Elevated Expression Of Pro-inflammatory Cytokines Research Articles

The lasso peptide produced by Bacillus licheniformis MCC 2514 demonstrates efficacy in treating in-vivoSalmonella Typhimurium infection

Salmonella, a significant pathogen transmitted through food, presents a substantial threat to public health. The issue of antibiotic misuse is causing a quest for alternative replacements. An antimicrobial peptide, predicted as lasso peptide 2514 (LP-2514), derived from the probiotic bacteria Bacillus licheniformis MCC 2514, has demonstrated effectiveness against various foodborne pathogens including Salmonella. This study aims to assess the efficacy of this peptide in vivo. Mice infected with Salmonella Typhimurium received daily oral administration of LP-2514 (30 mg/kg/day) for 2 weeks until the symptoms subsided. After the treatment, biochemical and histopathological parameters were examined. LP-2514 treated mice demonstrated reduced infection, as evidenced by a 5-fold decrease in aspartate aminotransferase concentration and a 10-fold decrease in alanine aminotransferase concentration in plasma. Nitric oxide generation was decreased by 61.23 %, C-reactive protein by 75.9 %, and numerous antioxidant enzymes were elevated to suppress the infection. Increased expression of the anti-inflammatory marker Interleukin-10 (IL-10) by 43-fold was observed in treated mice, while untreated mice displayed elevated expression of pro-inflammatory cytokines indicating the severity of infection. Hence, LP-2514 successfully alleviated the disease symptoms caused by S. Typhimurium, thus exhibiting as a potential replacement for antibiotics or food-grade preservatives.

Humid heat environment causes anxiety-like disorder via impairing gut microbiota and bile acid metabolism in mice

Climate and environmental changes threaten human mental health, but the impacts of specific environmental conditions on neuropsychiatric disorders remain largely unclear. Here, we show the impact of a humid heat environment on the brain and the gut microbiota using a conditioned housing male mouse model. We demonstrate that a humid heat environment can cause anxiety-like behaviour in male mice. Microbial 16 S rRNA sequencing analysis reveals that a humid heat environment caused gut microbiota dysbiosis (e.g., decreased abundance of Lactobacillus murinus), and metabolomics reveals an increase in serum levels of secondary bile acids (e.g., lithocholic acid). Moreover, increased neuroinflammation is indicated by the elevated expression of proinflammatory cytokines in the serum and cortex, activated PI3K/AKT/NF-κB signalling and a microglial response in the cortex. Strikingly, transplantation of the microbiota from mice reared in a humid heat environment readily recapitulates these abnormalities in germ-free mice, and these abnormalities are markedly reversed by Lactobacillus murinus administration. Human samples collected during the humid heat season also show a decrease in Lactobacillus murinus abundance and an increase in the serum lithocholic acid concentration. In conclusion, gut microbiota dysbiosis induced by a humid heat environment drives the progression of anxiety disorders by impairing bile acid metabolism and enhancing neuroinflammation, and probiotic administration is a potential therapeutic strategy for these disorders.

Elucidating inflammation-induced cell fate decisions in primary human Tregs

Abstract Adoptive regulatory T-cell (Treg) therapy has remarkable efficacy in promoting immune tolerance in preclinical models of transplantation and autoimmune disease. However, lineage-tracing studies have revealed that Tregs can undergo epigenetic reprogramming in chronically inflamed tissue environments, resulting in the acquisition of proinflammatory functions and the capacity to exacerbate autoimmunity. Despite intense interests in developing Treg therapy for humans, inflammation-induced human Treg lineage-decommitment remains poorly understood. Here, we present a robust in vitro model of IL6, IL1β, and IL23-driven human Treg instability characterized by progressive FOXP3 and HELIOS downregulation, FOXP3 conserved non-coding sequence (CNS)-2 enhancer re-methylation, diminished in vitro suppressive function, and elevated proinflammatory cytokine expression. Single-cell transcriptomic and chromatin accessibility analyses of human Tregs undergoing destabilization revealed a gradual closing of a Treg-specific element (A) and a reciprocal opening of a competing element (B) at the IRF4 locus. CRISPR-mediated excision of the B element (IRF4ΔB) preserved Treg identity and enhanced in vitro suppressive activity following prolonged inflammatory exposure. Ongoing experiments aim to evaluate the in vivo function and stability of IRF4ΔB Tregs in a xenogeneic graft-versus-host model. These findings may facilitate the design of Treg therapeutics with greater potency and improved safety.

