bluuebunny/crossref_metadata_2025_split huggingface dataset:
The actin capping protein alpha-adducin is required for CD28 costimulation (IRM12P.658)
Authors: Butte Manish , Thauland Tim 
Published: January 2023

Abstract
Alpha-adducin (Add1) is a critical component of the actin-spectrin network, acting to cap the barbed ends of actin filaments, and recruiting spectrin to these junctions. Add1 is expressed at high levels in naïve T cells and is down-modulated upon TCR stimulation, but the role that Add1 plays in the cytoskeletal rearrangements that occur in motile T cells and during immunological synapse formation have not been investigated. Using CD4 T cells from knockout mice, we show that Add1 is necessary for complete activation of T cells in response to low levels of antigen, as measured by proliferation and cytokine production. Interestingly, the defective proliferation we observed in Add1-/- T cells was due to an inability to respond to respond to CD28 costimulatory signals. Additionally, we demonstrate that naïve and recently activated T cells lacking Add1 have a defect in motility. Using CD4 T cells transduced with GFP-tagged Add1, we found that Add1 is located cortically in non-motile cells, but rapidly moves to the nascent uropod in T cells initiating a crawling phenotype. While the bulk of GFP-Add1 is located in the uropod of crawling cells, brief accumulations are seen at the leading edge. Real-time imaging of interactions between transduced T cells and peptide-loaded antigen presenting cells revealed that Add1 becomes concentrated at the distal pole complex. Together, these results demonstrate that Add1 plays an unexpected and central role in T cell activation and migration.
LPS up-regulates FasL expression in Breg population in mice (IRM12P.643)
Authors: Li Xiaojuan , Wang Keng , Zeng Xiangzhou , Tao Lei , Zhang Yueyang 
Published: January 2023

Abstract
Regulatory B cell plays important role in negative immune regulation, it can exert the inhibitory functions partly by the secretion of IL-10. FasL is also considered to be associated with the immune regulatory function of B cells. Here, we first observed the expression of FasL in CD5+CD1dhi Breg population as well as other B cell subsets after LPS stimulation.In this study, splenocytes were isolated from C57/BL6 wild-type mice and cultured with LPS for 24-48 hours to activate Breg. Results showed that the expression of FasL in CD5+CD1dhi B cell subset is much higher than CD19+CD5+CD1dlow and CD19+CD5neg B cell subset. The lowest FasL expression was seen in CD19+CD5neg B cell subset. This is consistent with the expression of IL-10 in corresponding B cell subsets. In addition, studies showed that the expression of CD25 molecules in CD19+CD5+CD1dhi Breg was significantly higher than other two B cell subsets after stimulating by LPS for 24 hours. CD86 molecule was highly expressed in all these three B cell subsets, and it is higher in CD19+CD5+CD1dhi Breg compared with other B subsets. In contact hypersensitivity model, the expression of FasL in CD19+CD5+CD1dhi Breg after LPS activation showed significant difference in comparison with control group.These results suggested that FasL might also contribute to the inhibitory function of CD5+CD1dhi Breg population after LPS stimulation and thus participate in the regulation of some inflammatory immune diseases.
Nuclear export of NF-κB inhibitor, IκBα, is crucial for T cell function (IRM12P.644)
Authors: Lisiero Dominique , Tejera Melba Marie , Davis Shelly , Neldner Brandon , Suresh Marulasiddappa , Miyamoto Shigeki 
Published: January 2023

