bluuebunny/crossref_metadata_2025_split huggingface dataset:
MicroRNA-155: regulator of HSV-1 encephalitis but promoter of stromal keratitis (P6108)
Authors: Bhela Siddheshvar , Mulik Sachin , Rouse Barry 
Published: January 2023

Abstract
Herpes simplex virus (HSV) infection of humans can lead to life threatening herpes simplex encephalitis (HSE) and sometimes blinding ocular lesion, stromal keratitis (SK). Here, we show that mice with a deficiency of miR-155 are highly susceptible to HSE with a majority of mice (75-80%) dying after ocular infection with HSV. Acyclovir treatment (a day after virus reaches brain) reduced brain viral levels and protected miR-155 KO mice from HSE thus supporting the role for virus replication in brain as the cause of encephalitis. Furthermore, HSV infected miR-155 deficient mice developed compromised virus specific CD8 T cell responses. Moreover, miR-155 KO survivors developed attenuated ocular lesions and revealed significant reduction in pathogenic Th1 cells in corneas and lymphoid organs. Local delivery of antagomir-155 did not increase the incidence of HSE but led to profound reduction in pro-inflammatory milieu and significantly diminished SK lesions. In conclusion, we have discovered dual role for miR-155, a regulator of brain damage while a promoter of ocular immunopathology after HSV infection.
Interaction of mesenchymal stem cells with fibroblast-like synoviocytes via cadherin-11 promotes the angiogenesis by enhanced secretion of placental growth factor (P5113)
Authors: Cho Chul-Soo , Park Su-Jung , Kim Ki-Jo , Kim Wan-Uk 
Published: January 2023

Abstract
Bone marrow derived mesenchymal stem cells (MSC) exist in synovium of patients with rheumatoid arthritis (RA), yet the role of MSC in RA was elusive. Placental growth factor (PlGF) was known to be increased in RA synovial fluids, and blocking of PlGF attenuated the arthritis progression in mice. Herein, we investigated the migration of MSCs by PlGF and interaction of MSC with RA fibroblast-like synoviocytes (FLS). We observed that PlGF induced the chemotaxis of MSC in a dose-dependent manner. PlGF-mediated chemotaxis was inhibited by anti-flt-1 hexapeptide (GNQWFI) and by inhibitors of PI3-kinase (LY294002) and p38 MAPK inhibitor (SB203580), respectively, but not by ERK1/2 inhibitor (PD98059). MSC exposed to PlGF elicited increased phosphorylation of Akt and p38 MAPK. FLS constitutively produced PlGF, while MSC released negligible amounts of PlGF. However, coculture with MSC significantly increased the PlGF production in FLS, and this increase was depedent on the number of added MSC. As revealed by transwell experiments, direct cell contact was required to increase the PlGF production in coculture. Cadherin-11 was expressed both in FLS and MSC, and siRNA knockdown of cadherin-11 in MSC significantly abrogated the enhanced PlGF production. These data indicate that PlGF in synovial cavity could induce the migration of MSC to synovium, and homophilic interaction of MSC with FLS by cadherin-11 contribute to the progression of synovitis by enhancing the secretion of PlGF.
Human neutrophil peptides induce inflammatory atherosclerotic events (P5115)
Authors: Zhang Haibo 
Published: January 2023

Abstract
Atherosclerosis includes complex inflammatory events that leafs to leukocyte recruitment, adhesion and migration, foam cell formation, and platelet aggregation. Human neutrophil peptides (HNP), the major protein content in the azurophilic granules, are released upon PMN activation, and have been found in the lesion area of coronary artery diseases. We hypothesized that HNP play an important role in PMN-mediated inflammatory cardiovascular responses in atherosclerosis. Human coronary artery endothelial cells were stimulated with HNP at a clinical relevant concentration for 4 h and 8 h, followed by cocultured with human peripheral monocyters for 2 h. The monocyte adhesion to the endothelial cells and transmigration increased in the HNP-treated conditions than in the controls. Stimulation of human monocyte-derived macrophages with HNP resulted in oxidative stress that accelerated foam cell formation, which was attenuated by the administration of superoxide dismutase. Stimulation of platelets with HNP resulted in platelet aggregation and deletion of LDL receptor-related protein8 (LRP8), the only LRP phenotype expressed in platelets had no response to HNP. The HNP-induced production of reelin, a LRP8 ligand, by the arterial endothelial cells was required for platelet aggregation. In conclusion, HNP exert pro-atherosclerotic properties mediated through reelin-LRP8 signaling pathways.
Antigen-specific TCR-pMHC catch bond enables force to trigger T cell signaling (P5079)
Authors: Liu Baoyu , Chen Wei , Evavold Brian , Zhu Cheng 
Published: January 2023

