bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel CD141+ human blood plasmacytoid dendritic cell subtype produces high levels of IFN-α and acquires virus-associated cellular material from live tumor cells (VIR9P.1136)
Authors: Shih Tiffany , Dai Jihong , Singh Sukhwinder , Fitzgerald-Bocarsly Patricia 
Published: January 2023

Abstract
Dendritic cells (DCs) are a heterogeneous population important in regulating both innate and adaptive immunity. Human blood DCs are broadly characterized as pDC(BDCA2+), mDC1(BDCA1+), and mDC2(BDCA3+(CD141)). While much work has focused on the functional role of CD141hi mDCs, we investigated the maturation potential and functional significance of a novel subtype of classically defined plasmacytoid DCs (BDCA2+) co-expressing intermediate levels of BDCA3. Using flow cytometry, we identified four human blood DC subsets: BDCA2+/3-, BDCA2+/3int, BDCA2-/3int, and BDCA2-/3hi. Upon stimulation with TLR9 agonists CpG-A or HSV-1, the BDCA2+/3int DCs had the highest frequency of IFN-α+ and TNF-α+ cells among these DC subtypes. The BDCA2+/3int compared to BDCA2+/3- DCs also become more activated and mature with relatively higher expression of co-stimulatory and migratory surface receptors in response to HSV-1. IRF7, the master regulator of IFN production in pDCs, was constitutively expressed by BDCA2+/3- and BDCA2+/3int ­DCs but not by BDCA2- DCs. Both BDCA2+/3int and to a lesser extent, BDCA2+/3- DC preferentially acquired cellular material from HSV-infected Raji cells. These data indicate that BDCA2+/3int DCs exhibit major functions associated with classical pDCs and are phenotypically and functionally distinct from BDCA2-/3int and BDCA2-/3hi DCs. Together these results describe a novel CD141+ pDC subset that is very potent and virus responsive as compared to the CD141hi mDCs.
Single clone expression cloning and protein microarray platforms for the identification of novel viral immunomodulatory proteins (VIR9P.1157)
Authors: Tom Irene , Martin Nadia , Ramani Sree , Gonzalez Lino 
Published: January 2023

Abstract
Viruses encode proteins that interact with surface receptors on immune cells to evade recognition and elimination by the host immune system. In this study, we focused on the E3/49K protein of human adenoviruses D (HAdV D) a highly diverse protein uniquely found in HAdVs D that was recently demonstrated to suppress leukocyte activation and effector functions through an interaction with receptor tyrosine phosphatase CD45 on immune cells. To advance the search for novel immunomodulatory receptors targeted by the E3/49K protein, we utilized two complementary high-throughput screening technologies consisting of single clone expression cloning and protein microarray platforms. Two highly divergent E3/49 proteins, encoded by HAdV-28 and HAdv-53 serotypes, were systematically probed against thousands of interactions either expressed on the cell-surface or displayed on a protein microarray. We found that both HAdV-28 and HAdV-53 E3/49K proteins interacted with CD45. Furthermore, we report the discovery of two additional receptors specifically targeted by HAdV-28, the leukocyte immunoglobulin-like receptor 1 (LILRB1), a well known immune receptor with inhibitory functions, and putative neuronal cell adhesion molecule (PUNC). Interestingly, we found that PUNC is expressed in immune cells, suggesting a previously undescribed function in immunity. Here we demonstrate the feasibility of this approach for identifying proteins with previously unknown involvement in the human immune response.
Targeting HSV-1 protein ICP6 by RIP1 and RIP3 initiates necroptosis to restrict HSV-1 propagation in mice (VIR9P.1159)
Authors: Huang Zhe , Wu Suqin , Liang Yaoji , Han Jiahuai 
Published: January 2023

