bluuebunny/crossref_metadata_2025_split huggingface dataset:
T cell miRNA in multiple sclerosis pathogenesis (P5209)
Authors: Guerau-de-Arellano Mireia , Lovett-Racke Amy , Racke Michael 
Published: January 2023

Abstract
Multiple sclerosis (MS) is an immune-mediated disease that results in destruction of the myelin sheath and axonal degeneration. Interestingly, while myelin-specific T cells are present in peripheral blood mononuclear cells (PBMC) of both healthy controls and MS patients, they only become pathogenic in MS patients. This suggests that some regulatory checkpoint is bypassed in MS T cells, unleashing their autoimmune potential. By regulating protein-coding mRNAs, microRNAs (miRNAs) control important cellular processes. Specifically, we have previously shown that dysregulated miRNAs in MS patient’s naïve T cells promote pro-inflammatory Th1 immune responses. In this study, we explored whether differences in miRNA expression in memory T cells of MS patients further contribute to the pathogenesis of MS. Memory CD4 T cells were purified by magnetic bead sorting to 95% purity and subjected to a comprehensive Nanostring technology miRNA profiling. In a study on healthy (n=17) and seven MS patients (n=21), a number of miRs were found to be significantly different in MS compared to healthy controls. Among the identified miRs, many target genes known to be involved in T cell proliferation and apoptosis, activation, adhesion and regulation. These results identify miRNAs in memory T cells as MS biomarkers of biological significance and potential clinical value, and reveal potential new therapeutic targets in MS.
HMGB1 preconditioning protects against kidney ischemia reperfusion injury (P2126)
Authors: Wu Huiling , Steenstra Renske , C.S. de Boer Elianne , Zhao Cathy , Ma Jin , Chadban Steven 
Published: January 2023

Abstract
High-mobility group box1 (HMGB1) is an endogenous ligand for TLR4. We have reported that HMGB1 mediates kidney ischemia reperfusion injury (IRI) via TLR4. We aimed to determine: 1) the potential of preconditioning with rHMGB1 to block kidney IRI; 2) whether this effect is dependent upon TLR4; 3) whether this involves down-regulation of TLR signaling. Methods: Wild-type (WT) and TLR4-/- mice were receive rHMGB1 (20 ug/animal) or saline by i.p. injection 2 hours before 21 minute kidney ischemia. Results: WT mice pre-treated with rHMGB1 were protected against kidney IRI, with lower serum creatinine, less tubular damage, less tubulo-interstitial neutrophil, macrophage and CD4+ cell infiltration and less tubular epithelial cell apoptosis versus controls at day 1 and/or 5 post IRI. mRNA expression of cytokines IL6 & TNFa and chemokines CXCL2 & CCL2 in the kidney were significantly reduced by rHMGB1 pre-treatment at day 5. TLR4-/- mice were protected against kidney IRI, with no additional protection afforded by pre-administration of rHMGB1. The protective effect of rHMGB1 preconditioning on WT kidney involved Siglec-10, a negative regulator of HMGB1-TLR4 activation, which is induced through NF-kB signalling (p&lt;0.05 versus control). Conclusion: HMGB1 preconditioning affords significant protection from kidney IRI by negatively regulating TLR4 signaling through Siglec-10 and NF-kB signalling, indicating the therapeutic potential.
MyD88-dependent expansion of an immature GR-1+CD11b+ population from donor bone marrow reduces early mortality after allogeneic hematopoietic stem cell transplantation (P2166)
Authors: Lim Ji young , Youn Hyewon , Choi Eun Young , Min Chang-Ki 
Published: January 2023

Abstract
Myeloid-derived suppressor cells coexpressing both CD11b and Gr-1 antigens are a heterogeneous population of immature myeloid cells. Activation of inflammatory signaling through MyD88, presumably through ligation of multiple TLRs, plays a key role in the expansion of MDSCs. We investigated how the MyD88-dependent expansion of MDSCs from donor BM contributes to protection of GVHD. Lethally irradiated B6D2F1 mice were transplanted with C57BL/6 WT or MyD88 KO mice TCD-BM together with WT spleen T cells. Morbidity and mortality of GVHD were significantly worse in recipients of KO TCD-BM. The expression of MDSCs in blood, MLN and liver was reduced in the recipients of KO TCD-BM, whereas the percentage of donor T cells infiltrating gut and liver was markedly higher. In parallel, the percentages of donor T cells to undergo apoptosis in response to alloantigens in vivo were significantly decreased in recipients of KO TCD-BM. Moreover, in vivo administration of isolated MDSCs to recipients of KO TCD-BM attenuated the severity of GVHD. Administration of LPS to donor mice expanded MDSCs in BM with enhanced expression of MyD88 mRNAs. Recipients of TCD-BM from WT mice injected LPS also showed attenuated GVHD severity. In summary, MyD88-dependent expansion of MDSCs population from donor non T-cell component appears to be critical for attenuating GVHD severity. Incomplete expansion of MDSCs in target organs correlates with decreased apoptosis and increased infiltration of donor T cells.
In vivo reconstitution of human natural T regulatory cells in NOD/SCID IL2rγcnull mice by expression of human IL-2 (P2174)
Authors: Abraham Sojan , Pahwa Rajendra , Ye Chunting , Pahwa Savita , Jaggaiahgari Shashidhar , Manjunath N. , Shankar Premlata 
Published: January 2023

