bluuebunny/crossref_metadata_2025_split huggingface dataset:
MHC alleles influence CD8 T cell exhaustion and host survival during chronic viral infection (VIR10P.1164)
Authors: Christiaansen Allison , Varga Steven 
Published: January 2023

Abstract
Specific HLA alleles have been associated with enhanced control of chronic viral infections such as hepatitis C and HIV. However, the exact mechanism by which HLA alleles result in enhanced viral clearance is currently unknown. Infection of inbred C57BL/6 (B6) with the clone 13 (Cl-13) strain of lymphocytic choriomeningitis virus (LCMV) is widely used as a model of chronic viral infection. To determine the impact of MHC alleles on the progressive loss of CD8 T cell effector functions, MHC congenic mice were used to delineate the role of MHC alleles from those of non-MHC genes. B10.D2 x B6 F1 (D2B6F1) mice were bred that express H-2d/b on a B6 background and compared to H-2b B6 mice. Following Cl-13 infection, D2B6F1 mice maintain higher levels of CD8 T cell effector function and exhibit more rapid viral clearance than B6 mice. Strikingly, D2B6F1 mice exhibited 75% mortality following Cl-13 infection. CD8 T cell depletion ameliorated the Cl-13 induced disease in D2B6F1 mice indicating a critical role for CD8 T cells in mediating the immunopathology. The frequency of CD49d+ CD11ahi antigen-experienced CD4 T cells was also increased in Cl-13-infected D2B6F1 mice relative to B6 controls. Our results indicate that increasing MHC heterogeneity can have a critical impact on the breadth and effectiveness of the antiviral T cell response resulting in more rapid viral clearance at the cost of enhanced immunopathology following a chronic viral infection.
Partial reversal of exhausted T cell phenotype and memory re-differentiation in chronic HCV-infected patients receiving direct-acting antivirals (VIR10P.1165)
Authors: Burchill Matthew , Golden-Mason Lucy , Wind-Rotolo Megan , Rosen Hugo 
Published: January 2023

Abstract
Chronic infection with Hepatitis C Virus (HCV) results in T cell exhaustion and subsequent impairment of T cell immunity. Recently, novel therapies of direct acting antiviral (DAA) regimens were developed which induce rapid and sustained clearance of HCV. These DAAs have provided the unique opportunity to determine whether successful treatment-induced eradication of viral antigen leads to reversal of T cell exhaustion and reconstitution T cell effector function. Herein we found that treatment with DAAs resulted in the reconstitution of the immune compartment in the peripheral blood. Furthermore, DAA-mediated viral clearance induced the re-differentiation of the memory T cell compartment to a more effector like state. Finally, DAA treatment caused the down modulation of markers associated with T cell chronic exhaustion, most intriguingly, the co-inhibitory T cell immunoglobulin and ITIM domain (TIGIT). The down modulation of TIGIT was unique to DAA treatment, as this effect was not observed when patients were treated with standard pegylated IFN and ribavirin therapy. Collectively, our data demonstrates that rapid HCV viral clearance following treatment with DAAs resulted in the partial restoration of global and viral specific T cell immunity. These findings suggest that T cell chronic exhaustion can persist long term in the absence of viral antigen and that complete reversal of this phenotype requires interventions that are independent of the persistence of viral antigen.
B-lymphocytes expressing an immunoglobulin specificity recognizing the natural pancreatic beta cell autoantigen, peripherin, are rendered proliferatively anergic but still accelerate type 1 diabetes development in NOD mice. (BA3P.107)
Authors: Leeth Caroline , Chapman Harry , Arpa Berta , carrillo jorge , Carrascal Jorge , Rosell Estela , Verdaguer Joan , Serreze David 
Published: January 2023

Abstract
Type 1 diabetes (T1D) results from the destruction of insulin-producing pancreatic ß-cells by autoreactive CD4+ and CD8+ T-cells culminating in glucose dysregulation in both humans and the NOD mouse model. It is clear in the NOD mouse model and also likely humans that B-lymphocytes also play a key pathogenic role in T1D. A sizable proportion of B-lymphocytes isolated from pancreatic islets in NOD mice recognize the autoantigen, peripherin, a type II intermediate filament expressed widely in the peripheral and central nervous system. To further understand the role peripherin-reactive B lymphocytes play in the pathogenesis of T1D, we created NOD mice transgenically expressing non-secretory heavy and light chain transgenes encoding an immunoglobulin (Ig) recognizing peripherin derived from islet-associated B lymphocytes. These mice overwhelming produce B-lymphocytes expressing the transgenic peripherin-binding Ig molecule and develop T1D at a significantly accelerated rate compared with the standard NOD strain. Islet infiltration by lymphocytes also occurs earlier in these mice with the vast majority of islet-associated B-lymphocytes expressing the transgenic Ig. While these peripherin-reactive B lymphocytes are diabetogenic, they are also proliferatlively anergic and appear to require frequent replenishment from hematopoietic stem cells. These findings lend credence to the targeting of peripherin autoreactive B-lymphocytes as a possible T1D intervention.
Disruption of tolerance by ER stress in type 1 diabetes (BA4P.131)
Authors: Marre Meghan , Profozich Jennifer , Coneybeer Jorge , Geng Xuehui , Bertera Suzanne , Trucco Massimo , James Eddie , Piganelli Jon 
Published: January 2023

