bluuebunny/crossref_metadata_2025_split huggingface dataset:
A steroid-mimicking nanomaterial that mediates inhibition of human lung mast cell responses (IRM9P.725)
Authors: Dellinger Anthony , Zhou Zhiguo , Kepley Christopher 
Published: January 2023

Abstract
Water-soluble fullerenes can be engineered to regulate activation of mast cells (MC) and control MC-driven diseases in vivo. To further understand their anti-inflammatory mechanisms a C70-based fullerene conjugated to four myo-inositol molecules (C70-I) was examined in vitro for its effects on the signaling pathways leading to mediator release from human lung MC. The C70-I fullerene stabilize MC and act synergistically with long-acting β2-adrenergic receptor agonists (LABA) to enhance inhibition of MC mediator release through FcεRI-simulation. The inhibition was paralleled by the upregulation of dual-specificity phosphatase one (DUSP1) gene and protein levels. Concomitantly, increases in MAPK were blunted in C70-I treated cells. The increase in DUSP1 expression was due to the ability of C70-I to prevent the ubiquitination and degradation of DUSP1. These findings identify a mechanism of how fullerenes inhibit inflammatory mediator release from MC and suggest they could potentially be an alternative therapy for steroid resistant asthmatics.
Immunomodulation of volatile anesthetics (IRM9P.726)
Authors: Stollings Lindsay , Lu Binfeng , Xu Yan 
Published: January 2023

Abstract
Introduction: The impact of anesthetic exposure on the immune system is relatively unknown at both mechanistic and clinical levels. In this in vitro study, we employ immunological assays and understanding of immune cell function to evaluate the effect of volatile anesthetic (VA) exposure on bone marrow dendritic cells (BMDCs). BMDCc play a critical role in antigen presentation and link the innate and adaptive arms of the immune response. Hypothesis: We believe that VA exposure may modulate immune responses, specifically BMDC function. Methods: Bone marrow cells were harvested from C57BL/6 mice and cultured for six days to generate BMDCs. They were stimulated with low and high dose lipopolysaccharide (LPS). Simultaneously, the cells were exposed to 1.5% isoflurane and incubated for 5 hours. Upon completion of VA exposure, the BMDCs were lysed with Trizol, RNA extracted, and reverse transcript PCR used to generate cDNA. RT-qPCR was performed to evaluate gene expression of common BMDC cytokines. Results: BMDC exposure to isoflurane resulted in decreased gene expression of IL-10, IL-6, and IL-1β. RT-qPCR data indicated 2-4 fold decreases in gene expression of these cytokines. Conclusions: BMDCs exposed to VA in vitro displayed decreased gene expression of inflammatory cytokines. Significance: Better understanding of immunomodulation by anesthetics is critical for optimizing patient outcomes and improved perioperative management.
Quantitative phosphoproteomics reveals novel Vav1-dependent pathways in T cell receptor signaling (IRM10P.736)
Authors: Helou Ynes , Salomon Arthur 
Published: January 2023

Abstract
Vav1, a Rac/Rho guanine nucleotide exchange factor, is a critical component of the T cell receptor (TCR) signaling cascade and is rapidly tyrosine phosphorylated in response to T cell activation. Previous studies using Vav1 knockout models have determined its importance in TCR-dependent signaling. However, a wide-scale characterization of Vav1-dependent phosphorylation events is still lacking. Using quantitative mass spectrometry, a phosphoproteomic analysis of 668 tyrosine phosphorylation sites was performed on Vav1-deficient T cells across four time points of TCR stimulation. Compared to controls, cells lacking Vav1 expression showed statistically significant decreases in phosphorylation on actin cytoskeletal signaling proteins, supporting the role of Vav1 in cytoskeletal reorganization. Interestingly, loss of Vav1 led to perturbations in phosphorylation on signaling molecules proximal to the TCR. Furthermore, proteins implicated in negative feedback pathways, including CBL and PAG, showed altered phosphorylation profiles. Effects further downstream of the TCR were also observed in Vav1-deficient cells, notably, hyperphosphorylation of inhibitory sites on various cyclin dependent kinases, suggesting cell cycle arrest. This data demonstrates novel signaling networks regulated by Vav1 and support the pleiotropic functions of Vav1 downstream of the TCR.
Ca2+-TAGLN2 polymerizes G-actin in a mechanism crucial for T cell activation (IRM10P.738)
Authors: Jun Chang Duk 
Published: January 2023