Abstract
Regulatory T cells (TRegs) can suppress a wide range of immune cells, making them an ideal candidate for the treatment graft versus host disease (GVHD). The potential clinical translation of targeted therapy with in vitro expanded human nTRegs is being tested to prevent GVHD, which is a major cause for morbidity and mortality associated with hematopoietic stem cell transplantation. Their usefulness in therapy will depend on their capacity to survive, migrate and retain suppressive activity when introduced into a transplant recipient. The lack of a suitable animal model is a major impediment for investigating the behavior of adoptively transferred nTRegs in vivo. The aim of this study is to develop TRegs reconstituted humanized mice as a preclinical model for understanding their therapeutic usefulness in the transplantation setting. We show that injection of a plasmid encoding human IL-2 is necessary and sufficient for long term engraftment of in vitro expanded nTRegs in NOD-SCID IL2rγcnull mice. Furthermore, the reconstituted TRegs trafficked to different organs of the body and retained their characteristic suppressive function. Finally, in an IL-2 accelerated GVHD model, we show that these in vivo reconstituted TRegs are capable of preventing severe xenogenic response of human PBMCs. Thus, this novel hu-TReg mouse model offers a pre-clinical platform to study the in vivo function and stability of human nTRegs and their ability to modulate autoimmune diseases and GVHD.
The role of caspase-1 involved in autophagy activation in graft-versus-host disease model (P2178)
Authors: Lee Kyung Ho , Lee Hye Jin , Park Minhwa , Ryu Kyung-Ha , Woo So-Youn 
Published: January 2023

Abstract
Graft-versus-host disease (GVHD) remains a major complication after allogeneic hematopoietic cell transplantation. Although donor-derived T cells recognize host alloantigens and induce detrimental acute GVHD, the mechanism of the onset and progression of acute GVHD remain uncertain. In order to reveal the involvement of autophagy activation in acute GVHD pathogenesis, we used reduced intensity conditioning model (e.g., BU-CY conditioned mice) and compared the tissue damage and expression of autophagy-related genes. Recipient C57BL/6 and caspase-1 KO mice received busulfan (BU, 80 mg/kg) daily for 4 days, followed by cyclophosphamide (CY, 200 mg/kg) daily 2 days via intraperitoneal injection. Two days after, bone marrow cells and spleen cells were prepared from Balb/c mice and injected via tail vein. For three weeks, the clinical and histological GVHD score and Kaplan-Meier survival rate was observed. We found that the GVHD score showed the difference between C57BL/6 and caspase-1 KO recipient mice. In addition, the expression level of LC3B and Beclin-1 was decreased in caspase-1 KO mice. It implies that caspase-1 activation is involved in GVHD pathogenesis via autophagy pathway.
IVIg-induced anti-inflammatory monocytes (CD14 low, HLA-DR high) with a low CD80 and high PDL1 expression inhibits T cell activation in allogeneic mixed lymphocytes reactions (P2194)
Authors: Padet Lauriane , Bazin Renée 
Published: January 2023