Abstract
Necroptosis is a type of programmed necrosis that participates in host defense to eliminate certain pathogens. We show that receptor interacting protein 3 (RIP3 or RIPK3) restricts herpes simplex virus type 1 (HSV-1) propagation in mouse cells and in mice by mediating necroptosis of infected cells. ICP6 protein of HSV-1 triggers necroptosis by direct interaction with RIP1 and RIP3 through its RIP homotypic interaction motif (RHIM). ICP6 can be dimerized or oliogmerized by its C-terminal R1 homology domain. This leads to RIP1-RIP3 hetero- and RIP3-RIP3 homo-interaction and subsequent execution of necroptosis in HSV-1 infected cells. We show that both pro-necroptotic and anti-necroptotic viral RHIM exist since the RHIM in viral inhibitor of RIP activation (vIRA) of murine cytomegalovirus (MCMV) is known to inhibit necroptosis. Our data demonstrated that RIP1 and RIP3 can directly sense certain RHIM like sequences encoded by some viruses to initiate cellular responses for pathogen clearance.
HIV inhibits LPS-induced IL-27 production via HIV tat through the inhibition of TRAF-6, and consequent inhibition of PI3K and p38 and JNK MAPKs in human macrophages (VIR9P.1140)
Authors: Kumar Ashok , Gajnayaka Niranjala , Fernandez Jason , Angel Jonathan , Kozlowski Maya 
Published: January 2023

Abstract
Monocyte-derived macrophages (MDM) from HIV-infected patients and MDM infected in vitro with HIV manifest inhibition of cytokines including IL12. IL27, an IL12 family cytokine, was shown to inhibit HIV replication in macrophages. Whether HIV infection or HIV accessory protein(s) impact IL27 production in macrophages remains unknown. Herein, we show that in vitro HIV infection as well as intracellular HIV and HIV-tat peptides inhibited LPS-induced IL27 production in MDM suggesting that HIV-tat inhibits IL27 production by impairing TLR-4 signalling. To study the mechanism governing HIV-tat-mediated inhibition of LPS-induced IL27 production, we first established that p38 and c-Jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK), the phosphoinositide-3-kinase (PI3K), SRC homology region 2 domain-containing tyrosine phosphatase-1 (SHP-1) and Src kinases regulated LPS-induced IL27 production in MDM. HIV-tat caused TNF receptor associated factor (TRAF)-6 inhibition and consequent decreased phosphorylation of downstream PI3K, and p38 and JNK MAPKs implicated in LPS-induced IL27 production. However, SHP-1 and Src kinases were not involved in HIV-Tat-mediated inhibition of LPS-induced IL27 production. In contrast to HIV-tat, in vitro HIV infection of MDM inhibited LPS-induced p38 and JNK activation. Overall, HIV inhibits LPS-induced IL27 production via HIV tat through the inhibition of TRAF-6, and consequent inhibition of PI3K and p38 and JNK MAPKs in macrophages.
Tetherin (BST-2) promotes control of a persistent infection by reducing viral spread and T cell exhaustion (VIR10P.1173)
Authors: Kenyon Elizabeth , Nayak Debasis , Moseman E , McGavern Dorian 
Published: January 2023

Abstract
Type I interferons play a critical role in host defense against most viral infections. This is achieved in part through induction of innate antiviral proteins like tetherin (BST-2). BST-2 was identified based on its ability to “tether” viral proteins to infected cells and decrease virion release in vitro. How this protein functions in the host defense against a persistent viral infection in vivo is not entirely understood. To gain novel insights into BST-2 function, we examined its role during the establishment of a persistent lymphocytic choriomeningitis virus (LCMV) infection. Transgenic overexpression of BST-2 in cell culture decreased release of LCMV from infected cells. We uncovered in vivo that BST-2 is significantly upregulated early after viral infection in plasmacytoid / myeloid dendritic cells, monocytes / macrophages, and brain-resident microglia. Deletion of BST-2 enabled a persistence-prone strain of LCMV to transition more efficiently from the splenic marginal zone to the white pulp following intravenous inoculation. This resulted in enhanced T cell exhaustion, which was evidenced by reduced cytokine production and altered motility. Interestingly, these early alterations in antiviral immunity translated into delayed control of LCMV in peripheral tissues and lifelong persistence in the brain. These data demonstrate that expression of single innate antiviral protein can influence adaptive immune cell function and dictate the fate of a viral infection.
Genetic risk alleles associated with serologic autoimmunity in normal individuals (BA3P.113)
Authors: Raj Prithvi , Li Quanzhen , Karp David , Olsen Nancy , Sivils K. , Dozmorov Igor , Song Ran , James J. , Kelly J , Lauwerys Bernard , Gregersen Peter , Wakeland Edward 
Published: January 2023

