bluuebunny/crossref_metadata_2025_split huggingface dataset:
IL-12 inhibits memory CD8+ T cells localization to the respiratory tract and reduces protection against Influenza A virus. (P5093)
Authors: Slutter Bram , Harty John 
Published: January 2023

Abstract
Memory CD8 T-cells specific for conserved antigens from Influenza A virus (IAV), like nucleoprotein (NP), may provide an important line of defense when neutralizing antibodies are absent (e.g. IAV pandemic). Here we show, through local CD8 T-cell depletions, that NP specific memory CD8 T-cells have superior protective capacity against IAV when they are localized inside the respiratory tract (BAL fluid). Expression of the chemokine receptor CXCR3 on memory CD8 T-cells was essential for the maintenance of a local memory population in the respiratory tract. Interestingly, the inflammatory milieu during immunization seems critical for the ability of memory CD8 T-cells to express CXCR3. Exposure to interleukin 12 (IL-12), but not other signal 3 cytokines, led to reduced expression of CXCR3 on memory CD8 T-cells, through a STAT4 and T-bet dependant pathway. Neutralization of IL-12 during priming or selection of adjuvants that induce little IL-12, significantly increases CXCR3 expression on memory CD8 T-cells, enhances their numbers in the respiratory tract and provides superior protection against IAV challenge. Thus, CXCR3+ memory CD8 T-cells have a superior protective capacity against IAV, due to their capacity to populate the respiratory tract and IL-12 is a key regulator for the establishment of CD8 T-cell memory inside the respiratory tract.
EBI2 guides osteoclast precursors to bone niches and regulates osteoclastogenesis and bone mass homeostasis. (P5099)
Authors: Nevius Erin , Horowitz Mark , Insogna Karl , Ishii Masaru , Pereira João 
Published: January 2023

Abstract
Osteoclasts (OCs) are bone-lining cells derived from the fusion of monocytic precursors. Their exclusive positioning in contact with bone enables OC differentiation and the remodeling of bone outgrowth. However, the guidance cues that osteoclast precursors (OCP) follow for positioning at the bone surface remain poorly characterized. We demonstrate that EBI2 (Gpr183) was abundantly expressed in OCPs, and that autocrine EBI2 signaling was necessary for differentiation into mature osteoclasts in vitro. The expression of EBI2 and its ligands suggested that EBI2 signaling regulates OCP motility. Time lapse microscopy of OCP differentiation revealed reduced velocity and displacement of EBI2-deficient OCPs and mature OCs in vitro. Mice deficient in EBI2 or EBI2-ligands were osteopetrotic under homeostasis, and were protected from osteoporosis induced by estrogen deficiency. As osteoblasts (OBs) control osteoclast differentiation we hypothesized that they also recruit OCPs to bone niches. Indeed, OBs expressed EBI2-ligand synthesis enzymes, Ch25h and Cyp7b1, and secreted EBI2 ligands in vitro. We further demonstrate that EBI2-deficient OCPs were unable to efficiently migrate towards bone, and differentiated into smaller sized osteoclasts in vivo. Remarkably, overexpression of EBI2 was sufficient for directing OCPs to bone surfaces. Combined, these studies revealed a novel EBI2 controlled bone marrow niche, and identified a new candidate for the treatment of bone disorders.
Distribution, morphology and phenotypical characterization of lipid-laden multilocular cells in the aging thymus. (P5107)
Authors: de Mello Coelho Valeria , Andrade Leonardo , Taub Dennis , Borojevic Radovan , Langhi Larissa 
Published: January 2023

Abstract
Age-related thymic involution is characterized by decreased thymopoiesis and increased white adipose tissue in the perivascular space. Previously, we described the presence of intrathymic lipid-laden multilocular cells (LLMC) expressing factors known to promote thymic atrophy. In this study, we aimed to characterize the distribution, morphology and phenotype of LLMC. Our results show that LLMC are distributed in thymic capsule, parenchyma and surrounding blood vessels and increase with aging. Based on their shape and/or location, LLMC present globular, fibroblastoid or pericyte-like morphology. Our ultrastructural analyses showed that LLMC contain lipid droplets with distinct electrondensities and autolipophagossome-like structures in their cytoplasm. In addition, we found LLMC interacting directly with lymphocytes, endothelial cells and mast cells in the thymic parenchyma. Furthermore, mast cells were quantified and increase in thymus with age. By immunohistochemistry, we analyzed the phenotype of LLMC and we found cells positively stained with specific markers for pericytes (α-SMA, NG2), macrophages (CD11b, F4/80), pre-adipocytes (PPARγ2) and brown adipocytes (UCP1) in the aging thymus. In conclusion, LLMC are not simply differentiating adipocytes, but correspond to distinct cellular populations, including macrophages and mesenchymal-derived cells that assume a lipid-laden morphology and are able of interacting with thymocytes and distinct thymic microenvironmental cells.
Coxsackievirus B3 regulates T cell infiltration by LFA-1 modification through Rap1 activation (P5075)
Authors: Shim Seung-Hyun , Kim Dae-Sun , Nam Jae-Hwan 
Published: January 2023

