bluuebunny/crossref_metadata_2025_split huggingface dataset:
MicroRNA-155 and MicroRNA-21 promote the expansion of functional myeloid-derived suppressor cells (IRC5P.473)
Authors: Li Limin , Zen Ke 
Published: January 2023

Abstract
Myeloid-derived suppressor cells (MDSC) are one of the main cell populations that negatively regulate immune responses. However, the mechanism underlying the expansion of MDSC remains unclear. Using miRNA microarray and TaqMan probe-based quantitative RT-PCR assay, we identified microRNA (miR)-155 and miR-21 as the two most upregulated miRNAs during the induction of MDSC from the bone marrow cells by GM-CSF and IL-6. High levels of miR-155 and miR-21 also were detected in bone marrow and spleen MDSC isolated from tumor-bearing mice. Our results also showed that TGF-b promoted the induction of MDSC through upregulating miR-155 and miR-21 expression. Overexpression of miR-155 and miR-21 enhanced whereas depletion of miR-155 and miR-21 reduced the frequencies of cytokine-induced MDSC. Subpopulation analysis indicated that miR-21 and miR-155 induced the expansion of both monocytic and granulocytic MDSC. Furthermore, miR-155 and miR-21 showed a synergistic effect on MDSC induction via targeting SHIP-1 and phosphatase and tensin homolog, respectively, leading to STAT3 activation. Finally, dexamethasone treatment strongly enhanced MDSC expansion through upregulating miR-155 and miR-21 expression, and the effect of dexamethasone on MDSC induction was abolished by depleting cellular miR-155 and miR-21. These results demonstrate a novel miR-155/miR-21-based regulatory mechanism that modulates functional MDSC induction.
IL-22-producing Th cells regulate myeloid-derived suppressor cells in Helicobacter pylori-associated immunopathogenesis (IRC5P.456)
Authors: Zou Quanming , Zhuang Yuan 
Published: January 2023

Abstract
Th cell responses are critical for the immunopathogenesis of gastritis induced by persistent infection with Helicobacter pylori (H. pylori). IL-22-producing Th cells represent a new T-cell subset, but their response, regulation, function, and clinical relevance in H. pylori-induced gastritis are presently unknown. We found that IL-22-producing Th cells accumulated in gastric mucosa of cytotoxin-associated Ag (CagA)+ H. pylori-infected patients and mice. CagA+ H. pylori-activated DCs secreted IL-23, which favored IL-22-producing Th cell polarization. IL-22-producing Th cell-derived IL-22 induced CXCL2 chemokine production by gastric epithelial cells that were induced to express IL-22R1 by CagA+ H. pylori, which in turn promoted CXCR2-dependent migration of myeloid-derived suppressor cells (MDSCs). Subsequently, IL-22 induced MDSCs to produce proinflammatory proteins S100A8 and S100A9, and MDSCs itself exerted immunosuppressive roles by suppressing Th1 cell response, in doing so, contribute to the development of H. pylori-associated gastritis. Collectively, this study identifies a novel regulatory network involving IL-22-producing Th cells, which in conjunction with DCs, gastric epithelial cells, and MDSCs exert an inflammatory and immunosuppressive mixed effect within H. pylori-induced gastric microenvironment. Efforts to inhibit IL-22-producing Th cell-MDSC pathway might therefore prove a valuable strategy in the therapy of H. pylori-associated gastritis.
A potential pathogenic role of myeloid derived suppressor cells in autoimmune arthritis (IRC5P.457)
Authors: Guo Chunqing , Hu Fanlei , Li Zhanguo , Wang Xiang-Yang 
Published: January 2023

Abstract
Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of myeloid progenitor cells and immature myeloid cells. Although the role of MDSCs in tumor immune evasion during cancer progression has received much attention, its involvement in other inflammatory autoimmune diseases, such as rheumatoid arthritis (RA) remains largely unknown. We show that the levels of MDSCs are significantly elevated in RA patients and during the progression of collage-induced arthritis (CIA) in mice. While MDSCs in arthritic mice are phenotypically distinct from neutrophils or inflammatory monocytes, they display strong T-cell suppressive activity in vitro, resembling the functionality of tumor expanded MDSCs. Surprisingly, the expansion of MDSCs in lymphoid organs or inflamed joints positively correlate with the disease severity in arthritic mice and RA patients. Additionally, MDSCs from arthritic mice or RA patients efficiently promote the differentiation of naïve CD4+ T cell precursors into T-helper 17 (Th17) cells. Furthermore, pharmacologic elimination or antibody depletion of MDSCs attenuates a Th17 response in arthritic mice, which concomitantly reduces articular cartilage damage and ameliorates the established disease. Our results suggest that an excessive accumulation of MDSCs may exacerbate autoimmune arthritic disease by promoting inflammatory Th17 cells. MDSCs may be exploited as a potential cellular target of intervention in autoimmune arthritis.
Metalloproteinase activity inhibits IL-23p19 expression in dendritic cells by targeting membrane stem cell factor affecting lung IL-17 response. (IRC5P.458)
Authors: Oriss Timothy , Krishnamoorthy Nandini , Raundhal Mahesh , Morse Christina , Chakraborty Krishnendu , Khare Anupriya , Huff Rachael , Ray Prabir , Ray Anuradha 
Published: January 2023