Abstract
We screened 2628 normal individuals for antibodies binding to the mix of antigens in a human nuclear extract and identified 579 (26.05%) individuals with significant levels of IgG antibodies to self-antigens. Next, we analyzed 639 representative sera from ANA-, ANA+, ILE and SLEs on an autoantigen proteomic array, which identified 33 antigens strongly recognized by IgG autoantibodies in ANA+ group as compared to ANA- normals. Of these 33, 19 antigens were non-nuclear or cytoplasmic proteins and 14 were nuclear proteins, including known SLE associated antigens such as dsDNA and Histones. Antigen cluster analysis showed that DNA and RNA clusters are more frequent in SLE and ILE group, while matrix proteins and antiphospholipid antibodies clusters are more frequent in ANA+ normals. Next, all the individuals were genotyped with immunochip and subset by target sequencing. Quantitative genetic association test identified SNPs associated with ANA and auto-antigens. The strongest association signal was observed at HLA, where SNP rs3117103 near BTNL2, rs9268832 near HLA-DRA and rs2395252 in HLA-DQA2 gene showed strongest (10-7) association. Other signals were in/near BANK1, PTTG1 and CR1L genes. RNA sequencing analysis identified ANA risk alleles associated with up regulation of HLA-DRB1 in monocytes and BANK1 in B cells. Our data suggest that functional variations in or near HLA DRB1 and BANK1 gene may be associated with development of humoral autoimmunity in general population.
Ikaros mediated gene regulation in human systemic lupus erythematosus (BA4P.138)
Authors: Nagpal Kamalpreet , Tsokos George 
Published: January 2023

Abstract
Systemic lupus erythematosus (SLE) is an autoimmune disease of unknown etiology. Genetic susceptibility and molecular aberrations create an abnormal T cell phenotype. One of the key components contributing to signaling defects in SLE pathogenesis is the serine threonine phosphatase (PP2A). The factors affecting expression of PP2A in SLE T cells thus warrant an extensive study. We have previously shown that the transcription factor Ikaros binds to a site in the first intron of PP2A and acts as a repressor of PP2A expression. Here, we build upon this key finding of a novel regulatory mechanism involved in the pathogenesis of SLE. This intronic Ikaros binding site in PP2A harbors a single nucleotide polymorphism. We report that Ikaros exhibits differential binding to this site. Using oligonucleotide binding assays as well as EMSA, we demonstrate defective binding of Ikaros to the site containing the SLE risk SNP as compared to WT sequence. Luciferase reporter assays show that promoter activity of PP2A is increased in presence of this SNP. We are further analyzing the recruitment of Ikaros to this site in individuals with either WT or the variant allele, to test our hypothesis that increased levels of PP2A observed in SLE patients is at least in part due to reduced Ikaros binding at this site. To conclude, we demonstrate that the repressor Ikaros binds with less avidity to a PP2A intronic SLE risk variant and allows increased PP2A expression, a key molecule in SLE pathogenesis.
Galectin-1 plays an essential role in intravenous tolerance in experimental autoimmune encephalomyelitis (BA4P.139)
Authors: Mari Elisabeth , Rasouli Javad , Zhang Guang-Xian , Ciric Bogoljub , Rostami A 
Published: January 2023

Abstract
Multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE), are inflammatory demyelinating diseases of the central nervous system (CNS). EAE can be induced by immunizing mice with myelin oligodendrocyte glycoprotein-derived peptide, MOG35-55, in adjuvant. It has been previously demonstrated that intravenous (i.v.) injection of MOG35-55 post immunization induction suppresses disease development, a phenomenon called i.v. tolerance. The glycan-binding protein galectin-1, produced primarily by regulatory T cells plays an immunoregulatory role in EAE by inducing tolerogenic DCs and IL-10-producing regulatory type 1 T cells (Tr1). To examine the role of galectin-1 in i.v. tolerance, we administered MOG35-55 peptide i.v. to wild-type (WT) and galectin-1-/- (Gal1-/-) mice with ongoing EAE. MOG35-55 rapidly suppressed disease in the WT, but not in the Gal1-/- mice. Expression of pro-inflammatory cytokines IFN-gamma and IL-17A were reduced in the CNS and periphery of tolerized WT mice, while the number of Tr1 cells increased in the periphery. In contrast, i.v. MOG35-55 significantly increased IFN-gamma and IL-17A in the CNS and periphery of Gal1-/-mice and these mice had markedly fewer Tr1 cells in the periphery. Our data suggest that galectin-1 mediated i.v. tolerance induction is dependent on the downregulation of Th1 and Th17 pro-inflammatory responses, and enhanced development of Tr1 cells.
STAT3 signaling is essential for the germinal center maintenance and pathogenesis of lupus (BA4P.122)
Authors: Ding Chuanlin , Dascani Paul , Yan Jun 
Published: January 2023

