bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increased inflammation, impaired bacterial clearance, and metabolic disruption after Gram-negative sepsis in Mkp-1 deficient mice (135.23)
Authors: Liu Yusen , Wang Xianxi , Frazier W. Joshua , Meng Xiaomei , Nelin Leif D 
Published: January 2023

Abstract
MAPKs are crucial for TNF-α and IL-6 production by innate immune cells in response to TLR ligands. MAPK phosphatase (Mkp)-1 deactivates p38 and JNK MAPKs, abrogating the inflammatory response. We have previously demonstrated that Mkp-1-/- mice exhibit exacerbated inflammatory cytokine production and increased mortality in response to challenge with LPS and heat-killed Staphylococcus aureus. However, the function of Mkp-1 in host defense during live Gram-negative bacterial infection remains unclear. We infected Mkp-1+/+ and Mkp-1-/- mice with live E. coli i.v., and examined the effects of Mkp-1 deficiency on animal survival, bacterial clearance, metabolic activity and cytokine production. We found that Mkp-1 deficiency predisposed animals to accelerated mortality and was associated with more robust production of TNF-α, IL-6 and IL-10, greater bacterial burden, altered inflammatory mediator activities, and substantial changes in the mobilization of energy stores. Treatment with the bactericidal antibiotic gentamicin, given 3 h post E. coli infection, protected Mkp-1+/+ mice from septic shock yet had no effect on Mkp-1-/- mice. Thus, during Gram-negative bacterial sepsis Mkp-1 not only plays a critical role in the regulation of cytokine production but also acts to orchestrate the bactericidal activities of the innate immune system and control the metabolic response to stress.
The Research was supported by grants from NIAID (AI57798 and AI68956).
Bordetella pertussis filamentous hemagglutinin induces nuclear translocation of RelB/p52 in U-937 macrophages (135.24)
Authors: Abramson Tzvia , Kedem Hassya , Relman David 
Published: January 2023

Abstract
Filamentous hemagglutinin (FHA) is a dominant adhesin expressed by the respiratory pathogen Bordetella pertussis that also triggers inflammatory as well as immunosuppressive functions in the host. Given the role of NF-κB transcription factor family members in these functions, we examined the effects of FHA on NF-κB activation at early and late time points in two cell types relevant to natural infection: human bronchial epithelial (BEAS-2B) cells and human macrophage-like (U-937 derived) cells. We recently showed that FHA blocks proteasomal activity in both, the bronchial epithelial cell line and in monocyte-derived macrophages, resulting in accumulation of IκBα at 2 hours or greater incubation times. RelB and alternative NF-κB pathways regulate monopoiesis and monocyte-derived dendritic cell subset development. We report here that incubation of U-937 cells with FHA for more than 4 hours results in reduced levels of cytosolic RelB and increased levels of nuclear RelB and p52, as shown by Western blot analysis. No such effects were observed in bronchial epithelial cells (BEAS-2B). These data suggest that FHA induces nuclear translocation of RelB /p52 and activation of the alternative NF-κB pathway in U-937 cells, but not in BEAS-2B cells, and offer a molecular mechanism by which FHA might affect development and maturation of myeloid host cells.
Regulation of cell cycle and survival by type-I IFN and TLR7 in B-lymphocytes (135.43)
Authors: Priest Stephen O , Baumgarth Nicole 
Published: January 2023

Abstract
Innate signaling is an essential part of the anti-viral immune response. One such signal induced during an infection is type-I interferon (IFN), an anti-viral cytokine with immune modulatory effects on many cell types, including B cells. It also affects cell cycling and survival. Other signals are delivered via innate toll-like receptors (TLR) that can induce B cell proliferation in response to select microbial products, independent of, or in addition to B cell receptor signaling. Previous studies showed that these two innate stimuli affect the magnitude and quality of the local influenza virus-specific B cell response, and the sensitivity of B cells to non-specific activation via self-antigens. The precise mechanisms by which these innate TLR and type-I IFN signals exert their effects on the antiviral B cell responses, however, remain unclear. We show that type-I IFN regulates steady-state expression of innate viral recognition receptors TLR3 and TLR7 in B cells and their induction in local B cells following infection with influenza virus. IFN also induced several other factors regulating cell cycling and survival, notably cyclin D2 and Bcl-2, in these cells. Furthermore, stimulation by both TLR7 and type-I IFN, but not TLR3, strongly modulated cell cycle entry and survival of B cells. Our data identify the control of cell cycle and survival as key effects of TLR7 and type-I IFN on B cell responses. Supported by NIH AI51354.
CpG oligodeoxynucleotide incorporated basement membrane extract facilitate wound repair in mice (135.5)
Authors: Sato Takashi , Shimosato Takeshi , Klinman Dennis M 
Published: January 2023

