bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression profiling of B-1 and B-2 progenitors (36.15)
Authors: Tung James , Veys Kristine , Sembrano Daryl , Hall Casey , Ross Christian 
Published: January 2023

Abstract
B-1 and B-2 comprise the two B cell lineages. B-1 and B-2 cells can be distinguished by their surface phenotype and also by their developmental ontology, immunoglobulin repertoire, anatomical localization, and immune functions. Importantly, B-1 cells arise early in fetal liver while B-2 cells are generated in the bone marrow after birth. The appearance of B-1 and B-2 cells is the result of fetal B-cell development versus adult B-cell development. B-1 and B-2 cells are generated from distinct progenitor cells, namely B-1 progenitors and B-2 progenitors. B-1 progenitors express CD19 but do not express B220. In contrast, B-2 progenitors express B220 but do not express CD19. To determine the fate decisions that led to fetal versus adult B cell development, we sorted B-1 progenitor cells from fetal liver and B-2 progenitor cells from adult bone marrow and performed gene expression array analysis. In our poster, we will present the results of the expression array comparison between the two progenitor populations. We will confirm the expression array comparison results by molecular techniques and discuss the potential significance of these differences.
Ikaros null mice demonstrate defects in dendritic cell development. (36.17)
Authors: Brugmann William , Winandy Susan 
Published: January 2023

Abstract
Ikaros is a transcription factor that is expressed almost exclusively in cells of the hematopoietic lineage. Ikaros null mice lack several hematopoietic cell lineages including some dendritic cell (DC) subsets. Additionally, several Ikaros null bone marrow (BM) progenitor populations have a decreased expression of the receptor tyrosine kinase, Flt3. DCs can be generated in vitro by culture of BM with either GM-CSF or Flt3L (the ligand for Flt3). Our studies find that loss of Ikaros leads to a specific defect in the ability of BM precursors to generate DCs in response to culture with Flt3L but not in response to culture with GM-CSF. Those DCs that do develop from the culture of Ikaros null BM with Flt3L have an activated phenotype with higher expression of MHC class II and the costimulatory molecules CD40, CD80 and CD86 than their wild type counterparts. An examination of gene expression in Ikaros null BM progenitors cultured with Flt3L shows an inappropriately low expression of Irf4, Irf8 and Spib, genes encoding transcription factors known to be important for DC development. Studies are currently underway to determine whether enforced expression of Ikaros, Flt3 or one of the above-mentioned transcription factors can rescue DC development upon culture of Ikaros null BM with Flt3L. These studies will provide a potential molecular mechanism for the impaired development of DCs in Ikaros null mice.
Cell intrinsic E47 is required for stem cell self-renewal and differentiation but is dispensable for short-term myeloid development (36.2)
Authors: Borghesi Lisa , Yang Qi , Esplin Brandt 
Published: January 2023

Abstract
The immune system is constantly replenished by a rare population of hematopoietic stem cells (HSC) residing in the bone marrow of adult organisms. E-proteins, the widely expressed basic helix-loop-helix (bHLH) transcription factors, appear to contribute to HSC activity, but their specific cell intrinsic functions remain undefined. In contrast to a recent report, we show that E47 is dispensable for the short-term myeloid differentiation of HSCs. In our quantitative assays, E47 deficient progenitors show competent myeloid production in vitro and in vivo as well as under burden of a pathogen mimic. We also show that long-term myeloid and lymphoid differentiation is compromised due to the progressive loss of the self-renewal potential of HSCs in vivo. Compromised self-renewal of E47 null HSCs is associated with over-proliferation and premature exhaustion under replication stress. These observations suggest that cell-intrinsic E47 is dispensable for the short-term myeloid repopulation activity of HSCs and, by contrast, that E47 plays an essential cell-autonomous role in the self-renewal of HSCs by preventing hyperproliferation-associated exhaustion following replication stress.
CEACAM1 regulates granulopoiesis through inhibition of G-CSFR-Stat3 signaling in an ITIM-SHP-1 dependent manner (36.20)
Authors: Pan Hao , Shively John 
Published: January 2023

