bluuebunny/crossref_metadata_2025_split huggingface dataset:
Group B streptococci induce proinflammatory responses via a protein kinase D1-dependent pathway (INM7P.351)
Authors: Yi Ae-Kyung , Upadhyay Kirtikumar , Park Jeoung-Eun , Kim-Hoehamer Young-In , Talati Ajay , English B. 
Published: January 2023

Abstract
Group B streptococci (GBS) are one of the leading causes of life-threatening sepsis in neonates. Despite intervention with antibiotic therapy, the incidence of lethality is high among GBS-infected infants. The clinical symptoms of sepsis are related to the host-pathogen interaction and exaggerated proinflammatory cytokine production during the process via pathways dependent on Toll-like receptors (TLRs). Over the last few years, it has become evident that protein kinase D1 (PKD1) plays a significant role in the inflammatory process mediated by TLRs. However, it is currently unknown whether PKD1 is activated, and contributes to proinflammatory responses induced by live or antibiotic-killed GBS. In the present study, we found that both live and antibiotic-killed GBS induce activation of PKD1 that is dependent on the TLR signaling adaptor MyD88 and its downstream kinase IRAK1, but not TRAF6. Inhibition of PKD using a pharmacological inhibitor revealed that PKD1 is indispensable for GBS-mediated expression of various cytokines/chemokines in vitro and in vivo. Furthermore, systemic administration of PKD inhibitor protects D-galactosamine-sensitized mice from shock-mediated death caused by antibiotic-killed GBS. Our findings imply that PKD1 is one of the critical factors that play a regulatory role in GBS-induced proinflammatory reactions, and inhibition of PKD1 activation together with antibiotic treatment in GBS-infected neonates might be an effective way to control GBS diseases.
Loss of asparagine endopeptidase impairs autophagic degradation and enhances endotoxin-induced TNF-α production in M2 macrophages (INM8P.358)
Authors: peng baowei , Lan Bin , Guo Fang 
Published: January 2023

Abstract
Asparagine endopeptidase (AEP) has been shown to play important roles in innate immunity. Here, we show that AEP is a previously unrecognized regulator of autophagy in M2 macrophages. AEP interacted with PI3K p110α and suppressed PI3K activation on the endomembranes. AEP deficiency led to abnormal activation of PI3K, which converted phosphatidyinositol (4,5)-bisphosphate (PIP2) to phosphatidyinositol (3,4,5)-bisphosphate (PIP3) (PIP3). Decrease in PIP2 and increase in PIP3 resulted in impaired autophagic lysosome biogenesis and autolysosome clearance. Impaired autolysosome clearance in turn led to accumulation of NF-κB proteins, which promoted proinflammatory cytokine synthesis upon LPS stimulation. Moreover, AEP-/- mice showed significantly enhanced inflammation when stimulated with LPS or challenged with S. Japonicum eggs. Induction of autophagy with raramycin in AEP-/- mice and inhibition of autophagy with Bafilomaycin A1 in WT mice prevented and increased S. Japonicum eggs induced granulomas respectively. Thus, our data linked AEP to the immunosuppressive phenotype of M2 macrophages through promoting autophagy.
IgG anti-HA Fc glycoform modulation is predictive of influenza vaccine efficacy (IRC10P.412)
Authors: Wang Taia , Maamary Jad , Schlesinger Sarah , Ravetch Jeffrey 
Published: January 2023

Abstract
Protective anti-viral vaccines elicit high affinity, antigen-specific neutralizing antibodies through secondary diversification mechanisms involving the selection of B cells bearing somatically hypermutated B cell antigen receptors in the germinal center. This selection process involves the interaction of the B cell receptor with antigen retained in the form of immune complexes, thus dictating that Fc-Fc receptor (FcR) interactions contribute to the selection process. FcRs are diverse in function and can transduce immunomodulatory, activating, or inhibitory signaling depending on which receptor(s) are engaged; the sum of these activities contributes to the generation of protective IgGs through mechanisms including efficient antigen presentation and dendritic cell maturation as well as directing B cell activation and selection. Immune complex-FcR interactions are governed by the precise structure of Fc domains within an immune complex, which, in turn, depends on the subclass distribution and Fc glycan composition of antigen-specific serum IgG. We performed the first detailed structural analysis of IgG Fc domains following influenza virus vaccination and found complex regulation of both subclass and Fc glycoforms. The abundance of sialylated Fc glycans on HA-specific IgG was found to predict the quality of vaccine response suggesting a mechanism by which sFc glycans modulate B cell activation thresholds, thereby driving the production of neutralizing, high affinity IgGs.
Blocking fatty acid amide hydrolase reduces T cell activation and attenuates experimental colitis (IRC10P.405)
Authors: Singh Udai , Shamran Haidar , Singh Narendra , Guan Honbing , Mishra Manoj , Price Robert L , Nagarkatti Mitzi , Nagarkatti Prakash 
Published: January 2023

