bluuebunny/crossref_metadata_2025_split huggingface dataset:
TLR4/MD-2 and RP105/MD-1 differentially regulate LPS responsiveness in B cells (135.4)
Authors: Nagai Yoshinori , Ohta Shoichiro , Miyake Kensuke , Takatsu Kiyoshi 
Published: January 2023

Abstract
[Aims] TLR4/MD-2 is an essential complex for LPS recognition. RP105/MD-1 is a homologue of TLR4/MD-2 and is expressed in mainly B cells. RP105 or MD-1-deficient B cells show impaired LPS responsiveness, suggesting that B cells require both TLR4/MD-2 and RP105/MD-1 signals for LPS responses. However, precise mechanisms that functionally couple with the two types of complex remain unclear. Furthermore, as LPS stimulation activates B cells through both receptors, it is difficult to analyze the signals via TLR4/MD-2 and RP105/MD-1 differentially. To resolve this, we used agonistic mAbs to TLR4 and RP105 to explore differential roles for TLR4/MD-2 and RP105/MD-1 in B cell responses to LPS. [Methods] Mouse splenic B cells were stimulated with αTLR4 mAb, αRP105 mAb, or LPS in combination with IL-4. Expression of CD86, BAFF receptors (TACI, BAFF-R, BMCA), and CD138 was analyzed by FACS. For proliferation analysis, the B cells were stimulated with vehicles for 3 days and pulsed with 0.5 μCi [3H]-TdR. The μ to γ1 class switch recombination (CSR) was examined by analyzing the proportion of surface IgG1+ cells by FACS. [Results and Discussion] The αTLR4 mAb and αRP105 mAb induced massive B cell proliferation like as LPS. Expression of CD86 and BAFF receptors was induced by low doses of αRP105 (10 ng/ml), whereas those expression was very low by αTLR4 stimulation even at high doses (1 μg/ml). Combination of αTLR4 + IL-4 as well as LPS + IL-4 forced B cells to induce sIgG1+ cells. In contrast, αRP105 + IL-4 never showed this activity. CD138 expression was induced on B cells stimulated with αTLR4 but not with αRP105. These findings suggest that TLR4 and RP105 differentially regulate B cell response to LPS.
IFN-γ and IL-4 differentially regulate TLR-triggered induction of antimicrobial peptides by altering vitamin D metabolism (135.49)
Authors: Edfeldt Kristina , Liu Philip T. , Chun Rene , Krutzik Stephan R. , Adams John S. , Hewison Martin , Modlin Robert L. 
Published: January 2023

Abstract
Innate immunity is important for host defense against microbial infections and vitamin D has been shown to play a role in this response. Vitamin D is required for Toll-like receptor (TLR)-triggered induction of the antimicrobial peptides cathelicidin and DEFB4, but how acquired immunity influences this system is not known. The objective of this study was to assess the role of acquired immune cytokines on TLR-triggered vitamin D-dependent induction of antimicrobial peptides.
We showed that acquired immune cytokine responses influence antimicrobial pathways in innate immunity by regulating vitamin D metabolism. The Th1 cytokine IFN-γ induced bioconversion of 25-hydroxyvitamin D3 (25D3) to its active metabolite 1,25-dihydroxyvitamin D3 and resulted in a subsequent increase in cathelicidin mRNA in cells treated with a TLR2/1 ligand. In contrast, the Th2 cytokine IL-4 lead to induction of 25D3 catabolism by inducing 24-hydroxylase enzyme activity and consequently inhibited TLR2/1-triggered induction of the antimicrobial peptides cathelicidin and DEFB4.
In conclusion our results support a role for acquired immune cytokines in regulating vitamin D-dependent antimicrobial pathways in innate immunity.
KE is a Wenner-Gren Fellow
Long-term biphasic effects of estrogen exposure on murine bone-marrow derived macrophage TLR4 expression (135.52)
Authors: Rettew Jennifer A , Huet Yvette M , Marriott Ian 
Published: January 2023