Abstract
Coxsackievirus B3 (CVB3) infection has the potential to induce myocarditis. The following may be the mechanisms of CVB3-induced pathogenesis: viral infection directly causes injuries to cardiomyocytes through viral cytopathic effect and virus-activated T cell infiltration indirectly causes injuries to cardiomyocytes through inflammation. However, the detailed mechanism of T cell infiltration remains unknown. The present study observed that infiltrated T cells could be detected in the hearts of CVB3-infected mice. Meanwhile, attenuated CVB3 (YYFF) did not elicit T cell infiltration in infected mouse hearts. Rap-1, Ras family of small GTPases, is a critical regulator of T cell activation. CVB3 infection was found to activate Rap1 through cAMP induction. The downstream molecules of Rap1, ERK and p-CREB, which are involved in T cell activation and differentiation, were also activated after CVB3 infection. However, this result did not occur in the case of YYFF. This Rap-1 activation leads to an active form of LFA-1 on T cells that can be bound to intracellular adhesion molecule-1 (ICAM-1) on myocytes for T cell infiltration after CVB3 infection. This mechanism of CVB3-induced T cell infiltration may contribute to be a potential therapeutic agent for virus-induced myocarditis. Keywords: Coxsackievirus B3, YYFF, LFA-1
Non-invariant NKT cells cause diet-induced obesity by tissue inflammation (P5111)
Authors: Satoh Masashi , Eshima Koji , Takeuchi Emiko , Tamauchi Hidekazu , Iwabuchi Kazuya 
Published: January 2023

Abstract
The progression of obesity accompanies a chronic inflammatory process that involves both innate and acquired immunity. Mϕ, T cells and other immune cells have been shown to affect the development of obesity by modulating the chronic inflammation in visceral adipose tissue. NKT cells recognize lipid antigens and are also distributed in visceral adipose tissue. To examine the involvement of NKT cells in the development of obesity, WT and two NKT-cell-deficient strains, Jα18-/- and CD1d-/-, were fed a high fat diet. We reported that CD1d-/- but not Jα18-/- mice fed a high fat diet showed the least gain of body weight, and glucose intolerance and insulin resistance were not aggravated because of a reduced tissue inflammation. Furthermore NKT cells (non- invariant NKT) in visceral adipose tissue were accumulated in WT and Jα18-/- mice fed a high fat diet. In the present study we further examined stromal vascular fraction obtained from visceral adipose tissue. First, TCR-Vβ usage of NKT cells (TCBβ+NK1.1+) were analyzed. Notably, Vβ7+, Vβ8.1+ NKT cells were major subsets in spleen and liver, whereas Vβ5+, Vβ11+, Vβ12+ cells were mainly observed in stromal vascular fraction in WT mice fed a high fat diet. Vβ5+ subsets were also observed in Jα18-/- mice. Further characterization of NKT subsets and analyses of interactions of NKT cells and other SVF components may elucidate the development of obesity.
Transcriptome analysis of lung resident compared to spleen memory CD4 T cells reveals differential expression of genes controlling tissue egress (P5083)
Authors: Yudanin Naomi , Farber Donna 
Published: January 2023

