bluuebunny/crossref_metadata_2025_split huggingface dataset:
The chromatin remodeling landscape of T helper cell differentiation (88.6)
Authors: Wurster Andrea , De Supriyo , Precht Patricia , Wood William , Becker Kevin , Pazin Michael 
Published: January 2023

Abstract
T helper cell activation and differentiation occur in part through changes in gene expression. Dramatic changes in chromatin structure occur and are thought to play a role in regulation. Little is known about the remodeling enzymes responsible for these changes. Here, we asked how binding of the SWI/SNF remodeling subunit BRG1 changed genome-wide during T helper cell differentiation, using ChIP-seq. Globally, BRG1 binding was positively correlated with gene activity. We found BRG1 binding to promoter proximal regions but also found many distal BRG1 binding regions, including some known distal regulatory elements, suggesting a general role for BRG1 in long-distance gene regulation. BRG1 binding changed dramatically in response to both differentiation and activation. BRG1 binding was associated with DNase I Hypersensitivity and enhancer activity at newly identified regions. Moreover, many of these BRG1 binding regions are lineage or activation specific, a large number of them are greater than 10kb away from the nearest gene, and do not appear to be marked by a common histone code. Together, these findings suggest BRG1 integrates differentiation and activation signals to change chromatin structure. We speculate these events play a causal role in programming gene expression and cell fate. We also suggest that BRG1 binding may be a useful marker for identifying distal regulatory regions.
Heterogeneity of responses of cord blood mononuclear cells to lipopolysaccharide induced epigenetic modifications of the Foxp3 gene. (88.7)
Authors: Goldberg Michael , Elizur Arnon , Nadiv Orna , Kovalchuk Natalya , Katz Yitzhak 
Published: January 2023

Abstract
We previously demonstrated that a high proliferative response to lipopolysaccharide (LPS) in cord blood mononuclear cells (CBMC) correlates with a change from a Th2- to Th1-induced cytokine expression profile. Evidence from mouse models indicates that lipopolysaccharide (LPS) can induce and activate T regulatory (Tregs) cells. The expression of Tregs cells is at least partially controlled by epigenetic modifications in the promoter region of their transcription factor Foxp3. Our goal was to examine whether LPS can lead to the generation of Tregs in human CBMC by inducing epigenetic modifications in the Foxp3 gene promoter. CBMCs were treated with LPS (1ng/ml) or PHA (5 µg/ml). After 72 hours, genomic DNA was isolated, bisulfite treated and the 5’ promoter Foxp3 CpG island (-15 to -138) analyzed by direct sequencing of cloned PCR product and by real-time PCR utilizing methylation-sensitive primers. Treatment of CBMC with LPS increased unmethylated foxp3 promoter DNA in 4/12 patients. In contrast, PHA increased unmethylated promoter CpG islands in 9/12 patients. An increase of Foxp3+ Tregs were seen by FACS in response to PHA, but not to LPS. In conclusion, LPS can induce epigenetic modifications of the foxp3 promoter in a subset of infants, but additional signals are likely required for its induction of Treg cells. Future studies will evaluate whether these modifications alter the risk of developing atopy in susceptible infants.
Molecular basis of regulatory effect of medicinal plant components on the innate immune response through TLR4 signaling (89.1)
Authors: Honda Hiroe , Nagai Yoshinori , Miyake Kensuke , Takatsu Kiyoshi 
Published: January 2023

Abstract
The mammalian immune system consists of two branches: innate and acquired immunity. The innate immune system recognizes microorganisms via germline-encoded pathogen-associated pattern recognition receptors (PARRs) and plays a role in the first line of host defense against pathogens. Toll-like receptors (TLRs) belong to PARRs play indispensable roles for both innate and acquired immunity. One-third of the current top 20 drugs on the market are plant derived. Interestingly, anticancer drug Paclitaxel from Pacific yew tree interacts with human MD-2 and activates dendritic cells through TLR4. We examined effects of components from Glycyrrhizae Radix on the TLR-mediated innate immune response and NF-κB activation. Results: We found that Glycyrrhizic acid (GL, saponin) and Isoliquiritigenin (IQG, chalcone) from Glycyrrhizae Radix suppressed TLR4-mediated TNF-α and IL-6 production by lipid A-stimulated macrophage cells line. GL and IQG also inhibited NF-κB activation induced by lipid A. Western blot analyses revealed that both GL and IQG suppress lipid A-induced IκB-α degradation and ERK1/2 phosphorylation. Intriguingly, GL, but not IQG could inhibit the LPS binding to TLR4-MD2 detected by using anti-TLR4-MD2 mAb. Conclusion: Both GL (saponin) and IQG (chalcone) suppress TLR4-mediated inflammatory cytokine production and NF-κB activation. GL, but not IQG can inhibit TLR4 ligand binding to TLR4-MD-2, indicating that GL and IQG differentially regulate TLR-4-mediated signaling pathway.
Innate immune suppression by gas6 expressed by γδ T cells (89.12)
Authors: Hedges Jodi , Radke Jay , Kimmel Emily , Zickovich Julie , Jutila Mark 
Published: January 2023