Abstract
Ligation of c-kit by membrane-bound stem cell factor (mSCF) leads to DC IL-6 production and a Th17 immune response, which also requires heterodimeric IL-23. However, the mechanisms regulating IL-23 production in DCs are not fully understood. We found that IL-23p19 gene expression in lung DCs is dependent on mSCF, which itself is regulated by metalloproteinase activity. Th1-inducing conditions enhanced protease activity causing cleavage of mSCF whereas the opposite was true for Th17-promoting conditions. In metalloproteinase-deficient mice, Th1-inducing conditions maintained mSCF expression thereby enhancing IL-23p19 in DCs. The functional consequence of this was enhanced IL-17 production in T cell/DC co-cultures in vitro, and increased numbers of IL-17-producing CD4+ T cells in the lung. Conversely, mSCF cleavage from bone marrow DCs in vitro by recombinant metalloproteinase led to reduced IL-23p19 expression under Th17-inducing conditions with dampening of intracellular AKT phosphorylation, a key component of the c-kit signaling pathway. Collectively, these results show that IL-23 production in DCs can be regulated by metalloproteinase activity on the c-kit/mSCF axis to control IL-17 production in the lung.
Metabolic mechanisms underlying IL-33 mediated Th2 polarization and allergic airway disease (IRM7P.494)
Authors: Lott Jeremy , Matta Benjamin , Mathews Lisa , Sperling Anne , Turnquist Heth 
Published: January 2023

Abstract
IL-33 is a recent IL-1 cytokine with emerging pleotropic functions. Experimental studies have suggested that IL-33 supports Treg responses, drives CD8+ T cell IFN-γ production, and acts as a potent mediator of Th2 responses. The current study tests the hypothesis that IL-33 modulates mDC gene expression and pathway activities facilitating Th2 polarization. Using gene expression and efficiency analysis, we identified multiple genes involved in iron homeostasis and metabolism which were upregulated in mDC by IL-33. Desferrioxamine (DFO) was utilized to assess the impact of blocking mDC iron uptake during IL-33 stimulation on subsequent Th2 polarization and capacity to stimuli allergic airway disease (AAD). Generation of CD4+IL-5+ Th2 cells by IL-33-exposed DC was ablated by iron chelation, resulting in decreased IL-5 production and cellular proliferation. However, induced Th1 responses were unaffected in DFO-treated LPS-stimulated DC. Using an OVA/IL-33 mDC induced model of AAD, blocking DC iron uptake with DFO decreased several phenotypic hallmarks of the disease, including IgE (p&lt;0.05) and IL-33 production in the lungs of animals. In conclusion, iron uptake is necessary for IL-33 generation of pro-inflammatory DC supporting Th2 polarization. Blocking iron uptake in a model of mDC induced AAD alters disease phenotype when compared to control animals. These data suggest that regulation of iron uptake may be a potential mechanism behind IL-33 induction of Th2 responses.
A suppressive role of STAT1 in lupus-like chronic graft versus host disease (IRM7P.479)
Authors: Shao Wenhai , Lobue Monica , Gamero Ana , Cohen Philip 
Published: January 2023