Abstract
Numerous cell types, including T cells, respond to inflammatory stimuli by engaging the NF-κB signaling pathway. Classical studies with knockout mouse models demonstrated that T cell receptor (TCR) triggering of NF-κB is crucial for T cell function and proper response to pathogens. While the ability of IκBα, a main inhibitor of NF-κB, to dynamically localize between the nucleus and cytoplasm is a key regulatory mechanism in NF-κB signaling, the physiological significance of this nuclear shuttling in T cell physiology remains undefined. Our group has previously generated a knock-in mouse model, NfkbiaNES/NES, with a germline mutation in the nuclear export sequence (NES) of IκBα. T cell development in NfkbiaNES/NES mice is relatively unaffected as evidenced by normal thymus architecture and thymocyte development. However, mutant CD8+ and CD4+ T cells have severe defects in activation, function, and clonal expansion following infection by LCMV Armstrong. In particular, NfkbiaNES/NES CD8+ T cells failed to produce memory precursor effector cells. Even under competitive conditions in bone marrow chimeric mice, defective T cell expansion and memory formation were observed with NfkbiaNES/NES cells in response to LCMV infection. These findings reveal surprisingly widespread roles of nuclear export of IκBα in the regulation of activation induced NF-κB function in mature T cells in an infectious setting.
Macrophage tolerance to MyD88-dependent TLR agonists is mediated by LPS-/R848-induced miR-146a (IRM12P.649)
Authors: Nahid M. , Benso Lia , Shin John , Mehmet Huseyin , Hicks Alexandra , Ramadas Ravisankar 
Published: January 2023

Abstract
Toll like receptors (TLRs) TLRs facilitate the recognition of pathogens by immune cells and the initiation of the immune response, leading to the production of proinflammatory mediators. Production of proinflammatory mediators by innate immune cells such as macrophages is tightly regulated to facilitate pathogen clearance while limiting adverse impact on host tissue. Exposure to TLR ligands induces a state of temporary refractoriness to a subsequent exposure of a TLR ligand, a phenomenon referred to as ‘tolerance’. This study sought to evaluate the mechanistic regulation of TLR4 and TLR7/8 ligand induced tolerance to other TLRs by miR-146a. Using THP-1 macrophages as well as human M1 and M2 macrophages, we demonstrate that priming with a TLR4 agonist (LPS) or a TLR7/8 agonist (R848) induce tolerance to a panel of TLR ligands in macrophages, leading to the impaired production of a variety of cytokines and chemokines. We also demonstrate that overexpression of miR-146a is sufficient to mimic LPS- or R848-induced hyporesponsiveness. Conversely, the knockdown of miR-146a leads to LPS- or R848-induced TLR hyperresponsiveness. Furthermore, we demonstrate that while miR-146a dampens cytokine production following a primary stimulus with MyD88-dependent, but not MyD88- independent TLR pathways. Collectively, these data provide comprehensive evidence of the central role of miR-146a in TLR signaling tolerance to plasma membrane as well as endosomal TLR ligands in human macrophages.
Modification of self-reactivity on naïve T cell provides long lasting immune surveillance. (LYM6P.721)
Authors: Lee JunYoung , Kim Juhee , Surh Charles 
Published: January 2023

Abstract
It is reported that Ly6c+ CD4 T cell including Tregs and non Tregs exhibits relatively weaker self-reactivity to compare Ly6c- counterpart. Because mature T cells found in the thymus do not express Ly6c, it is possible that the weaker self-reactivity of Ly6c expressing CD4 T cells is obtained features in periphery rather than reflecting their natural bone TCR sensitivity. Furthermore, there are controversial reports for Ly6c inducing factor such as type 1 IFNs, developmental programming on T cell in thymus, and the influence of self-TCR signaling. Therefore, evaluating the true factors inducing Ly6c expression and meaning of Ly6c expression on T cell is required. By transferring Ly6c expressing Tregs into lymphopenic host, we found that self-reactivity of Ly6c+ Treg is almost absence rather than weaker to compare Ly6c- Treg. Ly6c+ Treg proportion in total Foxp3+ is lowest in neonatal period and highest in young adult mice but the ratio is declining with aging and the ratio is inversely correlates with effector Treg ratio. Since activation of Ly6c+ Treg cell readily down-regulate the expression of Ly6c, the decreased ratio of Ly6c+ Tregs may indicate activation of Ly6c+ Treg. Indeed, Ly6c+ Tregs can undergo self-ag induced proliferation in various conditions where there is accumulation of effector non Treg CD4 T cells. Our data suggest that the weaker self-reactivity of Ly6c+ CD4 T cell is not inherited from thymus but acquired phenotype.
Fungal recognition by Dectin-1 on dendritic cells induces IL-10 producing CD4+ T cells by GATA3 / C/EBP-β pathway (MPF4P.733)
Authors: Tajima Masaki , Fuss Ivan , Kitani Atsushi , Strober Warren 
Published: January 2023