Abstract
Type 1 diabetes (T1D) is an autoimmune disease in which autoreactive T cells target and destroy islet β cells. The events that break peripheral tolerance in patients genetically predisposed to autoimmunity are poorly understood. Many physiological and environmental triggers associated with T1D cause endoplasmic reticulum (ER) stress, which may increase abnormal protein post-translational modification (PTM). We hypothesized that β cell ER stress generates neo-antigens that activate autoreactive T cells in T1D. Chemical (Thapsigargin) induction of ER stress in murine islets or insulinomas increased their recognition by diabetogenic BDC2.5 T cells (28-1500 fold) through activation of the PTM enzyme tissue transglutaminase 2 (Tgase; 18 fold). Indeed, reduced Tgase expression decreased stress-induced immunogenicity (58%). Also, physiological conditions in vivo increased ER stress (300 fold) and Tgase activity (44 fold) in primary islets and transplanted insulinomas, increasing BDC2.5 IFNγ responses (22 fold). Thus, ER stress leads to PTM-dependent murine β cell immunogenicity. We are currently translating these findings to a human T1D model. Preliminary data confirm that ER stress in human β cells significantly increased IFNγ secretion by T cells isolated from T1D patients that recognize Tgase-modified β cell antigens (24-360 fold). Thus, Tgase-dependent PTM may also cause immunogenicity in human β cells, demonstrating the relevance of our murine studies to human disease.
Susceptibility to IBD is associated with with specific KIR and HLA ligand genotypes (BA4P.142)
Authors: Trachtenberg Elizabeth , Udell Julia , Osoegawa Kazu , Ladner Martha , Noonan David , McGovern Dermot , Rotter Jerome , Taylor Kent , erlich henry 
Published: January 2023

Abstract
Adaptive and innate host immune responses to intestinal microbes have been implicated in the pathogenesis of Ulcerative Colitis and Crohn’s Disease, the subtypes of Inflammatory Bowel Disease (IBD). Polymorphisms of the Killer Ig-like Receptors (KIR) genes, which encode receptors on natural killer cells, influence immune mediated diseases. Here we study the genetic contribution of KIR and their HLA ligands in UC and CD. HLA genotyping was performed by next generation sequencing and KIR genotyping with our MALDI-TOF assay. The KIR HLA ligands, Bw4/6 and C1/C2 were assigned using HLA-B and HLA-C residue positions 77-83. The case-control analysis consisted of 1232 Caucasian IBD patients (461 with UC, 771 with CD) and 203 Caucasian controls. The homozygous genotypic combination of KIR2DL3, KIR3DL1 (homozygous KIR A/A haplotype) and Bw6 (absence of Bw4) with a heterozygous C1/C2 genotype was protective (cf, C1/C1 and C2/C2) against ulcerative colitis (OR = 0.29, p &lt; 0.001). No significant association was found with KIR loci and their HLA-ligands with CD. In a C1/C2 heterozygote, signaling would be expected via both the KIR2DL3 receptor and the KIR2DL1 receptor. These data reveal a central role for a specific combination of KIRs and HLA ligands (i.e., homozygous KIR A haplotype, absence of Bw4 and C1/C2 heterozygosity) in protecting against UC disease and underscore the importance of analyzing KIR genotypes in the context of their HLA ligands in disease association studies.
Hypoxia promotes C5a-associated inflammation in rheumatoid arthritis via upreglating the microRNA miR-342-3p to inhibit IL-4R, STAT5b, ubiquitin specific peptidase 13 and EP300 (BA4P.123)
Authors: Liu Shuxun 
Published: January 2023

