bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification and characterization of langerin positive dendritic cells in the normal cornea and in transplantation. (145.27)
Authors: Saban Daniel , Hattori Taakaki , Chauhan Sunil , Dana Reza 
Published: January 2023

Abstract
A novel population of migratory dendritic cells (DCs), distinct from Langerhans cells (LC), was recently found to which also express langerin (CD207+) and reside throughout the body (skin, lung, gut, and liver). Moreover, such CD207+ DCs were shown to be important in generating immunity. Thus, we investigated whether CD207+ DCs exist in the cornea and their possible migration to lymph nodes (LN) in corneal alloimmunity. Methods: C57BL/6 corneas (n=30) were collected and epithelium separated from stroma. Tissue was pooled separately and digested enzymatically for FACS analysis of CD45, CD11c, CD207, CD205, and CD103. Immunohistology was also examined. Furthermore, BALB/c mice were allografted with C57BL/6 corneas and LNs evaluated for corneal CD207+ DCs vs. LCs. Results: Most epithelial and stromal DCs were CD207+ and co-expressed CD205+, but only the stromal subset expressed CD103+. Interestingly, following allotransplantation, the frequency of the stromal DCs (CD11c+ CD8a- CD207+ CD103+) decreased dramatically (by 4-fold) in ipsilateral LNs relative to naïve mice; whereas, the epithelial DCs (CD103-) markedly increased. A similar, but much less dramatic, trend was seen in the contralateral LN. Conclusions: This indicates the presence of CD207+ DCs in the cornea, distinct from LCs of the epithelium. Interestingly, a dramatic and diametrically opposed flux of such stromal DCs vs. LCs to LNs following transplantation suggests potentially differing functions in alloimmunity.
Extracellular purines serve as an innate trigger to allograft rejection (145.39)
Authors: Reichenbach Dawn , Li Qi , Demetris Anthony , Lakkis Fadi 
Published: January 2023

Abstract
Innate immune triggers are well studied in infectious models, yet they remain unclear in solid organ transplantation. Extracellular purines (e.g. ATP, adenosine), which signal through receptors on immune cells, modulate the extent of ischemia reperfusion injury. To test the effect of purinergic signaling on graft rejection, we used a cardiac transplant model in outbred mice in which accelerated graft rejection occurs within 4 days post-transplantation and is highly dependent on innate mediators. Treatment with NECA, an adenosine receptor agonist, 2 hours prior to heterotopic heart transplantation (n=8) completely abrogated accelerated rejection compared to untreated outbred mice (incidence = 28%, n=35). CD39 and CD73 are ectoenzymes responsible for metabolism of extracellular ATP to adenosine. To determine the effect of increased extracellular ATP in the local graft environment, hearts from CD73-deficient B6 mice were transplanted to BALB/c recipients. Accelerated rejection occurred in 24% of grafts from CD73-/- mice (n=17) compared to 2% of grafts from wt inbred controls (n=42). Skin transplants from CD39-/- and CD73-/- mice to BALB/c mice (n=8/group) rejected at the same rate as wt control B6 to BALB/c skin transplants (n=8), suggesting the effect was restricted to vascularized transplants. Our data suggests that modulation of purine metabolism serves as an early trigger of the innate immune response in vascularized organ transplantation.
Role of T cell subsets in promoting intestinal GVHD. (145.4)
Authors: Anthony Bryan , Wang Jiao-Jing , Gaughan Alice , Hadley Gregg 
Published: January 2023

Abstract
The relative contributions of CD4 vs. CD8 T cell subsets in graft-versus-host disease (GVHD) remains poorly defined. Previous studies in this lab have shown that the integrin CD103 is required for accumulation of CD8 T cells in epithelial compartments and concomitant epithelial injury during GVHD in MHC-mismatched transplant models. The goal of the present study was to define the role of the CD103 pathway in promoting GVHD following MHC-matched BMT, the most common clinical scenario. Our data showed no difference in the ability of WT or CD103-/- splenocytes to cause acute GVHD mortality in this transplant scenario. However, depletion of CD4 T cells on day 6 post transplant completely prevented acute GVHD mortality, despite a robust CD8 T cell response. These data suggested that acute gut injury and mortality elicited following BMT are mediated by CD4 T cells rather than CD8 T cells as is commonly assumed. Consistent with this hypothesis, CD4 depletion also prevented acute mortality following MHC-mismatched transplant. FACS analyses of long-surviving hosts in this model revealed that T cells infiltrating the host gut epithelium were initially CD103- but progressively acquired CD103 expression concomitant with progressive epithelial injury. These data indicate that CD103 is preferentially expressed by CD8 T cells at late post-transplant intervals, and that effective blockade of GVHD pathology will likely require combined blockade of the CD4 and CD103 pathways.
Loss of MRP-14 Augments Costimulatory molecule Expression and Exacerbates Cardiac Allograft Rejection (145.47)
Authors: Shimizu Koichi , Folco Eduardo , Rocha Viviane , Simon Daniel , Libby Peter , Mitchell Richard 
Published: January 2023

