bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determining the role of the Axl receptor tyrosine kinase in beta cell autoimmunity (P4089)
Authors: Manzoor Fatima , Kroger Charles , Wang Bo , Tisch Roland 
Published: January 2023

Abstract
Type I diabetes (T1D) is an autoimmune disorder characterized by the T cell mediated destruction of the insulin-producing beta cells. Mechanisms involving the breakdown of self-tolerance in T1D are ill defined. We have previously shown that T1D progression is inhibited in NOD mice lacking expression of Mer, a member of the TAM family of receptor tyrosine kinases. Mer is expressed by dendritic cells (DC) and is critical for mediating the tolerogenic effects of apoptotic cells (AC) on DC. Axl, another TAM receptor is co-expressed by DC and binds AC. The relative role of Mer and Axl in mediating the tolerogenic effects of AC on DC, and regulating beta cell autoimmunity are unknown. Accordingly, we assessed the effects of AC on bone marrow-derived and splenic NOD DC lacking Axl expression. Pretreatment with AC of DC showed that Axl was required for AC-mediated inhibition of DC activation and maturation. Axl-deficient DC failed to activate c-Src and STAT3, which are key signaling molecules needed for AC-induced inhibition of DC. Furthermore, incidence of T1D in NOD mice lacking Axl was significantly reduced. Collectively, these findings indicate that Axl contributes to AC-induced inhibition of DC, and has a role in regulating T1D progression.
Loss of STING eliminates proinflammatory gene induction in TrexI-/- deficient mice. (P4091)
Authors: Konno Hiroyasu , Ahn Jeonghyun , Barber Glen 
Published: January 2023

Abstract
Patients defective in the 3’ repair exonuclease 1 (Trex1) suffer from Aicardi-Goutieres Syndrome (AGS) which instigates lethal encephalitis characterized by high levels of type I IFN production being present in the cerebrospinal fluid. Trex1 deficient mice exhibit a median life span of approximately 9 weeks since as yet uncharacterized self-DNA, presumably normally digested by Trex1, activates intracellular DNA sensors which triggers cytokine production and causes lethal inflammatory aggravated myocarditis. STING is essential for triggering cytoplasmic DNA-dependent innate immune signaling that comprises the production of type I IFN. Loss of TREX1 was observed to augment ssDNA and dsDNA-mediated induction of type I IFN in a STING-dependent manner. The replication of HSV1 was greatly reduced in hTERT-BJ1 or MEF lacking TREX1 due to elevated STING-dependent cytokine production. Loss of STING was observed to significantly extend the lifespan of Trex1-/- due to prevention of myocarditis. Microarray analysis showed dramatically reduced levels of proinflammatory genes in the hearts of Sting-/- Trex1-/-, Sting-/+ Trex1-/- compared to Trex1-/- mice. Anti-nuclear autoantibody (ANA) observed to be highly prevalent in the sera of Trex1-/- mice was almost completely absent in the sera of Sting-/- Trex1-/- mice. These data indicates that STING is responsible for pro-inflammatory gene induction in Trex1 deficient mice and plausibly may be involved in AGS.
Epstein-Barr virus, CD40 functional mimic, latent membrane protein-1 drives cellular molecular mimicry in the presence of Epstein-Barr virus nuclear antigen-1 in a novel murine model of lupus-like disease (P4063)
Authors: Munroe Melissa , Anderson Jourdan , Gross Timothy , Stunz Laura , Bishop Gail , James Judith 
Published: January 2023