Abstract
Memory T cells, generated after pathogen encounter, persist in diverse tissue sites, including lymphoid and mucosal tissues. We previously identified a population of memory CD4 T (CD4TM) cells that were retained in the lung, and mediated optimal protective responses to respiratory virus infection. Spleen-derived CD4 TM cells circulated in multiple sites and were not protective. Here, we investigated potential mechanisms for these differential migration patterns by whole transcriptome analysis of lung and spleen CD4 TM cells. We isolated RNA from lung and spleen CD4 TM generated in vivo for subsequent RNAseq analysis. Our analysis revealed a set of genes that are differentially expressed in lung compared to spleen CD4 TM cells. Using unbiased gene ontology clustering (GO), functional pathway analysis (KEGG), and gene interaction network mapping (STRING9.0) we identified a cohesive gene interaction pathway that functions in cell motility and tissue retention. Along with other genes involved in cell adhesion and migration, the selected candidates included Sphingosine-1-phosphate receptor (S1PR1), CD69, Kruppel-like factor (KLF)-2, and KLF6, all known to regulate lymphocyte egress from tissues. Upon re-activation, lung CD4TM upregulated CD69 and KLF6, and downregulated S1PR1 and KLF2 compared to spleen CD4TM. These findings suggest that the upregulation of these genes in lung but not in spleen memory CD4 T cells may contribute to their tissue-specific retention in the lung.
Concurrent analyses of host-pathogen transcriptomes in avian polymorphonuclear cells following exposure to Salmonella enterica serovar Typhimurium (P4233)
Authors: Swaggerty Christina , Chiang Hsin-I , Zhou Huaijun , Kogut Michael 
Published: January 2023

Abstract
Salmonella enterica serovar Typhimurium are facultative intracellular bacteria that cause disease in numerous species, and infections resulting from poultry products are a major source of foodborne disease in humans. Young chicks are susceptible to Salmonella and heterophils, the avian equivalent to neutrophils, are involved in control of the bacteria. To identify simultaneous host-bacterial transcriptional changes, heterophils were isolated from 6-d-old chicks, exposed to S. typhimurium for 0-1h, total eukaryotic and prokaryotic RNA isolated from the same sample, and subjected to chicken whole genome and Salmonella microarrays. Heterophils exposed to S. typhimurium upregulated 2900 and downregulated 700 genes. Changes in S. typhimurium showed 1020-25 genes were upregulated and 846-967 downregulated. Gene ontology (GO) was evaluated on differentially expressed genes. Heterophils upregulated genes associated with regulation of cell differentiation, protein transport, macromolecule localization, and heterocycle metabolic processes and downregulated actin cytoskeleton organization and biogenesis, and cellular component organization and biogenesis. GO terms for upregulated S. typhimurium genes included fatty acid biosynthesis, flagellar assembly, glutathione metabolism, and the Type III secretion system. Beginning to characterize the host-pathogen interaction and global gene expression will provide insight into potential control mechanisms for this important foodborne pathogen.
The role of c-Myc in regulating HIV-1 Tat protein induced cytokine expression and consequent effects on opportunistic infection (P4235)
Authors: Pong John , Li James , Yim Howard , Lau Allan 
Published: January 2023

Abstract
The human immunodeficiency virus (HIV-1) trans-activator (Tat) protein is an important viral protein that is known to contribute to the acquired immunodeficiency syndrome (AIDS) pathogenesis via cytokine dysregulation. In this study, we recognized that c-Myc regulated primary blood derived macrophage (PBMac) immune response induced by HIV-1 Tat. Treatment of PBMac with HIV-1 Tat was able to upregulate c-Myc expression in a time dependent manner. We subsequently delineated that HIV-1 Tat regulated c-Myc expression and function through the activation of dsRNA-activated protein kinase (PKR), ERK1/2 and p38 mitogen-activated protein kinase (MAPK). By knocking down the expression of c-Myc with gene specific small-interfering RNA (siRNA), we demonstrated that c-Myc may be critical for the expression of the pro-inflammatory cytokines TNF-α and IL-6. To further investigate the role of c-Myc in AIDS pathogenesis and its effects in the fight against the opportunistic microbes, Mycobacteria avium intracellulare, was used as a pathogen model. Our recent results demonstrated that HIV-1 Tat induced c-Myc to dysregulate cytokine expression, which affects the M. avium intracellular survival in PBMac. In summary, c-Myc may play a significant role in the pathogenesis of AIDS by regulating the cytokine expression by HIV-1 Tat and possibly further enhancing the infection of opportunistic pathogens in AIDS patients.
Combined radiation and thermal injury induces a non-suppressive myeloid CD11b+ Gr1+ cell population (P4025)
Authors: Linz Brandon , Brickey W. , Mendoza April , Neely Crystal , Ting Jenny , Cairns Bruce , Maile Robert 
Published: January 2023

