bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrin α4β7 is an immunological marker for HIV preference in activated peripheral and cervical CD4+ T cells (VIR8P.1066)
Authors: Chang Theresa , Ding Jian , Tasker Carley , Lu Wuyuan , Lespinasse Pierre , Heller Debra 
Published: January 2023

Abstract
CD4+ T cells, the principal target in acute SIV and HIV infection, are crucial for the establishment and dissemination of HIV infection in mucosal tissues. Studies indicate that α4β7 CD4+ T cells are preferentially infected by HIV in vitro and during acute SIV infection. Integrin α4β7 is thought to promote HIV capture by target cells; however, the role of integrin α4β7 in HIV transmission remains controversial. In this study, we characterized immunological profiles of human cervical T cells and examined HIV preference in α4β7+ CD4+ T cells. In vitro all-trans retinoic acid differentiated peripheral CD4+ T cells were included as a comparison. In both peripheral and cervical cells, HIV preferentially infected CD38+ activated cells. Although integrin α4β7 was not the major determinant for HIV preference, the majority of HIV p24+ cells were found in activated CD4+ T cells expressing α4β7. Interestingly, CCR5 was not a marker for HIV preference. The cyclic hexapeptide CWLDVC and monoclonal antibody against integrin α4β7 did not block HIV attachment or gp120 binding to target cells regardless the presence of CD4, indicating that integrin α4β7 did not contribute to facilitating HIV capture by target cells. Our results suggest that integrin α4β7 may play a role in HIV susceptibility but not through promoting HIV binding to target cells.
Relative resistance to HLA-DM editing is a distinguishing characteristic of Type-1 diabetes associated HLA-DQ molecules (APP2P.100)
Authors: Zhou Zemin , Reyes-Vargas Eduardo , Escobar Hernando , Rudd Brant , Rockwood Alan , Delgado Julio , He Xiao , Jensen Peter 
Published: January 2023

Abstract
Homozygous HLA-DQ2, 8 or heterozygous 2/8 are highly associated with developing Type-1 diabetes (T1D), but the underlining molecular mechanism is not clear. HLA-DM is essential for editing peptides bound to MHC-II, thus influencing the repertoire of peptides presented by APCs, with potential impact on selection/activation of CD4+ T cells. We hypothesized that unique properties of T1D associated DQs, including different binding affinity for CLIP or other peptides & different sensitivity to DM editing, might confer high risk of T1D. Higher CLIP levels were found on the surface of DQ2+, 8+ or 2/8+ cells, compared to T1D protective DQ6+ cells, indicating a relative resistance to DM editing. HPLC-MS/MS analysis of eluted peptides from DQs showed that CLIPs containing longer N-terminal tails & more long peptides (&gt;20 aa) were loaded on DQ2, 8 or 2/8, compared to DQ6. Among eluted peptides, several were derived from known auto-Ag identified in T1D. Peptide binding motifs of DQ2, 8 & 2/8 were different from DQ6, but similar to that of DQ8 as previously reported. Furthermore, DQ peptide binding assay demonstrated that CLIP2 had higher relative binding affinity to DQ2, 8 or 2/8, compared to DQ6. Disruption of hydrogen bonds near P1 pocket in DQ8 reversed its DM editing resistance. Collectively, our results showed that the DM sensitivity of DQ2, 8 & 2/8 is lower than that of DQ6. The relative resistance to DM editing of the T1D associated DQs may contribute to the pathogenesis of T1D.
Eight novel H-2Kb and H-2Db restricted epitopes of ovalbumin (APP2P.109)
Authors: Karandikar Sukrut , Srivastava Pramod 
Published: January 2023

Abstract
CD8+ T cells recognize epitopes, which are generally eight to ten amino acid long peptides presented by MHC class I molecules. Ovalbumin (OVA) has two well documented H-2 Kb restricted epitopes: SIINFEKL- the immunodominant epitope and KVVRFDKL- the sub-dominant epitope. Analyzing the sequence of OVA with NetMHC, a peptide-MHC binding affinity prediction tool, revealed 17 additional putative epitopes presentable by H-2Kb or H-2Db. Eight of these 17 elicit antigen-specific CD8+ T cell responses in naïve C57BL/6 mice. We are currently testing the direct presentation and the immunodominance hierarchy of these epitopes.
Bacterial amyloids promote type I interferon production and accelerate autoimmunity (BA3P.206)
Authors: Gallo Paul , Rapsinski Glenn , Tukel Cagla , Gallucci Stefania 
Published: January 2023