Abstract
Immune dysregulation underlies SLE pathogenesis and EBV infection and abnormal latent protein expression are associated with SLE. EBNA-1 acts as a molecular mimic with SLE-autoantigens, while LMP1 acts a functional mimic of CD40 in an enhanced and dysregulated manner. Mice expressing a mCD40-LMP1 transgene (Tg) have autoantibodies by 2-3 months, but no overt autoimmune disease. This study evaluates the immune response to EBNA-1 in mCD40-LMP1 Tg mice and whether the addition of a molecular mimic accelerates lupus pathogenesis. Although anti-EBNA-1 levels are comparable in EBNA-1 immunized mCD40-LMP1Tg and mCD40 WT congenic mice (compared to adjuvant control and naïve mice), EBNA-1 specific proliferative and inflammatory cytokine responses, including IL-6, IL-17, IFN-γ, and TNF-α, are significantly enhanced (p &lt; 0.0001) in mCD40-LMP1 Tg mice. mCD40-LMP1 Tg mice immunized with EBNA-1 exhibit enhanced cellular responses (p &lt; 0.0001) to the EBNA-1 antigenic epitope PPPGRRP and the Sm B’ cross-reactive sequence PPPGMRPP. Enhanced cellular immune dysregulation with mCD40-LMP1 EBNA-1 immunization is accompanied by splenomegaly, increased serum BUN and creatinine levels, and elevated anti-dsDNA and ANA levels (p &lt;0.0001 compared to mCD40 WT mice, p &lt; 0.01 compared to adjuvant and naïve mCD40-LMP1 mice). These data suggest that expression of EBNA-1 and LMP1 may contribute to immune dysregulation that leads to pathogenic autoantigen-specific lupus inflammation.
Dendritic cells regulate the differentiation of inflammatory monocytes to affect Japanese encephalitis (P6118)
Authors: Eo Seong Kug , Choi Jin Young , Kim Seong Bum , Han Young Woo , Kim Bum Seok , Kim Jin Hyoung 
Published: January 2023

Abstract
Dendritic cells (DCs) as professional antigen-presenting cells have been known to play critical role in the initiation and modulation of the adaptive immune responses. Here, we will discuss the roles of CD11c+ DCs and functional modulation of inflammatory monocytes CD11b+Ly-6C+ in the progression of acute viral encephalitis caused by infection with Japanese encephalitis virus (JEV). The ablation of DCs exacerbated acute viral encephalitis and neuroinflammatory reactions following JEV infection. Also, the ablation of CD11c+ DCs induced early infiltration of inflammatory monocytes CD11b+Ly-6C+ in the central nervous system (CNS) and provided activated microglia and macrophages. This severed neuroinflammatory reaction was accompanied with early production of huge amount of pro-inflammatory cytokines, but type I IFN expression was not blunted in CD11c+ DC-depleted mice. In particular, the ablation of CD11c+ DCs induced immatured phenotype and morphology of CD11b+Ly-6C+ monocytes in lymphoid and inflammatory tissues. CD11b+Ly-6C+ monocyte developed in DC-depleted mice showed reduced antigen-presenting capacity and recovered phenotype when CD11c+ DCs were increased. These results suggest that CD11c+ DCs could regulate the differentiation of inflammatory monocytes CD11b+Ly-6C+ to affect clinical severity of JE.
Cytosolic interaction between MHC-I molecules and Derlin-1 is required for human cytomegalovirus US11-induced degradation of MHC-I molecules (P6122)
Authors: Jun Youngsoo , Cho Sunglim , Lee Miriam 
Published: January 2023

Abstract
Human cytomegalovirus (HCMV) US11 exploits Derlin-1-dependent endoplasmic reticulum-associated protein degradation (ERAD) to degrade major histocompatibility complex class I (MHC-I) molecules for immune evasion. US11 captures MHC-I molecules in the ER and convey them to Derlin-1, which then mediate their dislocation into the cytosol for degradation. The cytosolic tail of MHC-I molecules was shown to be required for dislocation to the cytosol, yet its precise role in the process remains unknown. Here, we found that the cytosolic tail of MHC-I molecules, although dispensable for interaction with US11, was required for their tight association with Derlin-1 in the presence of US11. Surprisingly, deletion of the C-terminal single amino acid of the cytosolic tail markedly disrupted the interaction between MHC-I molecules and Derlin-1, thereby rendering the mutant MHC-I molecules resistant to US11-induced degradation. Consistently, when MHC-I molecules were forced to interact with Derlin-1, through the transmembrane domain of US11 that had replaced that of the MHC-I molecules, the cytosolic tail or the C-terminal amino acid of the hybrid MHC-I became dispensable for dislocation. Thus, these results suggest that the cytosolic regions of Derlin-1 play a key role in interaction with the cytosolic tail of MHC-I molecules, and that this interaction is essential for Derlin-1 to dislocate them into the cytosol for degradation.
T cells utilize lamellipodia and filopodia for optimal intraluminal path finding (P5097)
Authors: Doh Junsang , Song Kwang Hoon , Kwon Keon Woo 
Published: January 2023