Abstract
Inflammatory bowel disease (IBD) refers to chronic inflammatory disorders of the gut with unknown etiology. Fatty acid amide hydrolase (FAAH) is the enzyme crucially involved in the modulation of intestinal physiology. We investigated the effects of FAAH inhibitors on the dextran sodium sulfate (DSS) induced model of colitis. FAAH inhibitors diminished the overall clinical score, reversed the colitis-associated inflammation score, and reversed body weight loss after DSS induced colitis. The frequency of activated CD4+ T cells in the spleen, mesenteric lymph node (MLN), and Peyer’s patches (PP) was reduced after FAAH inhibition as compared to the control group. Further, the frequency of macrophages, natural killer (NK1.1), and NKT cells in PP, and the concentration of inflammatory cytokines and chemokines also declined after FAAH inhibition. FAAH treatment also resulted in greater than 1.5 fold changes in 26 miRs in MLN and 217 miRNAs in PP. Among these, eight anti-inflammatory miRNAs were validated by RT-PCR analysis. Pathway analysis also validated that differentially regulated miRNAs target mRNA associated with inflammation. Taken together, these results indicate that FAAH modulates colitis severity by reducing activated T cells at sites of inflammation and suppresses other immune mediators such as systemic cytokines and inflammatory miRNAs through regulation of miRs. In summary, our results suggest that FAAH inhibitors may be developed as a novel therapeutic agent for IBD.
Tim-1 is essential for induction and maintenance of IL-10 in regulatory B cells and their regulation of tissue inflammation (IRC11P.435)
Authors: Xiao Sheng , Kuchroo Vijay 
Published: January 2023

Abstract
T cell Ig and mucin domain (Tim)-1 identifies IL-10-producing regulatory B cells (Bregs). Mice on the C57BL/6 background harboring a loss of function Tim-1 mutant showed progressive loss of IL-10 production in B cells and with age developed severe multi-organ tissue inflammation. We demonstrate that Tim-1 expression and signaling in Bregs are required for optimal production of IL-10. B cells with Tim-1 defects have impaired IL-10 production but increased proinflammatory cytokine production including IL-1 and IL-6. Tim-1-deficient B cells promote Th1 and Th17 responses but inhibit the generation of regulatory T cells (Foxp3+ and IL-10-producing type 1 regulatory T (Tr1) cells) and enhance the severity of experimental autoimmune encephalomyelitis (EAE). Mechanistically, Tim-1 on Bregs is required for apoptotic cell (AC) binding to Bregs and for AC-induced IL-10 production in Bregs. Treatment with AC reduces EAE severity in wildtype (WT) but not Tim-1-deficient Bregs. Collectively, these findings suggest that in addition to serving as a marker for identifying IL-10-producing Bregs, Tim-1 is also critical for maintaining self-tolerance by regulating IL-10 production in Bregs.
Preeclampsia is characterized by fetal NK cell activation and a reduction in regulatory T cells (IRC11P.427)
Authors: Loewendorf-Snead Andrea , Yesayan Maria , Nguyen Tina , Kahn Daniel 
Published: January 2023

