bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of pro-inflammatory responses by S100A9 (P6124)
Authors: Tsai Su-Yu , Segovia Jesus A. , Mgbemena Victoria , Chang Te-Hung , Tessier Philippe A. , Tardif Melanie , Bose Santanu 
Published: January 2023

Abstract
Several Damage-Associated Molecular Patterns have been known to play an important role in inflammation. However, whether DAMPs are involved in lung inflammation during infection is not clear. In order to examine the important mechanisms of DAMPs during virus infection, influenza A virus infection model was used to study the role of S100A9, one of DAMPs, during lung pathogenesis. Here, we show that S100A9 is induced and secreted from flu-infected macrophages via a “non-damage” pathway. Since DAMPs are known to activate pro-inflammatory responses, we next examined whether purified recombinant S100A9 protein triggers pro-inflammatory responses in macrophages. Indeed, treatment of macrophages with S100A9 resulted in production of pro-inflammatory cytokines. The role of S100A9 during flu infection was also assessed by studying production of S100A9 in the respiratory tract of flu-infected mice. Upon flu infection, the production of S100A9 was induced in the lung and bronchoalveolar fluid. Moreover, the pro-inflammatory activity of extracellular S100A9 in the airway was obvious from robust production of pro-inflammatory cytokines in the lung. Thus our studies have identified S100A9 as a potent activator of pro-inflammatory response in macrophages and in the respiratory tract of mice. In addition, we uncovered ability of flu to induce S100A9 expression and production in macrophages and in the lung.
4-1BBL deficiency abrogates splenic hypotrophy observed following LCMV clone 13 infection in mice (P6130)
Authors: Mbanwi Achire , Wang Chao , Watts Tania 
Published: January 2023

Abstract
Mice infected with lymphocytic choriomeningitis virus (LCMV) clone 13 develop a prolonged viral infection that is used as a model to study HIV infection in humans. The tumor necrosis factor (TNF) receptor family member 4-1BB, and its ligand, 4-1BBL, have been established as powerful modulators of anti-viral immunity. Here we reveal a novel role for 4-1BBL in splenic contraction following LCMV infection. At day 8 post-infection, WT and 4-1BBL-/- mice show spleens that are 2 times the average pre-infection weight. However, by 2 months following infection, a time point at which virus is no longer detectable in the spleen, WT spleens show splenic atrophy, contracting up to 50% below baseline, whereas 4-1BBL-/- spleens contract back to baseline size. Interestingly, although 4-1BBL-/- spleens show increased cellularity, there is a deficit in the frequency of a B220-TCRβ-CD11bintCD11cintNK1.1+ natural killer (NK) cell population. The change in spleen size and NK population is observed in 4-1BBL-/-, but not 4-1BB-/- mice, suggesting a 4-1BB-independent 4-1BBL mechanism. Using bone marrow chimeras, as well as NK depleting antibodies, work is in progress to elucidate the cell type on which 4-1BBL is required for these effects and the potential role for NK cells in controlling splenic contraction following viral infection. This study suggests a novel role for 4-1BBL in splenic contraction and could have important implications for understanding the resolution of inflammatory conditions.
Understanding the role of TLR3- and MyD88-dependent signaling in the development of B cell responses to RepliVAX WN, a live attenuated single cycle flavivirus. (P6132)
Authors: Xia Jingya , Winkelmann Evandro , Gorder Summer , Milligan Gregg 
Published: January 2023

Abstract
TLR3- and MyD88-mediated signaling have been shown to play an important role in the development of antiviral B cell immunity. However, there has been no comparative investigation on the mechanisms by which these two pathways influence the B cell response. The role of these signaling pathways was examined by quantifying specific B cell development events during the humoral response in TLR3-/- and MyD88-/- mice following immunization with a single cycle attenuated West Nile vaccine. Expression of CD69 and CD86 early activation markers as achieved by activated B cells from wild type mice differed between TLR3-/- and MyD88-/- mice, and fewer IgM secreting B cells were detected in draining lymph nodes and spleens of MyD88-/- compared to TLR3-/- mice. Fewer germinal center B cells were detected in MyD88-/- mice compared to wild type or TLR3-/- mice. This finding was consistent with fewer IgG secreting B cells in MyD88-/- compared to TLR3-/- mice over the course of the antibody secreting cell response. Both TLR3 and MyD88 deficiency affected differentiation to long lived plasma cells whereas the absence of MyD88-dependent, but not TLR3-dependent signaling, impaired the development of memory B cells. Collectively, these results demonstrate that innate signaling through MyD88- or TLR3-dependent pathways results in differential effects on early B cell activation, germinal center cellularity, IgG-secreting cell number, memory B cell memory and long-lived plasma cell differentiation.
Toll-like receptor 3 involvement in Coxsackievirus B 4 acceleration of type 1 diabetes. (P6134)
Authors: McCall Kelly , Schwartz Frank , Thuma Jean , Benencia Fabian , James Calvin , Malgor Ramiro , Courreges Maria 
Published: January 2023