Abstract
Immune cells circulating in inflamed blood vessels undergo series of adhesion cascades to leave out of blood vessels to infiltrate into inflamed tissues. It has been shown that leukocytes crawl a considerable distance before they undergo transendothelial migration (TEM), but how they steer their crawling direction to find TEM sites is not well understood. To determine whether flow direction or EC orientation has predominant roles on the direction of T cell crawling, we fabricated well-aligned EC layers by culturing ECs on nanogrooved surfaces and applied shear flow either parallel or perpendicular to the direction of EC orientation. Regardless of flow direction, T cells crawled along the EC orientation. Then, we further identified guiding cues on ECs and found out that T cells tend to crawl along the valleys of topographical landscapes of EC layers while avoiding nuclei of ECs. By using pharmacological inhibitors for Arp 2/3, which nucleate actin filament branching to form lamellipodia, and cdc42, a small GTPase regulating filopodia formation, we found out that T cells utilize lamellipodia to sense topography of EC layers and filopodia to sense nuclei of ECs. Importantly, inhibitor-treated T cells crawled much longer distances than untreated T cells before they underwent TEM, suggesting that lamellipodia and filopodia of T cells are critical for optimal intraluminal path finding.
Consequences of dendritic cell necroptosis on the immune system (P5105)
Authors: Young Jennifer , He Tina , Reizis Boris , Winoto Astar 
Published: January 2023

Abstract
Dendritic cells (DCs) are essential in eliciting protective responses against pathogens, thus appropriate DC functions are essential in maintaining proper immune responses. The maintenance of DC homeostasis relies heavily on apoptosis to prevent disease development, and inhibition of DC apoptosis has been previously reported to induce systemic autoimmune disease. Fas-associated death domain-containing protein (FADD) is a critical adaptor protein that interacts with caspase-8 to transmit apoptotic signals downstream of the tumor necrosis factor family of death receptors. More recently, an alternative form of cell death, termed necroptosis, was reported to be downstream of the death receptors. Necroptosis is caspase-independent and requires the kinase activities of receptor interacting serine/threonine protein kinase 1 (RIP1) and RIP3. To investigate the role of FADD in DC death, DC-specific FADD conditional knockout mice were generated. Interestingly, these mice developed an inflammatory phenotype. We further elucidated the cause of inflammation by crossing the mice to RIP3-/-, MyD88-/- and MyD88flox/flox mutant mice. Our recent findings based on the analysis of these mice will be discussed.
“Bundling” of SIRPα into plasma membrane microdomains is essential for effective monocyte and macrophage binding interactions with CD47 and signaling (P5117)
Authors: Ha Binh , Liu Yuan 
Published: January 2023

Abstract
SIRPα is an ITIMs-containing, cell surface signaling receptor expressed on myeloid leukocytes. Through binding interactions with CD47, a universally expressed counter-receptor, SIRPα regulates important immunological processes including neutrophil and monocyte transmigration to inflammatory loci and macrophage recognition of phagocytic targets. While their crucial roles have been demonstrated, the mechanisms underlying the dynamic interactions between SIRPα and CD47 remain to be characterized. By cell adhesion assays, we found that freshly isolated peripheral monocytes and cultured monocytic cells (THP-1 and U937) express abundant SIRPα, but do not effectively bind to CD47. In contrast, monocytes that had transmigrated across endothelia, and macrophages differentiated from THP-1 or obtained from murine tissues, displayed a high avidity of SIRPα binding. Labeling of SIRPα on the cell surface observed a diffuse distribution pattern on naïve monocytes, but highly punctate patterns on transmigrated monocytes and macrophages. Protein crosslinking and sucrose density co-sedimentation confirmed that SIRPα in latter cells form oligomerized complexes through which SIRPα achieves high avidity binding to CD47. Furthermore, such SIRPα complexes contain SHP-1 and are localized in cholesterol-rich lipid domains in the plasma membrane, and their dynamic formation involves Src-family tyrosine kinase-mediated phosphorylation.
IL-5 produced by natural helper cells suppresses neutrophil function during influenza infection. (P4239)
Authors: Gorski Stacey , Braciale Thomas 
Published: January 2023

