bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modulation of autoimmunity associated with blocked nuclear export of histone Deacetylase 7 in thymocytes by CCR9 and the NOD genetic background. (P4088)
Authors: Kasler Herbert , Lim Hyung , Lee Intelly , Verdin Eric 
Published: January 2023

Abstract
Histone Deacetylase 7 (HDAC7) is a chromatin-modifier that, like other Class IIa HDACs, regulates cell differentiation through extracellular signal-dependent nucleo-cytoplasmic shuttling. We recently showed that nuclear export of HDAC7 in response to TCR signaling in thymocytes is required for negative thymic selection, and that thymic expression of a constitutively nuclear mutant of HDAC7 (HDAC7-ΔP) consequently causes lethal autoimmunity. Although the block in negative selection appears broad, in C57bl/6 mice autoimmunity is largely restricted to the abdominal viscera, with lethality due to exocrine pancreatitis. Investigating the cause of this restricted autoimmunity, we noted abnormally high expression of CCR9, a receptor associated with abdominal homing, in the CD8 T cells of HDAC7-ΔP mice. While this suggested that the type of disease caused by HDAC7-ΔP was due to its effects on both negative selection and chemokine receptor expression, we found that expression of HDAC7-ΔP in a CCR9-deficient background lengthened survival but did not alter the tissue distribution of autoimmune attack. In contrast to this result, we found that expression of HDAC7-ΔP in the NOD genetic background extensively altered the tissue distribution of autoimmunity and also greatly reduced mean survival time. These results shed significant new light on how a specific molecular lesion affecting thymic selection can interact with different genetic backgrounds to produce distinct disease outcomes.
CASPASE-12 genotype influences the expression of systemic lupus erythematosus in African-Americans (P4090)
Authors: Hermel Evan , Fuchs Trista , Kelly Jennifer , Moser Sivils Kathy , Velasco H. Eduardo 
Published: January 2023

Abstract
CASPASE-12 (CASP12) modulates inflammation by down-regulating inflammatory cytokines. CASP12 is a risk factor for sepsis in persons of African ancestry, as the functional CASP12 allele is present in about 20% of persons of African descent. Nearly all other human populations lack a functional CASP12 gene. Systemic lupus erythematosus (SLE) is a serious and complex autoimmune disease affecting multiple organ systems and is most common in African-American (AA) women. To determine if CASP12 may be protective against SLE, 596 AA SLE patients and 296 healthy controls from the Lupus Family Registry and Repository were genotyped for CASP12. Serum from 30 patients and controls was assayed by antibody arrays for 23 inflammatory cytokines and chemokines. There was a significant association between CASP12 and protection against serositis. CASP12 homozygosity was seen only in controls, and CASP12 was only in female, but not male patients without serositis compared to those with serositis. In male patients, CASP12 was protective against the development of arthritis. Expression of the Mig chemokine was statistically different between patients and controls, independent of genotype. No influence of CASP12 genotype was seen upon serum cytokine levels in patients vs controls. The results indicate that CASP12 is protective against lupus serositis and arthritis in AA patients, with possible gender influences for both. In addition, chemokines may contribute to the pathogenesis of SLE.
A short murine lupus-susceptibility Sle2c1rec1sublocus functions as both contributor and modifier of autoimmune disease in CD95 deficiency (P4098)
Authors: Xu Zhiwei , Morel Laurence 
Published: January 2023

