ELISA Measurements Research Articles

Development of Cell-Assembled Human Endomysial-Type Biomatrix Substrate for the Detection of Celiac Disease Autoantibodies

The endomysial antibody (EMA) immunofluorescent test is a highly specific method to detect disease-specific autoantibodies in celiac disease (CD) by their binding to natural transglutaminase-2 autoantigen in tissue sections, and it is used as a compulsory confirmatory test in the non-invasive diagnosis of CD. The classical EMA substrates are the monkey esophagus and the human umbilical cord. It is increasingly difficult to use these tissues due to ethical concerns and animal welfare regulations. In this study, we developed, in cell culture, an endomysium-type extracellular biomatrix assembled by human umbilical cord vein-derived endothelial cells which binds CD antibodies in a similar pattern as monkey esophagus and has similar macromolecular composition. Evaluating retrospectively and prospectively tested patient cohorts, including 130 CD cases and 105 non-celiac controls, IgA-class celiac antibody detection on the biomatrix was equally specific (100%) as EMA testing on tissues, and had higher sensitivity (95.6% versus 91.2%). Both EMA tests were less sensitive, but more specific than transglutaminase-based ELISA measurements. The decellularization of the biomatrix improved sensitivity, enabled the detection of IgG-class celiac antibodies, and allowed for simple reading without previous training. This easily available cell-assembled biomatrix substrate may replace substrate tissues in diagnostic EMA testing in the future.

Qinggan Yipi capsule ameliorates hepatic fibrosis in rats by down-regulating the TGF-β1/Smad2/3 signaling pathway and improving gut microbiota imbalance

Background and objectiveQinggan Yipi Capsule (QgYp) is a hospital preparation that has been used for many years in the treatment of chronic liver diseases. However, the mechanism of QgYp in ameliorating hepatic fibrosis (HF) remains unclear. This study aims to clarify the anti-liver fibrosis effect of QgYp and its mechanism of action.MethodsThis study uses a carbon tetrachloride (CCl4) induced HF rat model and TGF-β1 stimulated HSC-T6 cell line (rat HSCs) as experimental models. The therapeutic effects were evaluated through pathology, biochemical tests, and ELISA. The therapeutic mechanism of QgYp for HF was predicted through network pharmacology. The expression of TGF-β1/Smad2/3 related proteins was detected by qPCR analysis and Western blot analysis. The composition of the gut microbiota was analyzed using 16S rRNA gene sequencing.ResultsHistopathological analysis, serum biochemical tests, and ELISA measurements showed that QgYp effectively decreased the levels of ALT, AST, HA, LN, PCIII, and IV-C while improving collagen deposition and hepatocyte necrosis. Protein-protein interaction (PPI) network analysis screened HF-related genes, including peroxisome proliferator-activated receptor gamma (PPARG), tumor necrosis factor (TNF), and TGF-β1. GO and KEGG analyses indicated that QgYp significantly affects TGF-β signaling pathway. In addition, the results of qPCR and Western blot analysis from both in vitro and in vivo experiments indicated that QgYp significantly downregulated the expression of proteins and mRNA associated with the TGF-β1/Smad2/3 pathway. The 16S rDNA gene sequencing results showed that QgYp can increase the diversity and richness of the gut microbiota in HF rats and alter the composition of the gut microbiota.ConclusionQgYp could effectively ameliorate HF, and this effect might be connected to the downregulation of the TGF-β1/Smad2/3 pathway, the suppression of HSCs activation, and regulation of gut microbiota dysbiosis.

Inhibition of Neospora caninum activity by niclosamide: Evidence from in vitro and in vivo studies

Neosporosis caused by Neospora caninum (N. caninum) is one of the main causes of bovine miscarriage, but there are currently no effective drugs or vaccines for treatment and prevention. Our previous works have found that NLRP3 inflammasome activation participated in controlling N. caninum proliferation and niclosamide has been regarded as an NLRP3 inflammasome inducer. This study aimed to evaluate the resistance of niclosamide to N. caninum infection. Niclosamide-mediated NLRP3 inflammasome activation was determined by LDH and ELISA measurement of IL-1β release as a marker for inflammasome activation in a model of N. caninum-infected macrophages. The in vitro antiparasitic effect of niclosamide was further explored in Vero cells by plaque assays, qPCR, and Giemsa staining. The in vivo effects were investigated in N. caninum-infected mice by measuring parasite burden, histopathology, and survival. Results showed that niclosamide partially enhanced macrophage-mediated clearance of N. caninum via the NLRP3 inflammasome activation and displayed direct antiparasitic activity. Plaque assays confirmed significant inhibition of N. caninum growth, and niclosamide effectively reduced cell invasion and intracellular proliferation compared to toltrazuril. In vivo, after niclosamide treatment, the body weight was regained, survival rate was increased, tissue damage was reduced, and parasite burden in tissues was significantly decreased. The numerous vacuole formations were observed in niclosamide-treated N. caninum tachyzoites by electron microscopy. Mitochondrial membrane potential and ATP production of N. caninum tachyzoites were reduced considerably by niclosamide treatment. In conclusion, niclosamide showed strong potential as a therapeutic agent for N. caninum infection, offering a promising treatment option for neosporosis.