Abstract
Wound healing involves complex processes including re epithelialization and wound contraction. Recent reports showed that the innate immune pathway of TLR4-mediated MyD88 signaling can affect the healing process by modulating epithelial cell migration and the production of angiogenesis factors. However, it has not been elucidated whether the TLR9 pathway could promote wound healing.
Synthetic oligodeoxynucleotides (ODN) expressing unmethylated CpG motifs mimic the ability of bacterial DNA to stimulate an innate immune response via TLR9. We incorporated CpG ODN into a vehicle (basement membrane extract, BME) that slowly released bioactive ODN to wound sites. In vivo studies using an excisional skin biopsy model showed that CpG ODN treatment significantly accelerated wound repair in normal mice (p &lt; 0.0001). The same effect was observed in aged mice (whose wound healing was otherwise delayed). Consistent with these effects being mediated by CpG signaling via TLR9, CpG ODN did not accelerate wound healing in TLR9 knock out mice.
Histologic studies indicate that CpG treatment promoted the local accumulation of macrophages, increased the production of VEGF, and promoted neovascularization, resulting in accelerated granulation and wound closure (p &lt; 0.01). These findings suggest that CpG ODN may represent a promising novel therapy for wound repair.
CD180 is a positive regulator of TLR signals in B cells (135.64)
Authors: Chaplin Jay W , Kasahara Shinji , Clark Edward A , Ledbetter Jeffrey A 
Published: January 2023

Abstract
CD180 is a Toll-Like Receptor (TLR) that regulates the response of B cells and Dendritic Cells (DC) to TLR ligands. In the absence of CD180, B cell responses to TLR4/2 ligands are low, whereas LPS-stimulated DC produced more inflammatory cytokines. We examine the relationship of CD180 and TLR signals by in vitro B cell proliferation and cytokine production. Proliferation induced by anti-CD180 agonist antibody did not depend upon TLR signals and synergized with LPS in B cell proliferation; this synergy was mediated by LPS signals through MyD88 but not through TRIF. Anti-CD180 did not directly induce cytokine production by B cells but augmented IL-6, IL-10, and TNF-alpha production in combination with multiple TLR ligands. We also examine CD180 signals by in vivo injection of anti-CD180, which produced a greater than two-fold transient increase in splenic B cells without detectable toxicity. The B cell expansion peaked at day 3 and returned to normal levels by day 14. Proliferation of B cells isolated from injected mice was diminished at day 7 for CD180, LPS, and antigen signals. Responsiveness to CD180 and LPS returned to normal levels by day 14 while antigen signals remained attenuated. We conclude that CD180 signals interact with multiple TLR signals and can induce both transient B cell expansion and desensitization without overt toxicity.
A role of IgM antibodies in monosodium urate crystal formation and associated adjuvanticity (135.71)
Authors: Kanevets Uliana , Sharma Karan , Dresser Karen , Shi Yan 
Published: January 2023

Abstract
Uric acid is a product of purine metabolism that is secreted from injured or dying cells and can act as an endogenous adjuvant. However, uric acid must crystallize to monosodium urate (MSU) before it can activate dendritic cells and cause gouty inflammation. At normal serum uric acid levels, crystallization of uric acid is not observed in vitro. The crucial question therefore is how the crystals form and cause inflammation. It has been reported that serum from rabbits immunized with MSU, increased uric acid precipitation rates. When C57BL6 or Balb/c mice were immunized with MSU, they produced serum factors which bind to MSU crystals, a phenomenon absent in mu chain deficient IgH (or muMT) mice. These observations show that antibodies may be involved in MSU crystallization. Antibodies produced via B cell hybridomas, were observed to precipitate uric acid in vitro, with the variable region acting as the binding domain. Most importantly, the presence of antibody was instrumental in significantly increasing the basal level of inflammation and mediating the adjuvant effect of uric acid in antigen dependent T cell cytotoxicity in B cell deficient mice. Therefore, we have identified a factor in determining uric acid precipitation and possibly its ability to function as an endogenous adjuvant. This finding suggests a new mechanism of the pathogenesis of gouty arthritis and uric acid induced immune activation.
NLRP12 REGULATES TLR2/DECTIN-1 FUNGAL RECEPTOR SIGNALING THROUGH ASSOCIATION WITH CARD9 (135.74)
Authors: Lord Christopher , Goto Hisatsugu , Thomas Joseph M. , Mukherjee Sambuddho , Nambu Hiroya , Cramer Robert A. , Lin Xin , Wright Jo Rae , Williams Kristi 
Published: January 2023