Translocator protein (TSPO) is a biomarker of Zika virus (ZIKV) infection-associated neuroinflammation

ABSTRACT Zika is a systemic inflammatory disease caused by infection with Zika virus (ZIKV). ZIKV infection in adults is associated with encephalitis marked by elevated expression of pro-inflammatory cytokines and chemokines, as well as increased brain infiltration of immune cells. In this study, we demonstrate that ZIKV encephalitis in a mouse infection model exhibits increased brain TSPO expression. TSPO expression on brain-resident and infiltrating immune cells in ZIKV infection correlates with disease and inflammation status in the brain. Brain TSPO expression can also be sensitively detected ex vivo and in vitro using radioactive small molecule probes that specifically bind to TSPO, such as [3H]PK11195. TSPO expression on brain-resident and infiltrating immune cells is a biomarker of ZIKV neuroinflammation, which can also be a general biomarker of acute viral neuroinflammatory disease.

Granulocyte macrophage colony-stimulating factor-induced macrophages of individuals with autism spectrum disorder adversely affect neuronal dendrites through the secretion of pro-inflammatory cytokines

BackgroundA growing body of evidence suggests that immune dysfunction and inflammation in the peripheral tissues as well as the central nervous system are associated with the neurodevelopmental deficits observed in autism spectrum disorder (ASD). Elevated expression of pro-inflammatory cytokines in the plasma, serum, and peripheral blood mononuclear cells of ASD has been reported. These cytokine expression levels are associated with the severity of behavioral impairments and symptoms in ASD. In a prior study, our group reported that tumor necrosis factor-α (TNF-α) expression in granulocyte–macrophage colony-stimulating factor-induced macrophages (GM-CSF MΦ) and the TNF-α expression ratio in GM-CSF MΦ/M-CSF MΦ (macrophage colony-stimulating factor-induced macrophages) was markedly higher in individuals with ASD than in typically developed (TD) individuals. However, the mechanisms of how the macrophages and the highly expressed cytokines affect neurons remain to be addressed.MethodsTo elucidate the effect of macrophages on human neurons, we used a co-culture system of control human-induced pluripotent stem cell-derived neurons and differentiated macrophages obtained from the peripheral blood mononuclear cells of five TD individuals and five individuals with ASD. All participants were male and ethnically Japanese.ResultsOur results of co-culture experiments showed that GM-CSF MΦ affect the dendritic outgrowth of neurons through the secretion of pro-inflammatory cytokines, interleukin-1α and TNF-α. Macrophages derived from individuals with ASD exerted more severe effects than those derived from TD individuals.LimitationsThe main limitations of our study were the small sample size with a gender bias toward males, the use of artificially polarized macrophages, and the inability to directly observe the interaction between neurons and macrophages from the same individuals.ConclusionsOur co-culture system revealed the non-cell autonomous adverse effects of GM-CSF MΦ in individuals with ASD on neurons, mediated by interleukin-1α and TNF-α. These results may support the immune dysfunction hypothesis of ASD, providing new insights into its pathology.

Streptolysin S induces proinflammatory cytokine expression in calcium ion-influx-dependent manner

Anginosus group streptococci (AGS) are opportunistic pathogens that reside in the human oral cavity. The β-hemolytic strains of Streptococcus anginosus subsp. anginosus (SAA) produce streptolysin S (SLS), a streptococcal peptide hemolysin. In recent clinical scenarios, AGS, including this species, have frequently been isolated from infections and disorders beyond those in the oral cavity. Consequently, investigating this situation will reveal the potential pathogenicity of AGS to ectopic infections in humans. However, the precise mechanism underlying the cellular response induced by secreted SLS and its relevance to the pathogenicity of AGS strains remain largely unknown. This study aims to elucidate the mechanism underlying the host cellular response of the human acute monocytic leukemia cell line THP-1 to secreted SLS. In THP-1 cells incubated with the culture supernatant of β-hemolytic SAA containing SLS as the sole cytotoxic factor, increased Ca2+ influx and elevated expression of proinflammatory cytokines were observed. Significantly reduced expression of SLS-dependent upregulated cytokine genes under Ca2+-chelating conditions suggests that Ca2+ influx triggers SLS-dependent cellular responses. Furthermore, SLS-dependent enhanced expression of IL-8 was also implicated in the activation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) signaling pathways. The findings presented in this study are crucial for a comprehensive understanding of the real pathogenicity of SLS-producing β-hemolytic AGS in the latest clinical situations.