Abstract
Viruses are important in the pathogenesis of type 1 diabetes mellitus (T1DM). A pancreatrophic strain of coxsackievirus, CVB4, which is associated with the development of T1DM in humans, accelerates the development of T1DM in NOD mice. Toll-Like Receptor 3 (TLR3) is activated by viral dsRNA and is broadly expressed by NOD mice and human pancreatic beta cells, suggesting that TLR3 signaling may be important in CVB4 acceleration of T1DM. We used NOD mice deficient in TLR3 (TLR3 KO) to test the hypothesis that TLR3 signaling is important in CVB4 acceleration of T1DM in NOD mice. We report that TLR3 KO NOD mice are markedly protected from CVB4 acceleration of T1DM compared to wild type (WT) NOD mice. Similarly, we have observed that phenylmethimazole (C10), which has recently been shown to inhibit dsRNA-triggered TLR3 signaling, also delays CVB4 acceleration of T1DM in NOD mice. In preliminary experiments to investigate the mechanism by which TLR3 deficiency provides protection from T1DM in this model, we observed marked differences in T regulatory cell populations between TLR3 KO and WT NOD mice, and a significant enhancement of viral clearance in C10-treated NOD mice. These results indicate the distinct importance of TLR3 signaling in environmental (i.e. viral) induction of T1DM and that C10 could potentially protect β cells from virus-induced insulitis.
The effect of antibodies on endothelial cells during Dengue virus infection (P6138)
Authors: Bazzone Lindsey , Schieffelin John , Robinson James 
Published: January 2023

Abstract
Profound vascular leakage in conjunction with elevated viremia is the hallmark of Dengue Hemorrhagic Fever/Dengue Shock Syndrome (DHF/DSS). Antibody (Ab)-dependent enhancement (ADE), in which pre-existing, cross-reactive Ab enhance virus infectivity, is thought to be responsible for increased viremia, while loss of endothelial cell (EC) barrier integrity is the precursor to plasma leakage. However, the relationship between increased viremia and vascular leak has not been established. We hypothesize that DV-Ab immune complexes enhance infection of FcγR-bearing cells causing increased virus production and release of mediators contributing to enhanced EC infection and increased vascular permeability seen in DHF/DSS. Anti-DV human monoclonal Abs (HMAb) were generated by molecular cloning to study ADE. Human dermal microvascular EC (HMEC-1) were infected directly with DV or indirectly using media from K562 cells infected with DV+/-HMAb. HMEC-1 infection and infectious virion production were quantified by qRT-PCR and plaque assay, respectively. HMEC-1 monolayers were assessed by microscopy. Indirect HMEC-1 infection under ADE conditions caused enhancement compared to infection media without Ab, and resulted in aberrant changes in HMEC-1 cell morphology, indicating that under ADE conditions, K562 cells enhance DV infection of ECs by increasing the infectious viral load and potentially releasing soluble mediators that cause EC barrier dysfunction.
The expression of mouse interferon-γ by engineered rabies viruses protects mice from lethal CNS infection through effects on innate immunity. (P6141)
Authors: Barkhouse Darryll , Faber Milosz , Dietzschold Bernhard , Hooper D. 
Published: January 2023