Abstract
Preeclampsia affects 3 - 17% of pregnancies worldwide and entails serious consequences for both the mother and the fetus. Increasing evidence suggests that active tolerance of the mother towards the fetus does not suffice for healthy pregnancy but that instead bi-directional maternal-fetal tolerance is required. Thus, fetal immunopathology may play a significant role in the pathogenesis of pregnancy disorders. Nevertheless, the impact of preeclampsia on the fetal immune system is unclear. In this case-control study, we examined the phenotype of innate and adaptive immune cells from cord blood of 3rd trimester babies born to healthy mothers and compared them to cord blood from 3rd trimester babies born to mothers with symptomatic preeclampsia. We observed a decrease of CD56hiCD16- non-activated/regulatory NK cells in relation to CD56loCD16+ activated/effector NK cells results in a shift of the NK population toward activated/effector NK cells. The overall percentage of FoxP3+ Treg was significantly reduced, especially the FoxP3lo populations (Resting Treg and Cytokine Treg). Importantly, this reduction in FoxP3+ Treg affected the ratio of CD8+ effector T cells per FoxP3+ Treg in babies born to preeclamptic mothers. These observations indicate that there are significant fetal immune system derangements during preeclampsia. In how far these alterations are cause or effect of the disease is subject to further study.
REV-ERBα negatively regulates the Th17 mediated immune response (IRM15P.603)
Authors: Chang Christina , Liang Yuqiong , Bapat Sagar , Zhao Xuan , Solt Laura , Zhang Kevin , Downes Michael , Burris Thomas , Evans Ronald , Zheng Ye 
Published: January 2023

Abstract
Th17 cells are a major driver of autoimmune disease such as multiple sclerosis. The differentiation of the Th17 cell lineage is dependent on RORƔt, which is part of the ROR nuclear receptor family. In addition to their involvement in immune cell lineage commitment, RORs also play important roles in circadian clock regulation. In the circadian system, the function of RORs is countered by another pair of nuclear receptors, REV-ERBα and REV-ERBβ, which are transcriptional repressors that bind to the ROR binding motif (RORE) and suppress ROR target gene expression. We tested whether REV-ERBs are also negative regulators in the context of Th17 cell differentiation. REV-ERBα is specifically induced in Th17 cells, and it directly binds to the RORE motifs at the IL17 locus and represses IL17 expression. Constant expression of REV-ERBα in T cells protects mice against Experimental Autoimmune Encephalomyelitis (EAE), a mouse model of multiple sclerosis. Additionally, treating mice with a synthetic REV-ERB agonist can delay EAE development and reduce Th17 cell infiltration into the CNS. Together, these results suggest that REV-ERB can suppress Th17 differentiation and serve as a potential target for treatment of Th17 mediated autoimmune diseases.
Clues to follicular helper T cell function from BCL6 target genes (IRM15P.457)
Authors: Dent Alexander , Hollister Kristin , Wu Hao 
Published: January 2023

Abstract
The transcriptional repressor Bcl6 controls development of the follicular helper T cell (TFH) lineage, however the precise mechanisms by which Bcl6 regulates this process are unclear. Several models have been proposed for how Bcl6 control TFH differentiation, but this pathway remains incompletely understood. Knowledge of the genes controlled by Bcl6 in TFH cells would facilitate our understanding of how Bcl6 controls TFH differentiation as well as give insights into TFH differentiation, but an in depth description of direct Bcl6 target genes in T cells has been lacking. Here, we have taken advantage of Bcl6 conditional knockout mice and bioinformatic tools to discover a core set of 25 target genes bound by Bcl6 in T cells and repressed in TFH cells. Strikingly, a large percentage of these genes are involved in promoting cell division and proliferation, indicating that a key role for Bcl6 in TFH cells is to restrain the cell cycle. Additionally, we find evidence that Bcl6 can bind to and activate a subset of Tfh genes, via an unknown mechanism. Thus, we have gained important new insights into TFH cell regulation by analyzing Bcl6 target genes.
Differential expression of the adaptor protein HSH2 inversely affects class-switched antibody production and antibody-secreting cell generation (LYM7P.617)
Authors: Carrillo Alexia , King R. , Justement Louis 
Published: January 2023

Abstract
Hematopoietic Src homology 2 domain (HSH2) is a conserved adapter protein that exhibits differential expression in peripheral B cell subsets. The reason for this differential expression is not clear. Therefore, to assess the impact of differential HSH2 expression on B cell function, we employed mouse models expressing either high or low levels of HSH2. Following immunization with either TI or TD antigens, we observed a marked alteration in class-switched antibody (Ab) production that inversely correlated with HSH2 levels, with the greatest effect being on IgG3. Furthermore, in vitro and in vivo we observed a decreased number of class-switched Ab-secreting cells (ASC) in the HSH2hi mice and an increase in ASCs in the HSH2lo mice. Overall, these data show that HSH2 levels inversely correlate with class-switched Ab production likely through alteration of class-switched B cell differentiation into ASCs. This novel function of HSH2 reveals its importance in B cell biology. Because HSH2 acts as a potential rheostat able to modulate the production of class-switched B cells depending on its expression level, this highlights the potential for HSH2 to play an important role in disease processes involving class-switched Abs and for vaccine development where generation of class-switched high-affinity Abs is the goal.
Chitinase like protein BRP-39 suppress Th1 differentiation via regulation of IFNγ-STAT1 axis (LYM8P.633)
Authors: Kim Do-Hyun , Park Hong-Jai , Lee Jae-Ung , Kang Min-Jong , Lee Chun Geun , Elias Jack , Choi Je-Min 
Published: January 2023

