Incomplete Killing And Enhanced Activation of Islet-Reactive CD8+ T Cells by FasL-Expressing Dendritic Cells Limits Protection from Diabetes

AIMS: Autologous dendritic cells (DC) are a promising tool for induction of cytotoxic CD8+ T cell immunity against tumors and chronic viral infections. When armed with the death-inducing Fas-ligand (FasL, CD195), DC attenuate delayed-type hypersensitivity reactions and allotransplant rejection by promoting activation-induced cell death in T cells. We investigated the possibility of using FasL-expressing DC to induce deletion of islet-reactive CD8+ T cells in vivo, and to prevent destruction of pancreatic islets in a model of autoimmune diabetes. METHODS: DC, propagated from mouse bone marrow cells, were purified and made to express FasL and islet-antigen via plasmid transfection. CD8+ T cells (OT-I cells) recognizing the antigen, ovalbumin, were adoptively transferred to transgenic mice expressing ovalbumin in islets (RIP-OVAlo mice), and these mice were primed with ovalbumin. To test the potential of DC to prevent diabetes in this model, the mice were later intravenously vaccinated with the transfected DC. RESULTS: Transfected DC induced partial deletion of antigen-reactive CD8+ T cells in vivo and reduced the level of lymphocyte infiltration into pancreatic islets. Diabetes developed less frequently in vaccinated mice, but this effect was limited. Further in vitro analysis showed that FasL-expressing DC not only deleted many of the responding CD8+ T cells but also promoted the expansion of surviving cells and their IFN-? production. CONCLUSIONS: FasL-expressing DC can also have stimulatory effects on CD8+ T cells warranting further investigation into the optimal design of tolerance-promoting DC-vaccination to prevent autoimmune diabetes

Novel Biomarkers for Diagnosing Periprosthetic Joint Infection from Synovial Fluid and Serum

Background:Synovial fluid bacterial culture is the cornerstone of confirmation or exclusion of periprosthetic joint infection (PJI). The aim of this study was to assess synovial fluid and serum biomarker patterns of patients with total joint arthroplasty (TJA), and the association of these patterns with PJI.Methods:Synovial fluid and serum samples were collected from 35 patients who were admitted to the Arthroplasty Unit of the Department of Orthopaedics and Traumatology at Turku University Hospital. Of the 25 patients who were included in the study, 10 healthy patients with an elective TJA for osteoarthritis served as the control group, and 15 patients who were admitted due to clinical suspicion of PJI with local redness, swelling, wound drainage, pain, and/or fever and who had a positive synovial fluid bacterial culture served as the study group. Logistic regression was used to assess the ability of 37 biomarkers (including cytokines, chemokines, and growth factors) with commercially available tests to detect PJIs.Results:In synovial fluid, the concentrations of sTNF-R1 and sTNF-R2 (soluble tumor necrosis factor receptors 1 and 2) and BAFF (B-cell activating factor, also known as TNFSF13B) were significantly higher in the PJI group (p Conclusions:Synovial sTNF-R2 is a promising new biomarker for detecting PJI. We are not aware of any previous reports of the use of sTNF-R2 in PJI diagnosis. More research is needed to assess the clinical importance of our findings.Level of Evidence:Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.</p

Circulating cytokines in predicting development of severe acute pancreatitis

Peer reviewe

Maternal tiredness and cytokine concentrations in mid-pregnancy

Objective: Sleep disturbances relate to altered levels of inflammatory mediators in general population, but not much is known about the associations between sleep disturbances and inflammatory mediators during pregnancy. The present exploratory study investigated whether insomnia, tiredness, general sleep quality, and insufficient sleep duration during pregnancy relate to the concentrations of maternal peripheral circulating cytokines. As sleep disturbances are frequently observed in mood disorders, the results were controlled for symptoms of depression and anxiety. Methods: 137 participants were randomly drawn from a representative FinnBrain Birth Cohort. Serum concentrations of selected cytokines were analyzed using Multiplex bead arrays from blood samples drawn at the gestational week 24. The sleep disturbances were evaluated using the Basic Nordic Sleep Questionnaire. Depressive and anxiety symptoms were measured with the Edinburgh Postnatal Depression Scale and the anxiety subscale of the self-rated Symptom Checklist 90, respectively. Results: Enhanced tiredness was associated with cytokine concentrations of IL-2, IL-10, IL-12, IL-13, and TNF-alpha. The observed associations resembled a reversed U-shaped curve rather than being linear. Having a good general sleep quality was associated with higher logarithmic cytokine concentrations of IL-2, IL-4, IL-6, IL-10, IL-12, IL-13, and IFN-gamma. There was no evidence for associations between insomnia or sleep loss and cytokines. Conclusions: Maternal subjective tiredness and good general sleep quality were associated with altered levels of immunological markers during pregnancy. The association was independent from symptoms of depression and anxiety.Peer reviewe

Nonclinical Characterization of Bexmarilimab, a Clever-1-Targeting Antibody for Supporting Immune Defense Against Cancers

