Faculty Opinions recommendation of JAGN1 deficiency causes aberrant myeloid cell homeostasis and congenital neutropenia.

Abstract Abstract 2165 Secretory Leukocyte Protease Inhibitor (SLPI) is a cationic serine protease inhibitor with antiprotease, primarily anti-Neutrophil ELastase (NE), activities. Moreover, SLPI modulates intracellular signal transduction pathways such as NF-kB and Erk. The molecular interaction and the balance between NE and SLPI is tightly regulated. On the one side, NE upregulates the SLPI expression and at the other hand SLPI inhibits the NE-induced degradation of proteins. We identified severe diminished levels of SLPI mRNA in CD33+ myeloid cells and in PMNs of patients with severe congenital neutropenia (CN) harbouring either ELANE or HAX1 mutations, as compared to patients with cyclic neutropenia (CyN) and to healthy individuals. SLPI protein levels in plasma of CN patients were also significantly reduced. We further analysed whether diminished levels of SLPI are associated with the „maturation arrest“ of myeloid cells seen in CN patients. We inhibited SLPI using lentivirus-based transduction of the myeloid cell line NB4 with SLPI-specific shRNA and analysed ATRA-triggered myeloid differentiation. Indeed, myeloid differentiation was severely affected in NB4 cells transduced with SLPI-specific shRNA, as compared to control shRNA transduced cells. Further, we analysed the mechanisms leading to SLPI downregulation. Previously, we identified severely reduced mRNA and protein levels of NE in myeloid cells and in plasma of CN patients with either ELANE or HAX1 mutations, as compared to healthy individuals. Knowing that NE induces SLPI expression, we assumed that diminished NE levels may be responsible for the low SLPI expression in CN patients. Indeed, inhibition of NE in the myeloid cell line NB4 using NE-specific shRNAs led to diminished expression of SLPI mRNA, as compared to ctrl shRNA transduced cells. At the same time, we also found that transduction of the myeloid cell line NB4 with wild type (WT) NE resulted in the increased expression of SLPI mRNA but mutated (MUT) forms of NE as found in CN patients were not able to induce SLPI mRNA, as compared to ctrl transduced cells. Taken together, both diminished NE levels and mutations in ELANE gene may cause downregulation of SLPI. In summary, SLPI is severely downregulated in CN patients due to defective NE protein levels and ELANE mutations. As a consequence, the anti-microbial and antiinflammatory activities of SLPI are diminished in CN patients. Disclosures: No relevant conflicts of interest to declare.

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HPV16-associated tumors control myeloid cell homeostasis in lymphoid organs, generating a suppressor environment for T cells

Journal of Leukocyte Biology ◽

10.1189/jlb.3a0513-282r ◽

2014 ◽

Vol 96 (4) ◽

pp. 619-631 ◽

Cited By ~ 9

Author(s):

Simone Cardozo Stone ◽

Renata Ariza Marques Rossetti ◽

Aline Bolpetti ◽

Enrique Boccardo ◽

Patricia Savio de Araujo Souza ◽

...

Keyword(s):

T Cells ◽

Myeloid Cell ◽

Lymphoid Organs ◽

Cell Homeostasis ◽

Associated Tumors

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The Role of CX3CL1 and CSF1 in Maintaining Myeloid Cell Homeostasis in the Intima and Adventitia of the Aorta

Atherosclerosis Supplements ◽

10.1016/j.atherosclerosissup.2018.04.261 ◽

2018 ◽

Vol 32 ◽

pp. 86

Author(s):

Marwan G. Althagafi ◽

Clinton S. Robbins ◽

Myron I. Cybulsky

Keyword(s):

Myeloid Cell ◽

Cell Homeostasis

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Differential requirement for the Polycomb repressor complex 2 in dendritic cell and tissue-resident myeloid cell homeostasis

Science Immunology ◽

10.1126/sciimmunol.abf7268 ◽

2021 ◽

Vol 6 (63) ◽

Author(s):

Yifan Zhan ◽

Yuxia Zhang ◽

Shengbo Zhang ◽

Hannah Coughlan ◽

Pedro L. Baldoni ◽

...

Keyword(s):

Dendritic Cell ◽

Myeloid Cell ◽

Cell Homeostasis ◽

Repressor Complex

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Monocyte infiltration and proliferation reestablish myeloid cell homeostasis in the mouse retina following retinal pigment epithelial cell injury

Scientific Reports ◽

10.1038/s41598-017-08702-7 ◽

2017 ◽

Vol 7 (1) ◽

Cited By ~ 34

Author(s):

Wenxin Ma ◽

Yikui Zhang ◽

Chun Gao ◽

Robert N. Fariss ◽

Johnny Tam ◽

...

