bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anti-TRIM21 autoantibody and inflammasome interaction in pathogenesis of Sjogren's syndrome (BA3P.200)
Authors: Deshmukh Umesh , Szczerba Barbara , Kaplonek Paulina , Rybakowska Paulina , Bagavant Harini 
Published: January 2023

Abstract
Sjögren’s syndrome is a chronic autoimmune disorder mainly affecting the exocrine glands and is commonly associated with autoantibodies to TRIM21. This study was undertaken to determine the role of TRIM21-reactive antibodies in pathogenesis of Sjögren’s syndrome. NZM mouse strains (2758, 2328, 2410) were immunized with recombinant TRIM21 protein adsorbed on to alum. Mice were monitored for autoantibodies, serum cytokines and pilocarpine induced salivation. Although all NZM mouse strains generated a robust anti-TRIM21 antibody response, salivary gland dysfunction only occurred in the NZM2758 mice. Moreover, alum immunized NZM2758 mice also displayed some loss of glandular function. Serum levels of IL-1α and CXCL1 were upregulated in alum and alum-TRIM21 treated groups of NZM2758 mice. In contrast, levels of IL-2, IL-5, IL-6 and IL-17 were upregulated, only in the alum-TRIM21 treated mice. Antibodies from TRIM21 immunized mice penetrated live cells in vitro, and showed cytoplasmic staining. Passive transfer of sera from TRIM21 immunized mice induced salivary gland dysfunction in recipient mice, only if the recipients were pre primed with alum. Our study shows that in a genetically susceptible mouse strain, anti-TRIM21 antibodies directly affected salivary gland function and this phenomenon was dependent on the activation of inflammasome pathway. Thus, interaction between innate and adaptive immunity is critical for pathogenesis of Sjögren’s syndrome.
Altered regulation of T-cell signal regulating (TSR) molecules in systemic autoimmunity (BA2P.129)
Authors: Pinkhasov Julia , Acuna Dora , Singh Ram 
Published: January 2023

Abstract
Recent evidence suggests that besides the T-cell receptor (TCR), there are other signal regulating molecules that play a pivotal role in establishing signal threshold during thymocyte selection through a process known as TCR tuning. We examined the expression level of a number of potential T-cell signal regulating (TSR) molecules in the MRL mouse model of multi-system autoimmune disease. We found the expression levels of negative regulators (CD5, CD6, CD2, GITR) that attenuate signal to be reduced, while positive regulators (CD26) that augment signal were increased on thymocytes in MRL mice compared to the C3H control mice. Thymocytes from MRL mice showed increased activation and phosphokinase signal upon ex vivo stimulation. Moreover, TSRs were further reduced on activated peripheral T cells after disease onset in the MRL mice. The reduced levels of these TSR molecules correlated with increased responsiveness to TCR-mediated signal upon ex vivo stimulation and phosphokinase detection. The reduced TSR expression levels were due to increased levels of ubiquitination, which led to targeted protein degradation. Importantly, co-stimulation with agonistic antibody against the TSR molecule CD5 reversed the hyper-responsiveness to TCR stimulation. The ability of T cells to alter their internal signal threshold by altering TSR expression may be a novel mechanism for T cells to escape peripheral tolerance and exacerbate autoimmune disease progression.
Differential contributions for Bim and Nur77 in negative selection against ubiquitous and tissue-restricted self-antigens (BA2P.122)
Authors: Hu Qian , Baldwin Troy 
Published: January 2023

Abstract
The thymic cortex and medulla are both sites of negative selection, where high affinity encounter with ubiquitous (UbA) and tissue-restricted (TRA) self-antigens, respectively, is thought to result in clonal deletion. Our group has shown that Bim is not required for UbA-mediated deletion but is required for TRA-mediated deletion. Nur77 is another protein implicated in thymocyte apoptosis, though its mechanism of action and regulation remain unclear. Using a physiological TCR transgenic model, HYcd4, we found that Nur77 was also dispensable for clonal deletion against UbA. Though Nur77 and its family member Nor-1 were induced during negative selection in HYcd4 Bim-/- mice, caspase-3 activation remained abrogated. Concurrent expression of a TCR transgene with a Nur77 transgene significantly inhibited Nur77-mediated thymocyte apoptosis, suggesting that TCR signalling can impair the pro-apoptotic function of Nur77. In contrast to a recent study using the OT-II Rip-mOva system, we found that Nur77 deficiency only modestly inhibited TRA-mediated clonal deletion in OT-I Rip-mOva chimeras. Furthermore, in polyclonal Bim-/- or Nur77-/- mice, we observed an increase in anergic phenotype CD4+ T cells, which may indicate an increase in self-specificities due to a block in clonal deletion. Collectively, these studies highlight potential differences in the molecular mechanisms of negative selection against UbA versus TRA, as well as of MHC class I versus MHC class II restricted thymocytes.
T cell motility within lymph nodes fits a Levy signature (CAM1P.225)
Authors: Cannon Judy , Asperti-Boursin Francois , Fricke Matthew , Letendre Kenneth , Moses Melanie 
Published: January 2023