Abstract
MRP-14 serves as an early serum marker for monitoring acute allograft rejection. Despite functioning as a putative pro-inflammatory mediator, the pathophysiological role of MRP-14 in cardiovascular disease remains unknown. This study used murine cardiac transplantation to investigate the role of MRP-14 in cardiac allograft rejection using MRP-14-deficient mice. Results: In MHC class II allomismatched cardiac transplantation, allograft survival averaged 5.9±2.9 weeks (n=10) in MRP14-/- recipients compared to &gt; 12 weeks (n = 15, p&lt;0.0001) in wild-type (WT) recipients. At 2 week post-transplantation, MRP14-/-recipient allografts had significantly higher parenchymal rejection (PR) scores (2.8±0.8, n=8) than WT recipients (0.8±0.8, n=12,p&lt;0.0001). MRP14-/-recipients had significantly increased allograft accumulation of T cells and macrophages and mRNA levels of IFN-γ, IP-10, Mig, and I-TAC compared to WT recipients. MRP14-/- dendritic cells (DC) stimulated with IFN-γ expressed significantly higher levels of the co-stimulatory molecules CD86 and ICOSL, and mixed leukocyte reaction using allo-EC-primed MRP14-/- DC resulted in significantly higher antigen-presenting function than WT DC. MRP14-/- DC infected with retroviral vector of MRP-8/14 expressed less CD80 and CD86 than those infected with control vector. Conclusion: This study indicates that MRP-14 modulates DC APC function and T cell priming and deficiency of MRP-8/14 complexes exacerbates acute allograft rejection.
The type 2 TNF receptor plays a critical role in the activation of Tregs in vivo. (34.3)
Authors: Housley William , O'Conor Catherine , Clark Robert 
Published: January 2023

Abstract
Recent studies suggest that regulatory T cells (Tregs) exhibit functional and phenotypic plasticity dependent on the local cytokine milieu. Previous reports have shown that TNF-α stimulates Treg proliferation in vitro and that the type 2 TNF receptor (TNFR2) is expressed on a subset of Tregs with increased in vitro function. We now report that TNFR2 is up-regulated on all activated Tregs and is required for normal Treg suppression in vivo and optimal maintenance of Foxp3 in vitro. Using a model of colitis, wild type (WT) or TNFR2-/- Tregs were transferred into RAG-1-/- mice together with WT CD4+CD25- effector T cells (Teff). TNFR2-/- Tregs were significantly less capable of suppressing both IFNg production and colitis. Surprisingly, TNFR2-/- and WT Tregs, activated in vitro prior to transfer, as well as iTregs generated in-vitro from WT or TNFR2-/- Teff, were identical in suppressive capacity in vivo. These results suggest that TNFR2 plays a critical role in the initial activation of Tregs in vivo. To determine if TNFR2 is involved in the stability of Tregs, Foxp3-GFP Tregs were sorted into TNFR2 High and TNFR2 Low populations and stimulated in-vitro with CD3ab and IL-2. After 3 days, the TNFR2 low population contained significantly fewer Foxp3+ cells than the TNFR2 high population. Overall, our results suggest that TNF-α signaling through TNFR2 may play a critical role in the initial activation of Tregs and may be an important factor for maintaining phenotypic stability.
Baicalein inhibits the enhancing effects of cigarette smoke extract (CSE) on inflammatory cytokine production in IL-1beta activated mast cells (35.5)
Authors: Chi David , Wu Fangbai , Lin Ta-Chang , Hall Kenton , Wu Zong , Krishnaswamy Guha 
Published: January 2023

