bluuebunny/crossref_metadata_2025_split huggingface dataset:
Induction of immunological tolerance by pulmonary macrophages during chronic exposure to house dust mite antigen (P6212)
Authors: Bracken Sonali , Guernsey Linda , Szczepanek Steven , Natarajan Prabitha , Adami Alexander , Beck Jeremy , Ehsan Mohsin , Thrall Roger 
Published: January 2023

Abstract
Allergic asthma is a leading cause of morbidity in industrialized nations. While the emphasis of most studies pertaining to the attenuation of asthma after chronic antigen exposure has focused on the local generation of Tregs, little attention has been paid to the potentially crucial role of pulmonary macrophages (MΦ) in disease resolution. To determine whether these MΦ are involved in tolerance generation, C57BL/6 mice were challenged intranasally with house dust mite (HDM) extract both acutely (2 and 5 weeks) and chronically (11 weeks) to induce an asthma-like phenotype (n=3-6 per group). Compared to acutely-challenged mice, MΦ frequency increased over two-fold in the airways of chronic HDM-exposed mice (P&lt;0.001). This finding correlated with increases in local Foxp3+ Tregs as well as resolution of pulmonary eosinophilia (P&lt;0.01) and airway hyper-reactivity (P&lt;0.01). Flow cytometric analysis of naïve IL-10 GFP mice confirmed that pulmonary MΦ produce high amounts of IL-10. Following chronic HDM exposure, these MΦ may expand in the lungs and influence tolerance development directly through IL-10 or indirectly through effects on Tregs. We also observed 3- to 7-fold increases in serum MCP-1, MIP-1α, and MIP-1β following chronic but not acute HDM exposure, which suggests that these MΦ are derived from monocytes recruited to the site of inflammation. Collectively, these data suggest a novel role for pulmonary MΦ in the generation of tolerance in an experimental model of asthma.
Complement regulatory protein properdin promotes complement activation on platelets and increases platelet-leukocyte aggregate formation (P1311)
Authors: Ferreira Viviana , Saggu Gurpanna , Nauli Surya , Cortes Claudio 
Published: January 2023

Abstract
An increased number of activated platelets and platelet-leukocyte aggregates are found in patients with chronic inflammatory diseases. Activated platelets can activate the complement system. We have recently determined that properdin, a positive regulator of the alternative pathway that is produced mainly by stimulated leukocytes, promotes complement activation on activated, but not resting, platelets. Unfractionated properdin (that has non-physiological aggregates) induces formation of platelet-leukocyte aggregates. However, the roles that physiological dimers, trimers, and tetramers of properdin play, as well as the molecular mechanisms by which the alternative pathway is involved in this phenomena remain unknown. Here, we have determined that (a) activated platelets, as well as neutrophils, bind physiological forms of properdin and neutrophil-derived properdin; (b) properdin mediates a novel mechanism for alternative pathway activation on activated platelets; and (c) physiological properdin leads to increased platelet-leukocyte aggregate formation in thrombin receptor-stimulated whole blood. The effects of shear stress in properdin-induced aggregate formation and differences between leukocyte subpopulations in platelet-leukocyte aggregate formation have also been assessed. Our data support a role for properdin in cellular microenvironments, contributing to complement activation and aggregate formation, with potential consequences in inflammation pathophysiology.
Pro-apoptotic chemotherapeutic drugs induce non-canonical processing and release of IL-1β via caspase-8 activation in dendritic cells (P1353)
Authors: Antonopoulos Christina , Kaiser William , Mocarski Edward , El Sanadi Caroline , Dubyak George 
Published: January 2023