Abstract
Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease driven by genetic and environmental factors with unknown etiopathogenesis. The bm12→B6 chronic graft-versus-host disease (cGVHD) is a well-studied inducible mouse model of SLE. STAT1 is dynamically regulated during the course of immune and inflammatory responses. However, little is known about the role of STAT1 in autoimmune diseases. We induced cGVHD in B6.STAT1-KO and B6.WT mice by intraperitoneally injection of 1×108 splenocytes from bm12 mice. Mice were followed for autoimmune manifestations, such as mortality, skin rash, and renal involvement. Upon injection, WT mice developed anti-dsDNA autoantibodies starting at week 2 (as expected), with decline noted after week 4. In contrast, STAT1-deficient mice exhibited a prolonged and significant increase of anti-dsDNA autoantibody responses compared to WT mice (week 4 to week 8). Severe splenomegaly also developed in cGVHD STAT1-KO mice. Increased autoantibody titers were accompanied by increased proteinuria in mice lacking STAT1 due to immune complex deposition. Three months after injection, 40% of the STAT1-KO mice with cGVH disease were dead. Anti-dsDNA isotypes in cGVH diseased STAT1-KO mice were enhanced (IgG1 responses), but IgG3 responses were absent. STAT1 seems to suppress systemic autoimmunity by altering autoantibody isotype switching. Results from these studies may provide insights into the pathogenesis of STAT1 in SLE.
Production of class switched antibody secreting cells and antibody is inversely correlated with expression of the adaptor protein HSH2 (IRM8P.712)
Authors: Justement Louis , King R. 
Published: January 2023

Abstract
Control and HSH2 transgenic (HSH2-Tg) mice were compared to mice that express approximately 1/6th the normal level of HSH2 (HSH2-Lo) to determine if there is an inverse relationship between HSH2 expression and class switched antibody (Ab) production. In contrast to HSH2-Tg mice, HSH2-Lo mice have normal serum Ig titers for IgG1 and IgG2b and elevated titers of IgG3. HSH2-Lo mice also exhibit enhanced production of IgG1, and IgG2b, or IgG3 in response to challenge with either TD or TI Ag, respectively. Stimulation of B cells isolated from HSH2-Lo mice with anti-CD40 and IL-4 results in the production of significantly more antibody secreting cells (ASC) that produce IgG1 and IgE versus control B cells, whereas HSH2-Tg B cells produce significantly fewer class switched ASCs. Although HSH2 expression is associated with a modest effect on class switch recombination, changes in class switched ASC production are most closely linked to alterations in terminal differentiation of GC B cells into plasma cells. Terminal differentiation of class switched B cells from HSH2-Lo mice is significantly increased following in vitro stimulation, resulting in enhanced production of class switched ASCs compared to control B cells. Conversely, class switched B cells generated from HSH2-Tg mice exhibit a significant decrease in differentiation into ASCs in vitro. Thus, differential expression of HSH2 in the B lineage regulates multiple steps associated with the generation of class switched ASCs.
CD19 cytoplasmic tyrosines 482 and 513 mediating binding to PI3K are sufficient to reconstitute the T-dependent humoral immune response (IRM8P.713)
Authors: Justement Louis , King R. 
Published: January 2023

Abstract
CD19 is a co-stimulatory receptor on B cells that has been shown to play a critical role in regulating B cell differentiation and the humoral immune response. In mice lacking CD19 expression, B1 and marginal zone (MZ) B cell subpopulations are absent and the T-dependent humoral response is severely impaired in association with defective GC B cell generation and GC responses resulting in loss of class switching, affinity maturation and ultimately the failure to generate Ag-specific memory B cells and Ab secreting cells (ASC) that produce class switched, high affinity Abs. Previous studies have demonstrated the selective mutation of tyrosines 482 and 513 (4/5F mice) in the cytoplasmic domain of CD19 is sufficient to recapitulate the phenotype associated with complete loss of CD19 expression. In the present study, mice were generated in which CD19 is expressed containing only Y482 and Y513 in the absence of the other seven cytoplasmic tyrosine residues (4/5Y mice). Analysis of 4/5Y mice revealed that these residues alone are sufficient to restore B1 and MZ B cell development as well as the T-dependent humoral immune response. Studies to examine mice expressing CD19 with a selective mutation to either tyrosine 482 or 513 revealed a preferential requirement for tyrosine 482 to promote a normal humoral response. These data support the conclusion that CD19 predominantly contributes to normal B cell development and the T-dependent humoral response through its recruitment of PI3K.
Regulation of HSH2 adaptor protein turnover via a novel NF-κB-dependent mechanism is involved in determining the nature of the class switched antibody response (IRM8P.715)
Authors: VanValkenburg Arthur , King R. , Justement Louis 
Published: January 2023