Abstract
Actin dynamics is required for controlling T-cell activation and effector function. We report that TAGLN2, an actin-binding protein predominantly expressed in immunogenic cells—including CD8+ T cells, induces extensive actin polymerization under low-salt or high-Ca2+ conditions (where spontaneous nucleation and actin polymerization do not normally occur) and inhibits cofilin-induced depolymerization. Mutation of the Ca2+-binding motif results in impaired actin polymerization in vitro and T-cell function in vivo. TAGLN2 localizes to the outer actin ring in the immunological synapse; knockout of TAGLN2 (TAGLN2-/-) leads to diminished F-actin content and impaired actin ring formation in synaptic T cells. These cells demonstrate reduced PLC-γ phosphorylation and calcium signaling after T-cell receptor stimulation, suggesting a positive feedback calcium loop in this pathway. Furthermore, the cytotoxic function of TAGLN2-/- CD8+ T cells in targeting cells is inefficient. Thus, a novel mechanism of F-actin assembly mediated by Ca2+-TAGLN2 binding positively might affect T-cell functions.
Studying the role of CAML in T cell biology (IRM10P.741)
Authors: Chan Siaw Li , Lindquist Lonn , Bram Richard 
Published: January 2023

Abstract
Effective T cell function protects us from pathogens as well as cancer. However when T cell activation is dysfunctional, it has detrimental effects. If T cell activation cannot be shut down, it may cause autoimmunity. Therefore, it is crucial for us to study how T cell activation is regulated. Calcium modulating cyclophilin ligand (CAML) is a ubiquitously expressed endoplasmic reticulum protein. Using a transgenic conditional knock-out mouse model to delete CAML, we previously demonstrated that CAML is required for early embryonic development and thymopoiesis. Additionally, cells lacking CAML do not respond to EGFR stimulation due to a receptor recycling defect. However, the role of CAML in mature, peripheral T cells is not well understood. Here we provide preliminary data showing that loss of CAML in peripheral T cells leads to defective T cell activation and proliferation upon TCR stimulation, and inducing cell death through Fas ligand engagement. We hypothesize that CAML regulates components that are required to sustain optimum TCR signaling and function. T cell responsiveness to TCR stimulation is critical for T cells to deliver effector functions during antigen recognition and activation. Therefore understanding the regulation of TCR signaling by CAML will provide insight into novel mechanisms of immune regulation. These studies may provide potential treatments of immunodeficiency, autoimmunity or other inflammation associated diseases.
Optineurin and NEMO: a potential novel interplay to fine tune NF-κB activation upon TCR engagement. (IRM10P.742)
Authors: Montecalvo Angela , Kane Lawrence 
Published: January 2023

Abstract
Optineurin (OPTN) is a homolog of NF-κB essential-modulator (NEMO), the regulatory subunit of the IκB kinase (IKK) complex. Dysregulation of OPTN has been linked to several neurodegenerative diseases. Although OPTN shares with NEMO a high degree of homology, OPTN is not part of the same high-molecular weight complex containing IKKα and IKKβ. Although, OPTN cannot substitute for NEMO during (LPS)-induced NF-κB activation, OPTN negatively regulates TNF-α induced NF-κB activation by competing with NEMO for ubiquitinated proteins. We have investigated the potential role of OPTN during TCR induced NF-κB activation. OPTN overexpression down-regulates TCR-induced NF-κB activation in a dose-dependent manner. Furthermore we observed a transient loss of OPTN after stimulation of T cell lines or primary human or murine T cells. We further determined that the transient loss of OPTN upon TCR stimulation does not seem to be due to proteosomal degradation, suggesting a potential involvement of lysosomal degradation pathway. The present study provides new information regarding the role of OPTN in regulating NF-κB during TCR stimulation, thus revealing the possible importance of OPTN during inflammation and/or autoimmune diseases.
Impaired transitional B cell maturation in Flt3-ligand deficient mice. (LYM6P.775)
Authors: Medina Kay , Dolence Joseph , Gwin Kimberly , Hsu Fan-Chi , Shapiro Virginia 
Published: January 2023

