen Xie ◽

...

Keyword(s):

Rheumatoid Arthritis ◽

Hyaluronic Acid ◽

Dependent Manner ◽

Collagen Induced Arthritis ◽

Intracellular Degradation ◽

Main Pathway ◽

First Time

AbstractIn inflamed joints, enhanced hyaluronic acid (HA) degradation is closely related to the pathogenesis of rheumatoid arthritis (RA). KIAA1199 has been identified as a hyaladherin that mediates the intracellular degradation of HA, but its extracellular function remains unclear. In this study, we found that the serum and synovial levels of secreted KIAA1199 (sKIAA1199) and low-molecular-weight HA (LMW-HA, MW < 100 kDa) in RA patients were significantly increased, and the positive correlation between them was shown for the first time. Of note, treatment with anti-KIAA1199 mAb effectively alleviated the severity of arthritis and reduced serum LMW-HA levels and cytokine secretion in collagen-induced arthritis (CIA) mice. In vitro, sKIAA1199 was shown to mediate exogenous HA degradation by attaching to the cell membrane of RA fibroblast-like synoviosytes (RA FLS). Furthermore, the HA-degrading activity of sKIAA1199 depended largely on its adhesion to the membrane, which was achieved by its G8 domain binding to ANXA1. In vivo, kiaa1199-KO mice exhibited greater resistance to collagen-induced arthritis. Interestingly, this resistance could be partially reversed by intra-articular injection of vectors encoding full-length KIAA1199 instead of G8-deleted KIAA119 mutant, which further confirmed the indispensable role of G8 domain in KIAA1199 involvement in RA pathological processes. Mechanically, the activation of NF-κB by interleukin-6 (IL-6) through PI3K/Akt signaling is suggested to be the main pathway to induce KIAA1199 expression in RA FLS. In conclusion, our study supported the contribution of sKIAA1199 to RA pathogenesis, providing a new therapeutic target for RA by blocking sKIAA1199-mediated HA degradation.

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Essential role of IPS-1 in innate immune responses against RNA viruses

Journal of Experimental Medicine ◽

10.1084/jem.20060792 ◽

2006 ◽

Vol 203 (7) ◽

pp. 1795-1803 ◽

Cited By ~ 345

Author(s):

Himanshu Kumar ◽

Taro Kawai ◽

Hiroki Kato ◽

Shintaro Sato ◽

Ken Takahashi ◽

...

Keyword(s):

Rna Viruses ◽

Rna Virus ◽

Critical Role ◽

Nuclear Factor Κb ◽

Type I ◽

Innate Immune Responses ◽

Antiviral Responses ◽

Deficient Mice

IFN-β promoter stimulator (IPS)-1 was recently identified as an adapter for retinoic acid–inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (Mda5), which recognize distinct RNA viruses. Here we show the critical role of IPS-1 in antiviral responses in vivo. IPS-1–deficient mice showed severe defects in both RIG-I– and Mda5-mediated induction of type I interferon and inflammatory cytokines and were susceptible to RNA virus infection. RNA virus–induced interferon regulatory factor-3 and nuclear factor κB activation was also impaired in IPS-1–deficient cells. IPS-1, however, was not essential for the responses to either DNA virus or double-stranded B-DNA. Thus, IPS-1 is the sole adapter in both RIG-I and Mda5 signaling that mediates effective responses against a variety of RNA viruses.

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