Abstract
Interleukin (IL)-5 is a prototypical type II cytokine that is essential for eosinophil maturation and egress out of the bone marrow. We observed that eosinophil numbers progressively increase in the lungs during the course of experimental influenza A virus (IAV) infection in mice as a result of high level production of IL-5 by natural helper cells recruited to the infected lungs. Mice genetically deficient in IL-5 (IL-5 KO) demonstrate increased lung neutrophil numbers and decreased viral titers during the acute phase of IAV infection. However, this phenotype is not recapitulated in mice deficient in eosinophils (PHIL mice) suggesting an eosinophil independent function of IL-5 during infection. Unexpectedly, we found that like eosinophils, &gt;98% of neutrophils express the IL-5 receptor alpha subunit (CD125) in the lung throughout infection. Unlike eosinophils, where ligation of the IL-5R by IL-5 induces phosphorylation of STAT1 and STAT5, engagement of the IL-5R on activated neutrophils results in suppressed pSTAT5 and pSTAT1 signalling as well as decreased expression of the activation marker CD11b. Furthermore, neutrophils treated with IL-5 undergo accelerated cell death in vitro suggesting a potential mechanism for the enhanced neutrophil numbers seen in the IAV infected IL-5 KO. Overall these data suggest that IL-5 may serve a regulatory role during the acute phase of IAV infection by controlling the number (viability) and activation state of recruited neutrophils.
CD14/TRIF pathway regulates macrophage polarization and Th2 immune responses (P4257)
Authors: Tundup Smanla , Srivastava Leena , Nagy Tamas , Harn Donald 
Published: January 2023

Abstract
Stimulation of macrophages with LPS and/or IFNγ promote an M1 phenotype, whereas the Th2 cytokines IL-4/IL-13 or helminth products drive an M2 phenotype. How macrophage polarization is regulated at the signaling level is not well understood. We tested the ability of macrophages to undergo polarization when exposed to M1 activating agents (LPS or poly I:C) and the M2 activating agent IL-4 at the same time. Co-stimulated macrophages failed to polarize towards M2 as determined by flowcytometric measurement of Fizz1 expression. Inhibition of M2 polarization was CD14 dependent as CD14-/- macrophages did polarize to M2 in response to IL-4-LPS co-stimulation. We found that the CD14/TRIF/STAT1 pathway, in addition to mediating M1, negatively regulates IL-4R-STAT6 mediated M2 polarization. Examination of schistosome infected CD14-/- mice showed increases in expression of CD4+ specific IL-4, IL-5 and IL-13 cytokines as well as significant increases in the recruitment of M2 macrophages in liver granulomas, associated with greater granuloma size and collagen deposition compared to infected WT mice. By adoptive transfer, we confirmed that macrophages are indeed responsible for the CD14 mediated negative regulation of alternative activation in-vivo in response to schistosome eggs. Our data demonstrated a unique role of the CD14-TRIF pathway in regulation of macrophage M1/M2 plasticity and in regulating CD4+ T cell biasing and alternative activation of APCs during helminth infection.
Bacillus anthracis cell wall peptidoglycan activates human dendritic cells to promote naïve TH17 and TFH cell differentiation (P4207)
Authors: Kovats Susan , Roach Kimberly , Raisley Brent , Bajana Sandra , Turner Sean , Roberts Virginia , James Judith , Coggeshall K. 
Published: January 2023

Abstract
In cutaneous and inhalational Bacillus anthracis infection, innate responses by tissue dendritic cells (DC) will direct adaptive immunity. To dissect these responses, human DCs were incubated with killed vegetative bacteria or highly purified cell wall peptidoglycan (PGN) of the B. anthracis ΔSterne strain. Both vegetative bacteria and PGN stimulated the activation of human DCs, which involved upregulation of surface HLA-DR, the T cell costimulatory molecules CD40 and CD86, the lymph node homing chemokine receptor CCR7, and CD83. B. anthracis PGN and vegetative bacteria elicited production of TNFα, IL-6, and IL-23, but not IL-12p70 or IL-10. To determine the effect of this cytokine profile on CD4+ T cell differentiation, we compared the ability of B. anthracis PGN- and Escherichia coli LPS-stimulated DCs to induce the differentiation of naïve CD4+ T cells into T helper (TH) subsets. While LPS-exposed DCs induced the polarization of CD4+ T cells into TH1 cells producing IFNγ, PGN-exposed DCs directed the differentiation of TH17 cells producing IL-17. Exposure of DCs to either PGN or LPS induced TFH cells producing IL-21. In sum, B. anthracis PGN is a highly stimulatory cell wall component that activates human DCs to display T cell costimulatory molecules and secrete IL-6 and IL-23. Thus, in vivo, PGN-exposed DCs are likely to promote the differentiation of proinflammatory TH17 cells important for extracellular bacteria infections and TFH cells important for humoral immunity.
A role of interleukin-17A in modulating intracellular survival of Mycobacterium bovis BCG in murine macrophages (P4217)
Authors: Ling Wai Lim , Wang LiangJie , Pong John C. H. , Lau Allan S. Y. , Li James C. B. 
Published: January 2023