Abstract
Hypoxia-inducible miRNAs (hi-miR) are identified in hypoxia-associated physiological and pathological processes. Hypoxia plays a pivotal role in the pathogenesis of several inflammatory diseases, particularly rheumatoid arthritis (RA). However, the roles and underlying mechanisms of hi-miR in autoimmune diseases remain poorly understood. Considering that synovial dendritic cells (DCs) and C5a-associated inflammation are critical for RA pathogenesis, here we investigated what hi-miR regulated C5a-mediated inflammatory responsiveness of DCs. Hypoxia upregulated the expression of C5aR1 on DCs from human monocytes, consequently promoting C5a-mediated inflammatory responsiveness of DCs. Furthermore, hypoxia-upregulated miR-342-3p targeted STAT5b, EP300 and ubiquitin specific peptidase 13 (USP13), thus maintaining the high expression of C5aR1 on DCs via arresting STAT5 and STAT6-mediated downregulation of C5aR1 during monocytic differentiation into DCs. Moreover, blockade of miR-342-3p abnormally increased in RA models significantly represses the progression of RA models. So, our study identifies hypoxia-inducible miR-342-3p as an important mediator for DC and C5a-associated inflammatory pathogenesis in authoimmune diseases.
MCPIP1/Regnase is a negative feedback inhibitor of IL-17-mediated signaling and inflammation (CCR3P.200)
Authors: Gaffen Sarah , Garg Abhishek , Amatya Nilesh , Chen Kong , Cruz Juan , Grover Prerna , Whibley Natasha , Conti Heather , Hernandez Mir Gerard , Childs Erin , Smithgall Thomas , Biswas Partha , Kolls Jay , McGeachy Mandy , Kolattukudy Pappachan 
Published: January 2023

Abstract
IL-17 came to prominence with the discovery of Th17 cells. IL-17 induces inflammatory pathology in autoimmunity and certain infections, and thus constraint of this pathway is an essential part of its regulation. However, to date our understanding of IL-17 signaling checkpoints remains quite limited. Here, we identify MCPIP1 (Regnase-1, Zc3h12a) as a novel negative feedback inhibitor of IL-17 signaling. IL-17 treatment of fibroblasts stimulated increased MCPIP1 expression, whereas MCPIP1 silencing enhanced IL-17-mediated signal transduction. Conversely, reconstitution of MCPIP1-/- cells restricted IL-17 signaling, which was dependent on the MCPIP1 endonuclease domain, not its deubiquitinase domain. In vivo, MCPIP1 deficiency enhanced IL-17-dependent autoimmunity and host resistance to infection. Namely, susceptibility to candidiasis was reduced in MCPIP1 haploinsufficient mice, whereas IL-17-dependent pathology in EAE and pulmonary inflammation was enhanced. In addition to its well-documented capacity to degrade cytokine mRNA transcripts such as Il6, we found that MCPIP1 regulates some, though not all, IL-17-dependent promoters. In addition, we identified a novel function for MCPIP1 in mediating decay of mRNA transcripts encoding inflammatory receptors, including IL-17R subunits, in a manner independent of their 3’ UTR elements. This is the first demonstration that MCPIP1 restricts IL-17R signal transduction, and that this enzyme regulates inflammatory receptor expression.
Regulation of granulocyte colony stimulating factor by Fli-1, a novel transcriptional activator of inflammatory mediators (CCR3P.213)
Authors: Lennard Richard Mara , Brandon Danielle , Sato Shuzo , Zhang Xian 
Published: January 2023

Abstract
The Fli-1 transcription factor plays a significant role in the pathogenesis of systemic lupus erythematosus (SLE). Fli-1 expression is significantly increased in patients with lupus nephritis and lupus-prone mice with reduced Fli-1 expression (Fli-1+/-) live longer and have significantly less nephritis compared to wild type controls. Recently, Fli-1 has emerged as a critical regulator of inflammatory mediators, including MCP-1, CCL5, and IL-6. The cytokine, granulocyte colony stimulating factor (G-CSF) regulates neutrophil precursor maturation and survival, and activates mature neutrophils. In clinical settings, G-CSF increases the inflammatory response and worsens tissue damage. Previously, a significant decrease in neutrophil infiltration into the kidneys of Fli-1+/- lupus-prone mice was observed. In this study, a significant decrease in G-CSF protein expression was detected in stimulated endothelial cells transfected with Fli-1 specific siRNA. The murine G-CSF promoter contains numerous putative Fli-1 binding sites and five regions within the proximal promoter were found to be significantly enriched for Fli-1 binding. Transient transfection assays indicate that Fli-1 drives transcription from the G-CSF promoter and mutation of the Fli-1 DNA binding domain resulted in a 94% loss of transcriptional activation. In conclusion, we have discovered that Fli-1 plays a major role in the regulation of inflammatory cytokines and chemokines and inflammatory disease pathogenesis.
EZH2 in B lymphocyte commitment (HEM1P.229)
Authors: Jacobsen Jennifer , Kee Barbara 
Published: January 2023