Keyword(s):

Epithelial Cell ◽

Retinal Pigment Epithelial ◽

Cell Injury ◽

Retinal Pigment Epithelial Cell ◽

Retinal Pigment ◽

Myeloid Cell ◽

Mouse Retina ◽

Cell Homeostasis ◽

Pigment Epithelial ◽

Epithelial Cell Injury

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Inherited Biallelic Loss-Of-Function Mutations In CSF3R Define a Novel Type Of Severe Congenital Neutropenia With Full Myeloid Cell Maturation and Refractoriness To RhG-CSF

Blood ◽

10.1182/blood.v122.21.1025.1025 ◽

2013 ◽

Vol 122 (21) ◽

pp. 1025-1025

Author(s):

Alexa Triot ◽

Päivi M Järvinen ◽

Juan I. Arostegui ◽

Tomas Racek ◽

Jacek Puchalka ◽

...

Keyword(s):

Conflicts Of Interest ◽

Morphological Variability ◽

Myeloid Cell ◽

Cell Maturation ◽

Morphological Evidence ◽

Compound Heterozygous ◽

Neutrophil Granulocytes ◽

Severe Congenital Neutropenia ◽

Loss Of Function ◽

Congenital Neutropenia

Abstract Severe congenital neutropenia (SCN) is a heterogeneous group of disorders characterized by defective production and viability of neutrophil granulocytes and predisposition to life-threatening bacterial infections. Currently, OMIM lists five defined monogenic SCN: SCN1 ELANE, SCN2 GFI1, SCN3 HAX1, SCN4 G6PC3. Here, we describe a novel SCN subtype (SCN6) caused by recessively-inherited loss-of-function mutations in the gene encoding the granulocyte colony-stimulating receptor (CSF3R). We have identified four affected children in two distinct families. Family A had a homozygous missense mutation in close proximity of the highly conserved WSXWS motif (c.922T, p.Arg308Cys) and family B had two compound heterozygous small deletions provoking frameshift mutations (p.Gly316fs and p.Gly415fs). Mutated G-CSFR p.Arg308Cys protein was characterized by perturbed N-glycosylation and aberrant localization to cell surface. G-CSF induced phosphorylation of STAT3 and STAT5 was greatly diminished. In contrast to other SCN subtypes, all patients had morphological evidence of full myeloid cell maturation in bone marrow. However, none of the patients responded to granulocyte colony-stimulating growth factor (GCSF) treatment in vivo, confirming aberrant GCSF-receptor dependent signaling. Our studies highlight the genetic and morphological variability of SCN and provide evidence both for functional importance and redundancy of G-CSFR-mediated signaling in human granulopoiesis. Disclosures: No relevant conflicts of interest to declare.

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Interleukin 7 receptor (IL7R) is required for myeloid cell homeostasis and reconstitution by hematopoietic stem cells

10.1101/2020.09.02.280362 ◽

2020 ◽

Author(s):

Taylor Cool ◽

Atesh Worthington ◽

Donna Poscablo ◽

Adeel Hussaini ◽

E. Camilla Forsberg

Keyword(s):