Abstract
Intravenous immunoglobulin (IVIg) is a therapeutic preparation of human IgG isolated from plasma donations and has been proposed as a therapy to improve the rate of graft survival in patients with a high risk for antibody-mediated-rejection. Blocking of anti-HLA antibodies by anti-idiotypic IgG present in IVIg was proposed to explain the rapid effect of IVIg. However, a long-term reduction of anti-HLA alloreactivity in IVIg-treated patients suggests that IVIg modulates the functions of immune cells. In the present study, we showed using the allogeneic mixed lymphocyte reaction (MLR) as an in vitro model of allograft rejection and GvHD that IVIg strongly inhibits IL-2 secretion (T cell activation) and modulates the level of other pro- and anti-inflammatory cytokines secretion. To determine the mechanisms underlying the inhibition of T cell activation in MLR, we studied the effect of IVIg on the phenotype of the cells involved in MLR. Our results revealed that MLR inhibition by IVIg correlates with the induction of anti-inflammatory monocytes (CD14 low, HLA-DR high) with a low CD80 and high PDL1 expression. To evaluate the importance of PDL1 on the MLR inhibition, anti-PDL1 was added during the MLR. Blocking of PDL1 restored the MLR, as evaluated by IL-2 secretion. We thus propose that PDL1 plays a central role in the inhibition of MLR. Our results help to better understand how IVIg induces long-term peripheral tolerance and improves graft survival in transplanted patients.
ICOS-expressing Treg are required for resolution of CD8-mediated lung injury (P2198)
Authors: Gardiner Gail , Wu Qiang , Wagner Sarah , Shilling Rebecca 
Published: January 2023

Abstract
Long-term survival of lung allograft recipients can be hindered by the development of obliterative bronchiolitis (OB), a condition that has been linked to acute rejection. CD8+ T cells contribute to acute rejection by inducing lung epithelial injury; however, the mechanisms for mitigating this type of injury are unclear. Using an in vivo model of CD8-mediated lung rejection, we have found bystander CD4+ T cells are required for resolution of acute inflammation. The percentage of CD4+Foxp3+ Treg is significantly higher in inflamed lungs compared to controls, and the majority of these cells are ICOSHi in inflamed lungs. To determine the role ICOS expression plays in the ability of Treg to control inflammation, we investigated Treg cytokine expression levels and found WT Treg express more Il10 than Icos-/- Treg when stimulated in vitro. IL-10 production is also enhanced in WT Treg compared to Icos-/- Treg. Additionally, we saw WT Treg have enhanced proliferation compared to Icos-/- Treg. In vivo, we found Icos-/- CD4+ T cells are not sufficient for resolution of acute inflammation; however, addition of WT Treg rescues this defect. Together, these data suggest ICOS-expressing Treg are required for resolution of CD8-mediated lung injury due to a possible increase in IL-10 production or an enhanced ability to proliferate in vivo. Augmenting ICOS function on Treg after transplantation may protect the lung from acute rejection and prevent OB.
Granulocyte derived cationic peptide LL-37 prime hematopoietic progenitor cells through up-regulating glucose uptake and AMPK signaling (P2202)
Authors: Lee Hakmo , Park Ho Seon , Choi Ok Kyung , Park Jongwoo , Oh Ju Eun , Lee Won-Woo , Chung Sung Soo , Jung Hye Seung , Park Kyong Soo 
Published: January 2023

Abstract
It has been reported that activated granulocytes derived cationic peptide LL-37 positively prime responsiveness of hematopoietic progenitor cells (HPCs) to CXCL12 gradient through an ambiguous pathway. The goal of this study was to elucidate the mechanism of enhanced migration of LL-37 primed HPCs to CXCL12 gradient. We performed in vitro migration assay and found out that LL-37 pretreatment enhanced migration of HPCs to CXCL12 only in the presence of D-glucose, but not in the absence of glucose or in the presence of glucose uptake inhibitor, 2-deoxy-D-glucose (2-DG). This signifies that LL-37 may affect intracellular energy production machinery. So we tested if the priming effect of LL-37 is related to mTOR signaling since mTOR is a central regulator of nutrient sensing and glycolysis promoting glucose uptake and ATP production to match energy demands for cell migration. As we expected, LL-37 induced glucose uptake in mTOR signaling dependent manner. Also, LL-37 induced the activation of nutrient sensing AMPK and its downstream substrates. In line with this, pretreatment of AMPK activator AICAR promoted migration of HSPCs as well. These findings demonstrate that the priming mechanism of LL-37 is closely associated with increasing ATP production and the optimization of glucose uptake and ATP production for HPCs prior to transplantation would be particularly important in HPCs transplantation where the number of cells available for transplantation is usually limited.
Regulatory T cells in prevention of islet-graft rejection in humanized mice (P2230)
Authors: Yadav Mahesh , Szot Greg , Russ Holger , Guo Tingxia , Stephan Stephen , Kroon Evert , Brandon Eugene , D'Amour Kevin , Hebrok Mathias , Bluestone Jeffrey 
Published: January 2023