Abstract
EZH2 is the histone methyltransferase subunit of the Polycomb Repressive Complex 2 that catalyzes the repressive histone modification, H3K27me3. We hypothesize that EZH2 is required to repress alternative lineages during B cell development. Loss of EZH2 in hematopoietic cells leads to blocks in B and T cell development. Here we use an Il7racre mouse model to delete Ezh2 at the common lymphoid progenitor stage to study the role of EZH2 in B lymphocyte commitment. We confirm that Il7racreEzh2fl/fl mice have a cell-intrinsic block at the pro-B cell stage of development. Although there are normal numbers of pro-B cells in Il7racreEzh2fl/fl mice, EZH2-deficient pro-B cells are outcompeted by WT cells in competitive chimeras. By qPCR we find that there is modest upregulation of Gata3 and Nfil3, which regulate innate lymphocyte development. Future studies will investigate the developmental plasticity of EZH2-deficient pro-B cells.
A CTCF-dependent regulatory element in the mouse TCRα/δ locus shapes the TCRα/δ repertoire (HEM2P.233)
Authors: Chen Liang , Carico Zachary , Shih Han-Yu , Krangel Michael 
Published: January 2023

Abstract
The diversity of antigen receptors on T and B lymphocytes is generated by the assembly of variable (V), diversity (D), and joining (J) gene segments. At the TCRα/δ locus, Vδ-Dδ-Jδ rearrangement occurs in CD4−CD8− double-negative (DN) thymocytes, whereas Vα and Jα are joined in CD4+CD8+ double-positive (DP) thymocytes. We previously showed that CTCF is an important regulator of chromatin conformation and Vα-Jα recombination in DP thymocytes. Here we show that INT1-2, a pair of CTCF-binding elements (CBEs), plays an important role in shaping the TCRδ repertoire in DN thymocytes. INT1-2-/- mice have a restricted TCRδ repertoire with Vδ4 being strongly predominant. Chromatin conformation capture assays showed that INT1-2-deletion disrupts a stable loop between INT2 and TEA CBEs and promotes the formation of new interactions between TEA and CBEs that are upstream of INT1-2. This alteration of chromatin loops disrupts a locus conformation designed to grant diverse Vδ segments an opportunity to pair with Dδ and Jδ segments. Additional analysis of INT1-2-/- DP thymocytes revealed a restricted TCRα repertoire, which we believe occurs as a consequence of the restricted TCRδ repertoire.
RORgT modulates key features in adult thymopoiesis (HEM2P.235)
Authors: Guo Yanxia , MacIsaac Kenzie , Hawwari Abbas , Miller Richard , Ferguson Heidi , Vilas Deshmukh Sujal , Mudget John , Engstrom Laura , Piers Kyle , Baltus Gretchen , Barr Kenneth , Mehmet Huseyin , Correll Craig , Cua Daniel , Jones Dallas 
Published: January 2023

Abstract
Recent studies have elucidated the molecular mechanism of RORgT transcriptional network controlling Th17 cell lineage fate and effector function. RORgT was initially identified as a transcription factor required for thymopoiesis by maintaining survival of CD4+CD8+ (DP) thymocytes. There are increasing efforts to target RORgT for the treatment of autoimmune disorders, but it remains unclear how inhibition of RORgT in adult animals may impact thymic T cell development. Here, we show that RORgT is required to maintain adult thymopoiesis using both ERT2-CRE-mediated conditional genetic ablation and pharmacological inhibition with a selective small-molecule antagonist. RNA-SEQ analysis demonstrated that RORgT regulates thymocyte migration, positive selection, proliferation, inflammation and DNA synthesis involved in thymopoiesis beyond DP cell survival. RORgT also directly engages multiple target DNA in close proximity to key transcription factors such as T cell factor-1, Ikaros family zink finger protein 1 and others required for thymocyte development. Our work illustrates a new perspective in thymic development by showing that RORgT modulates adult thymopoiesis via cooperation with other major transcription factors.
HDAC3 is required for thymocyte positive selection (HEM2P.236)
Authors: Philips Rachael , Chen Meibo , McWilliams Doug , Belmonte Paul , Constans Megan , Hiebert Scott , Shapiro Virginia 
Published: January 2023