Abstract
The emergence of non-canonical (caspase-1 independent) IL-1β production has unveiled an intricate interplay between inflammatory and death-inducing signaling platforms. We compared the relative contributions of canonical versus non-canonical IL-1β processing in murine bone marrow-derived dendritic cells (BMDC) stimulated with pro-apoptotic chemotherapeutic agents such as doxorubicin (Dox). Dox induced a release of mature (17 kDa) IL-1β from LPS-primed BMDC that was temporally correlated with caspase-8 activation and greatly suppressed in BMDC from Casp8-/-Rip3-/- mice. The magnitude of Dox-stimulated IL-1β release from Casp1-/-Casp11-/- BMDC or wild-type (WT) BMDC treated with YVAD caspase-1 inhibitor was similar to that in non-YVAD-treated WT BMDC. Neither ASC nor NLRP3 were required for Dox-stimulated IL-1β release. In contrast, Dox-induced IL-1β release was suppressed in LPS-primed TRIF-/- BMDC. This indicated interaction with a TLR4-TRIF pathway for assembly of RIP1/FADD/procaspase-8 ripoptosome complexes. Current studies focus on characterizing the ability of Dox to induce down-regulation of cIAPs and/or cFLIP which act to restrain the stability/proteolytic activity of caspase-8 containing ripoptosomes. These findings show that Dox promotes caspase-8-dependent release of IL-1β, implicating direct effects of such genotoxic chemotherapeutic drugs on a non-canonical inflammatory cascade that may modulate immune responses in tumor microenvironments.
IRF-5 and NF-κB p50 co-regulate IFN-β and IL-6 expression in TLR9-stimulated human plasmacytoid dendritic cells (P1363)
Authors: McFarland Adelle , Steinhagen Folkert , Rodriguez Luis , Tewary Poonam , Jarret Abigail , Savan Ram , Klinman Dennis 
Published: January 2023

Abstract
Robust production of type I interferon (IFN) by plasmacytoid dendritic cells (pDCs) occurs in response to Toll-like receptor 9 (TLR9) activation by unmethylated CpG dinucleotides present in bacterial and viral DNA. Previous work using different CpG oligodeoxynucleotides (ODN) revealed that CpG-A ODN but not CpG-B ODN robustly induce IFN-α production in pDCs. Although CpG-B ODN do not efficiently induce IFN-α, they are capable of highly inducing IFN-β. However, it is currently unclear what factors mediate CpG-B ODN induction of IFN-β in human pDCs. Using nuclear translocation, siRNA and proximity ligation assays, we demonstrate a requirement for both IRF-5 and NF-κB p50 in the induction of IFN-β and IL-6 by CpG-B ODN in human pDCs. The finding that CpG-B ODN activation of IRF-5 leads to IFN-β production in human pDCs may have clinical importance as IRF-5 has recently been identified as a major risk locus in systemic lupus erythematosus (SLE), a disease largely driven by aberrant type I IFN production by pDCs. Overall, this study provides new insights into the transcriptional regulation of IFN-β and IL-6 induced by CpG-B ODN in human pDCs and identifies a clinically important link between IRF-5 and IFN-β.
Towards understanding the influence of lipid metabolism on CD8 T cell biology (P1136)
Authors: Kidani Yoko , Elsaesser Heidi , Hock M. , Vergnes Laurent , Williams Kevin , Argus Joseph , Marbois Beth , Komisopoulou Evangelia , Wilson Elizabeth , Osborne Timothy , Graeber Thomas , Reue Karen , Brooks David , Bensinger Steven 
Published: January 2023

Abstract
A hallmark of the adaptive immune system is the ability of CD8 T cells to undergo rapid clonal expansion in response to antigenic stimulation. To meet the biosynthetic requirements of rapid growth and proliferation, effector T cells must reprogram their metabolism to provide essential macromolecules. We have previously shown that mitogen signaling induces a gene expression program that drives de novo cholesterol and fatty acid biosynthesis, however the molecular events linking antigen receptor signaling with lipid anabolism remain poorly understood. Herein, we demonstrate an essential role for sterol regulatory element binding proteins (SREBPs) in the acquisition of effector cell metabolism. Without SREBP signaling, CD8 T cells are unable to grow and acquire the effector cell metabolism program, resulting in attenuated clonal expansion during viral infection. In contrast, SREBPs are dispensable for homeostatic proliferation, demonstrating a context-specific requirement for SREBP signaling during effector T cell blastogenesis. Mechanistic studies indicate that SREBP activity is required to maintain a level of cellular cholesterol sufficient to permit rapid ER and cellular growth. Taken together, these studies provide novel insights into the molecular signals underlying the metabolic reprogramming of CD8 T cell during the transition from quiescence to activation, and demonstrate the importance of SREBPs in regulating a cholesterol metabolic checkpoint during blastogenesis.
New insights into TRAF-mediated regulation of BAFF receptor signals (P1110)
Authors: Lin Wai , Hildebrand Joanne , Bishop Gail 
Published: January 2023