Abstract
A long-standing fundamental question in immune-biology is how T cells recognize, discriminate, and respond to pMHC molecules expressed by antigen presenting cells. The current study aims to address this question from the perspective of TCR-pMHC binding kinetics, focusing on the role of mechanical force. Particularly, we investigated how force regulates dissociation of single TCR-pMHC bonds and how such regulation impacts T cell responses. We used a single-bond mechanical assay to demonstrate that force unexpectedly stabilizes TCR-pMHC interaction on live T cells via an agonist-specific catch bond, where bond lifetime is prolonged by force. Concurrent Ca2+ imaging and binding measurement showed that a 10-piconewton durable force applied via agonist pMHC to a TCR is both sufficient and necessary to trigger intracellular Ca2+ flux. Triggering occurs after serial TCR-pMHC engagements to accumulate bond lifetimes above a threshold in the first minute of repeated force application. Furthermore, Ca2+ signaling strength negatively correlates with the number of short lifetimes. Our data support a T cell triggering model, where a mechanical force applied to the TCR delivers either an activating or inhibitory signal depending on the bond lifetime, such that agonists form catch bonds with the TCR to rapidly accumulate long lifetimes to activate the T cell, whereas antagonists form short-lived slip bonds that attenuate activation.
Altered adhesion receptor expression impairs recruitment of aged T cell to the nasal mucosa in response to influenza virus infection. (P5085)
Authors: Baaten Bas , Douglass Mia , Wong Lily 
Published: January 2023

Abstract
Influenza viruses cause significant annual illness and death in the elderly with recurrent seasonal epidemics and sporadic devastating pandemics. CD8 T cells are crucial for resolving influenza virus infection, can protect from divergent viruses, and are highly correlated with protection in the elderly. Due to its anatomical location, the nasal-associated lymphoid tissue (NALT) is crucial for the induction of the immune response, yet little is known regarding the requirements for optimal immunity at this mucosal site. We demonstrated that the number of antiviral CD8 T cells in the NALT was reduced in the aged. Phenotypic analyses of nasal T cells revealed that the carbohydrate-dependent rolling receptors L-Selectin, P-Selectin glycoprotein ligand-1, and CD44 were differentially expressed on aged T cells. We addressed the hypothesis that the reprogramming of adhesion receptor expression in the aged functionally impacts the migration of virus-specific CD8 T cells to the infected nasal mucosa. We demonstrated that rolling receptors, especially L-Selectin, were crucial for CD8 T cell recruitment to the NALT. Thus, the differential adhesion receptor expression profile on aged CD8 T cells may provide a mechanism that contributes to defective mucosal immunity in the elderly and our provides crucial information for novel strategies for improved nasal vaccines.
CD73 regulates nitric oxide production and inflammatory responses in Salmonella infected RAW 264.7 macrophages (P4223)
Authors: Costales Matthew , Alam Mohammad Samiul , Williams Kristina 
Published: January 2023

Abstract
Surface enzymes CD39 & CD73 mediate synthesis of extracellular adenosine that can regulate immune responses. Innate response to Salmonella infection involves efficient macrophage (MΦ) function. CD73 is expressed by variety of cell types & mediates anti-inflammatory responses. We investigated the role of CD73 in RAW 264.7 MΦ functions involving nitric oxide (NO) & proinflammatory responses after Salmonella infection. Macrophage mRNA expression of CD39 & CD73 were measured by qPCR after Salmonella antigen (ST-Ag) treatment. Proinflammatory cytokine mRNA & NO production were tested in ST-Ag treated MΦ with or without CD73-inhibitor (APCP) treatment. Phagocytosis & Salmonella-killing ability of RAW MΦ were also evaluated after GFP-Salmonella infection, in the presence of APCP. CD73 & CD39 mRNA were expressed in RAW MΦ & ST-Ag treatment significantly reduced their expression. ST-Ag treated & CD73-inhibited MΦ produced more NO & proinflammatory cytokines (e.g. IL1-β, TNF-α). Phagocytosis of GFP-Salmonella was much higher in APCP treated, infected MΦ compared to untreated infected cells. Phagocytosed Salmonella were more efficiently cleared from MΦ in the absence of CD73 as observed by fluorescence-microscopy. CD73-inhibition of MΦ during Salmonella infection can enhance proinflammatory cytokines & NO responses. Extracellular adenosine synthesized by CD73 suppresses anti-bacterial responses in macrophage which may impair immunity against intracellular Salmonella infection.
Complex role of immature myeloid cells in Salmonella Typhimurium infection (P4225)
Authors: Tam Jason , Kullas Amy , Mena Patricio , van der Velden Adrianus 
Published: January 2023