Abstract
It is widely recognized that genetic susceptibility plays a significant role in lupus-like autoimmune diseases. The Sle2c1 sublocus belongs to the lupus susceptibility Sle2 locus identified on the chromosome 4 of lupus-prone NZM2410 mouse, and resulted in T cell-mediated autoimmune pathology in the bicongenic Sle2c1.lpr strain. Subsequently, a new recombinant congenic Sle2c1rec1.lpr strain carrying an about 10 Mbp-long Sle2c1rec1 sublocus produced from Sle2c1.lpr mouse was validated with the same autoimmune phenotypes as does Sle2c1.lpr mouse. In current study, we generated four new congenic recombinant stains, Sle2c1rec1a.lpr, Sle2c1rec1b.lpr, Sle2c1rec1c.lpr and Sle2c1rec1d.lpr, and performed a fine mapping of their recombinant intervals and a detection of their phenotypic alterations. The overlapping region between the Sle2c1rec1a and Sle2c1rec1d intervals mapped to the middle part of Sle2c1rec1 strongly promoted T cell expansion, incidence increase in inflammatory dermatitis and production of IgG autoantibodies. In contrast, Sle2c1rec1b in the proximal part of Sle2c1rec1 led to significant decrease in incidence of inflammatory dermatitis. Besides, Sle2c1rec1c in the distal end of Sle2c1rec1 obviously interacted with the mid part of Sle2c1rec1 sublocus to enhance T cell expansion. Overall, our results showed that Sle2c1rec1 harbors at least three functional domains, which are involved in regulating T cell mediate autoimmune pathology in epistasis with Fas deficiency.
Expression of Ikaros family member molecules in lupus-prone mice: a preliminary analysis (P4102)
Authors: Divekar Anagha , Lee Michael , Singh Ram , Halder Ramesh , Guiterrez Miguel-Angel , Yang Xifeng , Ransom John 
Published: January 2023

Abstract
Ikaros family of zinc-finger proteins, namely Aiolos, Helios and Ikaros, are hematopoietic-specific transcription factors involved in lymphocyte development. Aiolos-deficient mice develop SLE-like disease, and Ikaros family members have been linked to the balance between T cell activation and tolerance. To begin to investigate the role of Ikaros proteins in SLE, we first determined the expression of these proteins in spleen cells of NZM.2328 mice that develop disease that mimics human SLE in many ways, including a profound female bias. Results show that Aiolos expression in T cells is significantly lower than that in B cells from NZM.2328 mice. Similar reduction in Aiolos expressing T cells was observed in old lupus-prone MRL-MpJ-Fas+/+ compared to age-matched control B6 mice. Almost all B cells expressed Aiolos in all mice tested, but the expression level was much lower in MRL-MpJ+/+ B cells than in control B6 B cells. In contrast to Aiolos expression, T cells expressing Helios were 3-4-fold higher in old NZM.2328 females than in age-matched male and younger female mice. Ikaros expression was also higher on both T and B cells in older NZM.2328 females than in age-matched male and younger female mice. Ongoing studies will investigate the relationship of dysregulated Ikaros family molecules with lupus disease and examine the role of this dysregulation in female bias and lupus pathogenesis.
Defining epigenome responses in T-cell arthritogenicity: in search for effectors of autoimmunity. (P4076)
Authors: Backdahl Liselotte , Holmdahl Rikard 
Published: January 2023

Abstract
Recent successes of therapeutic intervention of chronic inflammatory diseases using epigenetic modifiers such as histone deacetylase inhibitors and inhibitors of DNA methylation suggest that epigenetic reprogramming plays a role in the aetiology of these diseases. However, the disease mechanisms driving epigenetic modulation in chronic inflammation are poorly understood. One of the major problems with assessing epigenetic regulation is that it is cell specific. DNA methylation is here studied in a population of arthritogenic CD4 T cells that can transmit pristane-oil induced arthritis, a model for Rheumatoid arthritis, after injection into healthy rats. Pristane primed spleenocyte derived T cells subjected to 24 hrs treatment with 5-AZA Cytidine completely lose the ability to transfer arthritis. Demonstrating that arthritogenic T cells have an altered DNA methylation profile that can be reversed. On the transcription level, treated CD4 T cells showed significant increase in IL-10, TGFb and Foxp3 indicating that regulatory T cells to be important for the protective effect. Assessing cellular phenotypes, MHCII is decreased and CD8+ is increased, indicating that activated CD4 cells but not naïve, are being killed by the regulatory T cells. Furthermore 3 CpG sites in the IL10 promoter were differentially methylated after 5-AZA. Identifying specific epigenetic marks in the genome would provide excellent clues to disease pathways as well as serve as potential therapeutic targets.
Tregs from T1D subjects with a susceptible IL-2R gene SNP, respond aberrantly to IL-2 stimulation. (P4080)
Authors: Marwaha Ashish , Staiger Spencer , Hirschfield Aaron , Panagiotopoulos Constadina , Turvey Stuart , Buckner Jane , Tan Rusung 
Published: January 2023

