bluuebunny/crossref_metadata_2025_split huggingface dataset:
Divergent expression patterns of IL-4 and IL-13 define unique functions in type 2 immunity (56.22)
Authors: Reinhardt Richard , Liang Hong-Erh , Sullivan Brandon , Locksley Richard 
Published: January 2023

Abstract
Interleukin-4 (IL-4) and interleukin-13 (IL-13) are closely related cytokines critical to host responses against parasitic helminthes. We use reporter mice genetically engineered to mark cells producing IL-4 and IL-13 in vivo, allowing the temporal and spatial assessment of cytokine production at the single-cell level. In the lymph node, IL-4 is confined to T follicular helper (Tfh) cells. Unexpectedly, Tfh cells do not make IL-13. In contrast, tissue Th2 cells produce both cytokines. Divergent IL-4 and IL-13 production also occurs in innate immune cells. Basophils produce IL-4, while innate helper type-2 (Ih2) cells make only IL-13. Cytokine production by Th2 and Ih2 cells is intimately associated with high GATA-3 expression. Conversely, Tfh cells and basophils regulate IL-4 independently of GATA-3. Partitioning of the localization and cellular expression patterns of IL-4 and IL-13 helps explain the unique roles of these cytokines in anti-helminth and allergic immunity.
A positive feedback mechanism in the regulation of mammalian chitinase responses (56.29)
Authors: Vega Karina , Diaz-Arevalo Diana , Bagramyan Karine , Hong Teresa , Kalkum Markus 
Published: January 2023

Abstract
Immunosuppressed patients are highly susceptible to invasive fungal infections (IFI) such as invasive pulmonary aspergillosis, which is predominantly caused by the fungus Aspergillus fumigatus. An important component of the fungal cell wall is chitin, a polymer of N-acetyl-D-glucosamine (GlcNAc). Chitin is not produced by humans, however, the chitin degrading enzymes (chitinases) chitotriosidase (Chit-1) and acidic mammalian chitinase (AMCase) are. Chitinase is predominantly produced by activated macrophages, and may possibly aid in the defense against chitin-containing pathogens. We show that serum and bronchoalveolar lavage (BAL) chitinase levels are increased in patients with IFI, and in mice after pulmonary exposure to A. fumigatus conidia. Several different stimuli, including stimulation with chitin can lead to chitinase responses. In vitro stimulation of U937 human monocytes and RAW mouse macrophages with either chitin-particles (7-12 µm) or GlcNAc increased secreted and intracellular chitinase activity, the accumulation of intracellular Chit-1, and significantly increased the mRNA levels of Chit-1 and AMCase. Accordingly, we hypothesize that Chit-1 expression is regulated through a positive feedback mechanism involving the degradation of chitin to GlcNAc by host chitinases and GlcNAc recognition that in turn upregulates chitinase expression. This potential feedback mechanism of chitinase regulation may have utility in the diagnosis of IFIs.
IL-21 contributes to the control of infection and to the severity of gastritis during Helicobacter infection (56.3)
Authors: Algood Holly , Chaturvedi Rupesh , Wilson Keith , Washington M. 
Published: January 2023

Abstract
The immune response to Helicobacter pylori involves a mixed T helper-1, T helper-2, and T helper-17 response. It has been suggested that T helper cells contribute to the gastric inflammatory response during infection, and that Th1 and Th17 subsets may be required for control of H. pylori colonization in the stomach. The relative contributions of these subsets to gastritis and control of infection are still under investigation. Expression of IL-21, which may be produced by a number of T cell subsets, has been reported to increase during H. pylori infection. IL-21 plays a role in both B cell stimulation and T cell differentiation. To investigate the role of IL-21 in H. pylori, we infected IL-21 deficient mice and wild-type littermates with H. pylori strain SS1. At 3 months post-infection, we assessed colonization, gastric inflammation, cellular infiltrate in the stomach, and cytokine profiles in the gastric tissue. Specifically, H. pylori-infected IL-21-/- mice have higher levels of H. pylori in their stomachs (4.5±0.4x107 CFU v. 4.3±2.3x106 CFU, **p=0.004), significantly less gastritis (gastritis scores 3.8±0.2 v. 1.2±0.3, ***p=0.0002), and reduced expression IL-17 and IFNγ (*p&lt;0.05) compared to H. pylori-infected wild-type mice. Our results indicate that IL-21 contributes to the control of infection and severity of gastritis, suggesting IL-21 is required for activation of the immune response and induction of gastritis in response to H. pylori.
Differential kinetics of cell surface marker modulation with T cell activating reagents (57.14)
Authors: Tran Kimvan , Clor Julie , Tyagarajan Kamala 
Published: January 2023

