bluuebunny/crossref_metadata_2025_split huggingface dataset:
Group A Streptococcal Infection, Acute Rheumatic Fever and Rheumatic Heart Disease in the Solomon Islands
Authors: Sika-Paotonu Dianne , Liligeto Urijah 
Published: January 2023

Abstract
Group A Streptococcal (GAS) infection of the upper respiratory tract (and possibly skin) can trigger Acute Rheumatic Fever (ARF), an autoimmune condition if left untreated. Severe or recurrent attacks of ARF that also remain untreated, can lead to a type of permanent cardiac damage known as Rheumatic Heart Disease (RHD). RHD remains a significant cause of morbidity and mortality globally and is rare in developed countries. In Australia, New Zealand (NZ) and the Pacific Region, the disease burden of ARF and RHD amongst Indigenous and Pacific communities remain one of the highest in the world, usually affecting children and young adults. Since a GAS vaccine remains unavailable, the most effective recommended treatment and management strategy to prevent further GAS infections that can lead to ARF and RHD constitute of painful monthly intramuscular injections of Benzathine Penicillin G (BPG). These BPG injections are administered for at least 10 years or more and are referred to as secondary prophylaxis (SP). Due to the pain, formulation and other issues associated with regular BPG injections, adherence to SP remains problematic globally. A new Penicillin that supports better adherence to SP is urgently needed. This work sought to further understand the local context in the Solomon Islands concerning GAS, ARF and RHD. Preliminary findings indicate very high ARF and RHD rates present in the local setting, in addition to issues with access to ARF/RHD prevention measures with BPG. An electronic database to monitor ARF and RHD as a national disease register will be of clinical relevance to the local setting in the Solomon Islands. Research efforts in the Pacific Region contributing towards the generation of a new Penicillin for BPG SP will be of benefit.
Prevention of erythrocyte fragility and anaemia induced by extracellular histones
Authors: Kordbacheh Farzaneh , O’Meara Connor H , Coupland Lucy A , Lelliott Patrick M , Parish Christopher R 
Published: January 2023

Abstract

Introduction
Neutrophil extracellular traps (NETs) are released from neutrophils following activation by pathogens and/or tissue injury and exhibit anti-microbial activity. Uncontrolled formation of NETs can, however, become pathogenic, particularly via their associated histones, and induce endothelial cell death, systemic vascular obstruction, multiple organ failure and initiate coagulation by both activating platelets and damaging erythrocytes such that they become pro-thrombotic.

Study Objectives
Recently we discovered an additional effect of histones on erythrocyte, which is to enhance their fragility when they are subjected to shear stress associated with blood flow through the vascular system and spleen in particular. Our laboratory has synthesised a family of small polyanions (SPAs) which have been screened for their ability to neutralise the pathogenic effects of histones and NETs.

Methods
We have used a novel mechanically-induced shear stress method as well as an in vitro spleen filtration model to investigate the effects of mammalian histones ± SPAs, on RBC fragility. The in vitro findings were mirrored in vivo with the injection of histones and SPAs in mice.

Results
Our results revealed that free histones bind to erythrocytes with high affinity and render erythrocytes susceptible to lysis by shear stress in a dose-dependent manner and some SPAs could totally inhibit or reverse this phenomenon.

Conclusions
Based on these data we propose that erythrocytes can neutralise the damaging effects of histones in the circulation and also transport them to the spleen for disposal. Overload of this disposal system could cause the unexplained anaemia associated with sepsis, cancer and other pathological conditions.
Inhibitory effects of Klotho hormone on antigen-specific clonal expansion of CD4+ T cells
Authors: Hwang Haun , Bamezai Anil K 
Published: January 2023