Abstract
Gas6, a Vitamin K-dependent protein, is an agonist for the newly described suppressors of inflammation, the TAM receptor family. Transcripts encoding gas6 are unusually highly expressed in purified neonatal bovine γδ T cells, compared to αβ T cells and B cells. Vitamin K-dependent proteins are known for roles in blood coagulation and bone growth, as such there are drugs that affect Vitamin K pathways, the most common of which is Warfarin (Coumadin). We hypothesized that functional gas6 expressed by γδ T cells would be immunosuppressive and addition of Warfarin would be pro-inflammatory. Observations to date are consistent with these assumptions; addition of Vitamin K to bovine PBMC dampens the innate response of monocytes, and this effect is dependent on γδ T cells. Addition of recombinant human gas6 has a similar effect. Conversely, the removal of γδ T cells or the addition of Warfarin to longer term cultures enhances (monocyte-dependent) CD8+ T cell responses in an in vitro model of Mycobacterium avium ssp. avium infection. Also, consistent with expectations, preliminary data in mice suggest that very low dose oral Coumadin increased severity of chemically induced colitis, but decreased colony counts in Salmonella-induced enterocolitis. The expression of Vitamin K-dependent gas6 by γδ T cells that localize to mucosal surfaces may be significant considering the common usage of oral Coumadin and its known side effects.
Both VAMP4 and VAMP7 are indispensable for NK cell cytotoxicity: the requirement for two R-SNARE proteins in granule exocytosis. (89.24)
Authors: Krzewski Konrad , Gil-Krzewska Aleksandra , Watts James , Coligan John , Strominger Jack 
Published: January 2023

Abstract
Natural killer (NK) cells kill cancer and virus-infected cells through their cytolytic activity. The last step in NK cell cytotoxicity, fusion of lytic granules with the plasma membrane resulting in exocytosis of granule content, is still poorly understood. Proteins from the SNARE family mediate all membrane fusion events in the cell. Here we show that NK cells express all seven members of the R-SNARE subgroup. Two of these R-SNARE proteins, VAMP4 and VAMP7, are associated with lytic granules during cytotoxic interactions. However, only VAMP7 co-localizes with granules in non-activated cells. The differences in co-localization of these two R-SNARE proteins, with respect to perforin-containing cytotoxic granules, indicate that they have different functions in exocytosis. Using the tumor NK cell line, YTS, we show that RNAi-mediated disruption of expression of either VAMP4 or VAMP7 inhibits release of lytic granules and severely impairs NK cell cytotoxic activity. Furthermore, VAMP7 but not VAMP4 is involved in cytokine secretion and endocytosis in NK cells, indicating that VAMP7 is involved in many fusion processes and thus plays a more general function in NK cell activity than VAMP4.
Decreased production of neutrophil defensins and increased bacterial translocation in severely burned patients (89.33)
Authors: Kobayashi Makiko , Yoshida Shohei , Jeschke Marc , Inatsu Akihito , Herndon David , Suzuki Fujio 
Published: January 2023