Abstract
Regulatory T cells (Tregs) are potent suppressor of adverse immune reaction and have shown lot of promise in the preclinical studies for the treatment of autoimmune diseases and organ transplantation. In the current study we tested if ex vivo expanded human Tregs can be used to enhance the engraftment of human islets. To test this we developed a humanized mice model by injecting immune deficient NSG mice with human PBMCs or by injecting fetal-liver derived human CD34+ stem cells. Mice were transplanted with purified human islets or human embryonic stem cells (hESC)-derived islets and followed for graft function by measuring serum levels of human c-peptide. We demonstrate that hESC-derived islet graft or purified human islets were rejected by allogeneic PBMCs, which could be prevented by co-stimulation blockade using CTLA-4Ig and anti-CD40L antibodies. Adoptive transfer of ex vivo expanded human Tregs also rescued the rejection albeit not completely. We are currently generating Ag (islet Ag or allo-Ag)-specific Tregs to test their efficacy in preventing islet graft rejection in a mouse expressing human HLA (DR 0401). Our results indicate that ex vivo expanded Tregs can prevent islet graft rejection by allogeneic PBMCs and that humanized mouse could be an excellent model to test the safety and preclinical efficacy of different Treg population.
Graft acceptance achieved through TIM-4 blockade is dependent on interruption of dendritic cell TIM-4 costimulatory signaling (P2136)
Authors: Yeung Melissa , McGrath Martina , Shimizu Tetsunosuke , Snawder Benjamin , Ueno Takuya , Najafian Nader 
Published: January 2023

Abstract
TIM-4 on DCs and macrophages functions as a costimulatory molecule and PS receptor, mediating phagocytosis of apoptotic cells (AB). The relative importance of these functions in alloimmunity remains unclear. Combined treatment with anti-TIM-4 mAb and CTLA4Ig led to full-mismatch cardiac allograft acceptance (MST&gt;100vs30d,p&lt;0.001), with Treg expansion, decreased Teffector generation, but 10-fold increase in splenic AB. Further characterization of this aTIM-4 Ab showed it impairs AB uptake by macrophages but not DCs. In contrast, interruption of DC TIM-4 led to Treg expansion/induction. Since disruption of AB clearance is pro-inflammatory, we hypothesized that blockade of DC TIM-4 costimulation promotes GS, whereas blockade of its phagocytic function may be detrimental. To test this, we treated recipients with CTLA4Ig +gadolinium (blocks global phagocytosis) +/- aTIM-4. Gadolinium accelerated rejection, but addition of aTIM-4 still led to a 3.5-fold increase in GS (MST 30vs8d,p&lt;0.001). Finally, to confirm that interruption of DC TIM-4 costimulatory function is the predominant mechanism leading to graft acceptance, CD11c-DTR chimeras (for long-term DC depletion) were transplanted. Consistently, we found GS achieved by TIM-4 blockade is attenuated by near-complete DC depletion (MST 26vs20d,ns). In summary, TIM-4 appears to have opposing roles in alloimmunity. Its function as a costimulatory molecule on DCs promotes rejection, whereas its role as a PS receptor may be protective.
Poly(dG) oligo deoxynucleotide conjugated protein vaccine specifically targets skin APCs and induces robust T cell immunity in vivo. (APP3P.110)
Authors: Toussaint Helene , Ciccotelli Jo Erika , Erdos Geza , Carey Cara , Watkins Simon , Larregina Adriana , Falo Louis 
Published: January 2023

Abstract
The efficacy of current vaccines results from the induction of protective antibodies. However we still lack efficacious vaccines against many infectious agents that require durable and protective T cell immunity. Efficient and selective delivery of antigen and adjuvant to APCs in vivo remains a critical challenge to vaccine design. To accomplish both of these goals with a single delivery strategy we have designed an antigen and adjuvant delivery platform based on simple and direct coupling of Poly(dG) oligo deoxynucleotides to protein antigens. Initially we found that immunization of naïve animals by direct injection of conjugates of Poly(dG) and Ovalbumin, Poly(dG)-OVA induces priming of specific CTL responses, differentiation of naïve CD4 T cells into Th1 cells, induction of specific memory T cell responses and generation of specific antibody responses, in a scavenger receptor-dependent manner. Applying this strategy to HIV, we immunized mice with conjugated Poly(dG)-Gag and demonstrated potent induction of Gag-specific CTL and Th1-biased CD4 T cells immune responses in vivo. Further, in human models we show that intradermal injection of Poly(dG)-antigen conjugates result in efficient uptake by human dermal DCs that acquire potent T cell stimulatory functions. Our data suggests that the Poly(dG)-protein conjugate vaccine platform can both selectively target antigens to skin APCs and function as an APC-directed adjuvant to induce broad based cellular and humoral immunity.
Selective CB2 receptor agonist Gp1a attenuates EAE through modulating CD4 T cell differentiation and immune cell infiltration in the CNS (BA8P.131)
Authors: Kong Weimin , Li Hongbo , Tuma Ronald , Ganea Doina 
Published: January 2023