Abstract
Naïve T cell motility within lymph nodes (LNs) is crucial for the initiation of the T cell response. Multiphoton imaging has allowed direct visualization of T cell movement in LNs, demonstrating T cell search as a random walk. Different types of random walks exist in biological systems, including Brownian and Levy walks. Levy walks differ from Brownian walks by the presence of large steps, and naïve T cell motility in LNs had been assumed to be a Brownian walk. Recent evidence suggests that the motility of T cells in the brain is characterized by a Levy signature, not a Brownian walk. However, detailed analysis naïve T cells search within LNs has not been done. Here we present evidence that naïve T cells use a Levy signature to search in LNs. Using multiphoton microscopy, we determined displacement and step size taken by naive T cells in LNs. We find that naïve T cell motility show a heavy-tailed distribution characteristic of a Levy signature. However, we do not observe a classical Levy walk as defined by a power-law fit. Instead, the best fit for T cell motility is a log-normal distribution. We then used computer modeling to assess the efficiency of T cell search parameters. We find that heavy-tailed distributions are as efficient as the classical Levy walk at target search. These findings shed new light on the fundamental mechanisms driving T cell search for antigen within lymph nodes.
InsP4 negatively regulates dendritic cell cytokine secretion and migration to peripheral draining lymph nodes. (CAM1P.234)
Authors: Wang Xinxin , Wang Yaming , Xu Xiaolu , Swiecki Melissa , Colonna Marco , Huang Yina 
Published: January 2023

Abstract
Inositol 1,3,4,5-tetrakisphosphate (InsP4) is a novel second messenger that is critical for T and B cell development and activation. However, whether InsP4 has a similar regulatory role in dendritic cell (DC) function is not yet known. We show here that InsP4 differentially regulates ERK and Akt signaling in response to LPS activation of bone marrow derived DCs (BMDCs). InsP4 supports ERK activation but negatively regulates Akt and its down-stream signals. Interestingly, endogenous migratory DCs from InsP4 deficient mice and BMDCs migrated more efficiently to peripheral lymph nodes in vivo. InsP4 deficient BMDCs also have enhanced secretion of pro-inflammatory cytokines/chemokines and mediate stronger antigen presentation to antigen-specific T cells. Our data support an important role for InsP4 in DC migration and cytokine secretion, identifying InsP4 as a dual regulator of Akt and ERK signaling pathways that controls DC function.
Formyl peptide receptor 2 plays a role on the oxidized low-density lipoprotein-induced pathological events of atherosclerosis (CAM1P.238)
Authors: Oh Eunseo , Lee Ha Young , Kim Sang Doo , Seo Jeong Kon , Bae Yoe-Sik 
Published: January 2023

Abstract
During the pathological progress of atherosclerosis, the level of low-density lipoprotein (LDL) and its modification into oxidized LDL (oxLDL) are reported to be increased. Eventhough some scavenger receptors such as CD36 and RAGE have been considered as target receptors for oxLDL, involvement of other receptors should be investigated for oxLDL-induced pathological responses of atherosclerosis. Here, we observed that oxLDL-induced foam cell formation was inhibited by formyl peptide receptor 2 (FPR2) antagonist WRW4. oxLDL stimulated calcium increase and chemotactic migration in FPR2-expressing RBL-2H3 cells but not in vector-expressing RBL-2H3 cells. Moreover, oxLDL stimulated TNF-α production, which was also almost completely inhibited by FPR2 antagonist. Taken together our findings, we suggest that oxLDL stimulates macrophages, resulting in chemotactic migration, TNF-α production, and foam cell formation via FPR2 signaling, contributing to the pathological progress of atherogenesis. We also suggest that FPR2 can be regarded as a therapeutic target for the development of drugs to treat atherosclerosis.
Cancer cell technology as a tool for teaching basic principles of immunology (EDU1P.248)
Authors: Aguilar Robert , Tuohy Vincent 
Published: January 2023