Abstract
In order to generate functional peripheral T cells, proper gene regulation during T cell development is critical. Development involves both the activation and repression of genes as cells progress through each developmental checkpoint. Histone acetylation/deacetylation is one mechanism regulating gene expression. Acetylation by histone acetyl transferases (HATs) allows for gene expression and deacetylation by histone deacetylase (HDAC) enzymes promote gene silencing, and their role in regulating T cell development is not clear. In this study, our lab focused on HDAC3. We examined the role HDAC3 plays during T cell development by utilizing a CD2-Cre-mediated loss of HDAC3 (CD2icre HDAC3-cKO), which deletes early in thymocyte development. When HDAC3 is absent, there is a developmental block during positive selection, leading to the production of very few CD4 and CD8 SP thymocytes leading to a severe defect in peripheral T cell numbers. During positive selection, HDAC3-deficient DP thymocytes fail to down-regulate RORγt as they progress to the SP stage. Consistent with the failure to down-regulate RORγt, thymocytes post-positive selection express high levels of Bcl-xl and fail to express Bcl-2, which is required for their survival. Moreover, HDAC3-deficient thymocytes show increased apoptosis. These results suggest that HDAC3 is required for the down-regulation of RORγt during positive selection.
Histone deacetylase 3 is necessary for T cell maturation (HEM2P.238)
Authors: Hsu Fan-Chi , Belmonte Paul , Constans Megan , Chen Meibo , McWilliams Doug , Hiebert Scott , Shapiro Virginia 
Published: January 2023

Abstract
Recent thymic emigrants (RTEs) are newly generated T cells that need to undergo post-thymic maturation in the periphery. The mechanism of T cell maturation remains unclear. Histone deacetylase 3 (HDAC3) controls gene regulation, chromatin accessibility and genomic stability. However, the function of HDAC3 in T cell has yet to be elucidated. As we previously demonstrated that HDAC3 is a binding partner to NKAP, we hypothesize that HDAC3, like NKAP, may regulate T cell maturation. We generated CD4-cre HDAC3 cKO mice, which have similar numbers of DN, DP, CD4 SP and CD8 SP thymocytes as compared to WT mice; however, the peripheral numbers of CD4+ and CD8+ T cells are dramatically decreased in CD4-cre HDAC3 cKO mice. When we examined Rag1-GFP CD4-cre HDAC3 cKO mice, the majority of peripheral naïve T cells are Rag1-GFP+ RTEs indicating a block in T cell maturation. There is no defect in the positive selection, negative selection, migration, or homeostasis in CD4-cre HDAC3 cKO mice. However, expression of the complement inhibitor CD55, which is induced during maturation, is severely decreased. In the periphery, similar to NKAP-deficient T cells, HDAC3-deficient T cells are targeted for elimination by complement. In addition, HDAC3-deficient T cells have decreased sialic acid modifications on the cell surface, mainly due to α2-3, and α2-8 linkages, that recruit natural IgM to initiate the classical complement pathway. Thus, HDAC3 is required for T cell maturation.
A role for CD31 (PECAM-1) during T cell differentiation in the human thymus (HEM2P.239)
Authors: Douaisi Marc , Resop Rachel , Jamieson Beth , Uittenbogaart Christel 
Published: January 2023

Abstract
Although CD31 expression on human thymocytes has been reported, a detailed analysis of CD31 expression at various stages of T cell development in the human thymus is missing. Here we address the evolution of CD31 expression from the CD34+ hematopoietic precursor to the CD45RA+ mature CD4+ and CD8+ single positive (SP) T cells. Using 9-color flow cytometry, we show that CD31 is highly expressed on CD34+ progenitors and stays high until the early double positive stage (CD3- CD4+ CD8α+β-) when CD31 expression levels become low to undetectable. CD31 expression then increases and peaks on CD3high CD4+CD8+ double positive thymocytes. However, following positive selection, CD31 expression differs dramatically between CD4 and CD8 lineages: homogenously high on CD8 SP but low to negative on CD4 SP. Remarkably, there is a substantial subset of semi-mature (CD45RA-) CD4 SP thymocytes that lack CD31 expression. Moreover, FoxP3+ and ICOS+ cells are over-represented in this CD31- subpopulation. Despite the CD31- CD45RA- subpopulation, the majority of egress-capable mature CD45RA+ CD4 SP thymocytes expresses CD31. The variations in CD31 expression appear to coincide with three major selection processes occurring during thymopoiesis: TCRβ selection, as well as positive and negative selection. Considering the ability of CD31 to modulate the TCR’s activation threshold via the recruitment of tyrosine phosphatases, our results suggest a likely significant role for CD31 during T cell development.