Abstract
Infection is a major cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE). Curli is a bacterial amyloid that serves as a component of enteric bacterial biofilms. Patients are exposed to curli during urinary tract infections, gastrointestinal infections, and sepsis. Here we studied the immune response to curli amyloids in the context of murine SLE. We found that curli amyloids from bacterial cultures contain abundant nucleic acids and that exogenous DNA enhances amyloid fibrillization. Bone marrow-derived myeloid DCs strongly respond to curli-DNA composites, producing large quantities of IL-12, IL-6, and IL-10. Curli potently induces expression of IFN-β and IFN-stimulated genes. Using both natural and synthetic curli, we found that curli and nucleic acids synergize to activate DCs. Young, pre-disease lupus-prone NZBW-F1 mice injected i.p. with nucleic acid-containing curli produce high titers of anti-dsDNA and anti-chromatin autoantibodies within 2 weeks of the first injection, much earlier than mice treated with PBS. In conclusion, the bacterial amyloid curli contains nucleic acids which are integral to the immune response to bacterial biofilms. Curli is a potent activator of dendritic cells and can rapidly accelerate autoimmunity in lupus-prone mice. This work suggests that nucleic acid-containing bacterial amyloids are an important environmental trigger for lupus and that curli injection may be a novel method to accelerate murine lupus.
Molecular aspects of IL-13 up-regulation by CD8+ T cells from systemic sclerosis patients (BA3P.132)
Authors: Fuschiotti Patrizia , Cascio Sandra , Moss Alissa , Ivanco Dana , Domsic Robyn , Milcarek Christine , Medsger Thomas 
Published: January 2023

Abstract
Systemic sclerosis (SSc), an incurable connective tissue disease, is characterized by vascular damage, inflammation and fibrosis. T cells are important in pathogenesis and produce cytokines that contribute to the induction of fibrosis. We found that dysregulated production of the profibrotic cytokine IL-13 by effector CD8+ T cells is associated with more severe skin thickening in SSc and defects in the molecular control of IL-13 production, such as increased expression of the Th2-specific transcription factor GATA-3. Silencing of GATA-3 by siRNA blocks IL-13 production in CD8+ T cells, demonstrating a causal relation¬ship between GATA-3 and IL-13. GATA-3 is also highly expressed by CD8+ T cells in lesions of patients where it may be associated with overproduction of IL-13. Th1-specific T-bet induces IFN-γ production and inhibits Th2 cytokines, including IL-13, by antagonizing GATA-3 expression and/or function. Here we show that CD8+ T cells from patient blood express high levels of IL-13 and GATA-3 but levels of IFN-γ and T-bet similar to controls. We also found that the interaction between T-bet and GATA-3 in SSc CD8+ T cells is weaker allowing more GATA-3 to bind to the IL-13 promoter and induce its expression. We conclude that increased IL-13 expression by SSc CD8+ T cells results, at least in part, from reduced down-regulation of GATA-3 by T-bet. Our new insights will establish novel biomarkers of immune dysfunction in SSc patients that can be used as therapeutic targets.
Memory B cells are critical in gamma herpes virus driven disease enhancement of a mouse model for MS (BA2P.124)
Authors: Marquez Ana , Casiraghi Costanza , Shanina Iryna , Horwitz Marc 
Published: January 2023

Abstract
Genetic and environmental factors are known to be involved in the development of Multiple Sclerosis. However, the mechanism describing how these factors are responsible for the onset of MS has not been elucidated. One of the environmental factors believed to play an important role in the development of MS is previous infection with the Epstein Barr Virus (EBV). The study of the relationship between MS and EBV remains elusive since EBV only infects humans. We hypothesized that latent EBV infection alters the immune system’s response in genetically predisposed individuals, thereby exacerbating autoimmunity. To address this question our lab previously developed a model where latent infection with murine gamma herpesvirus 68 (γHV-68), the murine homolog to EBV, enhances the symptoms of experimental autoimmune encephalomyelitis (EAE), which closely resembles MS pathogenesis. These enhanced symptoms are driven by the upregulation of CD40 on dendritic cells (DCs) of latently infected mice which drives the priming of a strong TH1 response and a decrease in Tregs frequencies. Latency of γHV-68 mainly occurs in memory B cells and the virus is not found in the DCs driving the TH1 response. Here we demonstrate that latently infected memory B cells are the cells responsible for the upregulation of CD40 in DCs, most likely through the upregulation of type I interferons in DCs. This represents a novel mechanism by which infection with EBV can influence MS and other autoimmune diseases.
Genetic variant at ETS1 locus increases lupus risk and affects Stat1 binding (BA2P.115)
Authors: Lu Xiaoming , Zoller Erin , Weirauch Matt , Namjou Bahram , International Consortium on the Genetics of SLE The , Greis Kenneth , Shen Nan , Kaufman Kenneth , Harley John , Kottyan Leah 
Published: January 2023