Abstract
CEACAM1 (CD66a) is involved in many biological processes, including regulation of lymphocyte activation. Although granulocytes highly express CEACAM1, the role of CEACAM1 in granulopoiesis and granulocyte dependent immune responses is not well understood. We showed here that CEACAM1 expression correlated with granulocytic differentiation and CEACAM1-/- mice developed severe neutrophilia in a cell-autonomous fashion associated with hyper-proliferation of granulocyte progenitors. Also, the regulation of CEACAM1 on progenitor cells was granulocytic lineage specific. We found CEACAM1 acted as a co-inhibitory receptor for G-CSFR, leading to the down-regulation of Stat3 activity. This inhibitory effect was dependent on G-CSF induced phosphorylation of ITIMs on CEACAM1 and the recruitment of SHP-1. Moreover, CEACAM1-/- mice were hypersensitive to Listeria monocytogenes (LM) infection with accelerated mortality due to augmented neutrophil liver infiltration and enhanced cytokine levels. Reintroduction of CEACAM1 restored normal granulopoiesis and host sensitivity to LM infection upon transduction into CEACAM1-/- mice; Mutation of the Tyr residues in its ITIMs abrogated this restoration. Finally, knocking down Stat3 in CEACAM1-/- mice rescued normal granulopoiesis and attenuated host sensitivity to LM infection. Thus, we identified CEACAM1 as a co-inhibitory receptor for G-CSFR regulating granulopoiesis and affecting the host innate immune response to bacterial infections.
ENPP1 is a novel cell surface marker of germinal center and memory B cells and is highly expressed in plasma cells (36.3)
Authors: Wang Hongsheng , Shin Dong-Mi , Gonzalez-Garcia Ines , Abbasi Sadia , Feng Jianxun , Morse Herbert 
Published: January 2023

Abstract
The ectonucleotide pyrophosphatase phosphodiesterase 1 (ENPP1), also known as plasma cell (PC) alloantigen 1 (PC-1), is expressed on PCs and many non-lymphoid tissues. ENPP1 hydrolyzes NTP to generate NMP and pyrophosphate (PPi). PPi is an important factor for controlling mineralization of the bone. In addition, ENPP1 directly associates with the insulin receptor and regulates insulin receptor signaling. Abnormal expression of ENPP1 has been associated with diabetes and insulin resistance. Although ENPP1 was first identified in PCs, its expression and function in B lineage cells remains poorly understood. Here we describe a previously unknown expression pattern of ENPP1 in murine late stage B cells. By using an anti-ENPP1 mAb and flow cytometry, we found that the expression levels of ENPP1 in early and mature naïve B cells were relatively low. However, germinal center (GC) B cells, PCs and memory B cells expressed 2-4-fold more ENPP1 than resting B cells. Moreover, gene expression profiling studies of primary lymphomas in NFS.V+ congenic mice revealed high expression levels of ENPP1 in plasmacytomas, immunoblastic lymphomas, and centroblastic-follicular lymphoma types, corresponding with their PC and GC origins. These studies demonstrate that ENPP1 can be a useful marker for identification of stages in GC and post-GC cell differentiation and of lymphomas with a GC or PC origin. The function of ENPP1 in B cells is currently under investigation.
Identifying molecules that “fine-tune” T cell antigen receptor signaling during thymocyte selection. (36.40)
Authors: Pinkhasov Julia , Lee Jan , Li LiQi , El-khoury Dalal , Lesourne Renaud , Hwang SuJin , Zhang Yongqing , Weng Nan Ping , Love Paul 
Published: January 2023

Abstract
The prevailing view of thymocyte selection is that the fate of developing cells is dictated exclusively by the affinity/avidity of the expressed TCR for self-MHC/self-ligand. We hypothesize that there is significant plasticity in the signaling processes that control T cell development and that the ability to ‘fine-tune’ the TCR signaling response, through the regulated expression of molecules that positively or negatively impact the TCR signaling response operates to maximize the TCR repertoire. One example of a ‘fine-tuning’ molecule that was previously characterized is the cell surface protein CD5. We found that CD5 is an inhibitory tuning receptor, and its surface expression is directly and proportionately regulated by the affinity of the TCR for selecting ligand. In order to identify additional candidates for ‘TCR-tuning’, we employed a TCR transgenic experimental system where TCR expression was fixed on all developing thymocytes and where the affinity of the positively selecting TCR/self-MHC/self-ligand interaction could be altered by changing the MHC haplotype. Thymocytes that successfully underwent selection under conditions of relatively low or relatively high avidity interactions were analyzed by microarray. These experiments identified CD5 as well as several additional potential tuning molecules not previously thought to play a role in ‘TCR-tuning’. Our results provide important new insights into the genetic and molecular processes that control thymocyte selection.
Alterations in Bone Marrow Stroma with Aging (36.5)
Authors: Bilwani Fareena , Knight Katherine 
Published: January 2023