Abstract
Testicular cancer mainly affects men between the ages of 20 and 39, but it is the most common neoplasm in men between the ages of 15 and 34. The National Cancer Institute states that localized testicular cancer has a recurrence rate of 15-20%, and those tumors, including Sertoli or Leydig cell derived, do not respond well to chemotherapy or radiation treatment. My summer research was centered on the effort to better characterize the immune response to a testicular tumor. This was accomplished through the use of different immunology techniques such as proliferation assays, immunohistochemistry, ELISA, and ELISPOT. My lab experience inspired me to design a unit curriculum which will help elucidate the various physiognomies of tumor growth. Students first learn and apply the essential techniques of cancer cell culture. The testicular cancer cell line I-10 (CCL-83, ATCC) is used to familiarize students with routine feeding and maintenance, subculturing, counting, and cryopreservation. I-10 cell RNA is converted to cDNA and qualitatively analyzed for inhibin-alpha gene expression, which serves as a tumor marker, using RT-PCR. Then, they analyze previously formalin-fixed, paraffin embedded murine testes (normal and cancerous) using H&E staining and immunohistochemical staining for CD3, inhibin-alpha, and IgG. Upon completion of this unit, students demonstrate these learned skills in a combined written and practical examination.
Unique progenitors in adult mouse bone marrow expressing CD127 (IL-7Rα) and high level of cKit efficiently develop into all lymphocytes including T cells and innate lymphoid cells (HEM2P.266)
Authors: Ghaedi Maryam , Lichy Nesim , Takei Fumio 
Published: January 2023

Abstract
All lymphocytes are thought to develop from common lymphoid progenitors (CLPs) that are found in the Lin−Sca-1locKitloCD127+Flt3hi bone marrow (BM) cell population. However, only small numbers of T cells and innate lymphoid cells (ILCs) are generated from CLPs transplanted into irradiated mice, suggesting that they might mainly develop from alternative progenitors such as lymphoid-primed multipotent progenitors (LMPPs). We now have identified novel progenitors in adult mouse BM that efficiently develop into all lymphocytes including T cells and ILC2s. The novel progenitors are similar to LMPPs and found in the cKithiSca-1+Flt3+ BM cell subset, but unlike LMPPs they express the lymphoid lineage marker CD127, thus resembling early thymic progenitors (ETPs). Upon transplantation into irradiated mice, CD127+ LMPP-like cells robustly engraft and develop into T, B, NK cells and ILC2s. They are more efficient than LMPPs and CLPs in generating T cells and ILC2s. Similar to LMPPs, they also retain myeloid potentials. Flt3L-deficient mice have greatly reduced LMPPs and CLPs but have almost normal numbers of CD127+ LMPP-like progenitors, pre-ILC2 in the BM and mature ILC2 in the lung. While the exact relationship between CD127+ LMPP-like progenitors, CD127- LMPPs and CLPs are yet to be clarified, these results suggest that CD127+ LMPP-like BM cells are important progenitors for T cells and ILC2s independent of CLPs.
Plasma cell gene expression depends on ELL2 (HEM2P.271)
Authors: Bayles Ian , Milcarek Christine , Park Kyung Soo 
Published: January 2023

Abstract
ELL2, the eleven-nineteen lysine rich leukemia gene, a transcription elongation factor, has been found to play vital roles in Igh mRNA production, myeloma cell survival, and in HIV tar:tat mediated viral RNA transcription. We previously showed that ELL2 is responsible for Igh mRNA being both alternatively processed to the secretory-specific form and increased in its abundance, leading to high levels of secreted Ig protein and a robust immune response. ELL2 associates with pTEFb in a super elongation complex. We made conditional knockouts of ELL2 in mouse B cells using loxp/ CD19 cre. The splenic B cell populations of T3 and mature plasma cells in the whole mouse are reduced in the knockouts. The ELL2 cKO results in decreased serum Ig levels and severe reduction in antigen specific responses against NP-ficoll and NP-KLH. Recall responses are also impaired. LPS stimulation of splenic B cells shows decreased maturation to B220loCD138+ plasma cells with the expression of IRE1, XBP-1 spliced form, and cyclin B2 significantly lower in the cKO than LPS stimulated WT mice. The processing of the Igh mRNA to the secretory-specific form is suppressed in the conditional ELL2 knockouts with a compensatory increase in Igh membrane mRNA. Production of the unfolded protein response is thus impaired. Analysis of the ELL2 knockouts may lend insight into the relationships between Ig secretion, cell growth and the unfolded protein response in plasmablasts and long term plasma cells.
Generation and resolution of bivalent chromatin during hematopoiesis (HEM2P.259)
Authors: Ghosh Amalendu , De Supriyo , Bell Jeremiah , Weber Brittany , Wood William , Becker Kevin , Sen Jyoti , Bhandoola Avinash , Sen Ranjan 
Published: January 2023