Abstract
α-Defensins are antimicrobial peptides produced by human neutrophils (HNPs). Because severely burned patients are greatly susceptible to gut-associated infections, in this study, the role of HNPs on the resistance of burn patients to bacterial translocation was investigated. PMN were isolated from peripheral blood of severely burned patients, as previously described. These cells (2 x 106 cells/mouse) were inoculated to X-irradiated and decontaminated NOD-SCID IL-2rγ-/- mice (BP-chimeras) orally infected with 106 CFU/mouse of Enterococcus faecalis. The mortality rates of the chimeras were compared with those of chimeras created with healthy donor PMN (H-chimeras). Also, without any stimulation, PMN (1 x 106 cells/ml) were cultured for 18 hrs, and HNP 1-3 in their culture fluids were measured by ELISA. In the results, a 100% mortality rate was demonstrated in a group of BP-chimeras orally infected with 106 CFU/mouse of E. faecalis, while all of H-chimeras survived after the same infection. Healthy donor PMN produced 35.1 ng/ml of HNP 1-3. However, PMN from 5 out of 18 burned patients did not produce HNPs, and trace amounts of HNP 1-3 were produced by PMN from other 13 out of 18 burned patients. These results indicate that the abilities of PMN to produce HNPs are impaired in severely burned patients, and the susceptibility of thermally injured patients to enterococcal translocation may be influenced by the impaired HNP production.
Measurement of rare innate immune cell activation directly in whole blood using imaging flow cytometry. (89.36)
Authors: George Thaddeus , Hall Brian , Mordecai Scott , Friend Sherree , Kong Raymond 
Published: January 2023

Abstract
Signal transduction pathways regulate innate immune cell activation and thus have a critical influence on the effectiveness of host defense against pathogens. Binding to pathogen epitopes triggers signaling cascades that result in the translocation of transcription factors from the cytoplasm to the nucleus, which can be directly measured using microscopy. However, innate immune cells present significant challenges to image-based analysis due to their rarity and the need for simultaneous multispectral immunophenotyping. These challenges have historically required enrichment prior to imaging, even when using high speed imaging cytometry. Recent advancements in multispectral imaging flow cytometry have reduced these barriers, and in this study we show image-based measurement of NFkB activation in two innate immune cell types found in human whole blood. In the first set of experiments, we show dose and time kinetic activation of NFkB translocation specifically in monocytes by LPS and TNF-α. In the second set we show TLR-mediated activation of non-enriched circulating plasmacytoid dendritic cells, which represent less than 0.1% of periperal blood leukocytes. Our results in each of these systems uniquely demonstrate a method to perform image-base measurement of rare immune cell function directly in whole blood samples.
Size-dependant gold nanoparticles attenuation of CpG DNA-induced TLR9 signaling by modulation of lysosome (89.42)
Authors: Tsai Chiau-Yuang , Lei Huan-Yao 
Published: January 2023

Abstract
Gold nanoparticles (GNPs), also called colloidal gold, have first appeared in antiquity in China and Egypt for therapeutic purposes although its active mechanism remains poorly understood. To explore the immunological effects of GNPs in macrophage is of great interest since macrophages are essential phagocytic and antigen-presenting cells in the immune system. Toll-like receptors (TLRs) are the most important sensors for microbial infection by recognizing microbial components and nucleic acids in infected host cells. We are interested in the effect of GNPs on macrophages. We found that GNPs accumulated in lysosome after phagocytosis efficiently inhibit TNF-α and IL-6 production by CpG DNA (TLR9). TLR9-mediated pathways of NFκB, JNK, and ERK were also affected in GNPs-treated macrophages. Interestingly, impaired CpG DNA-induced TNF-α production by GNPs was size-dependant in RAW macrophages; small GNPs have high inhibitory effects. Otherwise, GNPs neither had cytotoxicity and pro-inflammetory cytokines production nor altering the uptake and intracellular transport of CpG DNA and lysosome acidification. Elevated lysosomal cathepsins expression and activities by GNPs suggests that GNPs is a cysteine protease modulator to attenuate TLR9 signaling in macrophages. We conclude that GNPs can attenuate CpG DNA-induced TLR9 signaling through modulation of lysosome and this effect is size-dependant.
Protein-DNA complex is the major malaria parasite component that activates dendritic cells (89.60)
Authors: Wu Xianzhu , Gowda Nagaraj , Kumar Sanjeev , Gowda Channe 
Published: January 2023

Abstract
Dendritic cells (DCs) are the key cells that sentinel pathogens, initiate and shape protective immunity to malaria. However, how malaria parasites trigger immune responses in DCs remains unclear. Here, we purified merozoites, food vacuoles and parasite membrane fragments released during the Plasmodium falciparum schizont burst to homogeneity and tested for their capacity to activate Flt3-ligand differentiated bone marrow DC (FL-DC). We found that merozoites were the only components that activate FL-DC by a TLR9-dependent pathway. Further characterization demonstrated that, a protein-DNA complex is the exclusive parasite component that activates FL-DCs. In addition, polylysine and chitosan, can also impart stimulatory activity to parasite DNA, indicating that complex formation involves ionic interactions. Merozoites and DNA-protein complex could also induce the production of inflammatory cytokines in human blood DCs. Hemozoin is neither a TLR9 ligand for DCs nor it functions as a carrier of DNA into cells. Further, while TLR9 is critical for DCs to help NK cells to produce IFN-γ in response to merozoites, this receptor is not required for NK cells to secret IFN-γ; cell-to-cell contact among myeloid DCs, plasmacytoid DCs and NK cells is required for IFN-γ production. Together, these results contribute substantially toward the understanding of malaria parasite recognition mechanisms, and have important implications for the development of vaccine against malaria.
A genomics approach to understand γ/δ T cell function in the gut epithelial compartment. (90.11)
Authors: Barrett Desire , Cheadle Christopher , Soloski Mark 
Published: January 2023