Abstract
The production of naïve B cells in bone marrow (BM) is critical for maintaining a diverse peripheral B cell pool to fight infection and establish lifelong immunity. The generation of naïve B cells is impaired in Flt3-ligand (FL-/-) mice contributing to reductions in splenic B cells. The goal of this study was to determine the consequence of FL-deficiency on splenic B cell maturation. We found significant reductions in numbers of transitional (TS) and follicular (FO), but not marginal zone (MZ) B cells in FL-/- mice. Mixed BM chimeras revealed that the reduction in TS B cells was cell extrinsic, linking microenvironmental signals to TS B cell maturation. FL administration into FL-/- mice restored the deficiency in TS B cells that do not express Flt3, suggesting that a FL responsive component of the microenvironment is critical for TS maturation. Intracellular Ki67 revealed a significant decrease in the proliferative capacity of TS cells in FL-/- mice. Expression of a Bcl2 transgene did not rescue TS cells, uncoupling FL-deficiency to Bcl2-regulated survival pathways. BAFF-R expression and serum levels of BAFF were comparable in WT and FL-/- mice, supporting BAFF-independent regulation of TS cells. These observations support an integral indirect role for Flt3 signaling in regulation of TS B cell maturation in the spleen.
The fate of B cells in HIV infection - shifting the balance from plasma cell towards regulatory B cell (Breg) differentiation (LYM6P.776)
Authors: Kaltenmeier Christof , Gawanbacht Ali , Lindner Stefanie , Beyer Thamara , Härter Georg , Grüner Beate , Bommer Martin , Kirchhoff Frank , Schrezenmeier Hubert , Jahrsdörfer Bernd 
Published: January 2023

Abstract
Certain regulatory lymphocyte populations suppress T cell expansion in a granzyme B (GrB)-dependent manner. Recently, we found that human B cells also contribute to immune regulation by interleukin (IL-)21-dependent expression of GrB. GrB-expressing Bregs are induced by incompletely activated CD4+ T cells, which express high levels of IL-21, but only low CD40 ligand. In contrast, fully activated CD4+ T cells strongly induce plasma cell differentiation. Here we demonstrate that up to 60% of B cells from HIV-infected patients with high viremia exhibit a regulatory (Breg) phenotype with expression of GrB and potent suppression of T cell proliferation by GrB-dependent degradation of the T cell receptor zeta-chain (TCR-zeta). These results are supported by additional findings showing that T cells in HIV-infected individuals produce high levels of IL-21, while expressing only low levels of CD40L and TCR-zeta. Importantly, soluble CD40L multimers can restore the differentiation of Bregs derived from HIV-infected individuals into plasma cells. Our results suggest that incompletely activated CD4+ T cells in HIV patients lead to a misrouting of B cell differentiation into Bregs at the cost of fully functional plasma cells. Apart from a disturbed humoral immune response these B cells may further aggravate the immune status of HIV patients. The use of CD40L multimers may disrupt the defective B cell-T cell interactions and may prove beneficial for future HIV vaccination approaches.
Generation of IgA plasma cells during a secondary response in the absence of IgA memory B cells (LYM6P.800)
Authors: Pape Kathryn , Taylor Justin , Xiong Huizhong , Lafaille Juan , Jenkins Marc 
Published: January 2023

Abstract
IgA antibodies are important for protection against infection at mucosal surfaces. Despite this importance in protective immunity, the differentiation of IgA B cells is not well understood. To address this issue, an antigen-based enrichment method was used to track polyclonal B cells specific for the model antigen R-Phycoerythrin (PE) during the course of a T-dependent immune response. While 10-40% of the PE-specific short lived plasma cells expressed IgA, less than 0.05% of the PE-specific germinal center and memory B cells expressed IgA. Despite the lack of IgA memory B cells, secondary antigen challenge resulted in the generation of large numbers of PE-specific IgA plasma cells that appeared at times prior to the appearance of IgA plasma cells during the primary response. Since IgA memory B cells were infrequently detected, we hypothesize that IgA plasma cells generated during the secondary challenge are the result of a secondary switch from memory B cells expressing other isotypes. We are currently examining the role that individual isotypes of memory B cells play in the generation of IgA plasma cells by looking for IgG switch remnants in the PE-specific IgA plasma cells generated after secondary challenge, and by testing the ability of purified isotypes of memory B cells to produce IgA plasma cells after transfer and challenge of recipient mice.
Hypoxia, metabolism, and long-lived plasma cells (LYM6P.765)
Authors: Minges Wols Heather , Aguilera Alexya , Witte Pamela 
Published: January 2023