Abstract
Simultaneous assessment of cell surface phenotypic markers, activation markers such as CD69 and apoptosis related markers such as CD95/FAS can provide deeper understanding of mechanism and impacts of in vitro mitogenic stimulation on immune cell populations.. Kinetic and dose response studies of PBMC’s with different stimulants was performed and followed with novel simplified assays that could assess levels of CD69 and CD95 on T and B cells followed by plate-basedmicrocapillary flow cytometry. Information on the CD4, CD8, CD3,CD19, CD45 expression levels was also obtained. Our results demonstrate that while CD4 expression on CD4 T cells was rapidly downregulated with phorbol myristate acetate or combinations with ionomycin, but was not impacted by PHA treatment. Tracking of CD95 expression levels demonstrate the elevation of CD95 on T and B cells with PHA treatment with no significant loss in CD4 expression levels. Correlation of T celll activation markers and apoptotic markers and expression levels of phenotypic markers would facilitate further elucidation of the mechanism of T cell activation.
Amelioration of β-glycerophosphate-induced vascular calcification by the IL-10 family of cytokines (57.25)
Authors: Kang Haeng-A , Lee Ki-Mo , Kang Hyung-Sik 
Published: January 2023

Abstract
Vascular calcification is a hallmark of cardiovascular diseases. The IL-10 family of cytokines has been known to suppress the tumor progression in a variety of human cancers, but its role has not yet been investigated in vascular calcification. To determine whether the IL-10 family of cytokines can inhibit vascular calcification, the effect of the IL-10 family of cytokines on vascular calcification was examined in β-glycerophosphate (β-GP)-induced vascular smooth muscle cells (VSMCs) calcification model. Calcium deposition was declined in the IL-10 family of cytokines-treated calcified VSMCs. The expression of Runx2 and alkaline phosphatase was also suppressed by the IL-10 family of cytokines in the calcified VSMCs. The IL-10 family of cytokines inhibited β-GP-induced activation of the Wnt/β-catenin signaling pathway in VSMCs. These results suggested that the IL-10 family of cytokines ameliorated vascular calcification by suppressing the expression of Runx2 and alkaline phosphatase through the blockade of the Wnt/β-catenin signaling pathway. These findings collectively suggest that the IL-10 family of cytokines plays a critical role in the regulation of vascular calcification, and it may be a potential target for the therapy against cardiovascular diseases.
The ubiquitin E3 ligase Cul4B regulates TTP protein turnover and TNFα mRNA stability independent of p38 (57.6)
Authors: Brooks Seth , Pfeiffer Jason 
Published: January 2023

Abstract
TNFα is a central mediator of inflammation and is critical for host response to infection and injury. TNFα biosynthesis is controlled by transcriptional and post-transcriptional mechanisms allowing for rapid, transient production. Tristetraprolin (TTP) is an AU-Rich Element binding protein that regulates the stability of TNFα mRNA. Previous work has demonstrated that TTP function is regulated by activation of both the p38 and ERK kinase pathways and that TTP protein is rapidly degraded by a proteasomal mechanism. Using a novel screen for TTP interacting proteins, we identified Cullin 4B (CUL4B), a scaffolding component of the CRL family of ubiquitin E3 ligases. shRNA knockdown of Cul4B causes a significant reduction in TNFα protein and mRNA in resting and LPS stimulated (100 ng/ml 90 min) mouse macrophage RAW264.7 cells. Cul4B knockdown also reduces TTP protein levels. Moreover, the TNFα half life was reduced from t1/2=68.7 min to t1/2=38.9 min. TNF-3’UTR luciferase assays utilizing wild-type and mutant TTP, which cannot be phosphorylated by p38, indicate that Cul4B operates independent of p38 activity. Based on the data to date, we conclude that Cul4B acts to inhibit TTP protein turnover and in turn limit TTP mediated decay of the TNFα mRNA. Thus, the loss of Cul4B enhanced both TTP protein and TNFα mRNA turnover. Further studies are ongoing to establish the mechanism through which Cul4B operates.
Inhibition through PD-1 is crucial for protection against M. tuberculosis infection (58.1)
Authors: Lazar-Molnar Eszter , Chen Bing , Jacobs William , Nathenson Stanley 
Published: January 2023