Subgingival titanium wire implantation induces weak inflammatory responses but does not promote substantial T cell activation.

Titanium is a biocompatible material commonly used for dental treatments. However, the detailed mechanism underlying the weak biological activity of titanium has not been elucidated. We investigated both the inflammatory responses and T cell activation induced by solid titanium in the gingiva in mice. Both titanium and nickel wire implantation promoted neutrophil infiltration into the gingiva on day 2. Nickel, but not titanium, wire implantation enhanced proinflammatory cytokine expression and dendritic cell activity in gingival tissue by day 2. Nickel wire implantation enhanced the activity of T cells in draining lymph nodes on day 5. Moreover, T cell and neutrophil infiltration and elevated proinflammatory cytokine expression in the gingival tissue were still observed on day 5. However, no such augmented biological responses were observed after titanium wire implantation. These findings suggest that, unlike nickel, solid titanium does not induce sufficient inflammatory responses leading to T cell activation in gingival tissue.

Impact of the SARS-CoV-2 nucleocapsid 203K/204R mutations on the inflammatory immune response in COVID-19 severity

BackgroundThe excessive inflammatory responses provoked by SARS-CoV-2 infection are critical factors affecting the severity and mortality of COVID-19. Previous work found that two adjacent co-occurring mutations R203K and G204R (KR) on the nucleocapsid (N) protein correlate with increased disease severity in COVID-19 patients. However, links with the host immune response remain unclear.MethodsHere, we grouped nasopharyngeal swab samples of COVID-19 patients into two cohorts based on the presence and absence of SARS-CoV-2 nucleocapsid KR mutations. We performed nasopharyngeal transcriptome analysis of age, gender, and ethnicity-matched COVID-19 patients infected with either SARS-CoV-2 with KR mutations in the N protein (KR patients n = 39) or with the wild-type N protein (RG patients n = 39) and compared to healthy controls (n = 34). The impact of KR mutation on immune response was further characterized experimentally by transcriptomic and proteomic profiling of virus-like-particle (VLP) incubated cells.ResultsWe observed markedly elevated expression of proinflammatory cytokines, chemokines, and interferon-stimulated (ISGs) genes in the KR patients compared to RG patients. Using nasopharyngeal transcriptome data, we found significantly higher levels of neutrophils and neutrophil-to-lymphocyte (NLR) ratio in KR patients than in the RG patients. Furthermore, transcriptomic and proteomic profiling of VLP incubated cells confirmed a similar hyper-inflammatory response mediated by the KR variant.ConclusionsOur data demonstrate an unforeseen connection between nucleocapsid KR mutations and augmented inflammatory immune response in severe COVID-19 patients. These findings provide insights into how mutations in SARS-CoV-2 modulate host immune output and pathogenesis and may contribute to more efficient therapeutics and vaccine development.

Expression Profile of miR-199a and Its Role in the Regulation of Intestinal Inflammation.

Early weaning stress impairs intestinal health in piglets. miRNAs are crucial for maintaining host homeostasis, while their implication for animal health remains unclear. To identify weaning-associated miRNAs, piglets were sampled at day 0, 1, 3, 7 and 14 after weaning. The data indicated that the highest levels of miR-199a-5p in jejunal villus upper cells were observed on day 14 after weaning, while the lowest levels in crypt cells were noted on day 7 and 14. In contrast, miR-199a-3p was down-regulated in both of these two cells on day 7 after weaning compared with day 0. Both miR-199a-5p and -3p were differently expressed along the villus-crypt axis. To further clarify the function of miR-199a, mice deficient in miR-199a were exposed to dextran sulfate sodium (DSS) to induce colitis. Results revealed that silencing of miR-199a enhanced sensitivity to DSS-induced colitis. Moreover, the increased morbidity and mortality were correlated with enhanced inflammatory cell infiltration, elevated pro-inflammatory cytokine expression, impaired barrier function, and a concomitant increase in permeability-related parameters. Bioinformatic analysis further demonstrated that lipid metabolism-related pathways were significantly enriched and Ndrg1 was verified as a target of miR-199a-3p. These findings indicate that miR-199a may be important for animal health management.