Abstract
Over the past 10 years, genetic association studies have identified over 55 systemic lupus erythematous (SLE)-risk loci. Genetic variants in ETS1 have been associated with SLE in several independent studies in populations of Asian ancestry. Several recent studies have implicated Ets1 as a critical driver of B and T cell function; indeed, mice deficient in Ets1 develop an SLE-like autoimmunity. rs1128334, in the 3’ UTR of ETS1, has been associated with the decreased expression of Ets1. We performed a fine-mapping study of over 20,000 subjects of two multi-ancestral cohorts using genotyped and imputed variants spanning the ETS1 locus. By constructing genetic models using frequentist and Bayesian association methods, we identified a set of variants that are most likely to be causal. Of the three variants that we tested, only rs6590330 differentially binds lysate from B cell lines as assessed by electrophoretic mobility shift assays and DNA affinity precipitation assays. We found that the active form of the transcription factor Stat1 binds the risk allele of rs6590330 but not the non-risk allele using mass spectrometry, a finding confirmed by Western blot analysis. rs6590330 is in strong linkage disequilibrium with rs1128334 and is predicted to also be associated with decreased Ets1 expression. We propose a model in which the risk allele of rs6590330 increases SLE risk by binding Stat1 and depressing the expression of Ets1.
Shared VH1-46 gene usage by anti-desmoglein 3 antibodies in pemphigus vulgaris suggest a common mechanism for developing autoimmunity (BA2P.116)
Authors: Cho Michael Jeffrey , Lo Agnes , Mao Xuming , Nagler Arielle , Choi Eun Jung , Sharma Preety , Uduman Mohamed , Li Hong , Rux Ann , Farber Sara , Rubin Courtney , Kleinstein Steven , Sachais Bruce , Posner Marshall , Cavacini Lisa , Payne Aimee 
Published: January 2023

Abstract
Pemphigus vulgaris (PV) is a potentially fatal blistering disease caused by autoantibodies (autoAbs) to desmoglein 3 (Dsg3). To better understand the mechanism by which PV Abs develop, we cloned human anti-Dsg3 Abs from four PV patients using phage display (n=2) or heterohybridoma (n=2). We identified VH1-46 anti-Dsg3 Abs from all 4 patients, comprising 5 unique heavy chain complementarity determining region (CDR) 3 sequences. All 5 Abs caused suprabasal blisters in human skin explants. Surprisingly, most VH1-46 Abs had few replacement mutations and did not show evidence of antigen-driven positive selection by focused binomial testing of mutation patterns. To determine if somatic mutations are required for Dsg3 binding, we reverted mutated Abs to their germline (GL) VDJ sequences. Three GL Abs bound Dsg3 by ELISA, with a 2- to 80-fold decrease in affinity as measured by surface plasmon resonance. Analysis of mutation patterns in 2 other Abs which lost Dsg3 binding after mutation reversion revealed homologous acidic amino acid CDR mutations. Site-directed mutagenesis indicated that these acidic residues are necessary and sufficient for Dsg3 binding. Our data indicate that VH1-46 autoAb gene usage is shared among PV patients which may be due to naive autoreactivity of some VH1-46 Abs or the requirement for very few acidic amino acid mutations in the CDRs to confer Dsg3 binding. Common VH1-46 autoAb gene usage may suggest a common mechanism for developing autoimmunity in PV.
Defective lysosomal degradation of immune complexes drives activation of cytosolic sensors in lupus-prone mice. (BA4P.210)
Authors: Monteith Andrew , Ah Kang Sun , Scott Eric , Costello Joe , Clarke Stephen , Vilen Barbara 
Published: January 2023