Abstract
BAFF receptor (BAFFR), a member of the TNFR superfamily, binds to the pro-survival cytokine BAFF to promote B cell development and survival, and deficiencies of either BAFFR or BAFF result in inhibition of B cell development. BAFF-R engagement recruits TRAFs 2, 3 and 6 and activates the non-canonical NF-κB2 pathway. Current models propose that TRAF3 mediates degradation of the NF-κB activating kinase NIK, concluding that BAFFR-mediated TRAF3 degradation is necessary and sufficient for NF-κB2 activation. However, our recent studies of a mutant BAFFR indicate that this model is inadequate to fully explain how BAFFR activates the NF-κB2 pathway. The A/WySnJ mouse harbors a spontaneous mutation of BAFFR in which 8 residues of the cytoplasmic tail are replaced by 22 amino acids from a viral genome. Engagement of this mutant BAFF-R fails to activate the NF-κB2 pathway, and A/WySnJ mice have a substantial B cell deficiency. However, the mutant BAFF-R shows no decrease in recruitment or receptor-mediated degradation of TRAF3, demonstrating that TRAF3 degradation is not sufficient to allow NF-κB2 activation. Our recent data instead suggest that recruitment of TRAFs 2 and 6 and the signaling protein Act1 may play important roles in BAFFR-mediated NF-κB2 activation.
H3K4 methylation profiling reveals distinct epigenetic signatures in CD4 T cell activation and memory formation. (P1146)
Authors: LaMere Sarah , Thompson Ryan , Komori H. , Mark Adam , Salomon Daniel 
Published: January 2023

Abstract
The roles of histone modifications in T cell activation and memory formation are poorly understood. Thus, we used RNAseq and ChIPseq in tandem to assess the impact of promoter H3K4 di- and trimethylation in naive vs memory human CD4 T cells at rest and 5 days after activation. Changes in H3K4me2 and me3 correlated strongly with changes in RNA expression when comparing naive and memory cells; e.g. increased H3K4 methylation with increased gene expression. These changes define unique signatures comprised of &gt;200 genes at rest and &gt;400 post-activation. Dramatically, activation of naïve CD4 resulted in differential H3K4 methylation of &gt;4000 genes while only ~800 changed with activation of memory. In contrast, activation-induced changes in gene expression and methylation correlated nearly perfectly in memory but poorly for naïve CD4 T cells. These data suggest a higher level of H3K4 methylation-based commitment in the memory subset 5 days after activation. We are presently doing the same studies for days 1 and 14 after activation to understand how quickly activation-induced H3K4 methylation changes occur and how well H3K4 methylation signatures are reflected 14 days after activation of naive cells. In sum, naïve and memory CD4 T cells demonstrate specific H3K4 methylation signatures, T cell activation is clearly an epigenetically dynamic process, and profiling of H3K4 methylation provides important insight into the epigenetic mechanisms driving the commitment to memory.
Polyclonal anergic CD4 T cells give rise to pathogenic TH1 and suppressive regulatory T cells during lymphopenia. (P1024)
Authors: Kalekar Lokeshchandra , Jenkins Marc , Mueller Daniel 
Published: January 2023

Abstract
Anergy is defined as a state of hyporesponsiveness during which T cells fail to respond to their cognate antigen. Studying anergy using non-transgenic animals has been difficult due to lack of distinguishing markers for anergic cells. We identified CD73 and Folate Receptor 4 (FR4) to be highly expressed in anergic cells from transgenic animals following gene array analysis. Here, we show that CD44hi polyclonal CD4 T cells from non-transgenic animals expressing CD73 and FR4 are hyporesponsive following in vitro stimulation. Anergic T cells with specificity for a known self-antigen also express these markers. Adoptive transfer of these cells into lymphopenic animals leads to reversal of their anergic phenotype and differentiation to Tbet+ TH1 T cells and Foxp3+ regulatory T cells. Selective ablation of Treg cells, which arise following adoptive transfer, leads to accelerated weight-loss and lymphoproliferative disease in mice receiving these anergic cells. Our data suggest that anergy is not a stable state and anergic cells can reverse to diverse functional phenotypes. This finding has important implications for cancers, where anergy reversal and helper T cell differentiation in tumor infiltrating lymphocytes would be a favorable outcome, as well as for autoimmunity, where anergy reversal associated with Treg development could be beneficial.
In vivo treatment with MK801, an ionotropic NMDAR antagonist, reduces experimental autoimmune encephalomyelitis. (P1042)
Authors: Schatzmann Peron Jean , Brandão Wesley , Fickinger Andira , Rossato Cristiano , Costa Matheus , Oliveira Daniel , Saraiva Câmara Niels Olsen 
Published: January 2023