Inhibition of PERK Kinase, an Orchestrator of the Unfolded Protein Response (UPR), Significantly Reduces Apoptosis and Inflammation of Lung Epithelial Cells Triggered by SARS-CoV-2 ORF3a Protein.

SARS-CoV-2 ORF3a accessory protein was found to be involved in virus release, immunomodulation and exhibited a pro-apoptotic character. In order to unravel a potential ORF3a-induced apoptotic and inflammatory death mechanism, lung epithelial cells (A549) were transfected with in vitro synthesized ORF3a mRNA. The protein's dynamic involvement as "stress factor" for the endoplasmic reticulum, causing the activation of PERK kinase and other UPR-involved proteins and therefore the upregulation of their signaling pathway executioners (ATF6, XBP-1s, PERK, phospho eIF2a, ATF4, CHOP, GADD34), has been clearly demonstrated. Furthermore, the overexpression of BAX and BH3-only pro-apoptotic protein PUMA, the upregulation of Bcl-2 family genes (BAX, BAK, BID, BAD), the reduced expression of Bcl-2 in mRNA and protein levels, and lastly, the cleavage of PARP-1 and caspase family members (caspase-3,-8 and -9) indicate that ORF3a displays its apoptotic character through the mitochondrial pathway of apoptosis. Moreover, the upregulation of NFκB, phosphorylation of p65 and IκΒα and the elevated expression of pro-inflammatory cytokines (IL-1b, IL-6, IL-8 and IL-18) in transfected cells with ORF3a mRNA indicate that this protein causes the inflammatory response through NFκB activation and therefore triggers lung injury. An intriguing finding of our study is that upon treatment of the ORF3a-transfected cells with GSK2606414, a selective PERK inhibitor, both complications (apoptosis and inflammatory response) were neutralized, and cell survival was favored, whereas treatment of transfected cells with z-VAD (a pan-caspase inhibitor) despite inhibiting cell death, could not ameliorate the inflammatory response of transfected A549 cells. Given the above, we point out that PERK kinase is a "master tactician" and its activation constitutes the main stimulus for the emergence of ORF3a apoptotic and inflammatory nature and therefore could serve as potential target for developing novel therapeutic approaches against COVID-19.

Elucidating Inflammation-induced Cell Fate Decisions in Primary Human Tregs

Abstract Adoptive regulatory T-cell (Treg) therapy is an emerging therapeutic paradigm for promoting immune tolerance in transplant and autoimmune disease settings. Prior investigations demonstrate that murine Tregs can undergo epigenetic reprogramming within chronically inflamed tissue environments, resulting in acquisition of proinflammatory functions and the capacity to exacerbate tissue damage. Despite the ramifications of Treg lineage decommitment for cell therapy applications, inflammation-induced human Treg cell fate decisions remain poorly understood. Here, we present a robust in vitromodel of IL6, IL1β, and IL23-driven Treg instability characterized by progressive FOXP3 and HELIOS downregulation, FOXP3conserved non-coding sequence (CNS)2 enhancer re-methylation, diminished in vitrosuppressive function, and elevated proinflammatory cytokine expression. To gain insight into the gene regulatory networks enabling the loss of Treg identity, we generated single-cell transcriptomic and chromatin accessibility profiles of primary human Tregs maintained in the presence or absence of IL6, IL1β, and IL23. Unsupervised clustering revealed a dysfunctional Treg population with an epigenetic signature consistent with murine Treg to “exTreg” conversion, including altered chromatin accessibility at the IFNγ, IL17A, and FOXP3CNS2 loci. Inference of transcription factor (TF)-associated changes in chromatin accessibility indicated a key role for E26 transformation-specific (ETS) family members. Ongoing experiments aim to identify specific TF modules that can be targeted to better safeguard the function and stability of Treg therapeutics.

The inflammatory profiles of pulmonary alveolar macrophages and alveolar type 2 cells in SCD.