Abstract
Immature myeloid cells are a heterogeneous population of cells that, under normal conditions, provide tissues with protective cells (e.g. macrophages, dendritic cells). Under certain pathological conditions, myeloid cell differentiation is overridden and immature forms of these cells accumulate in tissues. Immature myeloid cells that express CD11b and either Ly6C or Ly6G (isoforms of Gr-1) have been associated with immunosuppression in cancer and, more recently, infection. We report that large numbers of CD11b+Ly6Chi Ly6G- and CD11b+Ly6CintLy6G+ cells accumulate and persist in tissues of mice infected with Salmonella Typhimurium. The CD11b+Ly6Chi Ly6G- cells exhibited a mononuclear morphology whereas the CD11b+Ly6Chi Ly6G- cells exhibited polymorphonuclear and ring-shaped nuclear morphologies. The CD11b+Ly6Chi Ly6G- cells expressed surface MHC-I and II, and differentiated into macrophage-like cells following ex vivo culture. The CD11b+Ly6Chi Ly6G- cells were capable of inducing T cell proliferation in vitro, but only when their ability to produce nitric oxide was blocked. The CD11b+Ly6Chi Ly6G- cells also were capable of presenting antigen to T cells in vivo, albeit less efficiently than macrophages. These findings indicate that CD11b+Ly6Chi Ly6G- cells have a complex role in S. Typhimurium infection, providing a balance of immunosuppressive and protective functions where the tipping of this balance may be an important factor influencing the outcome of infection.
Understanding altered toll-like receptor function in the elderly (P4251)
Authors: Canan Cynthia , Rajaram Murugesan , Turner Joanne 
Published: January 2023

Abstract
As the number of elderly individuals increases, infectious diseases, such as influenza, pneumonia and tuberculosis have become a significant public health concern. Recent interest in pathogen recognition via toll-like receptors (TLR) and the ability of TLR agonists to generate enhanced vaccine immunogenicity has led to questions regarding altered immune function in the elderly. In contrast to young mice, recent studies in our lab have shown that in old mice, Mycobacterium tuberculosis infected pulmonary macrophages can utilize a TLR2 independent pathway to generate cytokine secretion. This new development of specific altered TLR function in the elderly requires more analysis before vaccines can be generated to increase protective immunity. In this study, we will elucidate the differences in cytokine profile in the presence and absence of TLR2 by siRNA knockdown in old mice. This will allow us to determine changes that impair protection against infectious disease in old age. We will also examine pattern recognition receptors that compensate for cytokine production in the absence of TLR2. Understanding the compensatory mechanism could give us insight into targeting alternate receptors as adjuvants in vaccines development. Investigation into these age-related alterations in TLR function is of utmost importance in order to boost vaccine’s potential to generate strong immunity in the elderly.
Regulation of neutrophil-mediated anti-microbial immunity by type 2 cytokines (P4253)
Authors: Krieg Carsten , Guglietta Silvia , Bouchaud Grégory , Boyman Onur 
Published: January 2023

Abstract
Neutrophils are innate immune effectors primarily acting as a first line of defense against bacterial infections. Interestingly, acute type 2 inflammation, as seen in allergic disorders or during parasitic infections, displays a striking reduction in neutrophils. Moreover, allergic patients show an increased susceptibility towards certain bacteria usually contained by neutrophils. Here, we show that both elevated and physiologic levels of distinct type 2 cytokines dominantly inhibit several functional aspects of murine and human neutrophils, thus impairing neutrophil-mediated bacterial immunity. In particular, type 2 cytokines were found to inhibit egress of neutrophils from bone marrow as well as their anti-bacterial cytotoxicity and migration. Notably, mice lacking type 2 cytokine receptor signaling or receiving blocking type 2 cytokine antibodies survived a lethal infection with different bacteria. Based on the afore-mentioned results, we postulate a prototypic role of certain type 2 cytokines in regulating neutrophil-mediated anti-bacterial immunity.
The facultative intracellular pathogen Cryptococcus neoformans is susceptible to in vivo clearance by alveolar macrophages (P4211)
Authors: Calverley Matthew , Harmsen Allen 
Published: January 2023