Abstract
Human mast cells play a role in the pathogenesis of inflammatory airway diseases. We have reported that CSE increased IL-6 and IL-8 production in IL-1beta activated human mast cells (HMC-1). Baicalein (BAI) has been shown to have anti-inflammatory properties. This study aimed to examine the effect of BAI on IL-6 and IL-8 production in HMC-1. Two ml of HMC-1 at 1 x 106 cells/ml were cultured either with or without IL-1beta (10 ng/ml), and in the presence or absence of mainstream (Ms) or sidestream (Ss) CSE (0.25 mg/ml or 0.125 mg/ml), and BAI (30 μM). Treated HMC-1 were incubated for 24 hours and culture supernatants were collected and analyzed for the levels of IL-6 and IL-8 by ELISA. Both concentrations of Ms and Ss CSE significantly increased production of both IL-6 (p &lt; 0.0001) and IL-8 (p &lt; 0.0005) in IL-1beta activated HMC-1. BAI (30 μm) decreased IL-6 and IL-8 production in the Ms CSE (0.25 mg/ml) + IL-1beta treated HMC-1 culture from 2615 ± 38 to 251 ± 19 pg/ml (p &lt; 0.0000001) and from 583 ± 37 to 179 ± 7 pg/ml (p &lt; 0.0005), respectively. A similar inhibitory effect of BAI was also observed in the Ss CSE + IL-1beta treated HMC-1 culture. Our results show that BAI inhibits the enhancing effects of CSE on inflammatory cytokine production in IL-1beta activated mast cells. It suggests that BAI may be a novel candidate for treatment of smoking related inflammatory airway disease (Supported by the Ruth R. Harris Endowment and RDC of ETSU).
Direct comparison of Dll1- and Dll4-mediated Notch activation levels shows differential lympho-myeloid lineage commitment outcomes (36.27)
Authors: Mohtashami Mahmood , Shah Divya , Nakase Hiroshi , Kianizad Korosh , Petrie Howard , Zúñiga-Pflücker Juan Carlos 
Published: January 2023

Abstract
In the thymus, Notch signaling is known to be essential for T-lymphopoiesis, with the Notch ligand Delta like 4 (Dll4) being uniquely involved in this process. However, using stromal cell cultures, either Dll4 or Dll1 has been shown to support T-lymphopoiesis. To address which Dll is more effective at inducing hematopoietic progenitor cells to give rise to T-lineage cells in vitro, we generated OP9 cells expressing a series of incrementally discrete and equivalent levels of Dll1 or Dll4. In keeping with previous findings, OP9 cells expressing high levels of either Dll1 or Dll4 gave rise to T-lineage cells with similar efficacy, and prevented the differentiation of B- and myeloid-lineage cells. However, at limiting levels of Dll expression, Dll4 maintained its ability to inhibit B-lineage choice and induce T-lineage commitment and differentiation at lower levels of expression than Dll1. This manifest property of Dll4 is evident despite its lower levels of steady-state surface expression than Dll1 on OP9 cells. The heightened effectiveness of Dll4 over Dll1 also corresponded to the induction of expression of Notch target genes, and inhibition of B- and myeloid-specific transcription factors. Furthermore, OP9 cells expressing levels of Dll4 equivalent to those present in thymic epithelial cells gave rise to T-lineage cells, as expected, but were also permissive for the differentiation of myeloid cells, while still inhibiting the generation of B-lineage cells.
Phenotypic and functional characterization of group 1 CD1-restricted autoreactive T cells in a transgenic mouse model expressing human group 1 CD1 and a CD1b-specific T cell receptor (36.31)
Authors: Li Sha , Choi Hak-Jong , Shanmuganad Sharmila , Wang Chyung-Ru 
Published: January 2023

Abstract
Unlike other MHC molecules, the CD1 family presents self and foreign lipid antigens to multiple T cell subsets. In humans, this family consists of group 1 CD1 molecules CD1a, b and c and group 2 molecule CD1d. While CD1d-restricted NKT cells have been well-studied, our knowledge of the development and function of group 1 CD1-restricted T cells has been limited by the lack of a suitable animal model. We have generated double transgenic mice (hCD1Tg/HJ1Tg) that express the human group 1 CD1 proteins in a pattern similar to that observed in humans in addition to a TCR from a CD1b-restricted autoreactive T cell clone. Like NKT cells, the majority of HJ1Tg T cells that develop in hCD1Tg/HJ1Tg mice express NK markers and exhibit an activated phenotype. In addition, HJ1Tg T cells are highly enriched in the liver. The development of HJ1Tg T cells with the NKT cell phenotype is group 1 CD1-dependent, as NK1.1+ HJ1Tg T cells are absent in HJ1Tg mice that lack the human group 1 CD1 genes. Upon stimulation with group 1 CD1-expressing dendritic cells, HJ1Tg T cells primarily secrete proinflammatory cytokines, including IFN-γ, IL-17A, IL-6 and MCP-1. These cytokine productions can be further enhanced in the presence of TLR agonists, a phenomenon also observed in autoreactive NKT cells. The similarities between the phenotype and functional properties of HJ1Tg T cells and NKT cells suggest that these two autoreactive T cell subsets may play similar immunological roles.
Arrested bone marrow resident T cell committed progenitors in athymic nu/nu mice can give rise to alpha-beta T cells in an OP9DL1 co-culture system. (36.34)
Authors: Chatterjea Devavani , Garcia-Ojeda Marcos , Schwager Zachary 
Published: January 2023