Abstract
Evidence from multiple laboratories agrees that long-lived humoral immunity derives from long-lived plasma cells (LLPC) that reside in the bone marrow (BM), and existing literature makes a compelling case explaining that short-lived PC die due to high metabolic stress. However, the mechanism by which LLPC escape the same fate as SLPC is unexplored. We tested the hypothesis that glycolysis is used by BM LLPC, which might be triggered by hypoxic areas of the bone marrow. Hypoxyprobe™-1 (PIM) was used as an indicator of BM LLPC residing in areas of low O2 tension. PIM positive stain in PC suggests that most BM LLPC reside in hypoxic niches. In addition, data obtained from both ELISPOT and 24h ELISA suggest that Ig secretion from BM cultured in a hypoxia chamber (3% O2) is slightly enhanced in hypoxic versus normoxic conditions. Since BM PC appear to reside in hypoxic niches, we assessed whether glycolysis is the predominant metabolic strategy employed by PC. Using the MitoTracker probe that fluoresces upon oxidation in respiring mitochondria, we found BM PC in both MitoTracker-hi and -lo populations, suggesting PC may differ in their metabolic strategies, using aerobic respiration and glycolysis, respectively. BM LLPC in both Mitotracker subsets are functional as determined by ELISA and ELISPOT. Future studies will assess the role of the plasma cell “niche” in promoting and sustaining a metabolic phenotype, which likely governs long-term immunity.
CD14+CD16+ monocytes play distinct role in Plasmodium vivax malaria (MPF3P.817)
Authors: Antonelli Lis , Leoratti Fabiana , Costa Pedro , Rocha Bruno , Diniz Suelen , Tada Mauro , Pereira Dhelio , Golenbock Douglas , Gonçalves Ricardo , Gazzinelli Ricardo 
Published: January 2023

Abstract
During malaria, the Plasmodium triggers high levels of cytokines, which both help the immune response controlling the parasite and contribute to the symptoms observed during the diseases. Our data show that monocytes are the main source of cytokines upon P. vivax infection, suggesting their important role during disease. While it is recognized that monocytes are heterogeneous, the physiological relevance of this is not yet completely understood. The different monocyte subsets seem to reflect developmental stages with distinct roles. Our goal is to define the role of monocyte during P. vivax infection. Our data show that higher levels of cytokines, accompanied by increased frequencies of monocytes in P. vivax-infected patients. The infection triggers the expression of activation markers, adhesion molecules and chemokine receptors on monocytes. Moreover, these cells can be distinguished into three monocyte subsets based on the expression of CD14 and CD16. Each of these subsets display an distinct profile, suggesting that they distinctly act during P. vivax infection to induce inflammation, control the infection and modulate immune response. Importantly, CD14+CD16+ monocytes displayed higher phagocytic activity and killing potential than their other counterparts. Identification of mechanisms that regulate monocyte responses during malaria will provide important information on the development of therapeutic strategies that are targeted to modify their particular cell subsets
Regulation of Helicobacter Pylori replication by macrophage PPARγ (MPF3P.823)
Authors: Kronsteiner-Dobramysl Barbara , Bassaganya-Riera Josep , Viladomiu Monica , Philipson Casandra , Schiff Eric , Hontecillas-Magarzo Raquel 
Published: January 2023

Abstract
Helicobacter pylori infects 50% of the human population and in about 15% of colonized individuals it can cause gastritis and gastric malignancies. Although previously considered an exclusively extracellular bacterium, H. pylori has been found inside gastric epithelial cells, macrophages and dendritic cells. Data from our mouse model show significant depletion of H. pylori from the stomach when macrophages acquired a pro-inflammatory phenotype due to the lack of the transcription factor peroxisome proliferator activated receptor gamma (PPARγ). To dissect the underlying mechanism, we polarized WT and PPARγ-deficient BM-derived macrophages towards an M1 phenotype prior to bacterial co-culture. Proliferation of H. pylori was almost completely abrogated in PPARγ-deficient M1 and the bacteria were cleared 6 hours earlier compared to WT M1, WT M0 and PPARγ-deficient M0. In line with the importance of an M1 like phenotype, gene expression results obtained from a time-course experiment showed higher iNOS expression in cells lacking PPARγ and increased NFκB activity upon bacterial challenge of cells treated with a PPARγ inhibitor. The importance of iNOS in bacterial clearance was confirmed by inhibition of iNOS resulting in increased re-isolation in both WT and PPARγ-deficient macrophages. Together our data suggest that PPARγ might be a critical factor in the outcome of H. pylori infection and thus represents a promising target for new therapeutic interventions.
CD8+ T cell activation in pathological giardiasis (MUC4P.837)
Authors: Keselman Aleksander , Singer Steven 
Published: January 2023