Abstract
Interleukin-17A has been demonstrated to participate in the pathogenesis of mycobacterial infections. Whether interleukin-17A regulates innate defense mechanisms of macrophage against mycobacteria remain to be elucidated. In the present study, we investigated the effects of interleukin-17A on modulating the intracellular survival of Mycobacterium bovis BCG in RAW264.7 macrophages. Our data revealed that the clearance of intracellular BCG in macrophages was significantly enhanced by interleukin-17A pretreatment. Moreover, interleukin-17A-enhanced clearance of intracellular BCG could be abrogated by addition of inducible nitric oxide synthase inhibitor. We observed that interleukin-17A pretreatment was able to synergistically enhance both nitric oxide production and inducible nitric oxide synthase expression in BCG-infected macrophages in dose- and time-dependent manner. We also revealed that interleukin-17A was able to specifically enhance BCG-induced phosphorylation of JNK, but not ERK1/2 or p38 MAPK. By using specific JNK inhibitor SP600125, the production of nitric oxide in BCG-infected macrophages with interleukin-17A pretreatment was significantly suppressed. Taken together, we confirmed the involvement of JNK pathway in interleukin-17A-enhanced nitric oxide production in BCG-infected macrophages. In conclusion, our study revealed an anti-mycobacterial role of interleukin-17A through priming the macrophages to produce nitric oxide in response to mycobacteria infection.
Respiratory syncytial virus strains induce differential innate immune and CD4 T cell responses (P4039)
Authors: Weiss Kayla , Varga Steven 
Published: January 2023

Abstract
Respiratory syncytial virus (RSV) infects the respiratory tract causing acute pulmonary disease in both children and the elderly. The host immune response contributes to disease severity. However, it is not currently clear to what extent RSV strain differences influence the host immune response and disease severity. To determine the impact of viral strains on the severity of RSV-induced disease, we compared several different RSV A isolates. Following infection with the line 19 strain of RSV, we observed increased weight loss and decreased airway function between days 1-4 p.i. as compared to RSV strains A2 or 2-20. On day 2 p.i., the total number of macrophages and neutrophils was increased following RSV line 19 infection. In addition, IL-1β and IL-6 protein levels were increased at day 2 p.i.. Inflammasome activation leads to secretion of mature IL-1β following RSV infection. Our results suggest that there is increased priming and activation of the inflammasome following RSV line 19 infection. Coinciding with the increased priming and activation of the inflammasome, we observe an increased Th17 response following RSV line 19 infection as compared to RSV A2 and 2-20. Neutralization of IL-1β and IL-6 results in a decreased Th17 response following RSV line 19 infection. Overall, our results demonstrate that RSV strains differ in their capacity to elicit a robust innate immune response, and subsequent CD4 T cell response, contributing to differences in disease severity.
Ptpn22 promotes immunization responses to Influenza A (P4043)
Authors: Crabtree Juliet , Verma Vikram , Wang Yaya , Liang Yuying , Peterson Erik 
Published: January 2023

Abstract
A variant allele of PTPN22 is a potent susceptibility factor for autoimmune diseases, including Rheumatoid Arthritis and Type I Diabetes. Ptpn22 is required in myeloid cells for selective promotion of Toll-Like Receptor signaling leading to Type I IFN production. Since Type I IFN are essential for anti-viral immunity and for efficient responses to viral immunization, we investigated the role of PTPN22 in response to vaccination. We tested the ability of Ptpn22 knockout mice to mount a protective immune response to vaccination against Influenza A virus. We found that Ptpn22 is required for efficient generation of both influenza-specific cytotoxic T lymphocyte and neutralizing humoral responses after vaccination with inactivated influenza. Further, upon challenge with live influenza, vaccinated Ptpn22 KO animals exhibit increased mortality, suggesting that defects in antibody and CTL responses associated with Ptpn22 deficiency result in decreased protection engendered by inactivated influenza vaccination. These findings indicate a requirement for Ptpn22 in protective immune responses to influenza vaccine. Moreover, they suggest that further studies of vaccine responsiveness should be mounted in human carriers of the disease-associated PTPN22 variant, since such carriers exhibit diminished Toll-Like Receptor-induced Type I IFN production by myeloid cells.