Abstract
Type 1 diabetes (T1D) results from the destruction of beta cells by autoreactive lymphocytes. Regulatory T cells (Tregs) maintain self-tolerance in part by suppressing the effector functions of self-reactive lymphocytes. Tregs require the cytokine interleukin-2 (IL-2) for survival and maintenance of their suppressive function. IL-2 binds to the high-affinity IL-2 receptor (IL-2R), leading to phosphorylation of signal transducer and activator of transcription 5 (STAT5) and downstream transcription of effector proteins.The IL-2 receptor gene has single nucleotide polymorphisms (SNPs), which are associated with T1D incidence. We hypothesized that T1D subjects with SNPs in the IL-2R gene possess Tregs that respond aberrantly to IL-2 and do not optimally induce signaling in the STAT5 pathway. PBMC from T1D subjects with a homozygous susceptible (GG), heterozygous (AG) and homozygous wild-type (AA) genotype for a SNP located in the rs3118470 locus of the IL-2R gene were stimulated with IL-2. Our results indicate that Tregs from individuals with the homozygous susceptible GG genotype have reduced levels of pSTAT5 compared to those with the AA genotype (p=0.0133). This provides evidence that Tregs from T1D subjects with SNPs in the rs3118470 locus of the IL-2R gene have diminished STAT5 phosphorylation in response to IL-2. This is a potential mechanism of defective Treg function in a genetically identifiable subset of children with T1D.
Autoimmunity developed in Hoxb8 knock-out mice (P4082)
Authors: Chen Shau Kwaun , He Xiao , Hu Dai , Jensen Peter , Capecchi Mario 
Published: January 2023

Abstract
Hoxb8 belongs to the homeobox transcription factor family. Hoxb8 knockout (KO) mice exhibit a compulsive grooming, similar to trichotillomania (an impulse control disease) in humans. Hoxb8 is expressed in multiple hematopoietic cells. Bone marrow (BM) cells from Hoxb8 KO are less competitive than wildtype (wt) BM cells in granulocyte/monocyte and T cell lineages, yet more competitive in B cell lineage. How these changes affect development and functions of lymphocytes remain unknown. Here we report that autoimmunity was developed in Hoxb8 KO. Hoxb8 KO sera contain autoantibody against several self-tissues, including brain, kidney and liver. Splenomegaly was found with a higher frequency in KO mice, associating with increased B and T cell numbers. The percentages of surface IgG+ B and activated T cells were significantly increased as well. Moreover, serum IgG levels showed an age-dependent increase: there were trends of increased IgG levels in 3 and 6 month old KO, compared to aged matched wt mice, but all IgG isotypes, except IgG3, were significantly increased in the 9-month-old KO mice. Finally, we showed that autoimmunity developed in Hoxb8 KO mice may not be the major cause of the excessive grooming behavior since compulsive grooming remains in Hoxb8/RAG2 double KO mice. This observation suggests that defects of Hoxb8 in the immune system may play a supportive but not a major role in the pathogenesis of compulsive behavior, which agrees with our microglia hypothesis.
Identifying modifier genes in Autoimmune Lymphoproliferative Syndrome (P4084)
Authors: Lo Bernice , Schäffer Alejandro , Paik Daniel , Davis Joie , Price Susan , Rao Koneti , Lenardo Michael 
Published: January 2023