Abstract
The NLR (nucleotide-binding domain, leucine-rich repeat) proteins are recently recognized as important intracellular regulators of host defense and immunity. One NLR gene, NLRP12/Monarch-1, has emerged as an important inhibitor of inflammatory gene expression in myeloid cells via regulation of TLRs and TNFR signal transduction. In contrast to its known role in regulating bacterial induced TLR activation of downstream genes, little is known about the role of NLRP12 in regulating the immune response to fungal pathogens. Here we show that NLRP12 modulates innate immune cellular responses to A. fumigatus by regulating TLR2/Dectin-1 fungal receptor signaling through its association with downstream signaling proteins CARD9 and Bcl10, but not Malt1. NLRP12, consisting of a pyrin, a nucleotide binding and a leucine rich repeat domain associates with the caspase recruitment domain containing proteins CARD9 and Bcl10 via the adaptor protein ASC. The most severe form of the NLRP12 disease associated mutant protein lacks the ability to associate with ASC, CARD9 and Bcl10 resulting in the lack of NLRP12's normal negative regulatory function. These data demonstrate the important role played by NLRP12 in modulating the innate immune response to fungal pathogens via its regulation of the TLR2/Dectin-1 induced CARD9 signaling pathway.
This work was supported by NIH grants HL-30923 and HL-68072 (JRW), NIH COBRE grant RR020185 (RAC) a SERCEB award and funding from CCBVP to KLW.
The promoter for the long isoform of mouse NKG2D is a B1 retrotransposon with a functional GABP site (136.24)
Authors: Lai Benjamin Chiehmin , Zhang Ying , Rogers Sally L , Mager Dixie L 
Published: January 2023

Abstract
The mouse gene for the natural killer (NK) cell activating receptor NKG2D produces two protein isoforms, NKG2D-S and NKG2D-L, which differ by 13 amino acids at the N-terminus and have different signaling capabilities. These two isoforms are produced through the use of alternative promoters but the regulation of these promoters has not been investigated. In this study, we show that rat NKG2D has the same splicing pattern as that of the mouse and we mapped transcriptional start sites in both species. We also show that the NKG2D-L specific promoter, active in both resting and stimulated NK cells, is derived from a rodent B1 retrotransposon that inserted before mouse-rat divergence. This B1 insertion is associated with loss of a nearby splice acceptor site that subsequently allowed creation of the short NKG2D isoform found in mouse but not human. Reporter assays suggest that the B1 promoter has no inherent lymphoid tissue-specificity. Finally, we have identified different binding sites for the ETS family member GABP within both the mouse and rat B1 elements that are necessary for high promoter activity.
This work was supported by the Canadian Institutes of Health Research and the Cancer Research Society.
An Allergy-Associated Polymorphism in a Novel Regulatory Element Enhances IL13 Expression (136.27)
Authors: Kiesler Patricia , Shakya Arvind , Tantin Dean , Vercelli Donata 
Published: January 2023

Abstract
The cytokine IL13 is a critical effector of T helper 2 (Th2)-mediated responses and allergic inflammation. We previously characterized the function of common IL13 variants that show strong, replicated associations with allergy-related phenotypes. We also demonstrated that during CD4+ Th cell differentiation, chromatin at the IL13 locus is extensively remodeled and becomes hypersensitive to nucleases at multiple sites. Among these, HS4 in the distal promoter is constitutively present in naïve and differentiated T cells, and spans a common allergy-associated SNP, IL13-1512AC (rs1881457). Here we characterize HS4 as a novel cis-regulatory element that upregulates IL13 transcription in Th2 cells and we show that the rs1881457 risk allele significantly alters HS4 activity and enhances IL13 promoter activity by creating a binding site for the transcription factor Oct-1. Experiments in mice heterozygous for an Oct-1 null mutation demonstrated that physiologic levels of Oct-1 are required for increased expression of the IL13-1512C promoter allele. Our results illustrate how a functional variant in a regulatory element may modulate susceptibility to a common complex disease.
Children with autism spectrum disorders (ASD) characterized by frequent viral infection and subsequent loss of cognitive skills differ in mRNA expression of peripheral blood monocytes from other ASD children (136.7)
Authors: Jyonouchi Harumi , Geng Lee , Streck Deanna , Toruner Gokce 
Published: January 2023