Abstract
C. Albicans is known to dramatically transit its morphology between the yeast and hyphal form, depending on its environment. In order to show how these two types of C. Albicans may induce T cell responses, naïve T cells were stimulated with bone marrow-derived dendritic cells in the presence of either form of this organism. The cells stimulated with the hyphal form produced high amount of immunosuppressive IL-10, but not when stimulated with the yeast form. As C. Albicans expresses various innate receptor ligands, T cells were stimulated in presence of both Dectin-1- and/or TLR2-specific ligands. The T cells produced IL-10 when stimulated with Dectin-1 ligand alone, but not when stimulated with both Dectin-1 and TLR2 ligands. This suggests that the hyphal form predominantly express Dectin-1 ligands whereas the yeast form express both Dectin-1 and TLR2 ligands. In accompanying molecular studies, we found that Dectin-1 stimulation (but not Dectin-1 plus TLR2 stimulation) leads to IL-4 production and that Dectin-1-stimulated IL-4-, STAT6-, and GATA3-deficient CD4+ T cells produce greatly reduced amounts of IL-10. Furthermore, CCAAT/enhancer-binding protein beta (C/EBP-β) KO CD4+ T cells were also deficient in IL-10 production. Finally, we found that C/EBP-β interacts with GATA3 and influences its function. Thus, Dectin-1-induced IL-10 production stimulated by certain fungal forms is set in motion by a GATA3 / C/EBP-β mediated effect on IL-10 transcription.
Co-inhibitory and co-stimulatory crosstalk regulates helper T cell differentiation and humoral immunity during Plasmodium infection (MPF5P.742)
Authors: Zander Ryan , Obeng-Adjei Nyamekye , Guthmiller Jenna , Kulu Divine , Li Jun , Ongoiba Aissata , Traore Boubacar , Crompton Peter , Butler Noah 
Published: January 2023

Abstract
Pathogen-specific T cells are subject to co-stimulatory and co-inhibitory signals, the balance of which promotes pathogen control while limiting immunopathology. During blood-stage Plasmodium infection, parasite-specific CD4 T cells express PD-1 and LAG-3 co-inhibitory receptors that coordinately limit CD4 T cell function. Blockade of PD-1/LAG-3 co-inhibitory signaling during chronic Plasmodium infection enhances CD4 T cell function and parasite control. In contrast to co-inhibitory receptors, the role of T cell co-stimulatory receptors during established Plasmodium infection has not been investigated. Here we show that CD4 T cells exhibit sustained expression of the co-stimulatory receptor OX40 during both human and experimental malaria. We hypothesized that co-stimulatory signaling can functionally counteract co-inhibitory circuits to maintain protective Plasmodium-specific CD4 T responses. In support of this, therapeutically activating OX40 during established experimental malaria enhances CD4 T cell activity, humoral immunity and parasite clearance. Our data also show that the effects of OX40 signaling are modified following simultaneous PD-1 blockade, which markedly impairs parasite-specific T follicular helper cell responses in an IFN-g-dependent manner. Collectively, our results identify that OX40 can be targeted to limit malaria parasite replication and reveal a previously unrecognized role of IFN-g as a negative regulator of Plasmodium-specific humoral immunity.
A pivotal interplay between TNF alpha and the IL-23-axis cytokines in regulating primary human intestinal epithelial cell apoptosis (MUC5P.753)
Authors: Juncadella Ignacio , Wang Chao-ting , Caviness Gary , Nabozny Gerald 
Published: January 2023