Abstract
The gut epithelial functions to provide a protective barrier from enteric pathogens as well as facilitate the absorption and distribution of needed nutrients. These functions are accomplished by the concerted action of a number of interacting cell types including epithelial cells, stromal elements and immune cells. We reason that cells of the immune system are an essential component for the functioning gut epithelia and are likely to play a role in the maintenance of epithelial integrity and function. We have used a genomic-based approach to understand how a novel subset of intraepithelial lymphocytes, γ/δ T cells, contributes to the functioning of the gut epithelial barrier. Using mouse strains deficient for TCR γ/δ, we examined the genes and pathways of the GI tract that are affected by the absence of the TCR γ/δ bearing subset. Our initial analysis revealed that the expression profiles of genes encoding proteins involved in maintaining epithelial integrity and tissue remodeling are regionally and selectively altered in TCR γ/δ deficient mice. In addition, we examined the affect of TCR γ/δ deficiency on the gene sets and pathways activated in the early stages of enteric infection with Salmonella enterica typhimurium. These results reveal abnormal regulation of the acute phase response implying a role for γ/δ T cells in regulating the response to injury. Collectively these studies reveal novel insights into the function of this novel immune cell subset.
Role of Muc1 in Helicobacter pylori gastric mucosal inflammation (90.15)
Authors: Guang Wei , Ding Hua , Kim K. , Blanchard Thomas , Lillehoj Erik 
Published: January 2023

Abstract
Helicobacter pylori (Hp) is a human pathogen that inhabits the stomach and duodenum. Hp causes chronic inflammation of the gastric mucosa (gastritis) that is strongly linked with the sequential progression to atrophy, metaplasia, dysplasia, and stomach cancer. However, greater than 80% of individuals infected with Hp are asymptomatic and it is unknown what factors influence the incidence and character of Hp-associated gastric disorders. Our previous studies demonstrated that the Muc1 epithelial mucin glycoprotein counter-regulates bacterial inflammation. Therefore, we investigated the role of Muc1 in controlling inflammatory responses to Hp infection. Muc1 knockout mice exhibited increased bacterial colonization of the stomach and greater inflammatory cytokine/chemokine responses compared with wild type mice following experimental Hp infection. Overexpression of Muc1 in human gastric AGS cells was correlated with decreased NF-κB activation and IL-8 production compared with cells expressing normal levels of Muc1. Conversely, knockdown of Muc1 expression in AGS cells was associated with greater activation of ERK1/2, increased phosphorylation of IκBα, augmented activation and nuclear translocation of NF-κB, and enhanced production of IL-8. Based on these results, we conclude that Muc1 plays an anti-inflammatory role in Hp gastric infection and that decreased Muc1 expression in a subset of Hp-infected individuals promotes the development of chronic gastritis and adenocarcinoma.
A small intestine trans-epithelial conduit system assists in lamina propria DC sampling (90.2)
Authors: McDole Jeremiah , Wheeler Leroy , Newberry Rodney , Miller Mark 
Published: January 2023

Abstract
The mechanisms by which lamina propria DCs sample antigens from the gut remains a crucial topic in mucosal immunology. DCs acquire antigen by several distinct processes including M cell transcytosis, specialized transport involving the neonatal Fc receptor, paracellular leak and by DC trans-epithelial dendrite extension. The continuous sampling of luminal contents by gut resident DCs could both contribute to rapid pathogen recognition and provide normal flora and food antigens for tolerance induction. We used two-photon microscopy, to examine DC sampling behavior in vivo and discovered a previously unreported small-intestine-trans-epithelial-conduit (SiTEC) system. We found that SiTECs could carry macromolecules across the epithelium to the lamina propria where they were taken up by resident DCs. SiTECs have a functional molecular weight cut-off of approximately 70kD based on dextran permeability and can pass small proteins as well. The SiTEC system presents a simple mechanism to deliver luminal antigens to lamina propria DCs for the maintenance of tolerance in the steady-state.
Education of intestinal DCs by lamina propria cells (90.6)
Authors: Vicente-Suarez Ildefonso , Park Yunji , Mucida Daniel , Bekiaris Vasileios , Koltsova Ekaterina , Ley Klaus , Ware Carl , Cheroutre Hilde 
Published: January 2023