Abstract
Interferon-γ (IFNγ) has immunostimulatory, immunomodulatory and direct anti-viral properties. Previous studies have demonstrated the importance of IFNγ signaling during the immune response to rabies virus (RABV) as well as other neurotropic viruses. Specifically, IFNγ mRNA expression in the brains of RABV-infected mice correlates with immune effector entry into the brain and virus clearance. To more directly study the effect of IFNγ on the virus host response in the CNS, we constructed three IFNγ-expressing RABV vectors with decreasingly pathogenic backbone structures. We report that intranasal infection of mice with control SPBN is highly pathogenic but similar infection with SPBNγ is not. In addition, IFNγ expression by the attenuated RABV GASγ strain renders it significantly more effective than the highly attenuated GASGAS virus in preventing the death of mice from an otherwise lethal dose of DOG4 RABV when both are simultaneously administered intracranially. Finally, post-exposure treatment (PET) with an intramuscular injection of GASγGAS prevents the generally lethal outcome of intranasal infection of mice with DOG4 RABV and significantly reduces morbidity as compared to other PET RABV strains. Analysis of a variety of parameters of immunity in vivo and in vitro indicates that the protection provided by virus-encoded IFNγ is largely due to its impact on the innate response.
Immune and neurological outcomes of maternal-transmitted cytomegalovirus infection (P6153)
Authors: Puddington Lynn , Lingenheld Elizabeth , Zhu Li , Paveglio Sara , Obar Joshua , Lefrancois Leo , Wu Carol 
Published: January 2023

Abstract
Human cytomegalovirus (CMV) infection is the most significant infectious cause of developmental brain disorders, likely due to the predilection of the virus to infect the central nervous system early in development and that the immune system is not fully functional to eliminate this infectious agent. The data show that mother-child transmission rates for human CMV are at least 10-fold higher when mothers have their first infection while they are pregnant than if they are immune prior to becoming pregnant (30-50% versus 3%, respectively). These numbers provide a compelling argument that to prevent congenital CMV infection, all women of child-bearing age should be immune to the virus. However, immune women harbor virus in a latent state that reactivates specifically in the mammary gland during lactation, resulting in transmission of virus together with anti-viral maternal antibodies to their breastfed infants. We have established a mouse model of murine CMV infection that closely replicates this human situation. We found that neonatal mice infected while nursed by mothers with latent murine CMV infection have widespread dissemination of infectious virus, including the brain. Interestingly, the virus-specific T cell repertoire in neonates that acquire murine CMV from breast milk orally from immune mothers is distinct from neonates that ingest virus alone. The potential to elicit protective versus detrimental immune and neurological outcomes is under investigation.
CD44 expression on insulin-secreting β cells enhances the development of type 1 diabetes (P5109)
Authors: Naor David , Assayag-Asherie1 Nathalie 
Published: January 2023

Abstract
CD44-knockout NOD (non-obese diabetic) females show resistance to type 1 diabetes (T1D) compared with wild type (WT) littermates. Surprisingly, resistance to T1D is effective despite the increased insulitis observed in CD44-deficient NOD females by histopathological analysis of the pancreatic islets Indeed, under inflammatory conditions, destruction or reduced function is observed in WT, but not, or to a lesser extent, in CD44-deficient NOD females. Substantial reduction of insulin content was detected in WT β cells, but not in CD44-deficient cells. Apoptotic damage to β cell after binding of hyaluronan to its CD44 receptor may enhance T1D development. The effect of CD44 expression on β cells is predominant over its expression on inflammatory cells, shifting the balance in favor of overt diabetes
Mechanical insights into the functional impacts of interactions between antigen-presenting cells and T cells (P5081)
Authors: Lim Tong Seng , Mortellaro Alessandra , Lim Chwee Teck , J. Hämmerling Günter , Ricciardi-Castagnoli Paola 
Published: January 2023

Abstract
Antigen recognition and discrimination by T lymphocyte are essential in initiating appropriate immune responses. The mechanisms underlying exquisite sensitivity and specificity of antigen discrimination are not fully elucidated but involved physical intercellular interactions between T cell and antigen-presenting cell (APC) including dendritic cells (DCs) and B cells. Using single cell force spectroscopy (SCFS), we have successfully probe mechanical interactions between DC and T cells in response to a panel of altered peptide ligands (APLs). In the presence of different type of APLs, DC:T conjugate displays different ranges of mechanical forces that match their corresponding T cell responsiveness. Strong cell-cell interaction forces are contributed not only by surface adhesion molecules including TCR:pMHC, CD28:B7 and ICAM-1:LFA-1 interaction pairs, but also dependent on the integrity of membrane cholesterol and cytoskeleton dynamics. As compared to B:T interactions, stronger DC:T cell-cell interactions are likely to provide a mechanically stable environment that induces potent functional T cell activation, suggesting that the measurement of mechanical forces could be a significant predictor of T cell functional activation efficacy. Our SCFS studies provide mechanical insights into the adhesive roles of cell surface proteins in regulating APC:T cell-cell interactions. Functional roles of TLR ligands in regulating APC:T interactions and T-cell responses will be discussed.
Migration within chemoattractant-defined niches regulates B cell receptor signaling, lymphocyte differentiation and survival (P5087)
Authors: Pereira Joao , Beck Thomas , Gomes Ana 
Published: January 2023