Abstract
With over one-third of the world's population currently infected with M. tuberculosis, there is an increasing need to develop novel vaccines and immunotherapies. Better understanding of the early immune responses in the lung is crucial for this purpose. We have shown that Programmed Death-1 (PD-1), a co-inhibitory receptor that is known to negatively regulate adaptive immune responses, is crucial for the development of a protective host response against M. tuberculosis. PD-1 deficient mice are extremely sensitive to tuberculosis, show uncontrolled bacterial proliferation in the lung and develop severe necrotic pneumonia, with dramatically reduced survival. Cytokine responses in the lungs of PD-1-/- and wild-type mice were profoundly different, indicating a significantly altered inflammatory response in the absence of PD-1. PD-1 blockade in wild-type mice after M. tuberculosis infection resulted in decreased survival, suggesting that immunotherapeutic approaches targeting PD-1 blockade should be considered cautiously. By studying genetically modified mouse models that have altered PD-1 or PD-L expression, our data show differential contributions of PD-L1 and PD-L2 to the immune regulatory role of PD-1 observed in tuberculosis. By providing the mechanism on the immune regulatory role of PD-1 in tuberculosis, our data will allow for the identification of novel therapeutic targets, which can be of great value for future immunotherapy.
Chemoattractant regulation of Toxoplasma gondii-induced encephalitis (58.4)
Authors: Marino Ana Paula , Murphy Philip 
Published: January 2023

Abstract
Some leukocyte chemoattractants and their receptors have been reported to regulate outcome in T. gondii infection of mice, however, most have not yet been evaluated. We have begun to systematically and comprehensively survey chemoattractant receptors in T. gondii infection, using the natural peroral route of administration of the organism. Chemoattractant receptor mRNA was quantified from brain extracts from C57BL/6 mice infected with 10 cysts of the ME49 strain. Parasitism peaked in the brain on the 25th day post infection, and infection was uniformly fatal by day 100. The organism induced expression of the pro-inflammatory chemoattractant receptors C5L2, Ccr1 and Ccr5; the decoy receptors, Ccrl2 and CMKLR1; and the constitutively expressed receptor ligand Cx3cl1. Mice lacking the Cx3cl1 receptor Cx3cr1 had accelerated mortality, whereas mortality was delayed in mice lacking Fpr1, a classical chemoattractant receptor. Unexpectedly, animals infected with T. gondii also had a substantial increase of Ccr7 mRNA during the entire chronic phase, and Ccr7-/- mice exhibited dramatically increased mortality, in comparison with WT mice. The poster will focus on Ccr7, delineating the microbiologic and immunologic correlates of skewed mortality in infected Ccr7-deficient mice.
Dichotomous consequences of IL-23 signaling in chemically induced colitis in mice (59.2)
Authors: Cox Jennifer , Ghilardi Nico 
Published: January 2023

Abstract
The interleukin-23 (IL-23) pathway has emerged as a promising therapeutic target for inflammatory bowel disease and blockade of IL-23 signaling is beneficial in mouse models of intestinal inflammation. Although the pathogenic role of IL-23R on T lymphocytes is well established, the function of IL-23R on innate immune cells has not been thoroughly examined. Here we investigate the consequence of IL-23R deletion in dextran sodium sulfate (DSS)-induced colitis, a chemically-induced acute model of inflammatory bowel disease. In IL23R-/- and IL23p19-/- mice, we observed decreased weight loss, improved histological scores, and reduced leukocyte infiltrate following DSS exposure. Surprisingly, when the IL-23R-/- allele was crossed into Rag2-/- mice, we observed exacerbated disease characterized by delayed recovery, increased epithelial damage, and reduced pSTAT3 in the epithelium in IL23R-/-Rag2-/- mice. This defect in epithelial repair in IL23R-/-Rag2-/- mice was rescued with exogenous IL22-Fc, and epithelial pSTAT3 was restored to normal levels. Depletion of Thy1+ innate lymphoid cells eliminated the majority of IL22 production in the colon lamina propria of DSS-treated mice, suggesting that these are the major IL-23 responsive innate cells in this context. In summary, we provide evidence for a protective role of IL-23 in murine colitis with implications in the therapeutic blockade of IL-23 signaling.
Role of Smad4-deficient T cells in Gastrointestinal Inflammatory Disease (59.7)
Authors: Kim Byung-Gyu , Choi Sung Hee , Robinson Janet , Lee Hyoung-Gon , Letterio John 
Published: January 2023