Abstract
We have reported presence of an ASD subset distinguished by recurrent loss of previously acquired cognitive skills with worsening behavioral symptoms triggered by infection (typically viral), which may be associated with altered TLR responses important for neuro-immune interactions involving IL-1β. This study assessed gene expression of peripheral blood (PB) monocytes in this ASD subset (ASD-test group, N=14, median 7.8 yr) in comparison with control ASD (N=11, median 6.8 yr) and normal children (N=5, median 8yr). Both the ASD groups regressed at the onset of ASD and had high frequency of non-IgE mediated food allergy. The ASD test group also had lower IL-10 production with recall antigens than 24 normal controls. Microarray analysis revealed difference of mRNA expression (two fold or more) of 1593 genes in the ASD-test group and 2704 genes ASD-controls as compared to normal controls. IL-1 pathway related genes were over-represented in the ASD-test group (p=0.002) while IL-2, IL-3, IL-9, α-integrin (all p&lt;0.05), and TNF-α pathway (p=0.001) genes were over-represented in the ASD-control group (GeneSpring GX). Among 844 genes belonging to both the ASD groups, IL-2 and IL-3 pathway related genes were enriched (p&lt;0.05). Our results indicate notable difference in the ASD test and control groups at the level of mRNA expression in PB monocytes, supporting our previous results. Partly funded by Jonty Foundation and ARI.
Characterization of naive CD4+ T cells with specificity to self-antigen (137.21)
Authors: Moon James J , Jenkins Marc K 
Published: January 2023

Abstract
During thymic development, T cells with specificity to self-antigens are deleted, thereby ensuring that the peripheral repertoire is devoid of potentially autoreactive clones. However, the ultra-low frequency of naive epitope-specific T cells has made the direct test of this theory technically unfeasible in the past. Using peptide:MHC (pMHC) multimers coupled with magnetic bead enrichment, we have directly studied endogenous polyclonal populations of naive CD4+ T cells with specificity for an I-Ab-restricted model antigen, 2W1S, that is foreign in C57BL/6 mice (B6) or self in mice transgenically expressing the model antigen (Act-2W). Act-2W mice contained a population of 2W1S-specific T cells that was about 25% the size of that in B6 mice, demonstrating that thymic deletion of self-antigen specific T cells is incomplete. Nonetheless, these cells were tolerant to 2W1S, as they did not develop autoimmune responses or respond to large doses of exogenous 2W1S antigen administered in vivo. Antigen receptors expressed by these cells exhibited features of reduced pMHC ligand binding affinity, indicating a preferential loss of high-affinity 2W1S-specific clones during thymic selection. Moreover, a greater proportion of 2W1S-specific T cells expressed FoxP3 in Act-2W mice than in B6 counterparts, suggesting that regulatory T cell development may also function as a mechanism of T cell tolerance to self-antigens.
This work was funded by NIH grants PO1-AI35296 and F32-AI063793.
Characterization of Sema4D and Sema7A mRNA Expression in Developing C57BL/6 Mouse Thymocytes (138.24)
Authors: Chatterjea Devavani , Linder Grace Elizabeth , Matthes David J 
Published: January 2023

Abstract
Semaphorins are a family of membrane-bound and secreted signaling molecules with active roles in nearly every organ system in processes ranging from heart morphogenesis to tumor development. We are investigating the potential roles of these molecules during T cell development in the thymus. Using Real Time PCR, we have characterized the mRNA expression of Sema4D and Sema7A, semaphorins with known peripheral immune system activity, in subsets of developing thymocytes. While Sema4D and Sema7A mRNA is expressed by all subsets of thymocytes, there appears to be no differential expression of these transcripts between CD4-CD8-, CD4+CD8+, CD4+, and CD8+ populations. While Sema7A expression has previously been described in the human thymus, this is the first time Sema4D and Sema7A mRNA expression has been reported in the murine thymus.
Increases in miRNA Expression in Aged Thymocytes (138.25)
Authors: Thoman Marilyn L , Virts Elizabeth L 
Published: January 2023