Abstract
Chitinase is evolutionary conserved enzyme that participated to regulation of parasite life cycle and anti-parasitic immune response. Chitinase like protein, which lack a chitinase activity by mutations of enzyme site also involved to anti-parasitic innate immunity, but their roles in T cell immunity has not been studied. Here, we investigated the role of mouse CLP BRP-39 in T cell immunity. BRP-39 is up-regulated in naïve CD4 T cell upon TcR stimuli. Although BRP-39-/- mouse does not have significant difference, BRP-39-/- T cells showed increased production of IL-2 and IFN-γ with hyper-proliferative response to TcR stimuli. In addition, BRP-39-/- naïve T cells more strongly differentiated into Th1 cells with up-regulated T-bet and Runx3 while their differentiation into Th2 was reduced with lower IL-4, 5 production and JunB expression. Also, pSTAT1, 4 were increased in BRP-39-/- Th1 cells while their Th2 cells showed lower pSTAT6 than WT. We found that expression of PTPN2, a phosphatase which regulate pSTAT1 was reduced in BRP-39-/- Th1 cells and extrinsic BRP-39 treatment could not recover the phenotype suggesting intrinsic BRP-39 down-regulate IFNγ expression through inhibition of IFNγ/STAT1 signaling pathway. Collectively, our results demonstrate for the first time novel regulatory roles of BRP-39 in T cell activation and differentiation, and suggest possibility of novel therapeutic target for regulation of Th1 related autoimmune diseases.
Apical receptors on M cells can be used as mucosal immune modulator (MUC9P.749)
Authors: Jang Yong-Suk , Kim Sae-Hae , Lee Hayan , Park Jisang 
Published: January 2023

Abstract
Intestinal epithelial cells which are exposed to microbes tightly restrict the influx of luminal antigens. They also contribute to establish the tolerogenic immune microenvironment through the induction of retinoic acid, TGF-β, and IL-25 production. However, intestinal contents are continuously introduced into Peyer’s patches through M cells which are specialized epithelial cells to take up the luminal antigens. Consequently, Peyer’s patches constitute specialized immune microenvironment. Although the mechanism for luminal antigen uptake into M cells is not clearly defined, many studies suggest the role of apical proteins of M cells as a mediator for antigen influx. Here, we report the expression of C5aR, TLR 1/2, ATP-gated P2X7 receptor (P2X7R), and formyl peptide receptor 2 (FPR-2) on apical area of M cells. In addition, we found that receptor itself and/or crosstalk among these receptors were able to regulate not only modulation of the Peyer’s patch microenvironment but also transcytosis of luminal antigens. Especially, when LL-37, one of ligands for P2X7R and FPR-2, was applied to oral mucosal vaccine model, it promoted the induction of antigen-specific immune response through M cell antigen-targeting and modulation of Peyer’s patch microenvironment. Collectively, we conclude that interaction between luminal antigens and apical receptors on M cells initiate the signaling for immune induction and that these receptors could be used as new targets for oral vaccine delivery.
Bioactive molecules in the &lt;10kDa fraction of the Lactobacillus helveticus R0389 and Lactobacillus rhamnosus R0011 secretomes down-regulate IL-8 production by HT-29 human intestinal epithelial cells induced by pro-inflammatory stimuli (MUC9P.752)
Authors: Jeffrey Michael , Green-Johnson Julia 
Published: January 2023