MiR-99a-5p up-regulates LDLR and functionally enhances LDL-C uptake via suppressing PCSK9 expression in human hepatocytes.

MicroRNAs (miRs/miRNAs) play pivotal roles in modulating cholesterol homeostasis. Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to low-density lipoprotein receptor (LDLR) at the surface of hepatocytes and accelerates its degradation in lysosomes, thereby impairing the clearance of circulating low-density lipoprotein cholesterol (LDL-C) from plasma. Thus, suppressing PCSK9 expression level has become an effective approach for treating hypercholesterolemia. Here, we sought to identify novel miRNAs that inhibit PCSK9 expression. By in silico analyses, miR-99a-5p was predicted to bind to human PCSK9 mRNA. Following transfection of miR-99a-5p or anti-miR-99a-5p in human and mouse hepatocytes, qRT-PCR, Western blot, immunofluorescence, ELISA, flow cytometry, LDL-C uptake, and cellular cholesterol measurement were performed. miR-99a-5p overexpression potently inhibited PCSK9 expression, thereby up-regulating LDLR, functionally enhancing LDL-C uptake and increasing intracellular cholesterol levels in human, but not in mouse, cells. Conversely, anti-miR-99a-5p upregulates PCSK9, leading to a reduction in LDLR, attenuation of LDL-C uptake, and a decrease in the intracellular cholesterol levels of human hepatocytes. Furthermore, miR-99a-5p was shown to bind to the predicted target site "UACGGGU" in the 3'-UTR of human PCSK9 mRNA via a luciferase reporter assay in combination with site-directed mutagenesis. MiR-99a-5p potently downregulates the expression of PCSK9 by directly interacting with a target site in the human PCSK9 3'-UTR, thereby up-regulating LDLR and functionally enhancing LDL-C uptake in human hepatocytes. MiR-99a-5p could serve as an inhibitor of PCSK9 for treating hypercholesterolemia to inhibit atherosclerosis.

Decursin protects against DSS-induced experimental colitis in mice by inhibiting the cGAS-STING signaling pathway.

While studies have shown that Angelica gigas Nakai (A. gigas) can alleviate ulcerative colitis in mice, the therapeutic role of its main active ingredient, decursin, is uncertain. Therefore, we aimed to investigate the protective effect and mechanism of decursin against inflammatory bowel disease (IBD) in vivo using mice. IBD was simulated via induction with 3% dextran sodium sulfate (DSS), with or without daily treatment with decursin (10 mg/kg or 20 mg/kg) or 5-amino salicylic acid (5-ASA; 100 mg/kg) for 14 days. Mice were weighed and monitored daily for disease activity index (DAI) scoring. Colon tissues were collected for histopathological staining analysis, and serum was collected for ELISA measurement of proinflammatory cytokines. Western blotting was employed to analyze colonic expression levels of the tight junction-related proteins ZO-1, Occludin, and Claudin 1, as well as cGAS-STING signaling pathway-associated proteins. The expression levels of major proteins were verified using immunohistochemistry and immunofluorescence. Compared with the control group, DSS-induced mice showed decreased body weight, increased DAI scores, shortening of the colon, disrupted colon tissue structure, increased serum levels of proinflammatory cytokines, increased expression of factors involved in activating the cGAS-STING signaling pathway, and reduced expression of ZO-1, Occludin, and Claudin 1. Under decursin treatment, the pathological state of IBD was less severe, proinflammatory factors were downregulated, and activation of the cGAS-STING signaling pathway was inhibited. Our findings indicate that decursin helps restore the intestinal mucosal barrier and prevents activation of the cGAS-STING signaling cascade, alleviating experimental IBD in mice.