Abstract
Autoimmune Lymphoproliferative Syndrome (ALPS) is an inherited disorder of defective lymphocyte apoptosis, characterized by chronic lymphadenopathy and/or splenomegaly, autoimmune cytopenias, and the expansion of a unique population of CD4-CD8- α/β T cells. ALPS is predominately caused by mutations in Fas with incomplete penetrance. In order to identify modifier genes and understand the mechanism of incomplete penetrance of disease in ALPS, we performed a linkage study using five large families with multiple ALPS patients and healthy Fas mutation-positive relatives (HMPRs) in each family. We identified a putative modifier locus shared by two of the families and a few potential linkage intervals shared by two of the other families. To screen large numbers of family members for an apoptosis defect, we developed a fast assay for testing lymphocyte Fas-mediated apoptosis susceptibility ex vivo, which we have named the FasT Kill assay. The conventional in vitro apoptosis assay takes over a week to obtain results whereas our assay using multi-parameter flow cytometry to specifically analyze apoptosis of the Fas-sensitive effector memory T cells in PBMCs can yield a diagnosis within a single workday. Using the FasT Kill assay, we could rapidly identify patients with apoptosis defects for the diagnosis of ALPS and compare the severity of apoptosis defects among ALPS patients or HMPRs. The results of these genetic analyses will be discussed.
Sex-specific effects of Sca-1/Ly-6A on development of B lymphocyte in the bone marrow (P4384)
Authors: Bamezai Anil , Vacharathit Vimvara , DeWolf Sean 
Published: January 2023

Abstract
Stem cell antigen-1 (Sca-1, also known as Ly-6A) is highly expressed on the hematopoietic stem cells (HSC) and on early lymphoid progenitors, but the role this cell surface protein plays in the development of B cells in the bone marrow is unknown. We report here that the absence of Sca-1/ Ly-6A protein in mice regulates B cell development in the bone marrow in a sex-specific manner. Significant impairment of B cell development was observed in female mice lacking the Sca-1/Ly-6A protein, while this impairment was not observed in Sca-1/Ly-6A deficient males. In contrast, higher percentages of NK1.1+ cells were observed in the thymus from Sca-1/Ly-6A deficient females, while the male mice lacking Sca-1/Ly-6A did not show any alteration when compared to the wild type controls. The deficiency of Sca-1/Ly-6A did not impair development of T cells in the thymus of mice of either sex. These findings indicate that Sca-1/Ly-6A plays an important role in B cell and NK1.1+ cell development and suggests a functional interaction between Sca-1/Ly-6A and female sex hormones in regulating development of B cells and NK1.1+ cells.
Central B-cell tolerance mediated by Aicda and Myd88 (P4404)
Authors: Kuraoka Masayuki , Snowden Pilar , Nojima Takuya , Liao Dongmei , Zhang Wenli , Kelsoe Garnett 
Published: January 2023

Abstract
Elimination of autoreactive B cells and establishment of self-tolerance is crucial for the prevention of autoimmunity, nonetheless, the mechanism(s) of B-cell tolerance are not fully understood. Recently, we and others have reported that activation-induced cytidine deaminase (AID) and myeloid differentiation primary response gene 88 (MyD88) play unexpected roles in establishing central B-cell tolerance in mice and humans. AID expression in bone marrow immature B cells is synergistically elevated by anti-IgM F(ab’)2 and oligo CpG DNA co-stimulation; reaches to near germinal center levels in 24 hours, but the synergistic effect was not observed by anti-IgM and lipopolysaccharide co-stimulation. These results imply that co-ordination between BCR- and intracellular Toll-like receptors/MyD88 signals regulate AID expression in immature B cells. This synergy was not seen in mature follicular B cells. To explore molecular pathway(s) downstream of AID in B-cell tolerance, we analyzed B-cell development in uracil-DNA glycosylase (UNG)-deficient mice. Unlike AID- or MyD88-deficient background, UNG-deficiency did not impair central B-cell tolerance; because UNG-deficiency severely impairs class-switch recombination (CSR) but not somatic hypermutation, our results imply CSR, e.g., “locus suicide recombination”, may not play a major role in central B-cell tolerance.
Bcr-Abl expression overcomes aging-associated functional declines in B-Lymphopoiesis leading to increased leukemogenesis (P4406)
Authors: Henry Curtis , Marusyk Andriy , Zaberezhnyy Vadym , Casas Matias , Serkova Natalie , Clambey Eric , DeGregori James 
Published: January 2023

