bluuebunny/crossref_metadata_2025_split huggingface dataset:
Disease stage-dependent response of lupus-prone mice to antibiotics
Authors: Mu Qinghui , Zhang Husen , Luo Xin M 
Published: January 2023

Abstract
Little is known on the role of commensal bacteria in lupus. We previously showed that a higher abundance of Lactobacillaceae and a lower abundance of Lachnospiraceae are correlated with improved lupus symptoms in lupus-prone MRL/lpr mice. In the same study, it was noted that Lactobacillaceae (“good” bacteria) was more abundant in the gut of pre-disease lupus mice, while Lachnospiraceae (“bad” bacteria) was relatively more abundant after disease onset. We thus hypothesized that antibiotic use after disease onset might have a greater impact on “bad” than “good” bacteria, thus attenuating the disease. To test this hypothesis, we treated MRL/lpr mice with antibiotics starting from 3 weeks (pre-disease, Abx-3w) or 9 weeks of age (after disease onset, Abx-9w). Consistent with the results obtained from germ-free MRL/lpr mice, Abx-3w did not change disease course or severity. Treatment with Abx-9w, however, was able to significantly reduce spleen and lymph node weight, serum level of anti-dsDNA IgG, proteinuria, and renal pathology. Bacterial profiling analysis revealed that &gt;99% of bacteria were removed by Abx-3w, while 20% bacteria remained with Abx-9w treatment, where Lactobacillales and Enterobacteriales were enriched. Further studies are underway to investigate the immunological mechanisms of how Abx-9w attenuated lupus in these mice. The results of this study will increase our understanding of how environmental triggers, such as antibiotic use, are associated with lupus.
Characterization of the microbiome in association with reduced diabetes incidence in AhR deficient NOD mice
Authors: Ehrlich Allison , Pennington Jamie , Greer Renee , Shulzhenko Natalia , Kerkvliet Nancy 
Published: January 2023

Abstract
AhR activation by the ligands TCDD and Cl-BBQ leads to potent immunosuppression and prevents hyperglycemia in NOD mice. In addition to exogenous treatment, AhR can be activated by endogenous ligands that control inflammation. AhR−/− mice on the C57Bl6 background have enhanced inflammatory responses following infectious or allergenic exposure in comparison to AhR wild type mice. We generated AhR−/− mice on the NOD background and hypothesized they would display an increased incidence of diabetes. Surprisingly, the opposite finding was observed; in the absence of AhR, female NOD mice have a significantly reduced onset of diabetes in comparison to wild type mice. A similar trend was observed between knockout and wild type male mice. While immune cell composition was unchanged in the pancreatic LN, an increase in the percentage of F4/80+ macrophages and CD25+Foxp3+ T cells was observed in mesenteric LN of NOD.AhR−/− mice. Changes in gene expression in the ileum of NOD.AhR−/− mice included reduced Gzmb, Il10 and Lcn2. Commensal bacteria (including SFB and Akkermansia) have been identified that influence diabetes incidence in the NOD mouse model. It has been shown that microbial biproducts can activate AhR, and in turn, AhR activation (or lack thereof) can impact the microbiome. Thus, we hypothesize that NOD.AhR−/− mice have altered microbiota and that these changes contribute to the reduction in diabetes incidence. Initial observations demonstrated changes in fecal consistency and an increase in SFB associated with AhR deficiency. Current studies are focused on determining if shifts in the microbiome are directly associated with the reduction of diabetes incidence in NOD.AhR−/− mice.
Metabolic inhibitors elimiante the expansion of autoimmune follicular helper T cells but not that induced by T-dependent-immunization in lupus mice
Authors: Choi Seung-Chul , Yin Yiming , Morel Laurence 
Published: January 2023