The lung microenvironment plays a crucial role in maintaining lung homeostasis as well as the initiation and resolution of both acute and chronic lung injury. Acute chest syndrome (ACS) is a complication of sickle cell disease (SCD) like acute lung injury. Both the endothelial cells and peripheral blood mononuclear cells are known to secrete proinflammatory cytokines elevated during ACS episodes. However, in SCD, the lung microenvironment that may favor excessive production of proinflammatory cytokines and the contribution of other lung resident cells, such as alveolar macrophages and alveolar type 2 epithelial (AT-2) cells, to ACS pathogenesis is not completely understood. Here, we sought to understand the pulmonary microenvironment and the proinflammatory profile of lung alveolar macrophages (LAMs) and AT-2 cells at steady state in Townes sickle cell (SS) mice compared to control mice (AA). In addition, we examined lung function and micromechanics molecules essential for pulmonary epithelial barrier function in these mice. Our results showed that bronchoalveolar lavage (BAL) fluid in SS mice had elevated protein levels of pro-inflammatory cytokines interleukin (IL)-1β and IL-12 (p ⩽ 0.05) compared to AA controls. We showed for the first time, significantly increased protein levels of inflammatory mediators (Human antigen R (HuR), Toll-like receptor 4 (TLR4), MyD88, and PU.1) in AT-2 cells (1.4 to 2.2-fold) and LAM (17-21%) isolated from SS mice compared to AA control mice at steady state. There were also low levels of anti-inflammatory transcription factors (Nrf2 and PPARy) in SS mice compared to AA controls (p ⩽ 0.05). Finally, we found impaired lung function and a dysregulated composition of surfactant proteins (B and C). Our results demonstrate that SS mice at steady state had a compromised lung microenvironment with elevated expression of proinflammatory cytokines by AT-2 cells and LAM, as well as dysregulated expression of surfactant proteins necessary for maintaining the alveolar barrier integrity and lung function.

Noise and Alzheimer's disease

Alzheimer's disease (AD) is the most common form of degenerative dementia and the seventh leading cause of death. Numerous influencing factors for AD have been investigated: aging, female gender, genetics, unhealthy diet, hearing loss, unhealthy lifestyle, physical inactivity, insufficient sleep, head injury, depression, hypertension, and environmental factors (air pollution, aluminum, silicon, selenium, pesticides, lack of sunbathing, electric and magnetic fields). Recent animal and human studies point to a possible relationship between noise exposure and AD. The aim of this narrative review is to present basic pathological concepts of this relationship. Possible mediating factors that explain the influence of noise on AD are sleep disturbance, excitotoxicity, oxidative stress injury in the auditory cortex and hippocampus, and systemic inflammation. Studies on animals point to cognitive dysfunctions related to noise exposure: anxiety-like behavior, impaired learning and memory, increased glutamate levels in the hippocampus and reduced expression of N-methyl-D-aspartic acid receptor 2B. Neuropathological changes in animals exposed to noise include necrosis and apoptosis of hippocampal cells, accumulation of amyloid b, tau hyperphosphorylation and peroxidative damage in the hypothalamus and the auditory cortex, and the elevated expression of proinflammatory cytokines and microglial activation in the auditory cortex and hippocampus. Human brain scan studies have pointed to the positive relationship between traffic noise exposure and white matter volume in the body of the corpus callosum at the level of the auditory cortex. In conclusion, there is a biological plausibility of the noise-AD relationship, and noise countermeasures may be regarded as the prevention of AD.

Hepatic glycerol shunt and glycerol-3-phosphate phosphatase control liver metabolism and glucodetoxification under hyperglycemia

ObjectiveGlycerol-3-phosphate (Gro3P) phosphatase (G3PP) hydrolyzes Gro3P to glycerol that exits the cell, thereby operating a “glycerol shunt”, a metabolic pathway that we identified recently in mammalian cells. We have investigated the role of G3PP and the glycerol shunt in the regulation of glucose metabolism and lipogenesis in mouse liver. MethodsWe generated hepatocyte-specific G3PP-KO mice (LKO), by injecting AAV8-TBG-iCre to male G3PPfl/fl mice. Controls received AAV8-TBG-eGFP. Both groups were fed chow diet for 10 weeks. Hyperglycemia (16–20 mM) was induced by glucose infusion for 55 h. Hepatocytes were isolated from normoglycemic mice for ex vivo studies and targeted metabolomics were measured in mice liver after glucose infusion. ResultsLKO mice showed no change in body weight, food intake, fed and fasted glycemia but had increased fed plasma triglycerides. Hepatic glucose production from glycerol was increased in fasted LKO mice. LKO mouse hepatocytes displayed reduced glycerol production, elevated triglyceride and lactate production at high glucose concentration. Hyperglycemia in LKO mice led to increased liver weight and accumulation of triglycerides, glycogen and cholesterol together with elevated levels of Gro3P, dihydroxyacetone phosphate, acetyl-CoA and some Krebs cycle intermediates in liver. Hyperglycemic LKO mouse liver showed elevated expression of proinflammatory cytokines and M1-macrophage markers accompanied by increased plasma triglycerides, LDL/VLDL, urea and uric acid and myocardial triglycerides. ConclusionsThe glycerol shunt orchestrated by G3PP acts as a glucose excess detoxification pathway in hepatocytes by preventing metabolic disturbances that contribute to enhanced liver fat, glycogen storage, inflammation and lipid build-up in the heart. We propose G3PP as a novel therapeutic target for hepatic disorders linked to nutrient excess.