Abstract
Current paradigms attribute the association between aging and cancers to the accumulation of oncogenic mutations. Alternatively, we hypothesize that aging-associated reductions in the fitness of stem and progenitor cell populations should be conducive for increased selection of adaptive oncogenic mutations which can partially restore fitness, thereby promoting the initiation of cancers. We have explored how aging affects B-cell progenitor fitness and subsequently leukemogenesis. Here we show that IL-7 receptor (IL-7R) signaling is defective in aged B-cell progenitors leading to reduced phospho-STAT5 and Akt levels. Aged B-cell progenitors also exhibit altered expression of IL-7R regulated genes, including reduced Pax5, Myc and HPRT, and increased TNF-α. Both decreasing IL-7R signaling and increasing inflammation phenocopied aging-associated B-lymphopoiesis defects in young mice. Decreasing IL-7R signaling also promoted selection for Bcr-Abl expressing B-cell progenitors coinciding with increased leukemogenesis in vivo. Importantly, Bcr-Abl restored defective IL-7R signaling and inflammation-induced defects in these cells. These studies elucidate how reduced IL-7R signaling and increased inflammation promote aging-associated reductions in B-lymphopoiesis. Furthermore, we show that the selection for cells harboring oncogenic mutations (such as Bcr-Abl) is increased in aged backgrounds due in part to their ability to correct aging-associated fitness defects.
mTORC2 modulates αβT-cell receptor processing and surface expression during thymocyte development (P4414)
Authors: Chen Po-Hao , Chou Po-Chien , Oh Won Jun , Wu Chang-Chih , Hall Michael , Jacinto Estela , Werlen Guy 
Published: January 2023

Abstract
An efficient immune response relies on the presence of T-cells expressing a functional T-cell receptor (TCR). While the mechanisms generating TCR diversity for antigenic recognition are well defined, what controls its surface expression is less known. Here we found that mTOR complex 2 (mTORC2) modulates T-cell ontogeny by controlling the quantity of TCR that reaches the cell surface. Deletion of the mTORC2 component rictor at early stages of T-cell development led to aberrant maturation and increased proteasomal degradation of nascent TCR polypeptides. Consequently, the levels of TCR as well as other receptors, including CD4, CD8 and CD147 were significantly attenuated on the surface of rictor-deficient thymocytes. Since CD147 was also defectively glycosylated and expressed in SIN1-deficient fibroblasts, our findings suggest that mTORC2 is involved in the co/post-translational processing of membrane receptors. Thus, this novel function for mTORC2 provides a rationale to target this complex in disorders caused by deregulated expression of surface receptors.
The role of the Bcl-2 BH3 domain in thymocyte apoptosis (P4416)
Authors: Burger Megan , Kang Chulho , Winoto Astar 
Published: January 2023