Abstract
The expansion of follicular helper CD4 T (Tfh) cells is tightly associated with disease severity in lupus patients, following multiple studies in various mouse models showing that they are necessary for the production of class-switched high-affinity pathogenic autoAbs. We have recently shown that both glycolysis and mitochondrial oxidative metabolism are elevated in CD4 T cells from lupus prone B6.Sle1.Sle2.Sle3 (TC) mice as compared to B6 controls, and that a treatment combining 2-deoxy-D-glucose (2-DG), which inhibits glucose metabolism, and metformin, which inhibits oxygen consumption, normalized lupus T cell functions in vitro and reverted disease. We have expanded these results to B6.lpr, BXSB.Yaa and NZB/WF1 models of lupus. Remarkably, the number and the frequency of Tfh cells was normalized in these 4 models of lupus treated with a combination of 2DG and metformin, corresponding to a drastic reduction of autoantibodies. Treatment of normal or lupus-prone mice with the same inhibitors had however little effect on the production of TD antibodies or the expansion of Tfh cells following immunization with a nominal antigen. This suggests that Tfh cells supporting the production of autoAbs are quantitatively or qualitatively different from Tfh cells providing protective humoral immunity against pathogens. Moreover, it suggests that autoimmune Tfh cells have higher metabolic requirements than the metabolically quiescent Tfh cells that have been recently described in TD-responses. Studies to characterize the specific metabolic requirements of autoimmune Tfh cells are ongoing. Overall, our results predict that targeting Tfh cellular metabolism provides an effective and safe therapeutic approach for systemic autoimmunity.
CD4 Expression on Splenic DCs Coordinates their Positioning in a Cell-Intrinsic Manner and is Necessary for Optimal CD4+ T cell Activation
Authors: Stolley J. Michael , Campbell Daniel J. 
Published: January 2023

Abstract
The immunological dogma of MHC-class restriction states helper T cells expressing the co-receptor CD4 perceive antigen in the context of MHC-class II while cytotoxic CD8+ T cells recognize antigen presented on MHC-class I. Paradoxically, dendritic cells (DCs) which express high levels of MHC molecules (yet lack recombined antigen receptors) differentially express CD4 and CD8α, which have classically been used to subset DC populations within secondary lymphoid tissues. Why DCs concurrently express MHC molecules and T cell co-receptors has puzzled immunologists since their discovery on DCs in the mid 1990’s. However, studying the function of these molecules on DCs is confounded by the fact that their T cell counterparts are absent in CD4 or CD8α-deficient mice. Here using a mixed chimera system in which CD4 deficiency can be restricted specifically within the DC compartment, we show CD4-expression on DCs is necessary to drive optimal antigen-specific CD4+ T cell proliferation in vivo. Impaired T cell proliferation which occurs when DCs lack CD4 appears to result from their inability to efficiently access the T cell follicle. Therefore, DC-intrinsic CD4 expression coordinates the micro-anatomical positioning of DCs within the spleen and is necessary for optimal CD4+ T cell activation.
Trafficking of IL-17-producing CD4+, but not CD8+, T cells to the skin requires CCR6 expression
Authors: Kish Danielle , Fairchild Robert L 
Published: January 2023

Abstract
Contact hypersensitivity (CHS) is a CD8-mediated response to hapten sensitization and challenge of skin. During elicitation of CHS, hapten-primed CD8 T cells producing IFN-g and IL-17 are recruited to the challenge site by hapten-presenting endothelial cell (EC)-derived chemokines. Our previous results have shown that CXCL9 directs localization of IFN-g producing CD8 T cells to the challenge site, but chemokines directing localization of IL-17-producing CD8 T cells to the site remain unknown. DNFB hapten application to the skin of sensitized mice or to EC in culture induced TNFa-dependent expression of CCL20 within 1 h. Hapten-stimulated ELISPOT assay of flow-sorted CD8 T cells from draining lymph nodes of sensitized mice indicated many CCR6+CXCR3+ and CCR6+CXCR3− producing IL-17, but low numbers of CCR6−CXCR3+ cells producing IL-17. Hapten-induced IFN-g production was restricted to CXCR3+ CD8 T cells. Anti-CCL20 mAb did not inhibit CHS responses when given to sensitized WT mice during challenge and normal CHS responses were observed in sensitized and challenged CCR6−/− mice. Sensitized CCR6−/− mice had increased hapten-specific IFN-g and IL-17 producing CD8 T cells in the skin-draining lymph nodes when compared to sensitized WT mice. In contrast to sensitized WT mice, sensitization of CCR6−/− mice also induced high numbers of hapten-primed CD4+T cells producing IFN-g and IL-17. However, depletion of CD8, but not CD4, T cells from sensitized CCR6−/− mice abrogated the CHS response to hapten challenge. These results indicate that the CD8 T cell mediated CHS response can occur independently of CCR6 expression whereas trafficking of hapten-primed CD4 T cells to the skin to mediate the response requires CCR6.
Caveolin-1 is critical for Lymphocyte Trafficking into Central Nervous system during Experimental Autoimmune Encephalomyelitis
Authors: WU HAO , Deng Rui-xia , Chen Xing-miao , Wu Wu-tian , Shen Jian-gang 
Published: January 2023