Abstract
Antibody maturation as well as memory B and plasma cell differentiation occurs primarily in the germinal center (GC). Lupus may develop as a result of enhanced GC activity. Many factors involved in GC reaction, including T follicular helper (Tfh) cells, IL-21, IL-6, play critical roles in lupus pathogenesis. These inflammatory cytokines predominantly activate the STAT3 signaling pathway. Here, we demonstrate that STAT3 signaling in B cells is essential for antibody response as well as GC formation and maintenance. Increased cell apoptosis and down-regulated Bcl-xL expression are found in the STAT3 deficient GC B cells. The Tfh cell response is significantly decreased in B cell STAT3-deficient immunized mice. Further, STAT3 deficiency in autoreactive B cells results in decreased autoantibody production upon immunization with apoptotic cells. Results obtained using B cell STAT3 deficient MRL.Fas(lpr) mice suggest that STAT3 signaling contributes to the pathogenesis of lupus by regulation of autoantibody production. Our findings thus provide new insights into the role of B cell STAT3 signaling in the GC maintenance and pathogenesis of lupus.
Function of CK2 kinase activity in Th17 cell polarization and EAE (BA4P.125)
Authors: Gibson Sara , Qin Hongwei , Liu Yudong , Buel Amber , Benveniste Etty 
Published: January 2023

Abstract
Auto-reactive CD4+ T cells drive many autoimmune diseases including multiple sclerosis and colitis. Th1 and Th17 cells are pathogenic in the context of autoimmunity while Treg cells promote disease resolution. CK2 is a constitutively expressed and highly conserved serine/threonine kinase that promotes a number of pro-survival and pro-inflammatory signaling pathways including PI3K/Akt/mTOR, NF-κB, and JAK/STAT. These pathways are essential for CD4+ T cell activation and polarization, but little is known about how CK2 functions in T cells. Here we demonstrate that protein levels of the major catalytic subunit of CK2, CK2α, and CK2 kinase activity are elevated in murine CD4+ T cells polarized to the Th1 and Th17 phenotypes in vitro compared to naïve CD4+ T cells. Furthermore, CK2α expression is elevated in CD4+ T cells that are activated and infiltrate the central nervous system during EAE, a murine model of MS. Using the small molecule inhibitor CX-4945, which targets CK2α, we demonstrate that CK2 kinase activity promotes Th17 cell polarization in vitro, but not the polarization of Th1 or Treg cells. Additionally, in vivo treatment with CX-4945 during EAE resulted in a dampened MOG-specific Th17 response and a decrease in IL-17A+ and IL-17A+IFN-γ+ CD4+ T cells present in the central nervous system. Our data implicate CK2 as a novel regulator of T cell differentiation, and suggest that CK2 could be targeted in Th17 cell driven autoimmune disorders.
Exudate suction blister: a novel in vivo model of acute infllammation and resolution in humans. (CAM1P.145)
Authors: Motwani Madhur , De Maeyer Roel , Fullerton James , Marks Daniel , Smith Andrew , GIlroy Derek 
Published: January 2023

Abstract
Resolution of acute inflammation is an active process and its dysregulation may contribute to chronic inflammatory disorders. While animal models have been used to study resolution their appropriateness has been questioned. We describe a novel model of resolving inflammation in humans triggered by intradermal injection of UV killed E. coli into the forearm of healthy volunteers (n=30). Inflammatory exudate was drawn into a skin blister induced by negative pressure applied over the injection site. Blister cells were analyzed by flow cytometry while the cell free exudates were assayed for cytokines. To study the different phases of inflammation, blisters were raised at multiple time points up to day 14 post-injection. Vascular response was monitored by laser doppler. Onset (8hr) was characterised by peak erythema and neutrophilia (HLA-DR-/CD16++). By 24hr, neutrophil numbers had fallen by 80% while CD14+ monocytes and CD1c+ dendritic cell numbers increased, indicating resolution. At 48hr blood flow declined along with mononuclear cell numbers. Lymphocytes (CD4+, CD8+ and CD56+ cells) dominated the site at day 3 and persisted up to day 14. Levels of TNF-α, IL-8 and IL-1β were maximal at 8hr, IFN-γ at 24hr. This safe and reproducible model allows, for the first time, exploration of cells and soluble mediators in parallel with the clinical signs of resolution in humans. Potential applications include testing the efficacy of novel anti-inflammatory and pro-resolving drugs.
The flavonoid, rutin, ameliorates neurodegeneration in the retina of diabetic rats (CAM1P.164)
Authors: AlSharari Shakir , Fatani Amal , Ola Mohammad , Alrojayee Fatima , A. Al-Hosaini Abdulaziz 
Published: January 2023