Abstract
Numerous studies have shown that estrogens augment immune responses and have been demonstrated to increase resistance to bacterial infections. In addition, it has been shown that production of inflammatory cytokines following administration of LPS is attenuated in ovariectomized animals, which is reversed following exogenous estrogen administration. We have recently demonstrated that chronic in vivo exposure to estrogen, but not acute in vitro exposure, augments Toll-like receptor 4 (TLR4) expression on peritoneal macrophages although the mechanisms that underlie this disparity are unclear. In this study we have investigated the effect of in vivo removal of endogenous estrogen and high dose estrogen replacement on TLR4 expression on bone-marrow derived macrophages and/or their progenitor cells. We report that these cells isolated from ovariectomized animals that received high dose estrogen treatment have significantly less (~20%) cell surface TLR4 expression than those derived from sham treated mice or untreated gonadectomized animals following 7 days in culture. Importantly, this effect was not reflected by changes in total cell TLR4 content suggesting that estrogen does not affect TLR4 production. However, longer-term (14-16 day) culture of these cells resulted in an apparent reversal of this pattern with restoration of TLR4 expression on bone-marrow derived macrophages isolated from estrogen treated animals and reduction in the expression of this pattern recognition receptor on cells from untreated gonadectomized mice in a manner that is consistent with our previous observations in acutely isolated peritoneal macrophages. Interestingly, in vitro treatment of bone-marrow derived cells with varying doses of estrogen failed to mimic these effects suggesting that this reproductive hormone exerts its effects prior to macrophage maturation.
TLR agonists synergize with CD40L/IFN-γ to promote human dendritic cell synthesis of IL-12 (135.65)
Authors: Huang Alex , Carreno Beatriz M. , Linette Gerald P. 
Published: January 2023

Abstract
CD40L provides a critical signal to license DC for the effective generation of T cell memory. To investigate additional signals that might synergize with CD40L, we tested TLR agonists to promote IL-12 production by DC matured with the combination of CD40L/IFN-γ. Human monocyte-derived immature DC established by standard 6 day culture in GM-CSF/IL-4 were activated with human CD40L/IFN-γ plus optimal concentrations of individual TLR agonists for an additional 48 h and the supernatants were assayed for IL-12 p70 by ELISA. TLR 1/2, 4, 5, 6, and 8 agonists each resulted in significant increases in IL-12 production as compared to CD40L/IFN-γ alone with mean fold increases of 2.3, 4.0, 2.1, 3.5, and 8.8 respectively. TLR agonists 3, 7, and 9 had no effect. To further assess the potential synergy of TLR agonists with CD40L/IFN-γ mDC, we studied the capacity of CMV pp65 NLV peptide-pulsed mDC to stimulate antigen-specific CD8+ T cells from normal CMV sero-positive donors. The antigen-specific CD8 response as measured by tetramer-fold increase was significantly higher at day 10 using TLR/CD40L/IFN-γ activated mDC compared to conventional CD40L/IFN-γ mDC. We conclude that multiple maturation signals are required to license DC for the optimal generation of T cell memory.
Granulysin induces recruitment and activation of antigen presenting cells and acts as an immune adjuvant and alarmin (135.69)
Authors: Tewary Poonam , Yang De , de la Rosa Gonzalo , Li Yana , Krensky Alan , Clayberger Carol , Oppenheim Joost J 
Published: January 2023

Abstract
Granulysin (GNLY) is a 9-KD antimicrobial protein present in the granules of CTLs and NK cells. It kills a variety of pathogens, possesses antitumor activity and is expressed in diverse disease settings. Recently it was shown GNLY chemoattracts and activates monocytes. Here we demonstrate that GNLY (1) induces directional migration of monocyte derived DCs, (2) activates human dendritic cells (DCs) leading to the upregulation of phenotypic markers and production of proinflammatory cytokines and (3) induces functional maturation of DCs with the capacity to stimulate a mixed lymphocyte reaction (MLR). Intraperitoneal injection of human GNLY in mice causes a marked recruitment of inflammatory leucocytes and subsequent immunization with GNLY and OVA promotes antigen-specific immune responses, indicating that GNLY can activate both innate and adaptive immune responses. Thus, based on its capacity to recruit and activate antigen presenting cells and promote an in vivo antigen-specific immune response, we consider GNLY an immune alarmin.
NLRC4 is an innate immune detector of the bacterial type III secretion apparatus (135.72)
Authors: Miao Edward A , Mao Dat , Yudkovsky Natalya , Bonnea Richard , Aderem Alan 
Published: January 2023