Abstract
Multiple Sclerosis (MS) is a progressive autoimmune disease in central nervous system (CNS) with its pathogenesis not fully understood. In the present study, we demonstrated that caveolin-1, a major membrane scaffolding protein, plays a critical role in experimental autoimmune encephalomyelitis (EAE), a laboratory murine model of multiple sclerosis (MS). Immunized WT mice have increases of caveolin-1 expressions in serum and CNS tissues associated with disease development. After immunization, Cav-1knockout mice showed remarkable resistance with alleviated incidences and symptoms. With caveolin-1 deficiency, encephalitogenic T lymphocytes processed less efficient trafficking into CNS parenchyma, probably a sequence of declined expressions of adhesion molecule ICAM-1 and VCAM-1 in the white matter of CNS tissues. In agreement with in vivo studies, in vitro silencing of caveolin-1 in endothelial cells prevented the up-regulation of ICAM-1 expression, leading to less trans-endothelial migration of encephalitogenic TH1 and TH17 cells. Taken together, the results indicate caveolin-1 as an active modulator of lymphocyte trafficking into CNS and may be a potential therapeutic target for neuroinflammatory diseases.
Neutrophil recruitment limited by high affinity bent β2 integrin binding ligand in cis
Authors: Fan Zhichao , McArdle Sara , Mikulski Zbigniew , Gutierrez Edgar , Ginsberg Mark , Groisman Alex , Ley Klaus 
Published: January 2023

Abstract
Neutrophils are essential in innate immunity and inflammation. Many neutrophil functions are β2 integrin-dependent. Integrins can extend (E+) and acquire a high affinity conformation with an “open” headpiece (H+). The canonical switchblade model of integrin activation proposes that the E+ conformation precedes H+, and the two are believed to be structurally linked. Here, by using high-resolution quantitative dynamic foot printing (qDF) microscopy combined with a homogenous conformation-reporter binding assay in a microfluidic device, we show that a substantial fraction of β2 integrins on human neutrophils acquires an unexpected E−H+ conformation. Beside the observations consistent with the canonical switchblade model, we discovered a new alternative model that some β2 integrins transition from E−H− to E−H+ to E+H+ during activation. Using flow cytometry based Förster resonance energy transfer (FRET) assay, we find out that E−H+ β2 integrin binds its ligand intercellular adhesion molecule 1 (ICAM-1) in cis. And this cis binding significantly inhibits the conformational transitioning of β2 integrin from E−H+ to E+H+ and the neutrophil adhesion under flow, which indicates a novel endogenous anti-inflammatory mechanism inhibits neutrophil accumulation and inflammation.
Induction of adipose-resident NKT cells can be instructed by non ligand-binding motifs of the TCR β chain.
Authors: Vieth Joshua A , Das Joy , Ranaivoson Fanomezana , Comoletti Davide , Denzin Lisa K , Sant’Angelo Derek B 
Published: January 2023

Abstract
Invariant Natural Killer T (NKT) cells, a CD1d-restricted subset of αβ T cells, have been increasingly recognized for their role in a wide variety of functions associated with autoimmunity, cancer, infection, tolerance, and obesity. The semi-invariant TCR expressed by NKT cells is unique in its recognition of glycolipids presented by CD1d, heterodimer rigidity, and limited binding footprint compared to conventional TCR:MHC interactions. This distinctive interaction has been studied extensively in vitro, though the role of the rigid α:β heterodimer in the selection and development of NKT cells remains elusive. We investigated a hydrophobic patch on the β chain of the NKT TCR, suggested to play a role in heterodimer stability. Partial disruption of this patch, while permissive of ligand binding, resulted in decreased populations of NKT cells, diminished development, and effector function. Complete disruption of the patch resulted in the ablation of the NKT cell compartment entirely, while still accommodating conventional T cell development. NKT cells expressing the mutant NKT TCR acquired an adipose-resident NKT phenotype while in the thymus, and accumulated in the adipose tissue in mice. Hence, we show that in vivo, non-ligand binding regions of the NKT TCR are critical for the development of these important immune cells, and mediate the selection of adipose-resident NKT cells.
Development of a scurfy-like phenotype in Foxp3-YFP-cre NKAP cKO mice
Authors: Dash Barsha , Constans Megan , Chung Ji Young , Arocha Sinibaldo Romero , Shapiro Virginia 
Published: January 2023