Abstract
Bone marrow-resident committed T cell progenitors (CTP) are arrested at a Thy1.2hiLin-CD2- stage in athymic nu/nu mice. In WT mice, CTP progress to a Thy1.2hiLin-CD2+ intermediate stage that then can produce mature, function single positive T cells through thymic and extrathymic maturation pathways. The nu/nu bone marrow microenvironment, therefore, likely disrupts the T cell competence of these precursors during the transition from hematopoietic stem cell (HSC) to CTP prior to these cells leaving the bone marrow for the thymus or periphery. This defect is currently not characterized. We investigated the developmental potential of the arrested CTP from nu/nu bone marrow in a hyper-Notch signal environment induced by the OP9DL1 co-culture system that is able to support the development of mature single-positive T cells from HSCs, embryonic stem cells (ESC) and double negative thymocytes. We found that the OP9DL1 co-culture microenvironment allows the arrested nu/nu CTP to progress to the Thy1.2+Lin-CD2+ intermediate stage as well as to double positive CD4+CD8+ and single positive CD4 and CD8 αβ T cells. It is likely therefore that Notch signaling is compromised in the bone marrow of nu/nu mice and this dysregulated signaling results in the absence of acquisition of T cell competence by early hematopoietic precursors in the bone marrow of these congenitally athymic mice.
The development of iNKT cells is dependent on a full complement of functional CD3 ζ ITAMs (36.39)
Authors: Eitson Jennifer , Becker Amy , Norgard Michael , van Oers Nicolai 
Published: January 2023

Abstract
Invariant natural killer T (iNKT) cells are involved in the early phase of an immune response and are proposed necessary for reducing the severity of Lyme disease during Borrelia burgdorferi infection. Little is known about the number of functional TCR encoded ITAMs required for iNKT cell selection and expansion. We analyzed iNKT cell development in CD3 ζ transgenic lines with various tyrosine to phenylalanine substitutions (YF) that eliminated some or all phospho-ζ intermediates. iNKT cell numbers were significantly reduced in the thymus, spleen, and livers of the YF lines compared to wild type mice. Interestingly, the extent of cardiac tissue damage and inflammation in response to B. burgdorferi infections was similar in the YF lines compared to wild type controls, and even mice lacking all iNKT cells (Ja18-null animals). The relative expression of two key transcription factors, Egr2 and PLZF, was significantly reduced in the YF lines. This suggests that the magnitude of TCR/ITAM-driven signals controls the expression of two key transcription factors essential for iNKT cell development. Thus, while a full complement of functional CD3 ζ ITAMs is required for iNKT cell development, these cells are not essential for controlling arthritis or carditis following B. burgdorferi infections.
Modeling the Role of Antigen Stimulation in Treg vs. Teff Fate Selection (36.52)
Authors: Sekar John , Miskov-Zivanov Natasa , Turner Michael , Morel Penelope , Faeder James 
Published: January 2023

Abstract
Peripheral naïve T-cells differentiate into regulatory, helper and other effector cells in response to a cognate antigen. The relative numbers produced of each cell type are critical for immune tolerance and affect tumor and immune-related pathologies. Specifically, the differentiation of CD25+ Foxp3+ regulatory T cells (Treg) is dictated by antigen dose with sensitivity and maintenance effects from TGF-β and IL-2. These overlapping external signals are conveyed and regulated by key intracellular players such as PI3K, PTEN, DNMT1 and Akt/mTor, eventually converging on transcription factors that control the induction of Foxp3 expression. To better understand this intricate system, we have constructed a logical model in which each molecule type is treated as an on/off variable, permitting all known intracellular players to be modeled simultaneously without adjustable parameters. Key subsystems will be modeled later at higher resolution using chemical kinetics and these models will be linked to form a comprehensive, detailed model of T cell differentiation. As a preliminary result, the logical model reproduces the experimental observation that low dose antigen favors Treg induction in the absence of exogenous TGF-β or IL-2. Construction of this model has already suggested novel experimental avenues and identified key components requiring theoretical attention. Experiments suggest that a population model with interacting and evolving phenotypes is needed to complete the picture.
Molecular Basis for Loss of VH4-encoded pre-B cells in Mutant Rabbits (36.7)
Authors: Robbins Gregory , Knight Katherine 
Published: January 2023