Abstract
Early signaling events through the antigen receptor in CD4+ T cells occur in and around the lipid microenvironment of the plasma membrane. The plasma membrane of all eukaryotic cells have phospholipids, cholesterol and transmembrane/lipid anchored proteins organized in small and dynamic ordered (Io) and disordered (Id) –like phases. Lipid rafts are nanometer-sized, cholesterol and saturated phospholipid-rich domains that contribute to the Io phase. Interaction between CD4+ T cells with antigen presenting cells during antigen presentation stabilize and/or promote coalescing of Io nanometer size domains that are normally scattered on the plasma membrane. To assess the role of membrane order in CD4+ T cell responses we used recombinant klotho protein that is known to bind glycolipids in membrane lipid rafts and destabilize these nanometer-sized domains. Klotho is a naturally occurring protein in mice and humans - the soluble form of this protein circulates in the body, and acts as a hormone to promote longevity in mice as well as enhance cognitive function in humans. However, its possible immunologic effects are unknown. We have examined the effects of recombinant klotho protein on CD4+ T cell responses in-vitro. We found that klotho hormone inhibits clonal expansion of CD4+ T cell in an antigen-specific manner, promotes apoptosis in CD4+ T cells from younger mice (&lt; 8 weeks) although these inhibitory effects are minimal or not observed in CD4+ T cells from older mice (&gt;8 weeks). -In-vivo experiments to further investigate the role of soluble klotho protein are underway, and will be reported.
Dysregulation of Lipid Metabolism during Gram-Negative Sepsis in Mkp-1 Deficient Mice
Authors: Batty Abel J , Li Jinhui , Wang Xiantao , Ackerman William E. , Kirk Sean G , White William M. , Wang Xianxi , Anastasakis Dimitrios , Samavati Lobelia , Buhimschi Irina , Nelin Leif D. , Hafner Markus , Liu Yusen 
Published: January 2023

Abstract
Mitogen-activated protein kinase phosphatase (Mkp)-1 exerts its anti-inflammatory activities during Gramnegative sepsis by deactivating p38 and JNK. We have previously shown that Mkp-1+/+ mice, but not Mkp-1−/− mice, exhibit hypertriglyceridemia and hepatic glycogen depletion during severe sepsis. However, the regulation of hepatic lipid stores and the underlying mechanism of lipid dysregulation during sepsis remains an enigma. To understand the molecular mechanism underlying the sepsis-associated metabolic changes and the role of Mkp-1 in the process, we infected Mkp-1+/+ and Mkp-1−/− mice with Escherichia coli i.v., and assessed the effects of Mkp-1 deficiency on tissue lipid contents. We also examined global gene expression profile by RNA-seq in the livers. We found that in the absence of E. coli infection, Mkp-1 deficiency decreased liver triglyceride levels. Upon E. coli infection, Mkp-1+/+ mice, but not Mkp-1−/− mice, developed hepatocyte ballooning and increased lipid deposition in the livers. E. coli infection caused profound changes in gene expression profile of a large number of proteins that regulate lipid metabolism in wildtype mice, while these changes were substantially disrupted in Mkp-1−/− mice. Interestingly, in Mkp-1+/+ mice E. coli infection resulted in down-regulation of genes that facilitate fatty acid synthesis but upregulation of CD36 and Dgat2, whose protein products mediate fatty acid uptake and triglyceride synthesis, respectively. Taken together, our studies indicate that sepsis leads to a profound change in metabolic gene expression programs and Mkp-1 plays an important role in this process.
The ssDNA exonucleases PLD3 and PLD4 are required to prevent lethal primary HLH-like disease in mice
Authors: Gavin Amanda L , Huang Deli , Nemazee David 
Published: January 2023

Abstract
Leukocyte sensing of microbial genetic material often elicits beneficial proinflammatory cytokines, but dysregulated responses can cause severe pathogenesis. Genome-wide association studies have linked Phospholipase D3 (PLD3) to Alzheimer’s disease and PLD4 to rheumatoid arthritis and systemic sclerosis. PLD3 and PLD4 are endolysosomal proteins with no detectable phospholipase activity. PLD4 deficient mice have a mild inflammatory disease, marked by elevated interferon-γ (IFN γ) and splenomegaly. These phenotypes were traced to an altered responsiveness of PLD4-deficient dendritic cells to ligands of the single-stranded DNA (ssDNA) sensor Toll-like receptor 9 (TLR9). Thioglycolate elicited peritoneal macrophages from PLD3-deficient mice also had exaggerated TLR9 responses to particular ligands. Although PLD4 and PLD3 were presumed to be phospholipases, we found that they are 5′-ssDNA exonucleases that break down TLR9 ligands.
Mice deficient in both PLD3 and PLD4 died pre-weaning from an inflammatory disease with many similarities to primary hemophagocytic lymphohistiocytosis (HLH). The levels of IFN γ, IL-6, TNF α, IL-10 and ferritin were markedly elevated in the serum of Pld3−/−Pld4−/− mice. Low blood platelets, severe anemia, liver steatosis, and hemophagocytosis were evident in Pld3−/−Pld4−/− mice. The lethal inflammation in PLD3 and PLD4 deficient animals was only marginally improved by IFN γ deficiency, however inactivation of UNC93B1 rescues their survival, revealing excessive endosomal TLR signaling is responsible for driving the disease.
Microbiota-derived butyrate promotes cellular metabolism and memory potential of antigen-activated CD8+ T cells
Authors: Bedoui Sammy , Binger Katrina , Kallies Axel , Turner Stephen John , McConville Malcolm , Gebhardt Thomas , Bachem Annabell 
Published: January 2023