Abstract
NKAP is a transcriptional repressor required at various stages of conventional αβ T cell development. Here, we asked if NKAP is also required in regulatory T cells. To answer this, we created Foxp3-YFP-cre NKAP conditional knock-out (cKO) mice in which NKAP deletion occurs upon the expression of Foxp3 during Treg development in the thymus. Deletion of NKAP results in lethal autoimmunity necessitating euthanasia at 3–4 weeks of age that is reminiscent of Foxp3-deficient scurfy mice. Foxp3-YFP-cre NKAP cKO mice present uncontrolled conventional T cell activation, Treg abnormalities and a reduction of total number of Tregs in the periphery. Therefore, NKAP is required for Treg dependent peripheral tolerance.
Src-Like Adaptor Protein 2 regulates NKT lineage diversification
Authors: Tuttle Kathryn , Peterson Lisa K. , Bedel Romain , Zhang Jingjing , Dragone Leonard L. , Gapin Laurent 
Published: January 2023

Abstract
Natural Killer T (NKT) cells are a class of αβ T cells that express a semi-invariant T Cell Receptor (TCR) and recognize glycolipids presented by the non-polymorphic MHC molecule, CD1d. NKT cells are considered to be innate-like lymphocytes because they produce a robust cytokine response within hours of stimulation. This ‘poised effector’ state is acquired during development in the thymus, where NKT precursors differentiate into one of three distinct subsets and acquire TH1, TH2, or TH17 effector functions. It is not known which signals control the divergence of NKT1, NKT2 and NKT17 subsets. We have identified a novel role for Src-like adaptor protein 2 (SLAP2) in regulation of NKT cell development. We have found that SLAP2-deficiency causes accumulation of thymic NKT cells and alters lineage diversification. In the absence of SLAP2, the frequency and number of thymic NKT2 and NKT17 cells are increased with a concomitant decrease in NKT1 cells. SLAP2−/− NKT cells express elevated levels of PLZF and higher levels of CD5, both of which are downstream of TCR signals. Although SLAP2 has been shown to negatively regulate TCR signaling in vitro, analysis of SLAP2−/− thymocytes revealed that TCR levels and signaling in CD4+CD8+ double positive thymocytes are normal. These data suggest that SLAP2 does not directly regulate TCR during development, in vivo. The numbers and proportions of conventional αβ T cells are largely unaffected by SLAP2-deficiency. In light of these data, we predict that SLAP2 regulates signals that are important for NKT lineage diversification but are dispensable for conventional T cell development.
In utero induction of mixed chimerism results in deletion, receptor editing, and functional inactivation of antigen specific alloreactive B cells
Authors: McClain Lauren E , Kim Aimee G , Flake Alan W , Luning Prak Eline T , Peranteau William H 
Published: January 2023

Abstract

Purpose
B cell tolerance is critical for donor cell engraftment across immune barriers after in utero hematopoietic cell transplantation (IUHCT). Using our fetal transplant model we studied how B cells achieve tolerance to allogeneic MHC antigens.

Methods
10×106 C57Bl/6-GFP (H2Kb) bone marrow (BM) cells were injected intravenously into gestational day 14 Balb/c (H2Kd) fetuses. Mice were sacrificed at 3 days (P3), 1 and 4 months of age and donor-specific B cell tolerance including deletion, receptor editing and functional inactivation were assessed. Age matched naïve C57Bl/6 and Balb/c mice served as controls.

Results
The % of alloantigen specific splenic B cells was significantly decreased in allogenic chimeras as compared to controls (p=0.016) consistent with clonal deletion. Alloreactive B cells that escape deletion can undergo receptor editing. There was a significant increase in the % of B cells undergoing editing (lambda light chain expression) at P3 in recipients of IUHCT compared to controls (10.8% vs. 8.4%; p=0.02). Alloreactive B cells can be functionally inactivated such that they no longer make antibodies or express IgM. In contrast to naïve Balb/c mice immunized with C57Bl/6 splenocytes, immunization of recipients of IUHCT failed to elicit an anti-donor antibody response (MFI fold change: IUHCT-0.89 naïve-2.77; p&lt;0.05). Furthermore, IgM expression on alloantigen specific splenocytes in chimeric animals was lower than controls (MFI: chimeric-1206, control-1472 ; p=0.03).