Abstract
TNFα induces intestinal epithelial cell (IEC) cell death, likely responsible for barrier dysfunction and mucosal damage. However, studies addressing the role of TNFα on epithelial damage rely on Caco2 or HT29 cell lines and rarely primary IECs. Interleukin-23 (IL-23) pathway is genetically associated to IBD pathogenesis. IL-23-responsive cells produce the signature cytokines, interleukin-17 (IL-17) and interleukin-22 (IL-22). These cytokines are elevated in IBD patients, and may contribute to disease pathology. Here, we describe the synergistic interplay between TNFα and the IL-23 axis on IEC apoptosis. Using human IECs and organotypic cultures, we demonstrate that; TNFα treatment induces moderate to low proinflammatory gene expression compared to IL-17 and IL-22, TNFα and IL22 stimulation leads to upregulation of proinflammatory and proapoptotic genes and, IL22 but not IL17 enhances TNFα-induced cell death. Interestingly, the effect of IL22 was independent of IFNγ, contrary to previous findings. IL-22 stimulation resulted in TNFRI and TNFRII expression, likely making the epithelium more responsive to TNFα-induced cell death. In conclusion, this is the first demonstration between TNFa and the IL23-axis in driving IEC apoptosis and cell death. Also, while TNFα and the IL-23 axis contribute to IBD pathogenesis via different approaches; the interplay of these pathways may be linked to promote epithelial cell damage and barrier dysfunction resulting in disease progression.
CD4+ T cell-derived Interleukin-21 is required for the efficient clearance of Citrobacter rodentium (MUC5P.744)
Authors: Silberger Daniel , Zindl Carlene , Moseley Carson , Maynard Craig , Vallance Bruce , Zajac Allan , Weaver Casey 
Published: January 2023

Abstract
Interleukin-21 (IL-21) is critical for host defense against infections with intracellular and extracellular pathogens. Although most infections occur following an initial colonization at mucosal surfaces, no studies have addressed the role of IL-21 in controlling bacterial colonization and dissemination from the colon. Using a novel Il21fl/fl reporter and CD4-Cre conditional knockout mouse, we show that IL-21+CD4+ T cells are the dominant source of IL-21 required for the efficient clearance of the enteric bacterial pathogen Citrobacter rodentium. Consistent with the complete Il21-/- mice, we found that mice with a conditional deletion of Il21 from CD4+ T cells had a greater incidence and severity of colitis, increased bacterial dissemination to the spleen and liver, reductions in IFN-γ+ IL-17A- CD4+ T cells, and a decreased ratio of CXCR5+PD-1+ T follicular helper (Tfh) to FoxP3+ T follicular regulatory cells (Tfr) following infection. In association with impaired T cell differentiation, we found that conditional deletion of Il21 from CD4+ T cells lead to a reduction in the number of plasma cells and a reduction in C. rodentium-specific IgG. Finally, using bone marrow chimeric mice, we found that B cells and T cells require IL-21R expression to mediate the clearance of C. rodentium. These findings establish that IL-21-producing CD4+ T cells can inhibit the dissemination of enteric bacterial pathogens and enhance their clearance from the site of infection via humoral immunity.
CD47 deficiency ameliorates autoimmune nephritis in Faslpr mice via suppressing IgG autoantibody production (THER5P.912)
Authors: Shi Lei , Bian Zhen , Lv Zhiyuan , Liu Yuan 
Published: January 2023