Abstract
Diabetic retinopathy remains the leading cause of blindness worldwide. Dietary flavonoid, rutin may protect the diabetes induced retinal damage. The purpose of this study was to examine the ameliorative effect of rutin on diabetic rat retina through neurotrophic, inflammatory and immunological parameters. Diabetes was induced in male Wistar rats by streptozotocin (65mg/kg). Rutin (100mg/kg) was orally administered to normal and diabetic rats after two weeks of diabetes induction and continued for five weeks. After treatments, retinas were isolated and analyzed for potential neuroinflammatory and immunological markers. Our results indicate that the reduced level of brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the diabetic retina were significantly improved by rutin. Increased levels of soluble intracellular adhesion molecule (sICAM-1) and monocyte chemotactic protein (MCP-1) in the diabetic retinas were significantly attenuated to normal level by rutin. Reduced level of GSH in diabetic retina was increased and the increased level of TBARS in the diabetic retina was significantly decreased by rutin administration. The increased level of caspase-3, and decreased level of Bcl-2 in diabetic retina were significantly ameliorated to normal levels by rutin. These results suggest the effectiveness of rutin in protection of diabetic induced damage to the retina by maintaining neurotrophic support, and antioxidants levels.
T cell egress via the afferent lymph modulates the course of local tissue inflammation (CAM1P.149)
Authors: Debes Gudrun , Gómez Atria Daniela , Crosby Erika , Weinkopff Tiffany 
Published: January 2023

Abstract
T cells recirculate through extralymphoid tissues by entering from the blood and egressing via the afferent lymph. While T cell migration into effector sites is key to inflammation, the influence of T cell egress in this process is not known. In a mouse model, antigen recognition at the effector site reduced the egress of antigen-specific pro-inflammatory Th1 cells. Transgenic expression of ‘tissue exit receptor’ CCR7 enhanced egress of antigen-sequestered Th1 cells from the inflamed site and ameliorated inflammation. In contrast, lack of CCR7 on Th1 cells diminished their tissue egress while enhancing inflammation. Lymph-borne Th1 and Th17 cells draining the inflamed skin of sheep chemotaxed to the CCR7 ligand CCL21, suggesting the CCR7-CCL21 axis as a physiological target in regulating inflammation. In conclusion, exit receptors can be targeted to modulate T cell dwell time and inflammation at effector sites, revealing T cell tissue egress via lymph as a novel parameter of the pathophysiology of inflammation.
HSC-independent lymphopoiesis (HEM1P.228)
Authors: Ghosn Eliver , Yamamoto Ryo , Phillips Megan , Waters Jeffrey , Yang Yang , Nakauchi Hiromitsu , Herzenberg Leonore 
Published: January 2023

Abstract
The mammalian immune system develops progressively during ontogeny. In both mice and humans, the types of immune cells that develop in fetuses and neonates differ from those that develop in adulthood. Among lymphocytes, B-1, γδT, and iNKT cells are the earliest to emerge and persist at low frequencies thereafter. In contrast, B-2, marginal zone B (MZB) and αβT emerge later but rapidly rise to predominance in adults. The accepted dogma has been that a single hematopoietic stem cell (HSC) can give rise to all of these developmentally distinct immune cell subsets. However, our in vivo single-cell transfers show that bone marrow-derived long-term HSC give rise to B-2, MZB and B-1b but do not detectably reconstitute B-1a, providing definitive proof that B-1a develop prior to and independent of the HSC. These findings place B-1a in a separate lineage derived from HSC that are rare or missing in adults. Here, continuing with this study, we show that HSC harvested from fetal mice similarly fail to fully reconstitute B-1a in adoptive recipients, while unsorted E12 yolk sac cells fully reconstitute all B cell subsets. Thus, we have demonstrated that B-1a develop via an unsuspected pathway that is independent of the classical HSC development pathway. This finding introduces dramatic changes into the current understanding of the developmental landscape of the immune system. Further, it raises questions about human regenerative therapies in which HSC are used to restore hematopoiesis.