Abstract
The Hematopoietic Src Homology 2 (HSH2) adaptor protein is differentially expressed in mature, peripheral B cell subpopulations; exhibiting high-level expression in B1 and marginal zone B cells versus low-level expression in germinal center B cells, independent of gene transcription. HSH2 plays an important role in regulating the production of class switched antibodies through its effect on B cell class switching and terminal differentiation. Mouse models revealed that over expression of HSH2 in the B cell lineage attenuates the class switched antibody response, whereas reduced expression accelerates the class switched response. Thus, it is of significant interest to delineate the molecular mechanisms by which expression of HSH2 is controlled. Upregulation of HSH2 expression in response to TNF receptor family and TLR agonists occurs in an NF-κB-dependent manner, yet does not involve increased transcription of the HSH2 locus based on analysis of HSH2 mRNA levels. Additionally, maintenance of HSH2 expression is dependent on NF-κB signaling. Inhibition of NF-κB results in the rapid down regulation of HSH2 with a half-life of 1 hour, which is in contrast to the results obtained following treatment with cycloheximide or actinomycin D demonstrating that mRNA for HSH2 is stable and the protein itself has a half-life greater than 12 hours. These data support the conclusion that HSH2 protein stability is regulated post-transcriptionally via a novel NF-κB-dependent mechanism.
Disease stage-specific profiling of miRNA in experimental autoimmune encephalomyelitis (IRM9P.732)
Authors: Singh Jaspreet , Deshpande Mandar , Suhail Hamid , Giri Shailendra 
Published: January 2023

Abstract
MicroRNAs (miRNAs) are small non-coding RNA molecules acting as post-transcriptional regulators of many physiological processes. Their dysregulation is implicated in various diseases, including multiple sclerosis (MS). Experimental autoimmune encephalomyelitis (EAE) is a well accepted mouse model of human MS disease. Many of the discoveries of human MS disease mechanism and drug development have come from studies conducted in EAE model. Depending on the mice background, EAE mice mimic two most common form of human MS; chronic (in C57B/6 mice) and relapsing-remitting (RR, in SJL mice). Dysregulated miRNA levels in biological fluids, such as plasma and urine, represent a new source of biomarkers in MS and EAE. In this study, we report the first systematic identification of disease stage-specific (pre-onset, onset, peak and resolution) miRNA expression in the plasma and urine exosomes of chronic mouse model of EAE. Each disease stage was represented by a specific subset of miRNA expression. We report for the first time identification of miR-155 in SC and urine exosomes of EAE mice much earlier (day 6 post immunization) than disease onset (day 12). Further, we evaluated the drug response of copaxone and metformin on miRNA expression. Identification of disease-stage-specific miRNA biomarkers in non-invasive fluids like urine could be helpful for disease prognosis and for discrimination of clinical subtype, thereby aiding therapeutic decisions and monitoring of therapeutic effects.
Atg7 suppresses inflammatory responses in Klebsiella pneumoniae-infected mice by regulating the p38/IκB/NF-κB circuit (IRM9P.720)
Authors: YE Yan , Wu Min 
Published: January 2023

Abstract
Klebsiella pneumoniae (Kp) is a Gram-negative bacterium that can cause serious infections in humans, particularly invading lungs and intestines. Autophagy-related gene 7 (Atg7) has been shown to be associated with certain bacterial infections; however, the role of Atg7 in host immunity against Kp infection has not been elucidated. Here we showed that Atg7 expression was significantly increased in murine alveolar macrophage (MH-S) cells upon Kp infection, whereas knocking down Atg7 with siRNA increased bacterial burdens in MH-S cells. In addition, using biochemical assays and whole animal imaging analysis, we found that compared to WT mice atg7 knockout (KO) mice exhibited increased susceptibility to Kp infection, with decreased survival rates, increased bacterial burdens, and enhanced lung injury. Moreover, atg7 KO mice induced proinflammatory cytokines and superoxide production in Kp-infected lungs. Similarly, Atg7 silencing in MH-S cells markedly increased levels of cytokines. Mechanistically, we observed that Atg7 depletion regulated p38 phosphorylation which changed IκB binding and inhibited NF-κB nuclear translocation, thus exacerbating NF-κB-mediated cytokine secretion. Collectively, these findings indicate that Atg7 offers resistance to Kp infection by modulating both systemic and local production of proinflammatory cytokines via a p38IκB/NF-κB pathway.
ER stress-induced inflammasome activation promotes liver steatosis (IRM9P.723)
Authors: Zhang Jinyu , Li Zihai , Guo Beichu 
Published: January 2023