Abstract
Increasing sophistication of terrorist attacks and recent nuclear energy crises have amplified the interest in the immunobiology of combined radiation and burn injury (RCI). Burn is associated with immunosuppression and increased mortality with lower doses of ionizing radiation. Following trauma, putative myeloid derived suppressor cells (MDSCs; CD11b+Gr1+) have been described. We hypothesized that RCI-MDSCs display a suppressive phenotype and RCI will result in increased susceptibility to bacterial infection. C57BL/6 female mice underwent either a 20% total body surface area full thickness contact burn or sham procedure. All mice then received a single whole body dose of 5Gy γ-radiation. Mice were infected 14 days post injury with Pseudomonas aeruginosa intratracheally. Immune cells underwent apoptosis following RCI and infection, with CD11b+Gr1(Ly6C)+ cells being the predominant surviving cell type, which we isolated and cocultured 1:1 with untouched T cells. Surprisingly, T cells incubated with CD11b+Gr1(Ly6C)+ cells from RCI mice displayed greater proliferation, increased IFN-γ and decreased IL-10 production compared to MDSC from radiation-only mice. RCI mice were able to clear the P. aeruginosa infection significantly better than radiation-only mice. These data suggest that while RCI depletes immune cells, resistant CD11b+Gr1(Ly6C)+ cells represent a target population for modulation of bacterial clearance after injury.
Timing of post-influenza bacterial superinfection with MRSA dictates the outcome of MRSA pneumonia in mice (P4027)
Authors: Rynda-Apple Agnieszka , Harmsen Ann , Richert Laura , Erickson Anfin , Harmsen Allen 
Published: January 2023

Abstract
Secondary bacterial pneumonias caused by S. aureus, S. pneumoniae and H. influenzae are a common occurrence following influenza infection and are responsible for significant morbidity and mortality worldwide. Others have shown in murine models that 5-8 days after influenza challenge the susceptibility to secondary bacterial infections increases; though the mechanism of this increased susceptibility is still elusive. Here, we report that 2-3 days after influenza challenge (before the onset of clinical symptoms, i.e. body weight loss) mice actually have increased resistance to secondary infection with methicillin resistant S. aureus (MRSA). Importantly, despite this early protection from MRSA, the response to bacteria early in the influenza infection results in increased viral growth and subsequently death of mice. The mechanism of this increased resistance to secondary MRSA pneumonia early after influenza is dependent on the transient presence of IL-13 and on type I IFN signaling, as mice deficient in these cytokine or cytokine receptor do not show increased resistance to secondary MRSA pneumonia 2-3 days after influenza infection, and injection of exogenous IL-13 to mice co-infected with MRSA pneumonia on day 7 increases resistance to bacteria. Thus, depending on the time of secondary infection in relation to influenza, the disease phenotype contracted by mice is greatly different, awareness of which is important for the design of rational treatments in clinics.
Role of pathogenic natural antibodies and complement in a murine model of spinal cord injury (P4051)
Authors: Qiao Fei , Zhang Lixia , Yang Xiaofeng , Hua Yunpeng , Narang Aarti , Holers Michael , Kulik Liudmila , Song Hongbin , Tomlinson Stephen 
Published: January 2023

Abstract
Traumatic spinal cord injury (SCI) results in complement activation and inflammation, which are implicated in a secondary injury that determines the extent of functional recovery. SCI has similar pathophysiological characteristics to ischemia reperfusion injury (IRI), and IRI in some organs is initiated by the binding of “natural” self-reactive IgM to post-ischemic neoepitopes, with the subsequent activation of complement. We demonstrated that Ab deficient Rag1-/- mice are protected from SCI, and that injury can be restored by reconstitution with a self-reactive natural IgM mAb specific for annexin A4. Following SCI, IgM bound to the spinal cord in wt mice, and anti-annexin A4 mAb bound to the spinal cord in Rag1-/- mice. Furthermore, IgM and C3d (complement activation product) co-localized after injury. We constructed a single chain antibody (scFv) derived from the anti-annexin A4 hybridoma and investigated: 1. Its ability to block the binding of pathogenic self-reactive IgM after SCI and, 2. Its utility as a targeting vehicle for delivery of a complement inhibitor after SCI (by linking the scFv to the complement inhibitor, Crry). The scFv-Crry construct, and to a lesser degree scFv alone, were protective against SCI, as measured by improved functional recovery, tissue sparing and demyelination. Data indicate an important role for self-reactive IgM in initiating complement activation after SCI, and that post-SCI neoepitopes represent therapeutic targets.
Caspase-12 inhibits obesity and insulin resistance (P4057)
Authors: Skeldon Alex , Morizot Alexandre , Kozlitina Julia , Pause Arnim , Saleh Maya 
Published: January 2023