Abstract
The human gut microbiome has recently been associated with maintaining intestinal epithelial cell (IEC) homeostasis at the gastrointestinal interface by modulating host mucosal immune responses through varied mechanisms. The aim of this study was to compare the immunomodulatory activities of the L. helveticus R0389 and L. rhamosus R0011 secretomes on IEC. The human IEC line HT-29 was activated with a range of innate immune stimulants, to allow delineation of differential effects of the secretomes on Interleukin-8 (IL-8) production induced by varied stimuli. HT-29 IEC were co-incubated with either L. helveticus R0389 or L. rhamnosus R0011 secretomes and one of the following pro-inflammatory stimuli: interleukin 1-β (IL-1β), tumor necrosis factor-α (TNF-α); the toll-like receptor (TLR) agonists poly (I:C) (TLR3) or lipopolysaccharide (LPS) (TLR4), and alterations in IL-8 production were measured via enzyme-linked immunosorbant assay (ELISA). The L. helveticus R0389 and L. rhamnosus R0011 secretomes were also subjected to size fractionation to determine the size of the bioactive constituent of the secretome. Down-regulation of IL-8 was observed in HT-29 IEC co-incubated with the &lt;10kDa fraction of the L. helveticus R0389 secretome or the L. rhamnosus R0011 secretome, for all of the innate immune stimulants tested. These results suggest that both Lactobacilli may secrete a low molecular weight bioactive molecule that modulates host immune activity by IEC.
Optimized high resolution flow cytometry of FOXP3 and protein phosphorylation in cryopreserved human PBMC allows for sensitive and reproducible assessments of T cell IL-2 responsiveness in normal and type 1 diabetes-derived samples. (TECH2P.916)
Authors: Boyce Christopher , Gao Guojian , O'Donnell Erika , Ernst David , Tree Tim , Yang Jennie 
Published: January 2023

Abstract
Cryopreservation and cell function methods are of significant practical importance for labile FOXP3+ regulatory T cell (Treg) phenotypes. Using single cell assays to assess signaling responses to cytokines such as IL-2 within T-cell subsets defined by transcription factors (TF) provide insights into immune regulation. Concurrent FOXP3 and phosphoSTAT5 (pSTAT5) expression by flow cytometry (FC) is a fickle case for optimization. Previous intracellular FC methods have provided non-ideal resolution (stain indices ≤ 2.9) for FOXP3 staining. Previous attempts to co-visualize FOXP3 with pSTAT5 showed that fluorescence (FL) intensity signals are compromised leading to sub-optimal gating of low percentage FOXP3+ Treg; or reversion to CD25 expression to define cell subsets while foregoing measuring pSTAT5 induction by FL intensity. Our aim was to improve FL resolution of FOXP3 and pSTAT5 as applied to frozen PBMC using a previously optimized system. We evaluated samples from healthy donors and individuals with type 1 diabetes for IL-2 signaling responses by assessing IL-2 sensitivity, assay reproducibility and staining resolution. Significantly improved FC analysis of TF and pSTAT5 was achieved using BD‘s TF PhosphoPlus Buffer Set and previously optimized conditions for cell barcoding and freeze/thaw, thus enabling reduced assay variability and enhanced FOXP3 resolution. These methods lay additional foundation to assess IL-2 responsiveness in individuals with immune-related diseases.
Inhibition of matrix metalloproteinase-9 reduces clinical severity in a murine model of multiple sclerosis. (THER7P.944)
Authors: Onwuha-Ekpete Lillian , Tokmina-Roszyk Dorota , Fields Gregg 
Published: January 2023

Abstract
Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes that mediate the degradation of various components of the extracellular matrix. Their functions are essential for normal physiological processes such as wound healing, but their dysregulation is associated with various pathologies including autoimmune diseases such as Multiple Sclerosis (MS). Experimental Autoimmune Encephalomyelitis (EAE) is a well-established murine model of MS that is mediated by CD4+ T-cells. These cells penetrate the blood-brain-barrier (BBB), recruit other immune cells, initiate destruction of the myelin sheath, and cause axonal loss. MMP-9 is a hallmark enzyme in the progression of MS that is required for penetration of the BBB and generation of autoantigens in EAE. In addition, recent studies have demonstrated that MMP-9 contributes to normal intracellular function of various cell types including antigen activated T-cells; however, the intracellular role of MMP-9 in immune cell activation during EAE pathogenesis is not known. In this study, we used a highly selective MMP-9 triple-helical peptide inhibitor (THPI) that is a phosphinate transition state analog to examine antigen specific T-cell responses. We found that selective inhibition of MMP-9 can mitigate pathogenic T-cell activity and cellular trafficking as well as the clinical severity of EAE, suggesting that selective MMP-9 inhibition in MS can be a potent therapeutic option.