Abstract
The mammalian innate immune system uses Toll-like receptors (TLRs) and Nod-LRRs (NLRs) to detect microbial components during infection. Often these molecules work in concert; for example, the TLRs can stimulate the production of the pro-forms of the cytokines IL-1β and IL-18, whereas certain NLRs trigger their subsequent proteolytic processing via caspase 1. Gram negative bacteria utilize type III secretion systems (T3SS) to deliver virulence factors to the cytosol of host cells, where they modulate cell physiology to favour the pathogen. We show here that NLRC4/Ipaf detects the basal body rod component of the T3SS apparatus (rod protein) from S. typhimurium (PrgJ), Escherichia coli (EprJ and EscI), Burkholderia pseudomallei (BsaK), and Shigella flexneri (MxiI). These rod proteins share a sequence motif that is essential for detection by NLRC4; a similar motif is found in flagellin which is also detected by NLRC4. S. typhimurium has two T3SS: Salmonella pathogenicity island-1 (SPI-1), which encodes the rod protein PrgJ, and SPI-2, which encodes the rod protein SsaI. While PrgJ is detected by NLRC4, SsaI is not, and this evasion is required for virulence in mice. Our results indicate that macrophages respond to the activity of T3SS, not by sensing the specific translocated virulence factors, but rather by detecting the translocation apparatus that is conserved between pathogens. This reduces the number of host detectors required, a survival strategy that is divergent from that used by plants, where translocated effectors are detected on a gene for gene basis. Furthermore, the specific detection of the virulence machinery permits the discrimination between pathogenic and non pathogenic bacteria.
Regulation of IL-1beta and IL-23 production by beta-glucan in human dendritic cells (135.76)
Authors: Lyakh Lyudmila A , Cardone Marco , Riboldi Elena , Trinchieri Giorgio 
Published: January 2023

Abstract
We have previously demonstrated in human monocyte-derived dendritic cells (DCs), interleukin-23 (IL-23) is efficiently induced by the Dectin-1 ligands alone or in combination with Toll receptor 2/6 (TLR2/6) ligand Pam2C but not by the TLR4 ligand LPS alone. We found that the ability of various stimuli to induce Th17 cells depends not only on their induction of IL-23, IL-6, and TGF-β production in DCs, but also on their ability to induce bioactive IL-1β.
We considered whether the Dectin-1 receptor ligands were able directly or indirectly to activate the inflammasome. We found that only particulate but not soluble forms of β-glucan induced secretion of IL-1β in human DCs, and caspase-1 inhibitors blocked its secretion. LPS did not induce IL-1β secretion unless ATP was added to activate the inflammasome. Moreover, treatment with oxidized ATP or apyrase impaired the secretion of IL-1β by β-glucan-treated DCs.
We also observed that caspase-1 inhibitors or an IL-1 receptor antagonist significantly decreased the production of IL-23 by DCs stimulated with β-glucan. Our data indicate that endogenous IL-1β is involved in regulation of the IL-23 production. Thus, these results strongly suggest that activation of the inflammasome is necessary both for the production of IL-23 and for the development of Th17 responses. We are currently analyzing the molecular mechanisms of the inflammasome activation by dectin-1 ligands alone or in combination with TLR ligands.
This work was supported by the intramural program of the National Cancer Institute, NIH.
NLRs in mouse hepatocytes respond to specific ligands to activate NFκB (135.78)
Authors: Scott Melanie J , Liao Hong , Billiar Timothy R 
Published: January 2023