Abstract
Cryptococcus is a yeast commonly found in soil, decaying wood and bird excreta. Normally characterized as an opportunistic human infection, cryptococcosis is a leading cause of meningitis and death in HIV/AIDS patients in Sub-Saharan Africa. Recent Cryptococcus gattii outbreaks within healthy, immunocompetent populations in the Pacific Northwest are calling this characterization into question. Recent studies support the ability of Cryptococcus to replicate intracellularly, particularly in macrophages, leading to classification as a facultative intracellular pathogen. However, in vivo analysis of this capacity for intracellular replication in the context of a disease model for pulmonary infection has been lacking. Here we employ a GFP expressing strain of Cryptococcus neoformans and present novel dye labeling strategies to assess whether intracellular replication is productive in a mouse model of pulmonary cryptococcosis. We show that, while limited intracellular replication occurs, cryptococcal clearance by alveolar macrophages within the first forty-eight hours of pulmonary infection predominates. Cryptococcus may correctly be characterized as a facultative intracellular pathogen; however, alveolar macrophages possess the capacity to clear this pathogen, keeping early infection in check. Our finding, showing the importance of the alveolar macrophage in early cryptococcal clearance, opens the possibility of novel treatment strategies for a clinically important human pathogen.
The role of c-Myc in phagocytosis of mycobacteria in human macrophages (P4213)
Authors: Wang Liangjie , Li James C. B. , Lau Allan S. Y. 
Published: January 2023

Abstract
Tuberculosis remains a major cause of morbidity and mortality worldwide as a result of Mycobacterium tuberculosis infection. Macrophages are the major immunocytes to initiate host immunity against mycobacteria. Among the multiple strategies employed by macrophages to inhibit mycobacteria growth or kill intracellular mycobacteria, phagocytosis is the first step. Phagocytosis involves recognition, internalization and finally digestion of pathogens at phagolysosome. c-Myc is a transcription factor that regulates a variety of target genes. It can form a complex with Max and bind to the enhancer box sequences of the promoter to mediate the transcription. Recently, our group revealed that c-Myc has a potential role in regulating the antimicrobial responses in macrophages. Here, we further revealed that c-Myc may play a positive role in phagocytosis and contribute to host defense to mycobacteria. We demonstrated that mycobacteria could induce c-Myc expression in primary human macrophages. Using colony forming unit assay and cell imaging assay, we showed that pretreatment of c-Myc inhibitor, 10058-F4, could significantly reduce the amount of mycobacteria internalized by macrophages. In addition, the acidification of phagolysosome in mycobacteria infected macrophages was shown to be inhibited by 10058-F4. However, the action of c-Myc in the process of phagocytosis is independent of Rho family GTPases. In conclusion, c-Myc may play a role in phagocytosis of mycobacteria.
C1q promotes recognition and engulfment of H. pylori infected AGS cells and modulates inflammatory cytokine production in macrophages. (P4019)
Authors: Fox Sarah , Ryan Kieran , Das Soumita , Crowe Shiela , Ernst Peter 
Published: January 2023

Abstract
H pylori resides in the gastric lumen and is a significant risk factor for gastritis and gastric cancer. This organism promotes apoptosis of gastric epithelial cells that are subsequently cleared by local phagocytes. C1q, the recognition component of the complement cascade, is an important molecule in immune regulation where it promotes uptake of apoptotic cells and modulates inflammation. We demonstrated that H pylori infection induces apoptosis of gastric AGS cells in vitro and that apoptotic epithelial cells are recognized and engulfed by macrophages independent of the method of cell death. Further, C1q binds to apoptotic cells and is important in the interaction between apoptotic cells and macrophages. We show that the absence of serum reduced attachment of AGS cells to phagocytes by up to 90% and the addition of 40μg/ml of C1q was sufficient to restore normal binding. A comparable effect of C1q on internalization of AGS cells was observed using a flow cytometric assay. C1q, in the absence of serum, attenuated IL-6, TNF-α and IL-1β production induced by 100 ng/ml of LPS or 100 MOI H. pylori compared to controls (45-60% reductions). In conclusion, we show that C1q is important in the resolution of inflammation by facilitating the engulfment of apoptotic cells and inhibiting the pro-inflammatory cytokine responses. Further, the inhibition of host responses attributed to the engulfment of apoptotic cells may be induced by extracellular factors including C1q.
CAR-dependent intestinal epithelial wound repair is inhibited by JAML released from migrating neutrophils (P4047)
Authors: Parkos Charles , Weber Dominique , Sumagin Ronen , Neumann Philipp-Alexander , Leoni Giovanna , McCall Ingrid , Andargachew Rakieb , Brazil Jennifer , Nusrat Asma 
Published: January 2023