Abstract
A critical feature of B and T lymphocytes is their ability to recirculate between lymphoid organs. Cell motility, besides catalyzing encounters between rare lymphocytes and cognate antigens, is also believed to promote lymphocyte survival. For B lymphocytes, however, little is known about how they migrate, and neither it is known if and how motility is required for survival. In previous studies, we demonstrated that B cells are already motile during early stages of development in bone marrow. Using intravital microscopy, we now demonstrate that B cell motility within bone marrow is controlled by continuous CXCR4 signaling and by α4β1 integrin mediated adhesion to VCAM-1, a surprising and unprecedented example of haptokinetic motility within lymphoid organ interstitium. Remarkably, B lymphocytes engineered to express pertussis toxin (PTX, B-PTX cells), an irreversible inhibitor of gαi protein coupled receptors (GPCRs) and of lymphocyte migration, displayed exacerbated tonic BCR signaling. Consequently, sessile B-PTX cells were unable to differentiate and survive past the transitional T2 stage in the spleen, which resulted in a ~10-fold reduced mature B cell compartment. Furthermore, engagement of GPCRs by chemoattractants in B-lineage cells selectively reduced Igα phosphorylation via a mechanism that involves kinase inhibition. In conclusion, our studies demonstrate an essential role for chemotaxis in B lymphocyte survival via a direct link between GPCR and BCR signaling.
α-Iso-cubebenol has therapeutic effect against sepsis via CXCR2 (P4203)
Authors: Lee Sung Kyun , Jung Young Su , Kim Sang Doo , Kook Minsoo , Lee Ha Young , Choi Young Whan , Bae Yoe-Sik 
Published: January 2023

Abstract
α-Iso-cubebenol, a natural compound isolated from the Schisandra chinensis fruit, strongly enhances survival rate in cecal ligation and puncture (CLP) challenge-induced sepsis. Mechanistically, α-iso-cubebenol markedly reduces viable bacteria in the peritoneal fluid and peripheral blood, by increasing production of superoxide anion. α-Iso-cubebenol also significantly attenuates widespread immune cell apoptosis in a mouse CLP sepsis model, and inhibits the production of proinflammatory cytokines including interleukin-1β (IL-1β) and IL-6 in CLP mice and lipopolysaccharide-stimulated splenocytes. We also found that α-iso-cubebenol stimulated calcium increase and degranulation in human neutrophils. α-Iso-cubebenol also strongly induced neutrophil chemotaxis, which was completely blocked by a CXCR2 antagonist, SB225002. The increased survival rateby α-iso-cubebenol was also significantly attenuated by SB225002. Taken together, the results indicate that α-iso-cubebenol-induced anti-septicactivity was mediated by CXCR2, suggesting CXCR2 as an important target for theregulation of sepsis and inflammation.
Salmonella Typhi survives in the host by evading a complement-dependent neutrophil immuno-surveillance (P4221)
Authors: Wangdi Tamding , Lee Cheng-Yuk , Spees Alanna , Yu Chen zhou , Heinrich Volkmar , Baumler Andreas 
Published: January 2023

Abstract
Vi capsular polysaccharide in S. Typhi is an important virulence factor. However, its role is incompletely understood. Previously, we have shown that the Vi capsule prevents complement component 3 mediated clearance of S. Typhi by preventing C3 fixation on the bacterial surface. Here we used isolated mouse and human neutrophils to show, at single cell level, that Vi negative S. Typhi mutant (tviB-vexE) directly triggers a chemotactic response by neutrophils when co-incubated in a medium containing autologous serum whereas Vi positive wild-type S. Typhi (Ty2) does not. Using neutrophils from C3 and C5aR deficient mice, we also show that this chemotactic response requires the complement component 5a receptor (C5aR) in neutrophils suggesting that the detection of generated C5a as a result of complement activation on the bacterial surface is a non-redundant signal used by neutrophils to move towards the bacteria. Additionally, data from our in vivo mouse model show that higher number neutrophils were associated with tviB-vexE than the WT S. Typhi an hour post interperitoneal injection of bacteria. Taken together, our data suggest that Vi capsule helps evade neutrophil detection of S. Typhi by preventing activation of C5a-dependent chemotactic response.
RvE1 and phagocytosis of Porphyromonas gingivalis by PMN in type 2 diabetes (P4227)
Authors: Van Dyke Thomas , Herrera Bruno , Hasturk Hatice , Kantarci Alpdogan 
Published: January 2023