Abstract
Hepatocytes are microbial-responsive cells that express and activate Toll like receptors (TLRs). NACHT-LRR receptors (NLRs) are a family of more recently identified intracellular pattern recognition receptors. NOD1 and NOD2 are NLRs that respond to specific microbial ligands and activate NFκB through activation of RIP2/RICK. We hypothesized that hepatocytes express and activate NOD1/NOD2 signaling pathways as part of their function to initiate and regulate the innate immune system. High levels of NOD1, NOD2, and RIP2/RICK mRNA and protein expression were detected by quantitative PCR or Western blot in untreated primary isolated C57BL/6 hepatocytes. Hepatocytes were then treated with LPS (100ng/mL), iE-DAP (100ng/mL; NOD1-ligand), or MDP (10μg/mL; NOD2-ligand) for up to 60min. NOD-ligands were endotoxin free. NFκB activation by EMSA in hepatocytes treated with iE-DAP was similar or higher than after LPS-stimulation. However there was minimal NFκB activation after NOD2-ligand (MDP). NOD1/2, RIP2 mRNA expression increased significantly by 1h after stimulation with LPS, MDP or iE-DAP and was maximal by 4h, remaining elevated at 24h of stimulation. Together these data show hepatocytes respond to microbial ligands specific for NOD1 or NOD2 and increase their expression suggesting a role for these proteins in hepatic responses to infection.
Work supported in part by funding from NIH grant R01-GM-50441
Structure of NALP1/NLRP1 leucine-rich repeats and potential ligand binding (135.79)
Authors: Jin Tengchuan , jiang Jiansheng , Perry Andrew , Xiao Tsan 
Published: January 2023

Abstract
NALP1/NLRP1 is a prototype NLR family member and is involved in inflammasome formation and activation of caspase-1 in response to bacteria infections. The primary stimuli of NLRP1 appears to be the bacterial cell wall components, though the molecular mechanisms of recognition has remained elusive. The structure of a fragment of NLRP1 containing its leucine-rich repeats has been determined. The structure illustrates an unusual tetramerization of the leucine-rich repeats. There is a potential ligand binding site that appears to have affinity for sugar molecules.
Differentially Expressed MicroRNAs in Allergic Asthma Target Genes underlying Airway Hyper-Responsiveness and Goblet Cell Hyperplasia (136.22)
Authors: polikepahad Sumanth , Creighton Chad J , Zhu Huifeng , Harris Alan , Coarfa Cristian , Berel Dror , Milosavljevic Aleksandar , Corry David B , Gunaratne Preethi H 
Published: January 2023

Abstract
Asthma is an allergic disease that results in the obstruction of airways as a result of goblet cell hyperplasia and airway hyper-reactivity (AHR). Broad-spectrum P2-receptor antagonists and glucocorticoids are commonly used therapeutic agents for this disease. Niflumic acid (NA), an inhibitor of calcium-activated chloride channels is used to overcome corticosteroid-resistant asthma. Using Next Generation Sequencing, we dissected the asthma-related small RNAome in the lung before and after (FC) allergen challenge. We find a significant induction of microRNAs in FC from 40% to 74% suggesting an important role for miRNAs in asthma. Also, we uncovered 460 miRNA-up:mRNA-down and 17 miRNA-down:mRNA-up pairs that are significantly correlated in naïve and FC lung. The latter category contains a number of key genes induced during asthma and include miR-106b:P2X, miR-205:P2Y, miR-145:CLCA3 and miR-133a:GM-CSF. We also uncovered two novel miRNAs Asth-miR-1 and Asth-miR-2. Asth-miR-1 is predicted to target Toll-like receptor (TLR) adaptor TIRAP and IRAK which associates to activate NF-Kb, AP-1 and IRFs, and under some conditions, induce allergic lung disease. Asth-miR-2 is predicted to target ryanodine receptor 2 (RyR) that mediates Ca2+ release that induces airway smooth muscle contraction and bronchoconstriction. The integration of miR-106b, 205, 145 a, 133a and Asth-miR-1 and Asth-miR-1 2 with current therapies can potentially significantly enhance the efficacy and specificity of drugs used to combat asthma.
Epigenetic modifications control the phenotype of alternatively activated macrophages (136.4)
Authors: Ishii Makoto , Wen Haitao , Corsa Callie A S , Hogaboam Cory M , Dou Yali , Kunkel Steven L 
Published: January 2023