Abstract
Infection with the protozoan Giardia duodenalis is the most common intestinal parasitic disease in the United States. Clinical giardiasis presents with diarrhea and malabsorption of nutrients. One major pathological hallmark of giardiasis is the reduction of intestinal digestive enzymes, such as disaccharidases. Our lab and others in the field have demonstrated that CD8+ T cells are required for Giardia-induced disaccharidase deficiency but are not involved in protective immunity. In light of these observations, we have devoted our efforts to understanding how G. duodenalis infection activates intestinal CD8+ T cells to drive pathology. Analysis of surface marker expression on intestinal CD8+ T cells revealed an increased CD44hiCD69hi population following infection within the duodenal lamina propria. These activated CD8+ T cells produced IFNγ and TNFα. Furthermore, antibiotic treatment limits both CD8+ T cell activation and intestinal disaccharidase reduction in infected mice. Because the microbiota effects the development of these CD8+ T cell responses, we are currently determining if Giardia-activated CD8+ T cells are mounting a specific response to parasite antigen or are acting as bystanders. Further characterization of these intestinal CD8+ T cell responses to G. duodenalis infection will expand our understanding of pathogenesis and help identify novel therapeutic targets for the clinical setting.
COP9 regulates intestinal microbial ecology and susceptibility to colitis (MUC4P.839)
Authors: Wang Baomei , Deng Zhong-bin , Dryden Gerald , Miller Donald , Wei Ning , Zhang Huang-Ge 
Published: January 2023

Abstract
Inflammatory Bowel Disease (IBD) has been considered as the dysfunctional interplay between intestinal microbiota, epithelium and the immune system. Located at the heart of this complex interaction, intestinal epithelial cells (IECs) play a crucial role in coordinating commensal bacterial-dependent intestinal homeostasis. Separated from commensal bacteria by mucus layer, the mechanism that IECs confer a stable microbiota remains incompletely understood. Here, we reported that mice with an IEC-specific deletion of one subunit of COP9 signalosome, which regulates the ubiquitin-proteasome system, exhibited extreme susceptibility to dextran sulfate sodium (DSS) induced colitis. Deficiency of one subunit of COP9 resulted in dysfunction of paneth cell and colonic enterocyte, which led to impaired AMP (antimicrobial peptide) production, shifted composition of intestinal microbiota and skewed mucosal immune cells towards a proinflammatory phenotype. Deep sequencing and quantitative PCR analysis of luminal microbiota from proximal colon revealed a significant reduction of the relative abundance of Lactobacillus and increase of segmented filamentous bacteria. Correspondingly, the Th1/Th17 ratio is reversed in colonic lamina propria. Moreover, the susceptibility to colitis was alleviated by continued broad-spectrum antibiotic treatment. Collectively, these data suggest that COP9 signalosome in IEC regulates intestinal homeostasis by modulating the composition of microbiota.
Chronic morphine in the context of HIV infection, induce gut microbiome dysbiosis and lead to persistent GALT inflammation. (MUC4P.843)
Authors: Banerjee Santanu , Sindberg Gregory , Wang Fuyuan , Sharma Umakant , Johnson Timothy , Ramakrishnan Sundaram , Roy Sabita 
Published: January 2023

Abstract
Clinical observations show a strong correlation between microbial translocation and HIV disease progression. Chronic morphine, on its own, is known to induce bacterial translocation, impair immune activation and pathogenic clearance during infection and results in long-term persistent inflammation in the affected organs. Lack of response to therapy, and non-AIDS related comorbidities have been linked to immune activation as a consequence of microbial translocation. The gut microbiota plays a significant role in maintaining gut homeostasis and barrier integrity. Loss of microbes, which are part of the normal flora in healthy hosts, increase the susceptibility to a more virulent composition, that can contribute to barrier disruption and microbial translocation. In this study, we show that morphine induces bacterial translocation across gut mucosa, which is exacerbated with HIV infection. We also show HIV and morphine mediated gut microbiome changes and its influence on the immune system leading to persistent inflammation. Finally, we show that these co-morbidities preferentially favor class firmicutes over others and also increase adherence and alter virulence factors to tweak the host immune system to bring about the said effects.