Abstract
Glutamate is the most abundant and perhaps the most important neurotransmitter. It acts through metabotropic and ionotropic receptors. Reports demonstrated the expression of glutamate receptors on immune cells, as macrophages and T cells. Its role however is a matter of debate. Thus, we used MK801, a NMDAR antagonist to evaluate its role during an immune response. To evaluate the pathways involved, DO11.10 T cell clones were activated in vitro with or without MK801 or N-methyl D-Aspartate. Total and phospho ERK 1-2 were evaluated by western blot. Our data demonstrated that NMDAR activation increases ERK phosphorylation, reversed by MK801. Further, we performed in vitro Treg differentiation and the presence of MK801 increased the percentage of CD4+Foxp3+ cells. For in vivo experiments, C57BL/6 mice were immunized with MOG35-55 and treated or not with MK801 on days 0,1,2 and 3. At the peak of disease animals were sacrificed and Th1, Th17 and Treg cells were analyzed by flow cytometry. MK801 treated animals had milder disease when compared to controls. Interestingly, animals showed an increased frequency of Th1, Th17 and CD4+p-STAT-3+ infiiltrating brain and spinal cord. Our results demonstrated that glutamate signaling boosts the commitment of Th1 and Th17 cells. However, less-encephalitogenic cells are being generated. These findings contribute to the understanding of NMDAR on immune cells and also for a new point of view concerning its role in neuroinflammatory diseases.
T cell responsiveness to retinoic acid is required for immune mediated liver injury (P1046)
Authors: Deng Jie , Celaj Stela , Noelle Randolph , Gorham James 
Published: January 2023

Abstract
Inflammatory liver disease (ILD) contributes to significant morbidity and mortality. T cell mediated injury is a central event in the pathogenesis of ILD of a variety of etiologies; however, the specific driving mechanisms are not fully elucidated. Retinoic acid (RA), the active metabolite of vitamin A, plays fundamental roles in shaping the immune response. Although liver is the major site of retinoid storage in the body, the specific role of RA during liver inflammation has not been evaluated. Using the Concanavalin A (Con A) mouse model of ILD, we tested the hypothesis that RA is required for T cell mediated liver injury. Con A induced a significant increase in RA concentration in liver via heightened expression of RALDH, the rate-limiting enzyme in RA synthesis. Surprisingly, RALDH expression was found in liver CD11b+CD11c- macrophages, but not in liver CD11c+ dendritic cells. Using bioluminescence imaging of whole liver, we observed that RA signaling increases 25-fold after Con A. We evaluated the requirement for RA response in T cells using transgenic mice in which T cells specifically express a dominant negative RA receptor alpha construct. Mice with disrupted RA signaling in T cells developed significantly less liver damage than did mice with intact RA signaling. Thus, our findings illustrate that RA function is critical for immune-mediated injury in ILD, and suggest that liver macrophages have a specific role in provision of RA for liver T cells.
Identification of a novel cytokine amplification loop during influenza infection (P6142)
Authors: Teijaro John , Walsh Kevin , Rosen Hugh , Oldstone Michael 
Published: January 2023

Abstract
Pathogenic influenza viruses cause significant morbidity and mortality in humans. Influenza virus causes lung tissue damage by direct pulmonary epithelial injury and by its initiation of an aggressive innate inflammatory response. The sphingosine 1-phosphate (S1P) signaling system is well known for its role in modulation of immune cell trafficking. Using genetic and chemical tools to probe functions of the S1P1 receptor (S1P1-rec), we recently published that pulmonary endothelial cells (ECs) are central modulators of innate immune cell recruitment and cytokine responses early following influenza virus infection. Use of S1P1-rec agonist results in reduced influenza morbidity and mortality. While S1P1 receptor is found on ECs and lymphocytes within lung tissue, an S1P1-selective agonist suppressed cytokines and innate immune cell recruitment in wild-type and lymphocyte-deficient mice, clearly identifying pulmonary ECs as central regulators of cytokine storm. Now, we report a novel cytokine amplification loop requiring cellular cross-talk between pulmonary epithelial cells, ECs and plasmacytoid dendritic cells (pDCs). Cytokine amplification through this loop requires MyD88 and IRF7 signaling. Importantly, S1P1 signaling on ECs elicits a negative signal to pDCs leading to global suppression of cytokine amplification. These findings identify therapeutic control points to blunt pathology associated with influenza virus infection and further illuminate influenza pathogenesis.
Late cognate antigen interactions are required for CD4+ T cell survival during influenza infection. (P6146)
Authors: Bautista Bianca , McKinstry Kai , Strutt Tara , Swain Susan 
Published: January 2023