Abstract
Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by heightened production of autoantibodies to nuclear antigen resulting in immune complex (IC) formation. While the loss of tolerance in SLE has been connected with the formation of ICs, little is known about the mechanism of immune dysregulation. Recently, we found that low levels of ICs are displayed via FcγRs on dendritic cells, macrophages (MFs) and B cells from C57BL/6 mice. In contrast, cells from lupus-prone (MRL/lpr) mice show a 30-50-fold increase in surface bound ICs. We’ve demonstrated that MRL/lpr MFs fail to properly mature their lysosomes following phagocytosis of ICs, causing them to be recycled back to the cell surface 48-72 hours later. Impaired lysosomal degradation has been demonstrated to form frustrated phagosomes, which can leak vesicular cargo into the cytosol. Internalized ICs contain both nuclear antigen and IgG, both of which can bind to intracellular sensors. Here we demonstrate that impaired lysosomal degradation in MRL/lpr MFs results in dsDNA from ICs activating the cytosolic sensors Aim2 and IFI204. In addition, the IgG activates the cytosolic sensor TRIM21. The combined activation of these cytosolic sensors leads to increased cell death from pyroptosis and the secretion of the IFNα. Overall, we have defined a novel defect associated with SLE where the inability to degrade ICs drives the activation of cytosolic sensors that contribute to SLE related pathologies.
TLR9 restricts survival of anergic anti-DNA B cells in systemic lupus erythematosus yet is also required for their activation (BA4P.219)
Authors: Nickerson Kevin , Christensen Sean , Cullen Jaime , Meng Wenzhou , Luning Prak Eline , Shlomchik Mark 
Published: January 2023

Abstract
Anti-DNA autoantibodies are a clinical hallmark of systemic lupus erythematosus. Nucleic acid reactive B cells arise in the bone marrow even in healthy individuals, but are tolerized by mechanisms including receptor editing, functional anergy, and/or deletion. TLR9, a sensor of endosomal dsDNA, both promotes and regulates systemic autoimmunity in vivo, but the mechanisms of its apparently contradictory roles in autoimmunity remained unclear. Here, using the 3H9 anti-DNA B cell receptor (BCR) transgene in the autoimmune-prone MRL.Fas-lpr mouse model of lupus, we identify the stages at which TLR9 contributes to establishing and breaking B cell tolerance. Although TLR9 is dispensable for editing and establishment of anergy, TLR9 limits anti-DNA B cell lifespan in the periphery and is thus tolerogenic. In the absence of TLR9, anti-DNA B cells have much longer lifespans and accumulate in the follicle, neither activated nor deleted. These cells retain some characteristics of anergic cells, in that they have elevated basal BCR signaling but impaired induced responses and downregulate their cell surface BCR expression. Nonetheless, in older autoimmune-prone animals, TLR9 is required for spontaneous peripheral activation of anti-DNA B cells and their differentiation into AFCs via an extrafollicular pathway. Thus, TLR9 has paradoxical roles in regulating anti-DNA B cells: it helps purge the peripheral repertoire of autoreactive cells yet is also required for their activation.
Lymphotoxin-expressing marginal zone B cells support marginal zone integrity by maintaining the megakaryoblastic leukemia-1 expression (BA4P.221)
Authors: Li Hao , Hsu Hui-Chen , Wu Qi , Yang PingAr , Li Jun , Luo Bao , Fu Yang-Xin , Zhou Yong , Mountz John 
Published: January 2023

Abstract
Marginal zone macrophages (MZMs) engulf apoptotic debris and play a key role in preventing autoimmunity. We previously reported that in autoimmune BXD2 mice, there is a progressive reduction in the function and numbers of MZMs associated with a gradual decline in MZ B cells. MZ B cells, compared with follicular B cells, expressed higher levels of membrane bound lymphotoxin (mLT). A mixed bone marrow reconstitution(Ly5.1+Ltβr+ : Ly5.2+Ltβr-=1:1) in Rag1-/- mice with an biased repopulation of MZMs (88:12), demonstrated that LT was essential for the maintenance of MZMs. To identify the mechanism of mLT on the maintenance of MZMs, MZM gene expression of BXD2 mice treated with PBS or soluble LTβ receptor (LTβR-Ig) was analyzed by the Illumina MouseWG-6 chips. Pathway analysis revealed that megakaryoblastic leukemia-1(MKL1) mediated genes were the most significantly down-regulated by LTβR-Ig. MKL1 is a Rho kinase mechanosensing signal that mediates cell elasticity. There was dramatic reduction of MKL1 in MZMs of BXD2 and CD19.Cre LTβf/f mice, compared to normal B6 mice. Similarly, there were reduced MZMs as well as spontaneous development of germinal centers and autoantibodies in B6-Mkl1+/- mice, compared to Mkl1+/+ mice. Administration of CCG1423 (0.15 mg/kg), a Rho/MKL1inhibitor, to BXD2 mice exacerbated the loss of MZMs. Together, our results suggest a novel immune tolerance mechanism that LT+ B cells in the MZ support MZM integrity by maintaining cell elastic signal, MKL1
The role of a Stat4 deficiency in Atherosclerosis (CAM1P.237)
Authors: Taghavie-Moghadam Paresa , Butcher Matthew , Kaplan Mark , Nadler Jerry , Galkina Elena 
Published: January 2023