Abstract
B lymphopoiesis arrests in rabbits by 16 weeks of age, and data suggest that the bone marrow (BM) environment is responsible for this. We hypothesize that this arrest is due to differences in the BM stroma of young and adult rabbits. Using limiting dilution analysis to quantify the number of CFU in BM of 2 to 6 wk-old rabbits, we found an 8-10 fold decrease in the number of stromal progenitors by 6 wk-of-age. This decrease in stromal progenitors is reflective of the age-related decline in progenitor B cells in BM. Histology of BM sections reveals trabecular bone formation in young rabbits but not in adults; in contrast, BM from adults shows large amounts of adipose tissue. We tested the capability of stromal progenitors to differentiate into adipocytes or osteoblasts in vitro , and found that stromal progenitors from BM of young rabbits displayed a higher propensity to form oseoblastic colonies than do stromal progenitors from BM of adults, which more readily formed adipocytic colonies. We conclude that with aging, the number of BM stromal progenitors decreases dramatically, and further, that these progenitors from adults more readily differentiate into adipocytes than into osteoblasts. We suggest that these changes in BM are responsible for the arrest of B lymphopoiesis.
Analysis of signals that regulate the fate of early T cell precursors (36.53)
Authors: Al-Kuhlani Mufadhal , Ciriza Jesús , Peiris Tanuja , Ramos Joseph , Bañuelos Daniel , García-Ojeda Marcos 
Published: January 2023

Abstract
The differentiation process of Hematopoietic Stem Cells (HSC) to Common Lymphoid Progenitors (CLP), that give raise to dendritic, NK, B and T cells, depends on various cues received from their microenvironment. Notch-1 is a transmembrane receptor that plays a crucial role on CLP commitment towards T cell lineage at the expense of B cell fate. The role of the transcription factor GATA-3, as well as its regulatory interaction with Notch-1 signals during early T cell development, is poorly characterized. In vitro studies show that GATA-3-deficient (GATA-3-/-) T cell progenitors do not develop beyond the CD44+CD25+ double negative 2 (DN2) stage. Remarkably, GATA-3-/- DN2 cells generate B cells in the presence of constant Notch-1 signals, which normally block B cell development. These GATA-3-/- DN2 cell express elevated levels of Deltex-1, a Notch-1 regulator. Therefore, we hypothesize that GATA-3 transcriptional activity controls the expression of Deltex-1 and possibly other Notch-1 regulators. The expression levels of various regulators of Notch-1 in wild type and GATA-3-/- T cell progenitors will be evaluated using quantitative PCR. The effect of GATA-3 deficiency on the expression level of various genes involved in Notch signaling will be evaluated by qPCR array. Revealing the interaction mechanism of GATA-3 with Notch-1 will contribute to our understanding of how early lymphocyte progenitors become committed toward the T cell lineage.
Propagation of common lymphoid progenitors in OP9-DL1 co-culture results in generation of cells incapable of β-selection (36.54)
Authors: Van De Wiele C. Justin , Marino Julie , Davis Brenda , Tan Chibing , Taylor Ashlee , Teague T. Kent 
Published: January 2023

Abstract
Common lymphoid progenitors derived from murine bone marrow have previously been demonstrated to be capable of long-term propagation in OP9-DL1 co-cultures. Cultures of this type initially display a wave of differentiation to the double positive stage of T cell development that is observable at three to four weeks post-culture initiation. Continued propagation eventually produces a heterogeneous population of cells that collectively resemble thymocytes derived from animals incapable of β-selection. As TCRβ gene rearrangement occurs at this stage in normal thymocytes, we evaluated the rearrangement status of the co-culture derived cells. Sequential, weekly analysis revealed that TCRβ rearrangements occurred as expected in cultures that differentiated to the DP stage. After the initial wave of DP production however, TCRβ rearrangements were no longer detectable. Further analysis revealed that portions of the CD3 complex were expressed on the derived cells at levels equivalent to or higher than wild-type thymocytes at a similar maturational stage while pre-Tα levels were found to be expressed at a lower level. Finally, by using a novel in vitro β-selection assay, we demonstrate that the cultured cells still do not initiate differentiation past the DN3a stage. These data indicate that while ex vivo derivation and maintenance of T cell precursors is possible, standard OP9-DL1 culture conditions lead to development of cells resistant to induction of the β-selection program.
Thymocyte autoreactivity and altered thymic epithelial development in the absence of CD28-CD80/86 and CD40-CD40L interactions (36.69)
Authors: Williams Joy , Zhang Jingjing , Klug David , Nitta Takeshi , Kruhlak Michael , Sharrow Susan , Granger Larry , Adams Anthony , Gress Ronald , Takahama Yousuke , Hodes Richard 
Published: January 2023