Abstract
Although alternatively activated (M2) macrophages play critical roles in chronic diseases, little is known about the acquisition and maintenance of their phenotype. We investigated the mechanisms whereby chromatin remodeling can influence the expression of genes that define M2 macrophages. Bone marrow-derived macrophages were incubated with IL-4 (10 ng/ml) and the expression of M2 marker genes (Ym1 and found in inflammatory zone-1 (FIZZ1)) and the histone H3 lysine-27 demethylase Jmjd3 was measured by PCR. ChIP assays were performed to determine levels of histone H3 lysine-4 trimethylation (H3K4me3), histone H3 lysine-27 trimethylation (H3K27me3), and Jmjd3 associated with the promoter regions of Ym1 and FIZZ1. Macrophages treated with IL-4 were found to increase the expression of mRNA levels of Ym1 and FIZZ1. Concomitant with this augmented expression pattern were an increase in H3K4me3 levels and a decrease in H3K27me3 levels; a pattern consistent with enhanced gene expression. Furthermore, Jmjd3 mRNA and Jmjd3 recruitment to Ym1 and FIZZ1 genes were increased in macrophages treated with IL-4, suggesting that Jmjd3 participates in erasing H3K27me3 marks on the promoter regions of Ym1 and FIZZ1. We conclude that the M2-macrophage phenotype is epigenetically regulated, in part, via induction of the H3K27 demethylase Jmjd3. (NIH grants P01-HL031963, HL092845, HL89216 and HL031237)
Regulatory T Cells Suppress Expression of IL-2 by Responder T Cells via a Transcriptional Mechanism (136.40)
Authors: Luther Rita J , Randolph David , Deshane Jessy , Maynard Craig , Janowski Karen , Oliver Jimmy , Weaver Casey T 
Published: January 2023

Abstract
Interleukin-2 (IL-2) is a type I cytokine that undergoes transcriptional activation downstream of T-cell receptor engagement and CD28 co-stimulation. IL-2 has been shown to have a role in self-tolerance as the presence of this cytokine, shown in several mouse models, necessitates the presence of a sufficient population of T regulatory cells (T reg). Tregs have a critical role in limiting the development of autoreactive effector T cells from naïve precursors that have escaped negative selection within the thymus. Ongoing studies indicate several mechanisms by which Tregs suppress induction of effector T cell responses, one of which is the inhibition of IL-2 gene expression. While several studies have indicated an inhibition of IL-2 mRNA and protein expression by responder CD4+ T cells co-cultured with T regs, the mechanism (s) remains unclear, although effects on both IL-2 gene transcription and mRNA stability have been implicated. In order to examine transcriptional and post-transcriptional effects on IL-2 expression, we have generated an IL-2 BAC-in transgenic reporter mouse model, 2BiT, in which a Thy1.l reporter is expressed under control of the extended Il2 locus. Herein we show that the Thy1.1 IL-2 reporter is expressed with fidelity to the endogenous IL-2 genes. Co-culture assays indicate that transcriptional activation of the reporter in responder T cells is inhibited in the presence of T regs, despite modest effects on IL-2 mRNA half-life (t1/2). These findings indicate that T regulatory cells suppress IL-2 expression primarily through inhibition of transcription rather than modulation of IL-2 mRNA stability.
Acetylcholine Receptor-alpha Subunit Over-Expression in Experimental Myasthenia Gravis: A Possible Role for the Autoantigen in Pathogenesis (137.1)
Authors: Sheng JianRong , Prabhakar Bellur S , Meriggioli Matthew N 
Published: January 2023