Abstract
At the termination of an influenza infection, the majority of antigen-specific effector CD4 T cells undergo Bim-driven apoptosis leaving a small, heterogeneous population of memory cells capable of protecting against subsequent infection. The kinetics of the CD4 response is known to be influenced by the levels of inflammation and antigen, but the contribution of these to contraction and memory formation is unclear. To analyze these we isolated OT-II transgenic CD4 T cells at various days following PR8-OVAII infection and transferred them to either uninfected, PR8-infected (inflammation), or PR8-OVAII-infected (inflammation plus antigen) hosts. In hosts lacking cognate antigen, effectors underwent minimal cytokine-driven proliferation and began to contract as early as two days post transfer, while those in PR8-OVAII-infected hosts proliferated 3-fold and underwent apoptosis after a delay of 2-3 days, leading to greater recovery. To dissect how CD4 effectors nearing the time of contraction interpret external signals, we isolated donor OT-II CD4 effectors on days 6-8 following PR8-OVAII infection and cultured them with or without TCR stimulation. TCR signaling resulted in increased cell recovery, enhanced proliferation, and reduced ratios of Bim:Bcl2 promoting effector survival. Blocking IL-2 diminished the recovery of TCR-stimulated effectors, suggesting that the beneficial impact of late TCR signaling is dependent on autocrine IL-2 signaling.
β-catenin modulates inflammatory cytokine production and disease development in NOD mice (P5231)
Authors: Zirnheld Arin , Fan Chunlan , Kosiewicz Michele , Alard Pascale 
Published: January 2023

Abstract
Because of their various immune defects including the excess production of proinflammatory cytokines by dendritic cells, non-obese diabetic (NOD) mice provide a powerful model to understand Type I diabetes. We have found increased levels of nuclear and cytosolic β-catenin in BMDC from NOD mice. We have assessed its association with inflammatory cytokine production and disease development, and the reason for its accumulation. First, we transfected NOD or B6g7 BMDC with β-catenin siRNA or β-catenin plasmid and measured IL-12 production. We found that modulating β-catenin expression influences IL-12 production. We next examined potential defects in β-catenin phosphorylation in NOD BMDC as a mechanism of β-catenin accumulation. We found high levels of phosphorylation at two residues, S675 and S552, mediated by PKA and Akt respectively. Because these types of phosphorylation have been associated with increased stabilization, these data suggest that β-catenin accumulation may result from defective PKA or Akt activity. Finally, we inhibited β-catenin in vivo in NOD mice and measure the incidence of type I diabetes. We intraperitoneally administered quercetin, a β-catenin inhibitor, or intravenously injected BMDC treated with β-catenin siRNA into NOD mice. We found that both treatments reduced disease incidence. Overall, these data point to the importance of β-catenin as a therapeutic target for reducing the inflammation that leads to the development of Type I diabetes.
Foxp3-independent suppression of autoimmunity by anti-CD4-induced recessive tolerization of autoreactive T cells (P5222)
Authors: Sparwasser Tim , Mayer Christian 
Published: January 2023

Abstract
Non-depleting anti-CD4 monoclonal antibodies potently induce dominant infectious tolerance and Foxp3+ regulatory T cells (Tregs) have recently been implicated as a crucial underlying mechanism. However, it has not been explored whether anti-CD4 treatment has residual activity in the complete absence of Foxp3+ Tregs. Utilizing DEREG mice which allow for the inducible depletion of Foxp3+ Tregs by diphtheria toxin (DT), we found that the anti-CD4 clone YTS177.9 is able to fully inhibit CD4+ T cell activation in the absence of Foxp3+ Tregs in vitro. Moreover, anti-CD4 treatment of neonatal scurfy (sf) mice genetically devoid of functional Foxp3+ Tregs resulted in a rescue of the autoimmune phenotype. We thus discovered a novel Foxp3-independent mechanism of anti-CD4-induced tolerance. Foxp3-independent tolerance was recessive as opposed to classical dominant infectious tolerance requiring Foxp3+ Tregs. Given that anti-human CD4 antibodies are currently developed as therapeutics, our results provide valuable insights into anti-CD4-mediated tolerance and unexpectedly highlight a potential synergy of anti-CD4 antibodies with Foxp3+ Treg-modulating regimens for the treatment of human inflammatory diseases. Beyond, anti-CD4 antibodies might represent a novel therapeutic option for the human IPEX syndrome which is caused by Foxp3 mutations similar to the autoimmune disease of sf mice.