Abstract
CD28-CD80/86 and CD40-CD40L interactions are critical to the activation of mature T cells and also have significant effects on T cell development and repertoire selection. Notably, the effects of these costimulatory interactions can be bi-directional, affecting both CD28- and CD40L-expressing T cells and the B7- and CD40-expressing cells with which these T cells interact. We have therefore analyzed development of a self-tolerant T cell repertoire as well as the development of thymic cortico-medullary structure in mice deficient for both the CD28-CD80/86 and CD40-CD40L costimulatory pathways. We find that CD4 thymocytes from CD40/CD80/CD86 KO mice respond vigorously to syngeneic antigen presenting cells, in contrast to the weak responses of thymocytes from either CD40 KO or CD80/CD86 KOs. Interestingly, we also find that the thymic medullary epithelial compartment (mTEC) is uniquely disrupted in CD40/CD80/CD86 deficient mice. The profound reduction in thymic medullary epithelial cells in CD40/CD80/CD86 deficient mice is accompanied by a significant decrease in CD4 SP thymocyte expression of several TNF family members including LTa, LTb, and CD30L. Expression of RANK-L, previously shown to be critical for development of mTEC in the embryonic and adult thymus, is unaffected in CD40/CD80/CD86 deficient thymocytes. These results indicate that thymocyte-mTEC crosstalk mediated either directly or indirectly through CD40 and B7 pathways is critical to thymic stromal development.
Asp299Gly TLR4 polymorphism impairs sensing of Escherichia coli, Rickettsia akari and LPS-mediated activation of MyD88- and TRIF-dependent signaling pathways (37.17)
Authors: Medvedev Andrei , Song Chang , Quevedo-Diaz Marco , Qiu Fu , Figueroa Leandra 
Published: January 2023

Abstract
TLR4 is a key sensor of Gram negative bacteria and LPS. The Asp299Gly (D299G) and Thr399Ile (T399I) SNPs of TLR4 have been associated with increased risks or severity of certain bacterial infections and Gram negative sepsis. This study employed transfection-based complementation of TLR4-negative HEK293T cells to elucidate the role of TLR4 SNPs in sensing Gram-negative bacteria and LPS, and to determine their effect on LPS-elicited activation of MyD88- and TRIF-dependent signaling pathways. Overexpression of wild-type YFP-TLR4 led to marked activation of the NF-κB-dependent pELAM-luciferase reporter in HEK293/CD14/MD2 transfectants exposed to heat-killed E. coli, R. akari and LPS, whereas the D299G (but not T399I) TLR4 exhibited signaling deficiency. Likewise, LPS-mediated activation of TRIF-dependent pRANTES-luciferase and p125 (IFN-beta)-luciferase reporters was significantly lower in HEK293/CD14/MD-2 cells expressing D299G YFP-TLR4. Immunoprecipitation and immunoblot analyses revealed similar total expression levels of wild-type and mutant YFP-TLR4 proteins, and similar LPS binding was observed in HEK293/CD14/MD-2 cells expressing WT or mutant TLR4 species, as detected by FACS. Our data indicate that the D299G SNP impairs TLR4-elicited activation of MyD88- and TRIF-dependent signaling pathways in response to heat-inactivated Gram negative bacteria and LPS not due to lower expression levels of mutant TLR4 or impaired LPS recognition by D299G TLR4/MD2/CD14 complexes.
Blockade of triggering receptor expressed on myeloid cells (TREM) signalling during a primary influenza infection reduces susceptibility to secondary bacterial pneumonia (37.21)
Authors: Xin Gang , Wissinger Erika , Hussell Tracy 
Published: January 2023