MicroRNA-31 mediated by interferon regulatory factor 7 signaling facilitates control of Mycobacterium tuberculosis infection

Tuberculosis (TB) induced by Mycobacterium tuberculosis (M. tuberculosis) infection remains a global most deadly infectious disease. While development of more effective TB vaccines and therapeutics relies on identifications of true biomarkers designating an immune protection against M. tuberculosis infection, exact protective immune components against M. tuberculosis infection remain largely unidentified. We previously found that severe TB induced remarkable up-regulation of interferon regulatory factor 7 (IRF7) and IRF7-related gene signatures, implicating that some unknown downstream molecules in IRF7 signaling cascades may determine the M. tuberculosis infection outcomes and serve as a protective immune component against M. tuberculosis infection. Indeed, here, we observe that genetic ablation of IRF7 leads to more severe lung pathology, increased M. tuberculosis burdens, impaired differentiation of effector/memory T subsets, and extensively elevated expression of pro-inflammatory cytokines in lungs. Importantly, IRF7 is vital for sustaining expression of PD-1/PD-L1 and PD-1/PD-L1-modulated miRNA-31. Moreover, interventions of miRNA-31 expressions via administration of miRNA-31 agomir reduces lung pathology and bacilli burdens via inducing up-regulation of gene sets involved in biological processes of defense response or cellular and chemical homeostasis in lungs. Thus, this study uncovers previously unrecognized importance and mechanisms of IRF7-mediated miRNA-31 as a protective immune component against M. tuberculosis infection.

Short-Term Administration of HIV Protease Inhibitor Saquinavir Improves Skull Bone Healing with Enhanced Osteoclastogenesis.

Using immunomodulatory methods to address the challenging issue of craniofacial bone repair may be a potentially effective approach. The protease inhibitor saquinavir has been shown to inhibit the inflammatory response by targeting the toll-like receptor 4/myeloid differentiation primary response complex. Independently, inhibition of toll-like receptor 4 or myeloid differentiation primary response led to enhanced skull bone repair. Therefore, the authors aimed to investigate the effects of saquinavir on skull bone healing. The effects of saquinavir on skull bone healing were assessed by means of gene expression, histology, immunohistochemistry, and tomography in a mouse calvarial defect model. Subsequently, the role of saquinavir in cell viability, migration, and osteogenic and osteoclastogenic differentiation was also evaluated in vitro. One-week saquinavir administration improved skull bone healing based on micro-computed tomographic and histomorphometric analyses. Compared to the vehicle control, 1-week saquinavir treatment (1) enhanced osteoclast infiltration (tartrate-resistant acid phosphatase staining) at day 7, but not at days 14 and 28; (2) induced more CD206 + M2 macrophage infiltration, but not F4/80 + M0 macrophages at days 7, 14, and 28; and (3) elevated osteoclastogenic gene RANKL (quantitative polymerase chain reaction) expression and other osteogenic and cytokine expression. Furthermore, in vitro data showed that saquinavir administration did not influence MC3T3-E1 cell migration or mineralization, whereas higher concentrations of saquinavir inhibited cell viability. Saquinavir treatment also enhanced the osteoclastic differentiation of bone marrow-derived precursors, and partially reversed high-mobility group box 1-driven osteoclastogenesis inhibition and elevated proinflammatory cytokine expression. The improved skull bone repair following short-term saquinavir treatment may involve enhanced osteoclastogenesis and modulated inflammatory response following skull injury. The authors' work demonstrates improved skull bone healing by short-term application of saquinavir, a drug traditionally used in the treatment of acquired immunodeficiency syndrome. As such, saquinavir may be repurposed for skeletal repair.