Conclusion
B cell tolerance after IUHCT is achieved by partial deletion in alloreactive splenic B cells, receptor editing in early mature splenocytes, and the remainder of alloreactive B cells demonstrate a functionally inactive phenotype.
X chromosome gene Ddx3x is involved in B-cell development
Authors: Liu Ke , Karmele Erik P , Perlot Thomas , Penninger Josef M , Waggoner Stephen N , Harley John B 
Published: January 2023

Abstract
Ddx3x, located on the X chromosome, belongs to the DEAD box RNA helicase family. Ddx3x is previously implicated in RNA metabolism, cell cycle control, apoptosis, tumorigeneses and viral infections.
In the process of exploring the role of ddx3x in the female predominance of systemic lupus erythematosus, we found abnormalities in B-cell development within conditional ddx3x-deficient mice.
Breeding of ddx3x-floxed mice with Vav1-Cre mice led to deletion of ddx3x in hematopoietic cells (Vav1ddx3x). Ddx3x expression was reduced 80% in the bone marrow (BM) of Vav1ddx3x mice. Hematopoietic deficiency of ddx3x is associated with a reduced proportion and absolute number of B cells, starting at the small pre-B cell stage, and then subsequently immature B cells and mature B cells in bone marrow, relative to wild-type mice. In spleen, the frequency and number of follicular B cells (FOB) were significantly decreased whereas the numbers of marginal zone, germinal center and plasma-blast B cells were sustained. Mixed Vav1ddx3x and wild-type bone marrow chimera mice demonstrated a B-cell intrinsic effect. Surprisingly, despite fewer B cells in the BM and spleen, serum IgM, IgA and IgG titers were elevated in Vav1ddx3x mice, suggesting ddx3x may affect B-cell function as well.
In conclusion, we showed that ddx3x deficiency affects B-cell development resulting in a loss of B cells in bone marrow and the periphery and an increase in serum immunoglobulin levels.
EZH2 regulates cell cycle and survival in B and T lymphocyte progenitors
Authors: Jacobsen Jennifer Andrene , Woodard Jennifer , Kee Barbara L 
Published: January 2023

Abstract
The histone methyltransferase EZH2 catalyzes the H3K27me3 histone modification, which is broadly associated with repressed and poised chromatin. EZH2 is required for both B and T cell development, but its specific role in these lineages is not clear. Here we used an Il7racre to delete Ezh2 in all lymphocytes. We confirmed that EZH2 is required for B and T cell development, but found that it was dispensable during NK cell development. EZH2-deficient pro-B cells failed to expand in vitro, and showed increased apoptosis and cell cycle defects. These cells expressed increased mRNA from the cell cycle regulators, p16/INK4a and p19/ARF, which are encoded at the Cdkn2a locus and are known targets of EZH2 in other tissues. ARF prevents ubiquitin-mediated degradation of the tumor suppressor p53 leading to cell cycle defects and apoptosis. p53 was increased in EZH2-deficient pro-B cells and canonical p53 target genes were also increased. We crossed EZH2-deficient mice to the Cdkn2a−/− background to determine whether Cdkn2a upregulation affected B and T cell development in EZH2-deficient mice. Abrogation of Cdkn2a partially rescued B cell development and robustly restored T cell development in EZH2-deficient mice. These results indicate that EZH2 is required for survival and cell cycle regulation in B and T cell progenitors.
Regulation of B cell responses in allergy by histamine receptors
Authors: Velez Tania Estefania , Swartzendruber Julie A , Hulse Kathryn E , Bryce Paul J. 
Published: January 2023

Abstract
Histamine is a bioactive amine stored in mast cells and basophils and released upon antigen-specific IgE-dependent activation, mediating responses during allergic reactivity, including vasodilation, smooth muscle constriction and inflammatory cell recruitment. These are regulated through four receptors (H1R-H4R) that are differentially expressed on various cell types. Despite this, increasing evidence suggests that histamine can be produced during the priming phase of allergen responses, with H4R on dendritic cells being important for initiating Type 2 immunity. Here, we sought to determine the roles of these receptors in supporting antigen-specific B cell responses. Interestingly, our data demonstrates that both murine and human B cells only expressed H1R and H2R; these also showed differential expression levels on specific B cell subsets and upon activation. Using an Ovalbumin-alum (OVA-alum) model of allergic immunization, mice lacking H2R produced significantly lower levels of OVA-IgE, whereas mice lacking H1R were unaffected. Surprisingly, absence of both H1R and H2R (H1R/H2R DKO) exhibited undetectable levels of OVA-IgE. This was not due to T cell-intrinsic influences since restimulation of splenocytes from immunized H1R/H2R DKO mice showed that Th2 cytokine production was unaltered compared to WT. Instead, in vitro stimulation of B220+ B cells by αCD40 and IL-4 yielded significantly lower IgE production from H1R/H2R DKO mice than WT and defines a key requirement for these receptors in permitting B cells from generating IgE antibodies. Our data establishes a novel requirement for histamine, a molecule typically considered in regulating allergic responses, in supporting the generation of allergic sensitivity.