Abstract
Selective loss of Smad4 signaling in T cells leads to spontaneous gastrointestinal inflammation and cancer. However, the mechanism underlying the pathogenesis of these diseases is not completely understood. Here, we report that Smad4 is essential for TGF-β conversion of naïve T cells into Foxp3+ regulatory T (Treg) cells and for TGF-β suppression of effector T cells activity. We show that Smad4 deficient (Smad4KO) T cells do not generate Foxp3-expressing cells in inducible Treg (iTreg) differentiation condition. In suppression assays, iTreg cells from naïve WT T cells suppress T cell proliferation but Smad4KO T cells lack suppressive activity. In Smad4KO mice at 6 months of age, FoxP3+ Treg cells among CD4+ T cells are significantly reduced in the colon, but not in the thymus or spleen compared to those of WT. Moreover, TGF-β suppresses the proliferation of WT CD4+ T cells via cell cycle arrest and reduces the production of pro-inflammatory cytokines including INF-γ and IL-6, but TGF-β fails to suppress T cell proliferation and pro-cytokine production of Smad4 KO T cell. As expected, CD4+ and CD8+ T cells in the colon of Smad4KO mice are highly activated and produce pro-inflammatory cytokines, such as INF-γ and IL-6 greater compared with those of WT. Taken together, our results suggest the important role of Smad4 dependent TGF-β signaling in T cells in the maintenance of mucosal immune homeostasis and the pathogenic mechanism underlying gastrointestinal disease.
Beraprost enhances the APC function of B cells by upregulating CD86 expression levels (61.10)
Authors: Choe Jongseon , Kim Jini 
Published: January 2023

Abstract
Lipid mediators are emerging as important regulators of the immune system. Based upon our previous result that shows strong expression of prostacyclin synthase in the germinal center, we investigated whether prostacyclin would regulate the APC function of B cells. Due to the very short half-life of prostacyclin in experimental conditions, we used a more stable analogue beraprost. Beraprost increased the amounts of the costimulatory molecule CD86 but not CD80 on the surface of activated B cells in time- and dose-dependent manners. However, the enhancing effect of beraprost was not observed on memory B cells, centroblasts, and centrocytes. Beraprost required BCR and CD40 signals to upregulate CD86 expression levels. Other prostanoids such as PGE2, 6-keto-PGF1α, and PGF2α failed to alter CD86 expression levels, whereas other prostacyclin analogues were as potent as beraprost. Results carried out with receptor antagonists revealed that beraprost enhanced CD86 levels by binding to prostacyclin receptor IP and by increasing intracellular cAMP concentrations. Beraprost-treated B cells potently stimulated allo-T cells, which was significantly abolished by CD86 neutralization. Our data imply an unrecognized cellular and molecular mechanism about the germinal center reactions.
B cells inhibit and CR2 promotes antigen specific cellular immunity (61.15)
Authors: Silva Ines , Balin Samuel , Platt Jeffrey , Cascalho Marilia 
Published: January 2023

Abstract
Although T cells and B cells can respond immunologically to some tumors, whether and how they collaborate to control tumor growth is incompletely understood. To address this question we introduced a foreign antigen (HIV envelope), as a model for a tumor antigen, linked to C3d (AgC3d) in a tumor cell line and tested the fate of that line in isogeneic mice. AgC3d-positive tumors invoked antigen-specific antibodies and T cell-mediated IFN gamma secretion. Tumors expressing AgC3d grew more slowly than non-transfected cells and mice with tumors expressing AgC3d survived longer than mice with tumor alone. Slower growth of tumors was due to immunity directed against the viral antigen since AgC3d-positive tumors grew as fast as AgC3d-negative tumors in immune-deficient RAG-2 gammac-deficient hosts. Immunity and control of tumor growth required C3d since tumors expressing the antigen without C3d grew slower than tumors expressing AgC3d. Anti-tumor immunity depended on CR2 since tumors implanted in mice treated with CR2-Ig grew more rapidly than tumors grown in the absence of CR2-Ig. Control of tumors was not the direct result of C3d interaction with B cell CR2 as AgC3d-positive tumors grew slower and in some cases regressed in B cell deficient (JH-/-) mice than in wild type mice. Our findings suggest that C3d enables antigen specific responses by T cells and this response may be regulated by B cells.
Increased activity of proteasome associated deubiquitinating enzyme, USP14, accompanies lowered proteasomal proteolysis in primary human T lymphocytes during aging. (63.18)
Authors: Ponnappan Usha , Ponnappan Subramaniam , Ovaa Huib , Cane Stefania , Sullivan Dennis , Palmieri Michela 
Published: January 2023