Abstract
Developing B cells in mutant ali/ali rabbits predominantly utilize VH4 during VDJ gene rearrangement. However, most of the VH4-utilizing B cells encounter a severe developmental block at the pre-B cell stage. In contrast, wildtype rabbit B cells predominantly rearrange VH1, a gene &gt;90% identical to VH4, and develop normally. We seek to determine how these nearly identical VH genes have profoundly different effects on B cell development. We hypothesize that VH4-utilizing cells are blocked at the pre-B stage due to weak interaction of the μ-chain with surrogate light chain (SL). We expressed VH4-utilizing μ-chains in a pro-B cell line that expresses SL and found that VH4-encoded μ-chains exhibit a 2 fold reduction in preBCR surface localization compared to control VH1-encoded μ-chains. Remarkably, a single amino acid substitution in VH4-framework region 2 (FR2) from tyrosine to an evolutionarily conserved tryptophan, found in VH1 and most VH genes of other species, restored surface preBCR expression. We are testing if this tryptophan substitution in FR2 of VH4 is sufficient to rescue pre-B cell development. These studies should identify evolutionarily conserved VH structural regions required for efficient preBCR formation and B cell development.
IFNgamma Induces Expansion of Hematopoietic Progenitor Cells (36.9)
Authors: Zhao Xin , Ren Guangwen , Liang Li , Ai Phillip , Zheng Betty , Tischfield Jay , Shi Yufang , Shao Changshun 
Published: January 2023

Abstract
The balance between type 1 and type 2 helper T (Th1 and Th2) cells is critical for homeostasis of the immune system, since their distinct cytokine production profile directly determines the activation and functions of other immune cells. However, as the end-differentiated lineage cells, how these effector T cells influence the hematopoietic progenitor cells, is largely unknown. Here we showed that Th1 cell products, but not those of Th2 cells, caused a remarkable expansion o f lineage-Sca-1+C-kit+ (LSK) cells. IFNgamma was found to play a major role in this expansion by activating the expression of Sca-1 in lineage-Sca-1-C-kit+ cells, thus converting them into LSK cells. This process was dependent on IFNgammaR1 signaling, but only partially mediated by STAT1 pathway. Furthermore, such IFNgamma-induced LSK cells had a significantly higher colony forming units (CFUs), compared to control lineage-Sca-1-C-kit+ cells and control LSK cells, which might compensate for the loss of progenitor cells caused by the IFNgamma-treatment. Moreover, the IFNgamma-induced expanded LSK cells were verified as functional stem/progenitor cells through the competitive repopulation experiments in vivo. Finally, the IFNgamma-induced hematopoiesis was more biased toward the differentiation of myeloid lineages in vitro and in vivo. Therefore, our findings demonstrated a novel role of IFNgamma in hematopoiesis, thus providing a new insight into the clinical application of IFNgamma.
Comparison of Global Transcriptional Responses of Chicken Following Primary and Secondary Eimeria acervulina Infections (37.13)
Authors: Lillehoj H. , Kim Chul-hong , Kim Duk Kyung , Keeler C. 
Published: January 2023

Abstract
In this stuy, we compared chicken gene transcriptional profiles following primary and secondary infections with Eimeria acervulina using a 9.6K avian intestinal intraepithelial lymphocyte cDNA microarray (AVIELA). Gene Ontology analysis showed that primary infection significantly modulated the levels of mRNAs for genes involved in the metabolism of lipids and carbohydrates as well as those for innate immune-related genes. By contrast, secondary infection increased the levels of transcripts encoded by genes related to humoral immunity and reduced the levels of transcripts for the innate immune-related genes. Because the observed modulation in transcript levels for gene related to energy metabolism and immunity occurred concurrent with the clinical signs of coccidiosis, these results suggest that altered expression of a specific set of host genes induced by Eimeria infection may be responsible, in part, for the observed reduction in body weight gain and inflammatory gut damage that characterizes avian coccidiosis.