Abstract
Previous studies have shown an increased expression of AChR alpha (AChR-α) subunit transcripts in experimental autoimmune myasthenia gravis (EAMG). We examined the mRNA and protein expression of AChR-α, as well as the pattern of α-bungarotoxin labeling in muscle tissue from EAMG mice. AChR-α expression was profoundly increased in endplates from mice with severe EAMG, but this expression was distinct and greatly in excess of α-bungarotoxin labeling. These results suggest that loss of functional AChR increases transcription of AChR-α mRNA, but the expressed protein is "functionally inert," failing to compensate for loss of AChR, and very likely enhancing immunogenicity.
Title: CD8+CD62LhiCD25- cells induce skin inflammation in a psoriasis-like disease model and exhibit a Th1 phenotype (137.19)
Authors: Napierata Lee , Stedman Nancy , Benoit Stephen , Collins Mary , Nickerson-Nutter Cheryl , Young Deborah , Ma Hak-Ling 
Published: January 2023

Abstract
Previously we have shown that adoptive transfer of CD4+CD45RBhiCD25- T cells (naïve CD4 cells), into scid/scid mice can induce psoriasis-like disease. The affected mice develop scaly and raised skin plaques and immune features in this model mimic those of human psoriasis. Data from others suggests that skin infiltrating CD8+ T cells contribute to disease exacerbations in human psoriasis. To understand the role of CD8 cells in the mouse model of psoriasis, we adoptively transferred either naïve CD4 T cells, or CD8+ CD62LhiCD25- cells (naïve CD8 T cells) or combined naïve CD4 and CD8 cells into scid/scid mice and monitored disease progression. We found that adoptive transfer of naïve CD8+ T cells alone resulted in slightly less severe skin lesions when compared to either naïve CD4 T cell transfer or combined CD4 and CD8 T cell transfer. We also found that mice receiving CD8+ T cells experienced slightly reduced epidermal hyperplasia and inflammation than mice given other combinations of T cell transfer. Quantitative RT-PCR analysis of the mouse ear RNA and intracellular cytokine staining of the draining lymph node cells from these mice revealed that in comparison to mice given naïve CD4 cells, mice receiving CD8 cells expressed mainly a Th1 cytokine profile. Results here suggest that CD8 cells may also play an important role in perpetuating the development of skin lesions and exhibit mainly a Th1 phenotype.
Two populations of alternatively activated M2 macrophages (TLR4+ vs. Tim-3+) regulate inflammation and fibrosis in the heart during coxsackievirus-induced myocarditis (137.20)
Authors: Fairweather DeLisa , Frisancho-Kiss Sylvia , Coronado Michael J. , Frisancho J. Augusto , Cihakova Daniela , Rose Noel R. 
Published: January 2023

Abstract
Previously we showed that Toll-like receptor 4 (TLR4) and T cell Ig mucin-3 (Tim-3) cross-regulate each others expression on CD11b+ cells, with TLR4 increasing and Tim-3 reducing cardiac inflammation. We show here that TLR4 and Tim-3 are expressed on GR1+F4/80+IL-4R+ alternatively activated M2 macrophages from the heart during acute myocarditis, but are not expressed on GR1-F4/80+IL-4R- classically activated M1 macrophages. GR1+ cells also express the mannose receptor (CD206), caspase-1, IL-1β and IL-10. In gonadectomized male mice, M2 cells express significantly more Tim-3 and significantly less IL-1β with significantly reduced inflammation. In contrast, complement receptor 1/2 (CR1/2) deficient mice have a significantly increased TLR4+casp-1+IL-1β+ M2 population. Elevated expression of IL-1β by M2 macrophages in the heart leads to significantly increased myocarditis, fibrosis and heart failure in CR1/2 deficient mice. These data indicate that different M2 populations have contrasting roles on the development of heart disease: TLR4+casp-1+IL-1β+ M2 are associated with increased inflammation and fibrosis, while Tim-3+ M2 with decreased inflammation. Deciphering how M2 macrophage populations interact with autoreactive cells and antibodies will be critical in understanding the pathogenesis of autoimmune disease.
Supported by NIH grants R01 HL087033 (DF) and R01 HL67290 (NRR).