Abstract
CB2 agonists have beneficial effects in experimental autoimmune encephalomyelitis (EAE). Our previous studies showed that the CB2 selective agonist O-1966 inhibited EAE development and leukocyte rolling and adhesion to CNS microvasculature. Here we report that Gp1a, a highly selective CB2 agonist, inhibits EAE development following early treatment and improves recovery following late treatment. Gp1a treatment resulted in lower levels of demyelination, axonal loss, and immune cell infiltration. Our results indicate that early Gp1a treatment inhibits Th1 and Th17 and promotes Th2 and Treg differentiation both in vivo and in vitro. We confirmed that Gp1a inhibited Th1 and Th17 differentiation both in non-polarizing and polarizing conditions. Following later treatment, Gp1a reduced the accumulation of pathogenic immune cells in the CNS, which was associated with reductions in the expression of CNS chemokines and adhesion molecules and of chemokine receptors in T cells. We concluded that at least two mechanisms were involved in the beneficial effects of Gp1a in EAE, an early effect on Th1/Th17 differentiation and a later effect on the accumulation of pathogenic immune cells in the CNS. The combined effect of CB2 agonists on Th17 differentiation and immune cell accumulation into the CNS, suggest the CB2 receptors are potential therapeutic targets in neuroinflammation.
Tissue specific antigen expression shapes T cell repertoire and autoimmune potential (BA8P.133)
Authors: Martinez Ryan , Evavold Brian 
Published: January 2023

Abstract
In the following studies we have identified myelin oligodendrocyte glycoprotein (MOG) as one of the first antigens capable of inducing antigen-specific thymic derived Foxp3+ T regulatory cells (tTregs) and influencing the autoimmune disease potential of the MOG-specific CD4+ T cell polyclonal repertoire. By using MOG38-49:I-Ab tetramer enrichment we have been able to track MOG-specific CD4+ T cells in naive mice through experimental autoimmune encephalomyelitis (EAE). We have found the lack of MOG expression causes a lack of naïve MOG-specific tTreg cell diversion, but no significant difference in the number of MOG-specific effectors. Even though the MOG-specific effectors start at the same numbers in both WT and MOG deficient mice, the MOG-specific CD4+ T cells expand 5-10 fold greater in MOG deficient mice, have a consistently reduced frequency of tTregs and a higher TCR affinity. Upon adoptive transfer into MOG-expressing mice, donor CD4+ T cells from MOG deficient mice cause more rapid onset and increased severity of paralysis, which is correlated with increased expansion and TCR affinity of MOG-specific CD4+ T cells. This data shows the expression of self-antigen during T cell development generates a CD4+ T cell repertoire with an increased frequency of tTregs and a reduced per cell autoimmune potential, demonstrating the importance of tissue specific antigen expression to induce tolerance in T cell responding to self-antigen.
An unexpected role of Smad4 to control autoimmunity and T cell function (BA8P.125)
Authors: Wan Yisong , Gu Aidi , Wang Yunqi 
Published: January 2023

Abstract
Smad-dependent signaling pathway is known to mediate TGF-beta signal in non-lymphoid cells. How this pathway controls T cell function remains poorly understood. In particular, the function of Smad4 (co-Smad) in T cells is perplexing. On the contrary to the prediction that Smad4-deficient mice will pheno-copy TGF-betaR-deficient mice and develop aggressive autoimmunity, Smad4-deficient mice are phenotypically grossly normal. Two explanations may account for such observations. One is that Smad4 is dispensable for TGF-beta function in T cells. The other is that, while Smad4 is important for TGF-beta function in T cells, it is also critical to promote T cell function to offset its TGF-beta-dependent function. To test these possibilities, we generated DKO mice, where both TGF-betaR and Smad4 are deficient in T cells. Much to our surprise, Smad4 deletion rescued the lethal autoimmunity of TGF-betaR-deficient mice. DKO mice phenocopy Smad4-deficient mice. These findings suggest that the second explanation, albeit paradoxical, is correct. Further investigation revealed that, Smad4 is indeed required for TGF-beta function in T cells and, unexpectedly, it is also important to promote T cell function. These findings therefore identify a novel function of Smad4 critical for T cell function and autoimmunity. Here, we will discuss in detail these new findings and the potential underlying mechanisms.