Abstract
MicroRNAs (miRNAs) are small non-coding RNAs that control gene expression during cellular processes such as differentiation and development. Alterations in miRNA expression have been linked to age-related changes in mouse liver and Alzheimer disease in the human brain. We decided to investigate a possible role for miRNA activity in age-related thymic decline. To address this question, we isolated lin- triple negative (TN) thymocytes from young (4 months) and aged (24 months) mice, and compared the miRNA profile of 625 miRNAs using qPCR. Thirty-two percent of the miRNAs (199) exhibited a 3-fold or greater increase in the aged animals while only 5% (34 miRNAs) were down-regulated by 3-fold or more. The magnitude of the differences in miRNA expression between young and aged thymocytes was unexpected. The TN population encompasses at least four identifiable subpopulations, representing distinct steps in differentiation. It is likely that these subpopulations differ in miRNA profile. These TN populations are certainly present in varying frequency in young and aged murine thymus. Therefore, some of the overall miRNA expression differences may reflect compositional differences in the TN populations used for RNA isolation. This possibility is being examined by analysis of individually sorted subsets. More intriguing is the possibility that the large number of highly expressed miRNAs found in the aged TN population is indicative that protein expression in these cells is rigidly controlled. We are investigating this possibility by identifying gene targets for a subset of the most highly expressed mRNA. These data provide us with essential information concerning miRNA expression changes that may be associated with the age-specific decline in thymopoiesis.
Impact of Growth Hormone (GH) Deficiency and GH Replacement upon Thymus Function in Adult Patients (138.26)
Authors: Morrhaye Gabriel , Kermani Hamid , Legros Jean-Jacques , Martens Henri , Geenen Vincent 
Published: January 2023

Abstract
Context: In rodents, growth hormone (GH), insulin-like growth factor-1 (IGF-1), and GH secretagogues (such as ghrelin) reverse age-related changes in thymus cytoarchitecture and increase thymopoiesis. GH administration also enhances thymic mass and function in HIV-infected patients. Until now, thymic function has not been investigated in adult GH deficiency (AGHD).
Objectives: The objective of this clinical study was to evaluate thymic function in AGHD, as well as the repercussion upon thymopoiesis of GH treatment for restoration of GH/IGF-1 physiological levels.
Design: Twenty-two patients with documented AGHD were enrolled in this study. The following parameters were measured: plasma IGF-1 concentrations, signal-joint T-cell receptor excision circle (sjTREC) frequency, and sj/ß TREC ratio. Analyses were performed at three time points: firstly on GH treatment at maintenance dose, secondly one month after GH withdrawal, and thirdly one month after GH resumption.
Results: After 1-month interruption of GH treatment, both plasma IGF-1 concentrations and sjTREC frequency were significantly decreased. Decreases in IGF-1 and sjTREC levels were significantly correlated. There was also a significant decrease in intrathymic T cell proliferation as indicated by the reduced sj/ß TREC ratio. One month after reintroduction of GH treatment, IGF-1 concentration and sjTREC frequency were restored at the level before arrest of GH treatment. The sj/ß TREC ratio also increased with GH resumption, but did not return to the level measured before GH withdrawal.
Conclusions: In patients with AGHD under GH treatment, GH withdrawal decreases thymic T cell output, as well as intrathymic T cell proliferation. These parameters of thymopoiesis are completely or partially restored one month after GH resumption.
Importance of MHCII expression on thymic epithelium versus dendritic cells for the positive and negative selection of CD4 T Cells (138.28)
Authors: Jenkinson S. Rhiannon , Zuklys Saulius , Hollander Georg A , Koni Pandelakis A , Reizis Boris , Hodes Richard J 
Published: January 2023

Abstract
Development of T cells from T cell precursors occurs in the thymus through interactions of T lineage cells with thymic stromal populations. These stromal populations are distributed in an ordered fashion that defines thymic architecture and provides the environment for thymic differentiation. The successful generation of a mature and self-tolerant CD4 T cell repertoire requires that developing T cells pass at least two checkpoints; positive and negative selection. Positive selection has been reported to be mediated by cortical epithelial cells, allowing T lineage cells that have rearranged a T cell receptor capable of recognizing self peptide-MHCII complexes at appropriately affinity, to survive and commit to the CD4 lineage. Positively selected cells can then move into the medulla where they must pass negative selection, which acts to remove highly self reactive cells. MHCII is expressed in the medulla on both medullary epithelial cells and dendritic cells and plays a critical role in negative selection. To further examine the cell populations in which MHCII expression is important in CD4 T cell development in unmanipulated mice, we are characterizing the effect of selective inactivation of MHCII, using a panel of mice expressing cre recombinase specifically in epithelial cells or in dendritic cells in combination with an MHCII floxed allele.