Abstract
Microbiota modulate the immune system and recent studies suggest a functional relationship between microbiota, its metabolites and CD8+ T cells, but whether this link is also relevant for CD8+ T cell memory is unclear. We show that antigen-activated CD8+ T cells transferred into germ-free mice had transcriptional impairments in oxidative metabolism and failed to transition into memory cells with enhanced recall capacity. Conversely, the microbiotaderived metabolite butyrate promoted memory potential and secondary recall responses of activated CD8+ T cells. This was accompanied by metabolic rewiring of the T cells and uncoupling of the tricarboxylic acid cycle from glycolytic input, enabling preferential fuelling of enhanced oxidative phosphorylation through glutamine utilization and fatty acid catabolism. As such energetic adaptions promote memory T cell differentiation, our findings uncover an important role for microbiota-derived butyrate in rewiring the metabolism of activated CD8+ T cells in support of their long-term survival as memory cells.
TCR signal strength and antigen affinity independently modulate CD8+ memory T cell development
Authors: Solouki Sabrina , August Avery , Huang Weishan 
Published: January 2023

Abstract
CD8+ T cells play a critical role in adaptive immunity by maintaining the ability to differentiate into CD8+ memory T cells, which provide the basis of protective immunity. During an intracellular infection, CD8+ T cells pass through several characteristic phases before becoming mature memory cells. Initial antigen stimulation causes naïve CD8+ T cells to clonally expand and differentiate into short-lived effector cells (SLECs). Subsequently, SLECs undergo a contraction phase to give rise to memory precursor effector cells (MPECs); 5–10% of the MPECs survive the initial contraction phase and further develop into CD8+ memory T cells. We have shown that the non-receptor tyrosine kinase Itk, which regulates TCR signal strength, can significantly suppress CD8+ memory T cell development. We hypothesize that TCR signal strength, regulated by Itk, intersects with antigen affinity to modulate the development of SLECs and MPECs, leading to an increased proportion of memory CD8+ T cells. Utilizing Itk deficient OT-1 TCR transgenic mice, which carry CD8+ T cells specific for the Ovalbumin protein, an adoptive transfer model was established to exam the influence of TCR signal strength and antigen affinity in the development of CD8+ memory T cells. Our findings suggest that TCR signal strength and affinity independently contribute to CD8+ memory T cell development. Our data reveals that reducing both antigen affinity and TCR signal strength leads to enhanced and accelerated antigen-mediated proliferation and development of memory cells, and enhanced secondary expansion of these memory cells. In sum, our data suggests that TCR signal strength and antigen affinity are independent parameters that may be used to tune vaccine development.
Single cell multiomic analysis of chronically stimulated T cells displaying hallmarks of T-cell exhaustion
Authors: Nakamoto Margaret , Corselli Mirko , Taylor Ian , Saksena Suraj 
Published: January 2023