Abstract
Junctional adhesion molecule-like protein (JAML) expressed on neutrophils (PMN) has been shown to bind to the epithelial tight junction protein cocksackie-adenovirus receptor (CAR) and partially mediate neutrophil transepithelial migration. Since CAR has also been implicated in regulating epithelial barrier function, we investigated the contribution of JAML-CAR interactions to CAR-mediated mucosal epithelial homeostasis during inflammation. Here we report that JAML is shed from activated/migrating PMN and monocytes in a stimulus and dose-dependent manner that is mediated by zinc-metalloproteases. Using complementary in-vitro and in-vivo approaches, we demonstrate that CAR ligation by shed JAML as well as by adenoviral fiber knob protein-5, an analogous CAR ligand that binds to the same site as JAML, inhibits intestinal epithelial barrier function and impairs epithelial wound healing. Inhibitory effects of soluble JAML on CAR-mediated regulation of wound repair were secondary to downregulation of ERK-dependent epithelial cell proliferation. Lastly, an anti-JAML mAb that blocks JAML-CAR binding, reversed the inhibitory effects of JAML released by migrating PMN on epithelial wound repair. These findings represent a new mechanism by which transmigrating myelomonocytic cells actively shed TJ-binding ligands that alter epithelial homeostasis and contribute to disease pathophysiology.
Evaluation of vaccines against P. salmonis: analysis of acquired versus innate immune response (P4055)
Authors: Yañez Alejandro , Pontigo Juan , Carcamo Juan 
Published: January 2023

Abstract
The Salmonid Rickettsial Septicaemia (SRS) is one of the most damaging syndrome that affects salmon farming in Chile. The causal agent of this pathology is the bacterium called, Piscirickettsia salmonis and vaccination remains the best way to reduce the economic impact caused by this disease. Several vaccines are used based in bacterins and recombinant proteins. However, the modulation of the innate and humoral immune response has not been determined. Thus 3 prototypes vaccines were used to evaluate the functionality of cellular components of P. salmonis in the modulation of immune response. In order to evaluate the immunogenicity produced by the prototype AUSTTRAL-SRS vaccine in Atlantic salmon. We designed a trial where we injected three groups of fish with three different formulations in two doses. After three weeks, the fish of each group were challenged with a lethal dose (LD70) of P. salmonis. The result obtained by studying the interleukin gene expression, ROS and lisosyme analysis let us to conclude that the three prototype vaccines were able to largely stimulate the innate immune response. However, only one prototype was efficient to stimulate the specific acquire immune systems in fish and also was highly efficient to protect the vaccinated salmon against SRS. These results indicate that the used marker of the innate immune system were not a good vaccine markers compared with acquire immune response. INNOVA 11IDL2-10523
IL-36γ induction in the human female reproductive tract is microbe-dependent (P4009)
Authors: Herbst-Kralovetz Melissa , Radtke Andrea 
Published: January 2023

Abstract
The interleukin-1 (IL-1) family consists of pleiotropic cytokines that play a role in the initiation of immune and inflammatory responses. IL-36γ (IL-1F9) is a newly identified IL-1 family member that functions as an agonist. IL-36γ is highly expressed in epithelial cells of the intestine, lungs, and skin, however IL-36γ has not previously been characterized in the human female reproductive tract (FRT). Upon pathogen infection or during inflammatory disorders, IL-36γ is induced and signals through the IL-1R-related protein 2 receptor to trigger NF-κB expression and IL-6 and IL-8 production. Here, we demonstrate for the first time the expression and regulation of IL-36γ in human FRT epithelial cells. Utilizing a human 3-D FRT epithelial cell model previously shown to express functional TLRs similar to in vivo tissue, we demonstrate a unique IL-36γ expression signature upon microbial product stimulation. Treatment of the FRT cells with pathogenic microbial products resulted in a significant increase in IL-36γ expression by quantitative RT-PCR, however exposure of FRT cells to commensal bacteria showed no significant increase in IL-36γ. Induction of IL-36γ by microbial products appears to be TLR dependent. From this data we show for the first time that human 3-D FRT cells express IL-36γ and respond in a microbe-dependent manner. In conclusion, our work begins to elucidate a novel innate immune response mechanism involving IL-36γ induction during FRT mucosal infection.