Abstract
Our lab has previously identified CASPASE-12 as an inhibitor of the inflammasome, a multiprotein complex composed of a NLR, CASPASE-1, and potentially other adaptor proteins. The inflammasome has recently been identified as having a crucial role in the development of obesity and type 2 diabetes and we hypothesized that Caspase-12 may also play a role. Mice lacking Caspase-12 develop spontaneous obesity and insulin resistance. On a high fat diet (HFD), the mice develop a more severe phenotype, having increased liver triglycerides and metabolic defects including reduced respiration and activity. The adipose tissue of the Caspase-12-/- mice had increased macrophage infiltration and increased Caspase-1 processing and activation. Analysis of insulin signalling indicated that the Caspase-12-/- mice had increased insulin resistance in adipose, liver, and muscle tissue. The majority of the human population has a truncated and inactive CASPASE-12, however a proportion of people of African descent have a T125C SNP that restores the protein. To determine if Caspase-12 also had a protective effect in humans, we sequenced patients of the Dallas Heart Study for the T125C SNP. Preliminary analysis revealed a possible protective effect of a full length CASPASE-12 with respect to plasma triglycerides, however the effect was restricted to African American individuals without diabetes. No associations with body-mass index, diabetes prevalence, of fasting glucose levels were observed.
Induction of innate inflammatory responses is the major cause of liver toxicity associated with AAV-mediated RNA interference (P4007)
Authors: Tao Mi-Hua , Sun Cheng-Pu 
Published: January 2023

Abstract
Adeno-associated virus (AAV)-mediated RNA interference shows promise as a therapy for chronic hepatitis B virus (HBV) infection, but its low efficacy and hepatotoxicity pose major challenges. We have generated AAV vectors containing different promoters and a panel of HBV-specific short hairpin RNAs (shRNAs) to investigate factors that contribute to the efficacy and pathogenesis of AAV-mediated RNA interference. HBV transgenic mice injected with AAV vectors containing the U6 promoter produced abundant shRNAs, resulting in significant, but transient, HBV suppression and severe liver injury. AAVs containing the weaker H1 promoter did not cause liver injury, but their therapeutic efficacy was highly dependent on the sequence of the shRNA. Mice treated with the toxic U6 promoter-driven shRNA showed little change in hepatic microRNA levels, but a dramatic increase in hepatic leukocytes and inflammatory cytokines and chemokines. Hepatotoxicity was completely absent in immunodeficient mice and significantly alleviated in wild-type mice depleted of macrophages and granulocytes, suggesting that host inflammatory responses are the major cause of liver injury induced by U6 promoter-driven shRNA. Our results demonstrate that a combination of the H1 promoter and a highly potent shRNA can achieve sustained HBV suppression without inducing inflammatory side-effects.
Blocking vascular endothelial growth factor reduces granulomatous inflammation during murine mycobacterial infection (P4017)
Authors: Harding Jeffrey , Chen Yuli , Nagy Andras , Sandor Matyas 
Published: January 2023

Abstract
Vascular Endothelial Growth Factor is a potent pro-angiogenic factor that has broad and complex regulation over development, wound repair, and inflammation. Its importance in health and disease is underscored by its regulation over the growth and metastasis of many types of solid tumors. We have identified upregulation of VEGF protein in the granuloma during murine infection with mycobacterium. Here, using multiple approaches, we describe a previously unappreciated role of VEGF during murine infection with the Bacillus Calmette-Guerin strain of mycobacteria. We used a small peptide VEGF RTK inhibitor (SU5416), as well as employed novel transgenic mice with a hypomorphic VEGF allele (HypoVEGF Mice). We identify the cellular source of VEGF protein in the granuloma and show that, during acute infection, VEGF regulates inflammatory responses including cell accumulation and activation. Our data also show that inhibition of VEGF signaling can reduce the inflammation without limiting the host’s control of bacterial expansion. These results suggest that VEGF blockers, which have already passed phase III clinical trials in humans, could have special potential to ameliorate the fatal inflammatory responses during active tuberculosis. The finding that VEGF blockers can ameliorate granulomatous pathology could be relevant in the treatment in other diseases associated with granulomatous inflammation.