Abstract
T-cell exhaustion is a dysfunctional state caused by persistent antigen stimulation mediated by chronic infections or cancer. Current immunotherapy approaches focus on reinvigorating exhausted T cells through immune-receptor-blocking antibodies. A deeper understanding of the exhausted T-cell state is crucial for identification of new therapeutic targets. Single cell RNA-sequencing (scRNA-seq) is a powerful tool for resolving heterogeneity in complex systems like these; however the lack of protein information for the same cells can make it difficult to identify cells of interest or detect cellular responses. To resolve both mRNA and protein information in the same assay, we utilized DNA-conjugated BD™ AbSeq antibodies to profile protein and mRNA expression, using high-throughput sequencing analysis at the single cell level. Sorted T cells that had been transiently and chronically stimulated were multiplexed using the BD™ Single-Cell Multiplexing Kit and pooled before undergoing cell partitioning and cDNA capture on the BD Rhapsody™ system; this minimized batch effects and saved time and reagents. A panel of 400 mRNA targets alongside the 39-plex antibody panel was used for the study. We showed that cell-type resolution increased with higher protein plex, and the addition of mRNA information alongside protein markers revealed candidate protein markers for specific cell states. This study showcased the power of multiomics in analyzing heterogenous cell populations and cell states and answering complex biological questions.
Research Use Only. Not for use in diagnostic or therapeutic procedures.
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Lipid talk: Endocannabinoids regulate mucosal inflammation following helminth infection
Authors: Wiley Mark B , Batugedara Hashini , Bobardt Sarah , Argueta Donovan , Dillman Adler , DiPatrizio Nicholas V , Nair Meera G 
Published: January 2023

Abstract
More than 2 billion humans carry infectious parasites leading to chronic co-morbidities and growth retardation in children. Parasitic infections induce a T helper type 2 (Th2) immune response in the host to promote clearance which can lead to fibrosis if chronic. We recently showed that infection with the soil-transmitted nematode Nippostrongylus brasiliensis (Nb) induces overproduction of endocannabinoids (eCBs) in the host. Endocannabinoids are endogenous cannabis-like molecules that influence the development of obesity and are anti-inflammatory, however their function in infection is largely unknown. The overproduction of eCBs in Nb-infected mice was observed throughout infection in the infected lung and intestine. Pharmacological inhibition of cannabinoid receptor subtype 1 (CB-1R) with AM6545 (10 mg/Kg/2mL), a peripherally-restricted CB1R neutral antagonist, throughout Nb infection exacerbated weight loss of mice without altering food or water intake. This inhibition of CB1Rs led to a prolonged presence of eosinophils and neutrophils in the broncho-alveolar fluid and an accumulation of lymphocytes in the spleen. Furthermore, CB1R inhibition caused an increase in the expression of the mannose receptor on alveolar macrophages at day 8 post infection, indicating a sustained need for inflammatory resolution. Strikingly, we also found that Nb produces its own eCBs which vary in concentration based on stage of development, and that the eCB system is present in many parasitic nematodes including those that infect humans. These findings suggest that the eCB system is active in several hookworm species, and that host and helminth eCBs may influence immune and anti-inflammatory functions.
Type I Interferon confers susceptibility to Mycobacterium tuberculosis infection within granulomas of SIV co-infected non-human primates
Authors: Phuah Jia Yao , O’Connor Shelby , Scanga Charles A. , Mattila Joshua T. 
Published: January 2023

Abstract
Mycobacterium tuberculosis (Mtb) co-infection with human immunodeficiency virus (HIV) typically results in poor disease outcome for tuberculosis (TB). While the loss of CD4+ T cells due to HIV is known to cause increased TB disease susceptibility, the mechanisms which govern the loss of disease control in co-infected individuals are not well understood particularly within the lung granulomas that keep TB contained. This study aims to profile the transcriptional patterns of lung granulomas from non-human primates (NHP) co-infected with Mtb and simian immunodeficiency virus (SIV) as a model for TB-SIV co-infection in humans. We compared the transcriptional profiles of granulomas from four Mauritian cynomolgus macaques that were infected with SIV for six months and then co-infected with Mtb for eight weeks against animals that were infected with Mtb for eight weeks. Granulomas from co-infected animals were found to have generally elevated transcripts involved in Type I interferon pathways (IFIT1), anti-bacterial effectors (defensin A, cathepsin G) and evidence of increased neutrophilic inflammation compared to Mtb-only control lung granulomas. Pathways that were downregulated in co-infected animals were related to Type II interferon signaling (IRF8). These results suggest that SIV infection alters the host immune response in ways that may be advantageous to Mtb growth by lowering IFNγ responsiveness and promoting myeloid cell-associated inflammation. We hypothesize this leads to a more permissive and less antibacterial environment that promotes bacterial survival, dissemination, and ultimately leads to increased susceptibility of co-infected individuals towards TB disease.
Ruxolitinib, a selective JAK1/2 inhibitor, for the treatment of serious diseases caused by Staphylococcus aureus superantigens
Authors: Carnes Henry , Mehrkens Brittney , Stegman Molly , Rajagopalan Govindarajan 
Published: January 2023