Abstract
Over-expression of Bcl-2 has been shown to protect thymocytes from apoptosis by many stimuli except strong T cell receptor signals during negative selection. This might be due to Bcl-2 taking on a pro-apoptotic function during negative selection mediated through its BH3 domain, which is exposed upon interaction with the nuclear orphan receptor Nur77. To test this, we generated a T cell-specific transgenic mouse over-expressing Bcl-2 with a mutated BH3 domain. Consistent with our hypothesis, we observed that thymocytes expressing the Bcl-2 BH3 transgene were better protected from apoptosis by TCR stimuli in vitro than those expressing a wild-type transgene. To evaluate TCR-induced apoptosis in vivo, the Bcl-2 BH3 mutant transgenic mice were crossed to F5 and HY TCR transgenic mice. Vibratome cut thymic slices were treated acutely with F5 and HY TCR-specific peptides, circumventing the peripheral cytotoxic effects of in vivo peptide injection. Bcl-2 BH3 mutant transgenic thymocytes were almost completely rescued from peptide-induced apoptosis, but surprisingly, thymocytes expressing the wild-type Bcl-2 transgene were equivalently protected. Thus our results indicate that Bcl-2 has some pro-apoptotic function, but in contrast to previously published data in TCR-transgenic models, we conclude that Bcl-2 over-expression affords substantial protection from apoptosis accompanying negative selection.
A subset of Vγ4+ γδ T cells are derived from the adult murine thymus (P4462)
Authors: Colpitts Sara , Sheridan Brian , Pham Quynh-Mai , Lefrançois Leo 
Published: January 2023

Abstract
γδ T cells are a phenotypically diverse subset of immune cells with equally diverse functions in innate and adaptive immunity. We have identified a population of Vγ4+ γδ T cells that play an important role in protective immunity against oral Listeria infection. To further examine these cells, we generated mixed chimeras using a combination of neonatal thymocytes (neoThy) and adult bone marrow (BM). Surprisingly, the Vγ4+ population (identified as lacking expression of all other known γδ TCRs) was derived from both neoThy and BM progenitors demonstrating that the development of Vγ4 cells is not strictly limited to early ontogeny. Indeed, Vγ4 cells were found in the adult murine thymus, and, similar to other subsets of BM-derived γδ T cells, were the progeny of c-kit+ early thymic progenitors and required an adult thymus for their development. However, unlike the neoThy-derived subset, the BM-derived Vγ4 cells had a CD44intCD27+CD25- phenotype and did not produce IL-17 in naïve mice. However, when challenged with oral Listeria, there was a significant increase in BM-derived Vγ4 cells producing both IL-17 and IFNγ, but the overall contribution of this population to the anti-Listeria response was not significant compared to that of the neoThy-derived cells. Thus, we have discovered a unique population of Vγ4-expressing γδ T cells that emerge in adulthood.
A multipotent mesenchymal stem cell-like population in the postnatal thymus (P4466)
Authors: Pezzano Mark , Osada Masako , Singh Varan , Trozky Yana , Sant’Angelo Derek 
Published: January 2023

Abstract
Thymic microenvironments are required for the proper development of T cells. While significant turnover occurs, it is unclear whether populations of adult stem cells contribute to the maintenance of postnatal thymic epithelial microenvironments. Here, we utilize a keratin 5 promoter-driven, Tet-regulated H2BGFP transgenic model to localize label retaining epithelial cells (LRCs) in the postnatal thymus. A subset of LRCs was then used to generate clonal cell lines that retain the capacity to differentiate into a number of mesenchymal lineages including adipocytes, chondrocytes and osteoblasts supporting a mesenchymal stem cell-like phenotype. In culture, these cells maintained a diverse gene expression profile including expression of the stem cell markers Nanog, Oct4 and Sox2, genes associated with the maintenance of pluripotency, as well as genes associated with thymic epithelial cells including EpCAM, FoxN1, MHCII and Wnt4. Furthermore, the cells were found to express Sca1, PDGFRα, PDGFGRβ, CD29, CD44, CD49f, CD90 and CD106, similar to mesenchymal stem cells. Sorted GFP-expressing stroma that give rise to TMSCs contribute to thymic epithelial architecture when reaggregated with fetal stroma and transplanted under the kidney capsule of nude mice. Together these results show that the postnatal thymus contains a population of mesenchymal stem cells that can be maintained in culture and suggest they may contribute to the maintenance of functional thymic microenvironments.