Preclinical evaluation of [18F]FDG-PET as a biomarker of lymphoid tissue disease and inflammation in Zika virus infection

PurposeZika (ZIKV) is a viral inflammatory disease affecting adults, children, and developing fetuses. It is endemic to tropical and sub-tropical countries, resulting in half the global population at risk of infection. Despite this, there are no approved therapies or vaccines against ZIKV disease. Non-invasive imaging biomarkers are potentially valuable tools for studying viral pathogenesis, prognosticating host response to disease, and evaluating in vivo efficacy of experimental therapeutic interventions. In this study, we evaluated [18F]fluorodeoxyglucose ([18F]FDG)-positron emission tomography (PET) as an imaging biomarker of ZIKV disease in a mouse model and correlated metabolic tracer tissue uptake with real-time biochemical, virological, and inflammatory features of tissue infection.Methods[18F]FDG-PET/CT imaging was performed in an acute, lethal ZIKV mouse infection model, at increasing stages of disease severity. [18F]FDG-PET findings were corroborated with ex vivo wholemount-tissue autoradiography and tracer biodistribution studies. Tracer uptake was also correlated with in situ tissue disease status, including viral burden and inflammatory response. Immune profiling of the spleen by flow cytometry was performed to identify the immune cell subsets driving tissue pathology and enhancing tracer uptake in ZIKV disease.ResultsFoci of increased [18F]FDG uptake were consistently detected in lymphoid tissues—particularly the spleen—of ZIKV-infected animals. Splenic uptake increased with disease severity, and corroborated findings in tissue pathology. Increased splenic uptake also correlated with increased viral replication and elevated expression of pro-inflammatory cytokines within these tissues. ZIKV-infected spleens were characterized by increased infiltration of myeloid cells, as well as increased proliferation of both myeloid and lymphoid cells. The increased cell proliferation correlated with increased tracer uptake in the spleen. Our findings support the use of [18F]FDG as an imaging biomarker to detect and track ZIKV disease in real time and highlight the dependency of affected tissue on the nature of the viral infection.Conclusion[18F]FDG uptake in the spleen is a useful surrogate for interrogating in situ tissue viral burden and inflammation status in this ZIKV murine model.

Persisting Microbiota and Neuronal Imbalance Following T. gondii Infection Reliant on the Infection Route.

Toxoplasma gondii is a highly successful parasite capable of infecting all warm-blooded animals. The natural way of infection in intermediate hosts is the oral ingestion of parasite-contaminated water or food. In murine experimental models, oral infection (p.o.) of mice with T. gondii is applied to investigate mucosal and peripheral immune cell dynamics, whereas intraperitoneal infection (i.p.) is frequently used to study peripheral inflammation as well as immune cell – neuronal interaction in the central nervous system (CNS). However, the two infection routes have not yet been systematically compared along the course of infection. Here, C57BL/6 mice were infected p.o. or i.p. with a low dose of T. gondii cysts, and the acute and chronic stages of infection were compared. A more severe course of infection was detected following i.p. challenge, characterized by an increased weight loss and marked expression of proinflammatory cytokines particularly in the CNS during the chronic stage. The elevated proinflammatory cytokine expression in the ileum was more prominent after p.o. challenge that continued following the acute phase in both i.p. or p.o. infected mice. This resulted in sustained microbial dysbiosis, especially after p.o. challenge, highlighted by increased abundance of pathobionts from the phyla proteobacteria and a reduction of beneficial commensal species. Further, we revealed that in the CNS of i.p. infected mice CD4 and CD8 T cells displayed higher IFNγ production in the chronic stage. This corresponded with an increased expression of C1q and CD68 in the CNS and reduced expression of genes involved in neuronal signal transmission. Neuroinflammation-associated synaptic alterations, especially PSD-95, VGLUT, and EAAT2 expression, were more pronounced in the cortex upon i.p. infection highlighting the profound interplay between peripheral inflammation and CNS homeostasis.

Immune-related adverse events and symptom burden in patients with melanoma receiving adjuvant immune checkpoint inhibitor.