Abstract
Atherosclerosis is a chronic inflammatory process that leads to plaque formation in large and medium size vessels. Th1 cells constitute a majority of plaque T cells and play a pro-atherogenic role. Signal transducer and activator of transcription 4 (Stat4) is a transcription factor involved in Th1 cell differentiation. To test a role of Stat4 in atherogenesis, we bred Stat4-deficient (Stat4-/-) and atherosclerosis-prone Apolipoprotein E (Apoe-/-) mice. Stat4 deficiency resulted in a 70% reduction in plaque burden in Stat4-/-Apoe-/- vs Apoe-/- mice (p&lt;0.01). Surprisingly, reduced atherogenesis was not due to attenuated IFNγ production suggesting an IFNγ-independent pro-atherogenic role of Stat4. Stat4 is highly expressed in T cells, but also detected in macrophages (MΦ). To further test an impact of Stat4 deficiency in myeloid cells, we analyzed activation status of MΦ. Stat4-/-Apoe-/- CD11b+ MΦ expressed low levels of CD69, MHCII, and CD86 when pulsed with LPS vs Apoe-/- MΦ. Differentiated in vitro Stat4-/-Apoe-/- M1 or M2 MΦ also had reduced expression of CCL2 and CXCL10 vs Apoe-/- M1 and M2 MΦ. Importantly, the percentage of aortic Ly6C+ (p&lt;0.02) and CD68+ (p&lt;0.06) cells was reduced in Stat4-/-Apoe-/- vs Apoe-/- mice. The data provides evidence for a functional role of Stat4 in atherosclerosis by elevating levels of MΦ activation and aortic MΦ content, and thus promoting the localized aortic pro-inflammatory immune response. Supported by R01 HL112605 and Suppl.Grant 02S1.
Expression of CCL20 in hapten challenged skin induces recruitment of hapten-primed CD8 T cells producing IL-17 into the skin (CAM1P.229)
Authors: Kish Danielle , Fairchild Robert 
Published: January 2023

Abstract
Contact hypersensitivity (CHS) is a CD8 T cell-mediated response to skin sensitization and challenge with hapten. Hapten-presenting endothelial cell (EC) activate hapten-primed CD8 T cells to produce IFN-γ and IL-17 in the challenge site. These cytokines stimulate the EC to produce CXCL1 and CXCL2 that direct required CXCR2+ leukocyte recruitment into the skin challenge site for elicitation of CHS. This study investigated mechanisms directing hapten-primed CD8 cell localization to the hapten presenting EC in the challenge site. In the draining lymph nodes of hapten sensitized mice, CD8 T cells expressing CCR6 produce IL-17 in response to hapten-presenting cells and CD8 T cells expressing CXCR3 produce IFN-γ. Hapten skin challenge induces CXCL9/10 and CCL20 expression within 1 h and hapten labeling of EC cultures induces CXCL9/10 and CCL20. Anti-CCL20 antibody given at the time sensitized mice are challenged with hapten reduces IL-17 and CXCL1, but not IFN-γ, expression in the skin challenge site. IL-17 and CXCL1, but not IFN-γ, expression is also reduced in the skin challenge site of sensitized TLR4-/- mice, that have low CHS responses despite wild-type levels of hapten-reactive IFN-γ and IL-17 producing CD8 T cells in the skin draining lymph nodes. These results suggest that TLR4 activation of hapten-presenting EC is required to induce the CCL20 expression directing hapten-primed CCR6+ CD8 T cells to the challenged skin site to mediate CXCL1 production and elicit CHS.
Sounding the alarm: studying the role of signal cascades in the immune response (EDU1P.250)
Authors: Trice Mark 
Published: January 2023

Abstract
The purpose of this research opportunity was to investigate the methods and roles of cell signaling via protein cascades and their connections to the functionality of the immune system. During my summer internship, I worked with investigators at the United States Army Medical Research Institute for Infectious Diseases (USAMRIID) to develop and test the activity of man-made protease cascades that could someday mirror the complement system in its aggressive response to specific signal molecules. My research experience inspired me to develop a unit for a second year Biology/AP Biology course. Students will examine the effects of several factors, including protease concentration, substrate concentration, and a non-cascade reaction, on reaction rates through construction of both physical models and simulated protease cascades. In this unit, students first work with a hands-on physical manipulative model to familiarize them with how a protein cascade works. Then, all of the students will work in tandem on a kinesthetic activity modeling exactly how protein cascades behave. This activity allows for a cost-effective method of demonstrating protease cascades without expensive lab equipment and reagents. Students translate their knowledge into the application stage when they examine how protease cascades work in the human body and discuss various uses and effects of cascades, such as protein kinases, on the immune system.