Abstract
TREM-1 is a cell surface receptor, first described in neutrophils and monocytes, which act synergistically with Toll-like receptors and Nod-like receptors to enhance inflammation. In addition, soluble TREM-1 (sTREM-1) has also been detected in mouse and human sera, where it regulates TREM-1 signals by competing for binding to the as-yet-unknown natural TREM-1 ligand. sTREM-1 has been used as a predictive biomarker due to the fact that it is detected at high levels during severe pneumonia and sepsis. TREM-1 signalling has been manipulated experimentally in mouse models of septic shock using a synthetic peptide (LP-17) which blocks the interaction between TREM-1 and its ligand. LP-17 treatment significantly reduces the inflammatory responses associated with sepsis and improves the outcome of a lethal secondary Streptococcus pneumoniae infection in mice undergoing a primary influenza infection. Treatment with LP-17 also reduced bacterial colonization of the nasopharyngeal cavity and the airway. These data support the idea that manipulating TREM-1 is a suitable therapeutic strategy to control secondary bacterial pneumonias.
The expression of NODs and inflammatory cytokines in tissues of mice infected with Mycobacterium leprae (37.24)
Authors: Kang Tae Jin , Kim Tae Hoon , Lee Geum Seon , Kim Se-Kon , Jin Song Hou , Kim Dojin , Kim Kyungjae , Chae Gue-Tae 
Published: January 2023

Abstract
The nucleotide-oligomerization domain (NOD) is an important molecule involved in host defense. RICK/RIP2 contains a caspase recruitment domain and has been implicated in the activation of the transcriptional factor NF-kB downstream of Toll-like receptors and Nod-like receptors. In order to determine the function of Nod1 and Nod2 in M. leprae infection, we measured the Nod1 and Nod2 mRNA level in tissues of nu/nu mouse infected with M. leprae. The expression of NOD1 and NOD2 mRNA was induced in tissues of nu/nu mice infected with M. leprae. In addition, the expression of inflammatory cytokines such as TNF-α and IL-1β was increased in tissues of mice infected with M. leprae, compared to those of non-infected mice. We also established HEK 293 cells to express Nod1 and Nod2 cDNA. RICK expression is, interestingly, regulated by Nod2-dependent pathway in M. leprae infection. These results suggest that NOD family proteins may have a role in the immune response to M. leprae.
IRF5 deficiency severely impairs the development of T helper 1 responses following Leishmania donovani infection. (37.3)
Authors: Stager Simona , Paun Andrea , Joshi Trupti , Pitha Paula 
Published: January 2023

Abstract
The transcription factor Interferon Regulatory Factor 5 (IRF5) has been shown to be involved in the induction of proinflammatory cytokines in response to viral infections and TLR activation and to play an essential role in the innate inflammatory response. In this study, the experimental model of visceral leishmaniasis was used to investigate the role of IRF5 in the generation of Th1 responses and subsequent formation of Th1-type liver granulomas in Leishmania donovani infected mice. Here we show that IRF5 deficiency severely impairs the development of Th1 responses to L.donovani leading to the formation of Th2-type-like granulomas. These granulomas are characterized by a strong IL-4 response, upregulation of arginase 1 and Fizz1 mRNA and concomitant low iNOS expression. This study identifies IRF5 as a critical molecular switch for the development of Th1 immune responses following L.donovani infections and as an important molecule in the regulation of arginase 1 and iNOS expression.
Shaping the immune response to Francisella tularensis by the first infected cell (37.33)
Authors: Steele Shaun , Buntzman Adam , Hensley Lucinda , Kawula Thomas , Bixby Lisa , Frelinger Jeffrey 
Published: January 2023

Abstract
Francisella tularensis, the causative agent of tularemia, induces a host response that is dependent on the route of infection. Intranasal inoculations are more virulent and require fewer bacteria initially than an intradermal inoculation to produce a lethal infection (10^3 organisms in an intranasal inoculation versus 10^6 organisms in an intradermal inoculation). However, one day post infection, the bacterial load is similar in the spleen and lung regardless of the route of infection. This indicates that host response is specific to the infection site and that this response occurs within hours post infection. To test this hypothesis, 6-10 week old C57B6/J mice are given either intradermal or intranasal inoculations of live vaccine strain F. tularensis or fully virulent Schu S4 and, after four hours, the cell types are sorted by flow cytometry and examined to determine which cell populations are initially infected. Our initial results in the lung show that essentially all cells infected by four hours are alveolar macrophages, to the exclusion of other myeloid cells and lung parenchyma. To determine the important cytokines shaping the immune response, the alveolar macrophages are infected with F. tularensis in vitro and the cytokines the cells produce are analyzed. This will allow for targeted pharmacological alterations of the cytokine response and should influence the course of infection in vivo.