Abstract
Bivalent promoters, that are simultaneously marked by activation- and repression-associated histone modifications, have been proposed to maintain ES cell genes in a poised configuration. During differentiation such promoters resolve to fully active or inactive states, with associated changes in gene expression. Here we followed the fate of bivalent promoters during hematopoietic stem cell (HSC) differentiation to T lymphoid lineage committed cells. We show that HSC bivalents interconverted between monovalent and bivalent chromatin states at sequential developmental stages, with only a minority resolving to either monovalent state for the long-term. Conversely, bivalent promoters that were generated de novo interconverted between precursor states and bivalency. Neither generation nor resolution of bivalency was accompanied by changes in gene expression. Moreover, singly marked genes did not transition to the opposing monovalent state via a bivalent intermediate. Our observations reveal unprecedented dynamics of bivalent chromatin during hematopoiesis that suggests a developmental role beyond poising genes for future resolution.
Inhibition of B lymphopoiesis by myeloid-derived suppressor cells (HEM2P.262)
Authors: Kennedy Domenick , Knight Katherine 
Published: January 2023

Abstract
B lymphopoiesis declines with age in humans, mice, and rabbits. In rabbits, loss of B lymphopoiesis occurs as early as two months of age and correlates with an increase in adipose tissue in the bone marrow (BM). Increased adipose tissue has also been observed in the BM of aged humans and mice. We showed previously that adipocyte-derived factors inhibit B lymphopoiesis in vitro; however, the mechanism by which this occurs is unknown. Through co-cultures of mouse BM cells with OP9 stromal cells, we found that adipocyte conditioned medium (ACM) induces the generation or expansion of CD11b+ Gr1+ myeloid cells. Further, we found that these cells inhibit B cell development in vitro. The ACM-induced CD11b+ Gr1+ cells express arginase (Arg1) and iNos (Nos2), and functionally suppress CD4+ T cell proliferation, suggesting that these cells are classical myeloid-derived suppressor cells (MDSCs). Transwell and conditioned medium experiments show that inhibition of B lymphopoiesis by ACM-induced MDSCs is mediated through soluble factors. This study uncovers a previously unrecognized capacity of MDSCs to inhibit B lymphopoiesis and provides a potential target for therapeutics aimed at restoring B lymphopoiesis in aged individuals.
Development of a novel method for isolation of four developmentally distinct myeloid derived dendritic cells pre-cursors: phenotypic and functional analyses (HEM3P.283)
Authors: Rogers Peter , Hiltbold Elizabeth 
Published: January 2023

Abstract
Myeloid cell progenitors have the potential to give rise to dendritic cells which have a high capacity to stimulate adaptive immune responses as well as to cells with potent immunosuppressive activity. However, the stage in their development in which these functions are gained is poorly defined. Here, we developed a method for isolating progenitor populations at specific stages of development. Bone marrow cells were lineage depleted and cultured in GM-CSF to drive their differentiation toward a myeloid lineage for three days. Cells were then sorted based on Ly6C and CSF-1R (CD115) expression, two markers whose expression is known to change throughout myeloid ontogeny. We then monitored the developmental progression of each population based on the expression of these markers as well as other hallmarks of dendritic cell or myeloid suppressor cell phenotypes. We also measured the function of each population relative to antigen uptake and degradation as well as their response to stimulation by TLR agonists. Collectively, our results indicate that myeloid progenitors progress along this pathway: Ly6C-CD115- -&gt; Ly6C+CD115- -&gt; Ly6C+CD115+ -&gt; Ly6C-CD115+ -&gt; Ly6C-CD115+. Phenotypically, these populations represent CMP, MDSC, monocytes, immature DC, and more mature DC, respectively. These findings not only enhance our understanding of myeloid cell development and differentiation driven by GM-CSF, but also inform the design of GM-CSF-derived DC based vaccine strategies.
Over-, ectopic-expression of FoxN1 at early life adversely influences lymphopoiesis (HEM3P.280)
Authors: Ruan Linhui , Burnley Preston , Wang Liefeng , Mu Lili , Coder Brandon , Shaw Jennifer , Zhuge Qichuan , Su Dong-Ming 
Published: January 2023