Abstract
Staphylococcal superantigens (SSAgs), produced by Staphylococcus aureus, non-specifically activate 30–50% of all CD4+ and CD8+ T cells expressing certain T cell receptor (TCR) Vb gene families. SSAg-activated T cells rapidly produce large quantities of cytokines and chemokines resulting in a systemic inflammatory response syndrome (SIRS), which culminates in multi organ failure (MOF) and ultimately death. Through this process, SSAgs play a significant role in the immunopathogenesis of pneumonia, sepsis, and toxic shock syndrome. Because most cytokines produced during SIRS act through the Janus Kinase (JAK) signaling pathway, we hypothesized that therapeutics inhibiting JAK functions would attenuate SIRS, MOF, and lower mortality caused by SSAgs. We tested ruxolitinib (RUXO), an FDA-approved selective JAK 1/2 inhibitor. Several in vitro and in vivo studies were performed using HLA-DR3 transgenic mice because SSAgs bind to HLA class II molecules with higher affinity. In vitro, at 100, 10, and 1 mm concentrations, RUXO significantly inhibited SSAg-induced upregulation of CD25 and CD69 on both CD4+ and CD8+ T cell subsets as well as SSAg-induced production of IL-2, IL-17, and IFN-g in a dose-dependent manner at 24 and 48 hours. For in vivo studies, mice (5–6 per group) were gavaged with RUXO (100 mg/kg) or vehicle, twice daily on days −1, 0 and 1, challenged with SSAg (20 mg/mouse, i.p) on day 0 and euthanized on day 2. SSAg-induced SIRS, thymocyte deletion, upregulation of activation markers (CD69 and CD25), and immunopathology were significantly attenuated in RUXO-treated mice compared to vehicle-treated mice. Overall, JAK inhibitors such as ruxolitinib can be used as an adjunct to treat serious diseases caused by SSAg.
Pathogenic Mechanisms of Endothelial Damage in Severe Scrub Typhus
Authors: Soong Lynn , Trent Brandon , Liang Yuejin , Bouyer Donald W , Sun Jiaren 
Published: January 2023

Abstract
Our newly established lethal and sublethal Orientia tsutsugamushi infection mouse models, which mimic clinical/pathologic features of human scrub typhus, are valuable for mechanistic studies. A hallmark of lethal Orientia infection is Th1-skewed, but Th2-impared, immune responses, accompanied with severe endothelial damage and acute tissue injury. Importantly, while tissue bacteria peak at disease onset (D6) in mice, neutrophil and CD8 T cell influx/activation reach peaks in the lungs around D10 (prior to host death). We hypothesize a two-stage-dysfunction loop for lethal infection: 1) Orientia replication in phagocytes and endothelial cells (EC) triggers inflammatory responses and host defense machinery; and 2) infection-mediated release of DAMP molecules exacerbates vascular dysfunction. This hypothesis was supported by immunofluorescent co-staining of bacteria with leukocyte/EC/platelet-specific markers, multi-color FACS, Western blot, and qRT-PCR. The progressive loss of vasculature and junction proteins (VE-cad, occludin) and reduction in vascular function (angiopoietin 1, Tie2, pTie2) and CD41+ platelets in the lungs were positively linked to neutrophil and CD8 T cell influx and activation, rather than to body bacterial loads. The mechanisms of immune dysregulation were further examined by using infected human endothelial cells and mouse primary macrophage and neutrophil cultures, as well as knockout mice. While Orientia infection directly altered the Ang-Tie2 axis in EC, activated IL-33/IL-36-like DAMP molecules further contributed to vascular/tissue injury. Our studies, for the first time, have revealed immune dysregulation and prognostic biomarkers in the context of scrub typhus pathogenesis.