Abstract
The intestinal mucosa is constantly exposed to a vast load of antigens derived from nutrients and commensal bacteria but also from potential pathogens. In this situation intestinal dendritic cells (DCs) play a central role in the decision between suppressing inflammation or promoting host defense. Intestinal DCs display specific features that include the ability to promote gut homing of lymphocytes, the preferential induction of Foxp3+T cells and the inhibition of Th1 and Th17 differentiation. Interestingly the majority of these functions depend on the DCs ability to produce a vitamin A metabolite known as retinoic acid (RA). How intestinal DCs acquire this ability is largely unknown but it has been suggested that tissue specific factors produced by the intestinal epithelia might be required, among them RA itself. Here, we report that the interaction with stromal cells from the lamina propia imprints splenic DCs with a mucosal phenotype. The stromal cells in this study show characteristics that identify them as stromal organizing cells named after their ability to organize the development of secondary lymphoid organs. Our data implies that intestinal DCs might develop their specific characteristics in gut associated lymphoid tissues (GALT)
Intestinal microbiota and innate signaling via MyD88 promote the intestinal Th2 response to Trichinella spiralis (90.9)
Authors: Blum Lisa , Nel Hendrik , Fallon Padraic , Gagliardo Lucille , Cameron Jody , Leifer Cynthia , Appleton Judith 
Published: January 2023

Abstract
The role of commensal intestinal microbiota in colitis, type 1 diabetes, and other immune-mediated diseases has been established recently, but an influence on Th2 immunity in parasitic disease to has not yet been reported. Larvae of the parasitic nematode Trichinella spiralis move rapidly through epithelial cells in the intestine, where they induce a potent Th2 immune response. Here we report that mice deficient in the signaling adaptor MyD88 and mice treated with antibiotics to diminish the intestinal flora demonstrate reduced intestinal Th2 cytokine responses to T. spiralis. Furthermore, infection caused an overgrowth of intestinal bacteria. Parasite extracts and purified glycoproteins did not cause direct TLR activation in vitro. IL-33 (ST2L), which signals through MyD88 and is expressed by intestinal epithelial cells, also promoted the Th2 response to T. spiralis. These results reveal a previously undescribed interplay between an intestinal nematode, the mucosal immune system, and the commensal microflora.
The role of IL-6 in T-bet (-/-) mice in an allergic asthma model (91.10)
Authors: Fassbender Sonja , Übel Caroline , Böhm Livia , Lehr Hans-Anton , Finotto Susetta 
Published: January 2023

Abstract
IL-6 is a pleiotropic cytokine which induces Th2 type cells. IL-6 binds to IL-6R alpha chain and then induces gp130 dimerization resulting in the intracellular activation of Janus kinase and signal transducers and activators of transcription (STAT) pathways. We previously demonstrated that patients affected by allergic asthma have an increased level of soluble IL-6R which correlates with Th2 CD4+ T-cells in their airways. In a murine model of this disease, we also demonstrated that IL-6 inhibits the development of T-regulatory cells (Tregs) and local blockade of IL-6R resulted in the expansion of Tregs as well as Th1 cells in the lung. T-bet is a Th1-specific transcriptional factor. Mice lacking T-bet show increased asthmatic symptoms. We thus want to study the influence of T-bet on IL-6 mediated inhibition of Tregs. To this aim an antibody against IL-6R was applied to T-bet deficient mice (T-bet (-/-)) during allergen challenge. In preliminary studies we found that local blockade of IL-6R in T-bet (-/-) mice resulted in a reduced AHR and decreased lung eosinophilia. Furthermore we observed selective expansion of the CD4+ CD25+ Foxp3+ Tregs in the draining lymph-nodes taken from anti IL-6R-antibody treated T-bet (-/-) mice, compared to T-bet (-/-) untreated mice. These results suggest that local blockade of IL-6R in the absence of T-bet in allergic asthma could result in amelioration of the disease hallmarks because of inducing Tregs in the local draining lymph nodes.