Abstract
FoxN1 expresses in thymic epithelial cell (TEC) and skin epithelium to regulate their development. Prenatal mutation in FoxN1 results in thymic development failure and nude phenotype, while postnatal insufficient FoxN1 expression induces thymic atrophy, resulting in declined T-lymphopoiesis. Although enhancing FoxN1 expression in aged thymus promotes functional rejuvenation, whether FoxN1 over-expression at early age or ectopic expression in the bone marrow is beneficial for lymphopoiesis is unknown. Using our newly generated R26-STOPflox-FoxN1 (gain-of-function) mutant mice, which have an over-expressed FoxN1 after various promoter-driven Cre-mediated deletion of the roadblock STOPflox, we found that K14Cre-mediated prenatal FoxN1 over-expression resulted in a newborn lethal phenotype, displaying abnormal permeability in the skin. Ubiquitous deletion of the STOPflox mediated by uCreERT progressive leak in infant mice influenced TEC development, and T- and B-lymphopoiesis. Although the K5CreERT mediated FoxN1 over-expression in adult mice may be beneficial for postponing thymic aging, early induction of K5CreERT activation in infants induced adverse influences to thymoycte and hair follicle development. Therefore, FoxN1 has a stage and tissue sensitivity. Over- and ectopic-expression of FoxN1 at early life adversely influences immature thymic, T-, and B-cell, and skin epithelial development.
Essential regulatory role for factor H and properdin in the formation of platelet/granulocyte aggregates in human whole blood (HUM1P.301)
Authors: Blatt Adam , Saggu Gurpanna , Cortes Claudio , Ferreira Viviana 
Published: January 2023

Abstract
An increased number of activated platelets and platelet/leukocyte aggregates are found in patients with chronic inflammatory diseases including cardiovascular disease. Platelet/leukocyte aggregates are not only indicative of cardiovascular disease, but also play an important role in the initiation and progression of disease. The role that complement regulatory proteins properdin and factor H play in controlling the formation of platelet/granulocyte aggregates, as well as which factor H domains are essential for the interaction with platelets on which complement is activating remain unknown. Here, we have determined that (a) the C-terminus of factor H is critical for the ability of the protein to protect platelets from the alternative pathway of complement, (b) blocking of properdin function using an inhibitory antibody significantly reduces the formation of platelet/granulocyte aggregates, while adding properdin increases the formation of these aggregates in a dose-dependent manner, and (c) factor H controls the properdin-mediated formation of platelet/granulocyte aggregates. Our data support critical roles for properdin and the C-terminus of factor H in controlling the formation of platelet/granulocyte aggregates. These studies may contribute to the understanding of the pathophysiological mechanisms involved in the interaction between platelets and granulocytes in chronic inflammatory diseases.
Role of immune cell subsets in bone disease associated to chronic kidney disease and haemodialysis patients. (HUM1P.315)
Authors: Gigante Margherita , Cafiero Cesira , Brunetti Giacomina , Grano Maria , Colucci Silvia , Simone Simona , Ranieri Elena , Pertosa Giovanni , Gesualdo Loreto 
Published: January 2023

Abstract
Chronic kidney disease (CKD) is a progressive loss in renal function, which severity is classified in five stages, with stage 1 being the mildest and stage 5 being a severe illness evolving to hemodialysis (HD). Chronic inflammatory state in HD and CKD patients (pts) may contribute to the development of bone disease through the increase of osteoclasts (OCs), the bone resorbing cells. In pathological condition, immune cells and inflammatory cytokines belonging to tumor necrosis factor superfamily, such as LIGHT and RANKL, play a key role in osteoclastogenesis. The aim of our study was to evaluate the osteoclastogenic potential of unfractionated and T cell-depleted PBMCs from CKD and HD pts. We also evaluated the presence of circulating osteoclast precursors (CD14+/CD16+) and characterized the immune cell subsets for LIGHT and RANKL expression through flow cytometry and RT-PCR. PBMCs from HD and CKD pts (stage IV-V) showed a spontaneous osteoclastogenesis in vitro (80±7). Conversely, exogenous cytokines were essential to trigger and sustain osteoclastogenesis in CKD pts (stage I-II) and controls (10±4). It correlated with a significant increase of both LIGHT and RANKL expression on CD4+ T cells as well as CD14+CD16+ monocytes in HD and CKD pts (stage IV-V) compared to controls (p&lt;0.005). LIGHT and RANKL may represent a new link between immune cells activation and bone-associated disease in CKD and HD pts suggesting new potential therapeutic targets in the setting of these pts.