Abstract
Aging is accompanied by a significant decline in proteasomal proteolysis that underlies lowered induction of T cell functional response. As USP14, found in association with the proteasome is both necessary and important in mediating ubiquitin trimming from proteasomal substrates, we evaluated functional USP14 levels by employing active site probes for proteasome associated deubiquitinating enzymes (DUBS). Our studies for the first time demonstrate that in T lymphocytes obtained from elderly donors, USP14 activity is significantly higher than those from young donors, and additionally, increased functional activity of USP14 accompanies conditions under which 26S proteasome catalytic activities are inhibited. UCH37, another DUBS associated with 26S proteasome appears to demonstrate only a modest increase in activity. Alteration in USP14 activity appears to be reciprocally regulated by the catalytic function of the 26S proteasome. Increase in USP14 activity is accompanied by an overall increase in USP14 protein but not mRNA expression in cells from the elderly. Thus, DUB activity associated with the proteasome demonstrates compensatory increase in activity during aging, and may regulate local levels of monomeric ubiquitin.
Genomic evolution of the B7 family (63.28)
Authors: Ota Yuko , Krylov Vladimir , Tlapakova Tereza , Flajnik Martin 
Published: January 2023

Abstract
B7 ligands are expressed by different cell types and interact with receptors on T cells to generate signals required for immunoregulation. All B7 members have structurally distinct domains in the immunoglobulin superfamily (IgSF). Some variable (V) domains of B7 ligands contain an ancestral, so-called “VJ” IgSF domain, while some constant (C) domains are of the “C1-type,” a rare form found primarily in molecules associated with adaptive immunity. Phylogenetic analysis had suggested a relationship between the V domains of B7 and MHC-linked tapasin (TAPBP), suggesting that they share a common ancestor. To study the evolutionary origins and functional aspects of B7 ligands, we used a comparative genomics approach emphasizing the genome of the amphibian Xenopus, a high-connectivity model. All known B7 family members except CD80 were found in X. tropicalis. Some B7 genes show conserved synteny between human and frog, suggesting that they are ancient and thus vital for the immune system, while the other genes were taxon-specific, perhaps having novel functions. In a more thorough bioinformatics approach, we found un-assigned B7 family genes from different vertebrate taxa including human. One of these genes is B7-H6 and the Xenopus orthologue is linked to beta-2 microglobulin (B2M). B2M is MHC-linked in sharks, presumably in the primordial organization. Thus, linkage of a B7 precursor to the MHC seems to be ancestral as part of the pre-adaptive immune complex.
Cyclosporine-resistant, Rab27a-independent mobilization of intracellular preformed CD40L mediates antigen-specific T cell help in vitro (63.8)
Authors: Gardell Jennifer , Thauland Timothy , Parker David , Koguchi Yoshinobu 
Published: January 2023

Abstract
CD40L is critically important for the initiation and maintenance of adaptive immune responses. CD40L expression in CD4+ T cells is regulated transcriptionally and produced from new mRNA following antigen recognition. However, recent studies with two-photon microscopy revealed that most cognate interactions between effector CD4+ T cells and APCs are too short for de novo synthesis of CD40L. Given that effector and memory CD4+ T cells store preformed CD40L (pCD40L) in a secretory compartment that comes to the cell surface within minutes of antigenic stimulation, we and others have proposed that pCD40L might mediate T cell-dependent activation of cognate APCs during these brief encounters. However, it has not been shown that the relatively small amount of pCD40L is sufficient to activate APCs, owing to the difficulty of separating the effects of pCD40L from those of de novo CD40L and other cytokines in vitro. Here we show that pCD40L surface mobilization is resistant to cyclosporine or FK506 treatment, while this treatment fully inhibits de novo cytokine expression. This allows us to dissect the role of pCD40L in APC activation. We find that pCD40L mediates selective activation of cognate but not bystander APCs in vitro and pCD40L mobilization does not depend on Rab27a, which is required for mobilization of lytic granules. Therefore, effector CD4+ T cells deliver pCD40L specifically to APCs on the same time scale as the lethal hit of CTLs but with distinct molecular machinery.