Stem Cell ◽

Hematopoietic Stem Cell ◽

Myeloid Cell ◽

Lineage Tracing ◽

List Type ◽

Cell Homeostasis ◽

Hematopoietic Stem ◽

Adult Lung ◽

Interleukin 7 ◽

Deficient Mice

AbstractRespiratory diseases are a leading cause of death worldwide, with highly varied vulnerability to disease between individuals. The underlying reasons of disease susceptibility are unknown, but often include a variable immune response in lungs. Recently, we identified a surprising novel role of the interleukin 7 receptor (IL7R), a primarily lymphoid-associated regulator, in fetal-specified, lung-resident macrophage development. Here, we report that traditional, hematopoietic stem cell-derived myeloid cells in the adult lung, peripheral blood, and bone marrow also depend on IL7R expression. Using single and double germline knockout models, we found that eosinophil numbers were reduced upon deletion of IL7Rα. We then employed two Cre recombinase models in lineage tracing experiments to test whether these cells developed through an IL7Rα+ pathway. Despite the impact of IL7Rα deletion, IL7R-Cre labeled only a minimal fraction of eosinophils. We therefore examined the intrinsic versus extrinsic requirement for IL7R in the production of eosinophils using reciprocal hematopoietic stem cell transplantation assays. These assays revealed that extrinsic, but not eosinophil-intrinsic, IL7R is required for eosinophil reconstitution by HSCs in the adult lung. To determine which external factors may be influencing eosinophil development and survival, we performed a cytokine array analysis between wild-type and IL7Rα-deficient mice and found several differentially regulated proteins. These findings expand upon our previous publication that IL7R is required not only for proper lymphoid cell development and homeostasis, but also for myeloid cell homeostasis in tissues.HighlightsLoss of IL7Rα resulted in significantly fewer eosinophils in adult miceIL7R-Cre lineage tracing revealed minimal labeling of eosinophilsIL7Rα-deficient HSCs robustly reconstituted eosinophils in a WT hostWT HSCs failed to fully reconstitute eosinophils in IL7Rα-/- hostsSeveral cytokines are differentially expressed in WT and IL7Rα-deficient mice

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Mechanism of the Elevated UPR in CN Patients but Not in CyN Patients Carrying Same ELANE Mutations

Blood ◽

10.1182/blood.v118.21.14.14 ◽

2011 ◽

Vol 118 (21) ◽

pp. 14-14

Author(s):

Rainer Nustede ◽

Inna Kuznetsova ◽

Karl Welte ◽

Julia Skokowa

Keyword(s):

Cell Lines ◽

Mammalian Cells ◽

Target Genes ◽

Conflicts Of Interest ◽

Myeloid Cells ◽

Myeloid Cell ◽

Severe Congenital Neutropenia ◽

Healthy Individuals ◽

Congenital Neutropenia ◽

Cyclic Neutropenia

Abstract Abstract 14 Several studies found that in patients with severe congenital neutropenia (CN) harboring mutations in the ELANE gene mutated NE protein induced unfolded protein response (UPR) leading to elevated apoptosis and diminished differentiation of myeloid cells. However, it is unclear, why UPR was not detected in patients with cyclic neutropenia (CyN) carrying the same ELANE mutations, which have been found in CN patients. Several UPR components have been identified in mammalian cells, which include three transducers (IRE1, PERK, and activating transcription factor 6 (ATF-6) as well as one master regulator (BiP/GRP78). BiP is known to be regulated by ATF6. The activation of ATF6 and its target genes (GADD34, CHOP and BiP) in CN patients has not been studied yet. We were able to detect significantly elevated levels of ATF6 and BiP in myeloid cells of CN patients with ELANE mutations, in comparison to CyN patients and to healthy individuals. Therefore, we investigated the mechanism of UPR and activation of ATF6 and ATF6 target genes in CN patients in comparison to CyN patients. We transduced the myeloid cell lines HL60 and NB4 with lentiviral constructs contained either wild type (WT) ELANE cDNA, or mutated (MUT) ELANE cDNA and measured mRNA and protein expression of ATF6 as well as mRNA expression of ATF6 target genes. We compared the effects of three ELANE mutations: C42R, V145-C152del (both mutations presented in CN patients, but not in CyN patients) and S97L (typical for CN and CyN patients) with WT ELANE. We found that in both cell lines only C42R ELANE MUT, but not V145-C152del ELANE MUT or S97L ELANE MUT induced expression of ATF6, GADD34, CHOP and BiP, as compared to control transduced cells. Furthermore, we hypothesize that degradation of mutated NE protein by Secretory Leukocyte Protease Inhibitor (SLPI) might be involved in UPR induction. However, we detected only very low levels of SLPI mRNA in CD33+ myeloid cells and in PMNs of patients with severe congenital neutropenia (CN), as compared to patients with cyclic neutropenia (CyN) and to healthy individuals. The lack of the NE inhibitor, SLPI in CN patients may further contribute to elevated UPR triggered by ELANE MUT and normal levels of SLPI in CyN patients might protect from ELANE MUT-induced UPR. Indeed, inhibition of SLPI using SLPI-specific shRNA led to a significantly elevated expression levels of ATF6, GADD34 and BIP, as compared to ctrl shRNA transduced cells. More importantly, co-transduction of NB4 cells with SLPI shRNA in combination with ELANE S97L MUT (which is common for both CN and CyN patients), but not with WT ELANE led to elevated levels of ATF6, GADD34 and BIP. In summary, different ELANE mutations have different effects on UPR as judged by ATF6 activation and the level of ELANE-triggered UPR is regulated by SLPI. Disclosures: No relevant conflicts of interest to declare.

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