Abstract
Recent evidences suggest that obese animal exhibits increased endoplasmic reticulum (ER) stress and inflammation in the liver tissue. However, it is largely unknown how ER stress contributes to hepatic steatosis. In this study, we demonstrated that ER stress induced inflammasome activation and IL-1 beta production, leading to hepatic inflammation and steatosis. Our results show that tunicamycin (TM), an ER stress inducer, caused NLRP3 inflammasome activation, leading to increased IL-1 beta processing and production in macrophages and hepatocytes. We found that caspase-1 knockout (KO) mice treated with TM exhibited a less characterization of hepatic steatosis and inflammation compared with WT mice. Our data also demonstrated that ER stress-induced inflammasome activation and hepatic steatosis were partially attenuated by treatment with ER stress inhibitor tauroursodeoxycholic acid (TUDCA) and IRE1α inhibitor (4µ8C). Notably, hepatocytes from WT mice showed marked hepatocyte pyroptotic cell death with more than a fivefold increase compared with caspase-1 KO mice. Furthermore, our results show that ER stress promoted inflammasome activation and IL-1 beta production through IRE1α pathways. Taken together, our findings demonstrate that ER stress-mediated inflammasome activation plays an important role in liver inflammation and steatosis. Thus, ER stress could be potential targets for a novel therapeutic approach to prevent impaired inflammatory related liver diseases.
Cdk5 mediated coronin-1a phosphorylation is required for PLC-γ 1 mediated generation of inositol-1,4,5-trisphosphate and calcium mobilization after TCR activation (IRM10P.745)
Authors: Pareek Tej , Letterio John 
Published: January 2023

Abstract
The intracellular molecular signatures leading to T cell homeostasis and activation largely remains elusive. We have recently reported an unprecedented but important role for Cyclin-dependent kinase 5 (Cdk5) in regulating T cell activation and function, expanding the repertoire of nonneuronal activities for this kinase. In this study, we generated lineage restricted deletion of Cdk5 in T cells (Cdk5TKO-mice) to avoid embryonic lethality caused by the germ line deletion of the Cdk5 gene. Our results show a profound defect in Ca2+ mobilization, IL-2 production, and proliferation following TCR stimulation of mature peripheral T cells isolated from Cdk5-TKO mice. This phenotype was associated with a decrease in viability of activated T cells and Cdk5TKO-mice were refractory to induction experimental autoimmune encephalomyelitis (EAE), an observation associated with an increase in caspase-3 activity in the spleen of Cdk5TKO-mice following immunization. Here we show Cdk5 mediated phosphorylation of Coronin 1a at threonine- 418 regulates coronin-1a complex formation with phospholipase C-γ1 (PLC-γ1), which is essential for the generation of inositol-1,4,5-trisphosphate (InsP3) upon TCR stimulation, thereby mediating Ca2+ release from intracellular stores that is essential for T cell activation and survival. These findings support a rationale for pursuit of Cdk5-trageted therapeutic strategies for the prevention and treatment of autoimmune as well as lymphoproliferative disorders.
Defining a novel role for the NF-κB pathway in proximal TCR signaling. (IRM10P.746)
Authors: Watson Crystina , Beg Amer 
Published: January 2023

Abstract
In the accepted model of T cell activation, parallel and independent signal transduction pathways activate the transcription factors NF-κB, NFAT and AP-1 to drive clonal expansion of T cells in response to antigen. Surprisingly, we found that CD8 T cells lacking NF-κB subunits p50 and cRel fail to activate NFAT contributing to their severely impaired in vivo responsiveness. We further demonstrated that attenuated NFAT activation was due to diminished Calcium influx upon TCR engagement, and that this reduction was accomplished via sub-par phosphorylation of PLCγ. The functional relevance of impaired PLCγ activation was demonstrated by rescue of p50-/-cRel-/- T cell proliferation through pharmacological initiation of PKC and Calcium pathways. While no deficiencies in expression of TCR complex proteins were seen, we did note defects in early TCR-induced Lck and Zap70 activation, and reduced expression of IKKβ and IKKγ in p50-/-cRel-/- T cells. Beyond established roles in NF-κB activation, we show that IKKβ /γ are also crucial for TCR-induced Lck, Zap70 and PLCγ activation. These findings define a novel pathway of “retrograde signaling” in T cells whereby NF-κB subunits modulate expression of proteins which are crucial for early TCR-induced signaling. Therefore, robust T cell activation occurs in cells exhibiting baseline activation of the pro-survival NF-κB pathway either through TCR tickling or non-TCR pathways.