Abstract
Periodontitis is a complication of Type 2 diabetes that impacts control of glycemia and systemic inflammation. Resolution of inflammation is an active, temporally orchestrated process of the biosynthesis of novel mediators (Resolvin E1, RvE1). Dysregulation of resolution may impact human inflammatory diseases such as diabetes and periodontitis. We examined the role of RvE1 in Type 2 diabetes and periodontitis by over-expressing the RvE1 receptor CMKLR1 in Type 2 diabetic mice (db-/-/db-/-); activation pathways and PMN phagocytosis of a periodontal pathogen Porphyromonas gingivalis (P.g.) were compared to wild type (WT), db-/-/db-/- and CMKLR1 over-expressing non-diabetic FVB WT. We report increased progression of periodontitis in diabetic mice is accompanied by impaired PMN phagocytosis. RvE1 enhanced phagocytosis of P.g. by WT PMN, but not PMN from diabetic animals. Phagocytosis was further increased by CMKLR1tg PMN. RvE1 rescued phagocytosis by db-/-/CMKLR1tg PMN. RvE1 induced reductions in AKT and MAPK phosphorylation that were enhanced in the transgenic animals. We conclude that PMN phagocytosis is impaired in db-/-/db-/- mice that is refractory to RvE1. RvE1 enhances PMN phagocytosis in non-diabetic WT mice and rescues impaired PMN phagocytosis in type-2 diabetic mice that over-express CMKLR1. Persistent infection and chronic inflammation characteristic of type 2 diabetes and periodontitis are due, in part, to failure of resolution of inflammation pathways.
Functional heterogeneity of monocyte populations during influenza virus infection (P4243)
Authors: Duan Susu , Sharma Shalini , Thomas Oguin , Morris Melissa , Thomas Paul 
Published: January 2023

Abstract
Influenza infection in mice is characterized by waves of recruitment of innate immune cells into the lung. We have previously described TNF-α/iNOS-producing monocytes (TipDC) as promoting the anti-influenza adaptive immune response and contributing to disease pathogenesis. Here, we report the identification of a novel subset of monocytes, distinct from TipDCs and lung resident innate populations, that is recruited into the lung during influenza infection in mice. These monocytes had distinct morphology, phenotypic lineage marker expression (CD8α, CD103, F4/80 and Ly6C etc) and transcriptional profile from TipDCs. CCR2 signaling contributed to the recruitment of this monocyte subset into the lung, but it was not indispensable. They were not found in the lung-draining lymph nodes. Functionally, both these monocytes and TipDC could not stimulate CD4 T cell proliferation, but only this subset of monocytes suppressed CD4 and CD8 T cell proliferation, and they also induced high levels of Th17-associated cytokines from CD4 T cells. Our results highlight the heterogeneity of monocyte populations and their functional roles in anti-viral immunity to influenza infection. This heterogeneity may be harnessed for immune modulation strategies as novel therapeutics for influenza infection.
Mast cell mediated immune pathology during dengue virus infection (P4245)
Authors: St. John Ashley , Rathore Abhay , Raghavan Bhuvanakantham , Ng Mah Lee , Soman Abraham 
Published: January 2023

Abstract
Mast cells (MCs) promote immunosurveillance for pathogens in peripheral tissues and line the host vasculature. We observe that MC are activated by dengue virus (DENV), a flavivirus that is spread by mosquito vectors. MC activation by DENV during viremia elevates systemic levels of their vasoactive products, including the MC-specific protease, chymase, and promotes vascular leakage. Symptoms of DENV infection in humans include widespread vascular leakage, pooling of fluid within internal organs and, occasionally, severe hemorrhaging; however, the processes that underlie the immune-mediated vascular pathology during dengue infection are largely unknown. A component of dengue-induced vascular leakage is MC-dependent since mice that lack MCs have greatly reduced vascular permeability during infection. We show that treatment of infected animals with MC-stabilizing drugs restores vascular integrity during experimental DENV infection. Validation of these findings using human clinical samples revealed a direct correlation between MC activation and DENV disease severity based on the measurement of chymase as a serum biomarker. Our findings reveal that MCs mediate DENV-induced vascular pathology, and suggest MC-stabilizing drugs should be evaluated for their effectiveness in improving disease outcomes during viral hemorrhagic fevers.