Abstract
CD47, a self-recognition marker, significantly regulates both innate and adaptive immune response. To explore the potential role of CD47 in activation of autoreactive T and B cells and the production of autoantibodies in diseases such as systemic lupus erythematosus, we generated CD47-knockout in spontaneous lupus mice (Faslpr). In comparison with Faslpr mice, CD47-/--Faslpr mice exhibited a prolonged lifespan, with no apparent signs of autoimmune nephritis including glomerular cell proliferation, acute tubular atrophy and vacuolization. CD47-/--Faslpr mice had lower level of proteinuria, lower deposition of C3 and C1q in the glomeruli and lesser pronounced splenomegaly compared to the age-matched Faslpr mice. Serum levels of antinuclear antibodies and anti-double-stranded DNA antibodies in CD47-/--Faslpr mice were also significantly reduced. The mechanistic studies further suggested that CD47 deficiency might impair the antigenic challenge-induced production of mouse high affinity IgG but not IgM through reducing T follicular cell production, which results in an impaired formation of germinal centers in lymph tissue. In conclusion, our results demonstrate for the first time that CD47 deficiency ameliorates lupus nephritis in Faslpr mice via suppressing IgG autoantibody production.
Inhibition of branched chain amino acid aminotransferase 1 suppresses the severity of collagen-induced arthritis in mice (THER5P.905)
Authors: Papathanassiu Adonia 
Published: January 2023

Abstract
BCAT is the enzyme responsible for the reverse transamination of branched chain amino acids to corresponding α-keto acids. It exists as two distinct isozymes with mutually exclusive tissue distribution: a mitochondrial one (BCAT2) and a cytosolic one (BCAT1). The present study reports on the effect of BCAT1 inhibition on CIA, a murine model of rheumatoid arthritis (RA). Oral administration of ERG240, a small molecular weight BCAT1 inhibitor, alleviated the severity of the clinical development of CIA and exerted a strong protective effect on the integrity of the joints of affected animals. When the drug was given at 1000 mg/kg 5x per week for 4 weeks the clinical score and paw thickness was reduced by 40%. Immunohistochemical (IHC) analysis of preserved tissues revealed that ERG240 treatment reduced inflammation by ~50%, pannus formation by ~90%, cartilage damage by ~75%, and bone erosion by ~90%. Further IHC analysis indicated that the mechanism of action of ERG240 involved a reduction in the number of macrophages and osteoclasts present in the joints and CD45R+ cells in the bone marrow of the animals. Analysis of terminal sera, collected from treated and control animals, suggested that ERG240 administration also suppresses the levels of secreted cytokines such as TNF-α and RANKL. In vitro, ERG240 inhibited serum-driven migration of bone marrow derived macrophages. Collectively, the data indicate that BCAT1 constitutes a new druggable target for the treatment of RA.
A new bioinformatics analysis can reveal intestinal infection as a cause of graft rejection in islet xenotransplantation in non-human primate. (TRAN1P.940)
Authors: Kim Hyun-Je , Moon Ji-Hwan , Shin Jun-Seop , Kim Bongi , Kim Jung-Sik , Min Byong-hoon , Cho Kyo-ri , Kang Sung-Jun , Byun Nari , Phuong Thuy , Kim Jong-Min , Kim Sun , Park Chung-Gyu 
Published: January 2023

Abstract
Pancreatic islet transplantation is one of the most attractive treatment modality for select type 1 diabetes patients suffering from frequent hypoglycemia unawareness. However, because of the shortage of human donor organs, xenotransplantation is becoming more highlighted. Under this circumstance, we have recently achieved reproducible and consistent survivals of adult porcine islet for more than 180 days in the liver of five diabetic monkeys under immunosuppression regimen base on anti-CD154. Interestingly, among five monkeys, one has exhibited graft failure after having experienced severe intestinal infections. Because the porcine islets were exposed to direct blood flow from the intestine, intestinal infection would exert detrimental effect on porcine islets. To test this hypothesis, we performed RNA-seq with peripheral blood from graft maintaining monkey or rejecting monkey after intestinal infections. By using novel bioinformatics tool called Time-series RNA-seq analysis package, we demonstrated highly relevant activated immunologic pathway in graft rejecting monkey, but not in well maintaining monkey. Consistent with this notion, we further confirmed that porcine islets were indeed rejected by CD8+ T cells by immunohistochemistry. Taken together, we for the first time showed that a new bioinformatics analysis using peripheral blood RNA-seq data can pinpoint intestinal infection as a cause of graft rejection in intraportal islet xenotransplantation.
Endogenous graft-specific Tregs expand and differentiate into effector Tregs during the induction of tolerance to allografts (TRAN1P.949)
Authors: Young James , Chen Jianjun , Miller Michelle , Yin Dengping , Vu Vinh , Moon James , Alegre Maria-Luisa , Chong Anita 
Published: January 2023