Common lymphatic endothelial and vascular endothelial receptor-1 (Clever-1) is a multifunctional type-1 transmembrane protein that plays an important role in immunosuppression against tumors. Clever-1 is highly expressed in a subset of human tumor-associated macrophages and associated with poor survival. In mice, Clever-1 supports tumor growth and metastasis formation, and its deficiency or blockage induces T-cell-dependent killing of cancer cells. There-fore, targeting Clever-1 could lead to T-cell activation and restoration of immune response also in patients with cancer. This is studied in an on-going clinical trial [Macrophage Antibody To INhibit immune Suppression (MATINS); NCT03733990] in patients with advanced solid tumors where bexmarilimab, a humanized IgG4 antibody against human Clever-1, shows promising safety and efficacy. Here, we report the humanization and nonclinical characterization of physicochemical properties, biological potency, and safety profile of bexmarilimab. Bexmarilimab showed high affinity to Clever-1 on KG-1 cells and bound to Clever-1 on the surface of classical and intermediate monocytes derived from healthy human blood. Bexmarilimab inhibited the internalization of its natural ligand acetylated low -density lipoprotein into KG-1 cells and increased TNF alpha secretion from macrophages but did not impair phagocytic clearance. Bex-marilimab did not induce significant cytokine release in human whole-blood cultures, did not contain nonsafe immunogenic gly-cans, or show any significant binding to human Fcy receptors or complement pathway component C1q. In vivo , bexmarilimab showed dose-dependent duration of monocyte Clever-1 receptor occupancy in cynomolgus monkeys but did not induce a cytokine storm up to a dose of 100 mg/kg. In conclusion, these data support the clinical development of bexmarilimab for the restoration of immune response in cancers

Soluble CD73 in Critically Ill Septic Patients Data from the Prospective FINNAKI Study

Background CD73 dephosphorylates adenosine monophosphate to adenosine that is an anti-inflammatory molecule inhibiting immune activation and vascular leakage. Therefore, CD73 could be an interesting mediator both in sepsis and acute kidney injury (AKI). We aimed to explore the soluble CD73 (sCD73) levels and their evolution in critically ill patients with severe sepsis and, second, to scrutinize the potential association of sCD73 levels with AKI and 90-day mortality. Methods This was a post-hoc laboratory analysis of the prospective, observational FINNAKI study conducted in 17 Finnish ICU during 5 months in 2011-2012. Plasma samples of 588 patients admitted with severe sepsis/shock or with developing severe sepsis were analyzed at 0h (ICU admission) and 24h, and additionally, on day 3 or day 5 from a subset of the patients. Results The median [IQR] sCD73 levels at 0h were 5.11 [3.29-8.28] ng/mL and they decreased significantly from 0h to 4.14 [2.88-7.11] ng/mL at 24h, P Conclusions Compared to normal population, the sCD73 levels were generally low at 0h, showed a decrease to 24h, and later an increase by day 5. The sCD73 levels do not seem useful in predicting the development of AKI or 90-day mortality among patients with severe sepsis or shock.Peer reviewe

Consequences of the Lack of CD73 and Prostatic Acid Phosphatase in the Lymphoid Organs

CD73, ecto-5&#39;-nucleotidase, is the key enzyme catalyzing the conversion of extracellular AMP to adenosine that controls vascular permeability and immunosuppression. Also prostatic acid phosphatase (PAP) possesses ecto-5&#39;-nucleotidase/AMPase activity and is present in leukocytes. However, its role related to immune system is unknown. Therefore, we analyzed enzymatic activities and leukocyte subtypes of CD73 and PAP knockouts and generated CD73/PAP double knockout mice to elucidate the contribution of CD73 and PAP to immunological parameters. Enzymatic assays confirmed the ability of recombinant human PAP to hydrolyze [H-3] AMP, although at much lower rate than human CD73. Nevertheless, 5&#39;-nucleotidase/AMPase activity in splenocytes and lymphocytes from PAP(-/-) mice tended to be lower than in wild-type controls, suggesting potential contribution of PAP, along with CD73, into lymphoid AMP metabolism ex vivo. Single knockouts had decreased number of CD4(+)/CD25(+)/FoxP(3)(+) regulatory T cells in thymus and CD73/PAP double knockouts exhibited reduced percentages of CD4(+) cells in spleen, regulatory T cells in lymph nodes and thymus, and CD4(+) and CD8(+) cells in blood. These findings suggest that PAP has a synergistic role together with CD73 in the immune system by contributing to the balance of leukocyte subpopulations and especially to the number of regulatory T cells in lymph nodes and thymus.</p

The Role of Inflammatory Cytokines as Intermediates in the Pathway from Increased Adiposity to Disease

Objective This study aimed to investigate the role of cytokines as intermediates in the pathway from increased adiposity to disease.Methods BMI and circulating levels of up to 41 cytokines were measured in individuals from three Finnish cohort studies (n = 8,293). Mendelian randomization (MR) was used to assess the impact of BMI on circulating cytokines and the impact of BMI-driven cytokines on risk of obesity-related diseases. Results Observationally, BMI was associated with 19 cytokines. For every SD increase in BMI, causal effect estimates were strongest for hepatocyte growth factor, monocyte chemotactic protein-1 (MCP-1), and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and were as ratios of geometric means 1.13 (95% CI: 1.08-1.19), 1.08 (95% CI: 1.04-1.14), and 1.13 (95% CI: 1.04-1.21), respectively. TRAIL was associated with a small increase in the odds of coronary artery disease (odds ratio: 1.03; 95% CI: 1.00-1.06). There was inconsistent evidence for a protective role of MCP-1 against inflammatory bowel diseases.Conclusions Observational and MR estimates of the effect of BMI on cytokine levels were generally concordant. There was little evidence for an effect of raised levels of BMI-driven cytokines on disease. These findings illustrate the challenges of MR when applied in the context of molecular mediation.</p