TPS12147 Background: Adjuvant therapy with immune checkpoint inhibitors (ICIs) is approved for melanoma, but immune-related adverse events (irAEs) remain a challenge. Although acute toxicities are well defined, long-term AEs and impact on quality of life (QOL) are undetermined. Available data derived from clinical trials involve highly selected populations and do not reflect real world experience. Additionally, trials measure outcomes only at predetermined endpoints, and symptoms may vary throughout the course of therapy. Moreover, the pathogenesis of irAEs and symptoms remains poorly understood. We hypothesize that AEs and sustained inflammation induced by adjuvant ICIs increase symptom burden and negatively impact function and QOL in a subset of patients (pts), and elevated expression of pro-inflammatory cytokines and T cell signatures during therapy correlate with toxicity and symptom burden. Our preliminary data identified i) interleukin-6/Th-17 pathway as a possible mediator of irAEs, ii) immune reactivity and increases in inflammatory cytokines are associated with symptom burden in cancer survivors, and iii) prioritized 30 genetic markers conferring risk for irAEs in ICI-treated melanoma pts. Methods: This is a prospective longitudinal cohort study to evaluate potential toxicity/symptom burden and immune correlates in melanoma pts receiving adjuvant ICIs (NCT04990726). A total of 240 pts will be enrolled. Eligibility criteria: age ≥18 years (yrs), surgically resected stage II, III, or IV melanoma, initiating adjuvant nivolumab or pembrolizumab, no prior systemic therapy for melanoma, and no prior autoimmune diseases. Patients will be assessed at baseline (before ICI infusion) and every 3 months (mos) up to 2 yrs or until attrition or death. The primary endpoint is the incidence rate of any irAEs at 12 mos. Demographics, personal/family history, comorbidities, tumor history/stage, prior therapies, performance status, concurrent medications, and other factors that play a role in pts perceptions of disease are collected. At each visit, pts undergo a clinical evaluation to assess potential irAEs, new comorbidities, and tumor recurrence. Patient-reported outcomes of fatigue, depression, sleep disturbance, and QOL are collected at each visit to assess changes from baseline up to 2 yrs. In addition to standard methods of data collection at pre-specified times, we leverage mobile technology to capture symptoms and AEs in real time. Longitudinal blood samples will characterize pts immune signatures from baseline up to 2 yrs to evaluate their association with irAEs, symptom burden, and QOL, and to compare the genotype of pts with and without irAEs. To characterize the effect of adjuvant ICI on bone health, eligible pts are evaluated by whole body dual-energy X-ray absorptiometry at baseline and at 12 mos as an exploratory aim. The study is currently active, and 27 pts are enrolled. Clinical trial information: NCT04990726.

Endogenous Type I interferon signaling plays a pivotal role in restricted SARS-CoV-2 infection in human ACE2 transgenic mice

Abstract Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become pandemic, resulting in severe morbidity and mortality around the world. COVID-19 pathogenesis includes lung inflammation, cytokine storm and organ failures, but the mechanism underlying the disease remains to be studied. To determine what role(s) the well-characterized type I interferon (IFN-I)-mediated innate antiviral responses might play against SARS-CoV-2 infection, we treated hACE2 transgenic (Tg) mice, AC70 line, with mouse IFN-I receptor-specific monoclonal antibody prior to challenge with 106TCID50 of SARS-CoV-2 (US-WA-1/2020). Both IFN-blocked and-unblocked animals developed clinical signs of disease with body weight loss from day 3 and 100% mortality between 4 and 5 days post-infection with SARS-CoV-2 at high dose (106 TCID50). Although live virus was detected in the lungs and brain of both groups, live virus was detected only in the kidneys, liver, spleen, heart, and gastrointestinal tract of the IFN-blocked group. Elevated expression of proinflammatory cytokines and interferons including IFN-λ were detected in all organs tested in both groups. Immunostaining for SARS-CoV-2 spike protein along with profound histopathological observations in the lungs and brain of both groups show severe COVID-19 disease pathogenesis. Our results show that AC70 Tg mice are highly permissive to SARS-COV-2 infection and develop severe COVID-19. Furthermore, we show type I IFN-mediated signaling pathways play a critical role in restricting viral spread and are ideal for development of medical countermeasures (MCMs) against COVID-19.