Abstract
Peripheral transplantation tolerance is donor-specific and requires the presence of Tregs. We hypothesized that allospecific Tregs are critical for the donor specificity of tolerance. To date, studies of Foxp3+ regulatory T cells (Tregs) in transplantation tolerance have examined endogenous Tregs without defining their antigen specificity, or used seeded populations of TCR-transgenic T cells that only allow the study of induced Tregs. To study endogenous alloreactive Tregs in tolerance, we used a novel transgenic donor mouse that expresses the model antigen 2W and 2W:I-Ab tetramers to track 2W-specific (2W+) Tregs and Tconv cells. We used hearts from F1 (BALB/cxC57Bl/6.Act-2W) mice and C57Bl/6 recipients. Tolerance was induced with anti-CD154 (D0,7&14) + donor splenocytes (D0) or with CTLA-4Ig (D0&2). In both models, 2W+ Tconv increased 3-fold whereas the 2W+ Tregs increased 9-fold over naïve mice. 2W+ Tregs differentiated from a naïve, CD44loCD62Lhi to an effector CD44hiCD62Llo phenotype but 2W- Tregs largely did not. Without treatment, 2W+ Tconv cells increased 17-fold at D30 post-transplant whereas the 2W+ Tregs increased 6-fold. These observations unexpectedly show that graft-specific Tregs expand in tolerance and rejection, and that Tconv cells are uniquely constrained during tolerance induction. The ability to track the fate of endogenous donor-reactive Tregs is a powerful approach to gain insight into their fate in tolerance induction and maintenance.
Transient receptor potential melastatin 2 regulates autophagosome-lysosome fusion in macrophages and protect endoxemia (TUM6P.972)
Authors: zhang kai , Zhang ZhanQin 
Published: January 2023

Abstract
Background: Disruption of autophagy in macrophages can lead to inflammation and exacerbation of sepsis. Transient Receptor Potential Melastatin 2 (TRPM2), a nonselective Ca2+-permeable channel, is important for immune function of macrophage. However, whether TRPM2 participates in macrophage autophagy during endoxemia remains unknown. Methods: Endotoxemia was induced via intraperitoneal injection of lipopolysaccharide (LPS) in wild-type and TRPM2-deficiency mice. The mortality was evaluated. The protein levels of Rab7A and LAMP1 were assayed both in peritoneal macrophages from the LPS-challenged mice and LPS-stimulated bone marrow-derived macrophages (BMDMs). mRFP-GFP-Lc3 distribution in BMDMs were also analyzed by confocal microscopy. Results: TRPM2-/- mice challenged with LPS had increased mortality. In peritoneal macrophages from the LPS-challenged TRPM2-deficiency mice and LPS-stimulated TRPM2-deficiency BMDM, the expressions levels of RAB7A and LAMP1 were significantly decreased. Compared with that in wild-type macrophages, most puncta of mRFP-GFP-Lc3 in transfected TRPM2-deficiency cells were yellow (autophagosome) after LPS stimulation. Conclusions: TRPM2 may regulate the fusion of autophagosomes and lysosomes in macrophages after LPS stimulation, which may play important roles during endoxemia.