Decreased Insulin and Interleukin-6 Levels in Rattus Norvegicus Model of Polycystic Ovary Syndrome-Insulin Resistance Treated with a High Protein Diet

Hypercaloric in women of childbearing age is one of the causes of polycystic ovary syndrome (PCOS) with insulin resistance. Increased inflammation (tumor factor necrosis-α (TNF-α) and interleukin-6 (IL-6)) is the impact of endocrine and metabolic disorders involved due to metabolic syndrome, obesity, and diabetes mellitus. This study aims to evaluate whether a high-protein diet can reduce insulin and interleukin-6 levels, which are key indicators of polycystic ovary syndrome, and whether these changes can help in the treatment of the syndrome. This study used a prepost test only control design, true experimental, with a total sample of 6 female Rattus norvegicus rats aged 2–3 years (150–200 g). It consists of 4 groups, namely the negative control group (K-), the positive control group (K+), the treatment group (P), and the group without treatment (P-). The study examined the rat blood serum ELISA measurement of insulin and IL-6 levels. Anova test results of IL-6 levels (p = 0.002). Post-hoc test results of group K- and group P (p = 0.002), group K + and group P (p = 0.037), group K- and group K + (p = 0.437). The Anova test results of insulin levels between groups found a significant difference (p = 0.001). Post-hoc test of insulin levels of group K- and group P (p = 0.002), group K- and group K+ (p = 0.000), and group K+ with group P (p = 0.356). In group K and group P, the results of the ANOVA and post hoc tests on IL-6 levels and insulin levels with the provision of a high-protein diet show significant differences. This study suggests that a high-protein diet may be an effective therapeutic alternative in reducing the symptoms of polycystic ovary syndrome, especially in controlling high insulin and interleukin-6 levels.

AIMP2 accumulation in brain leads to cognitive deficits and blood secretion in Parkinson’s disease

BackgroundPropagation of neuronal α-synuclein aggregate pathology to the cortex and hippocampus correlates with cognitive impairment in Parkinson’s disease (PD) dementia and dementia with Lewy body disease. Previously, we showed accumulation of the parkin substrate aminoacyl-tRNA synthetase interacting multifunctional protein-2 (AIMP2) in the temporal lobe of postmortem brains of patients with advanced PD. However, the potential pathological role of AIMP2 accumulation in the cognitive dysfunction of patients with PD remains unknown.MethodsWe performed immunofluorescence imaging to examine cellular distribution and accumulation of AIMP2 in brains of conditional AIMP2 transgenic mice and postmortem PD patients. The pathological role of AIMP2 was investigated in the AIMP2 transgenic mice by assessing Nissl-stained neuron counting in the hippocampal area and Barnes maze to determine cognitive functions. Potential secretion and cellular uptake of AIMP2 was monitored by dot blot analysis and immunofluorescence. The utility of AIMP2 as a new PD biomarker was evaluated by dot blot and ELISA measurement of plasma AIMP2 collected from PD patients and healthy control followed by ROC curve analysis.ResultsWe demonstrated that AIMP2 is toxic to the dentate gyrus neurons of the hippocampus and that conditional AIMP2 transgenic mice develop progressive cognitive impairment. Moreover, we found that neuronal AIMP2 expression levels correlated with the brain endothelial expression of AIMP2 in both AIMP2 transgenic mice and in the postmortem brains of patients with PD. AIMP2, when accumulated, was released from the neuronal cell line SH-SY5Y cells. Secreted AIMP2 was taken up by human umbilical vein endothelial cells. Consistent with the fact that AIMP2 can be released into the extracellular space, we showed that AIMP2 transgenic mice have higher levels of plasma AIMP2. Finally, ELISA-based assessment of AIMP2 in plasma samples from patients with PD and controls, and subsequent ROC curve analysis proved that high plasma AIMP2 expression could serve as a reliable molecular biomarker for PD diagnosis.ConclusionsThe pathological role in the hippocampus and the cell-to-cell transmissibility of AIMP2 provide new therapeutic avenues for PD treatment, and plasma AIMP2 combined with α-synuclein may improve the accuracy of PD diagnosis in the early stages.

A-346 Evaluating 14-3-3η Detection in Finger Prick Blood Using Lateral Flow Technology: Advancing Clinical Laboratory Diagnostics

Abstract Background The protein 14-3-3η is a critical biomarker in the diagnosis and monitoring of autoimmune rheumatologic disorders, and its early detection is pivotal for patient outcomes. Previous research has established the significance of 14-3-3η as a biomarker, particularly in inflammatory polyarthritis, as well as patients’ and physicians’ interest in near-patient testing. While 14-3-3η is traditionally measured in serum via ELISA, this study explores the innovative use of lateral flow technology (LFT) for its detection in finger prick blood, addressing the urgent need for near-patient testing.This research aims to evaluate the technical and clinical performance of 14-3-3η measurement using LFT in comparison to standard ELISA methods, with an emphasis on its detectability in finger prick blood. Methods This study included two phases of testing involving patient serum and spiked whole blood. In the serum phase, 53 samples (19 NEG, ≤0.19 ng/mL, and 34 POS, 0.27 to 28 ng/mL 14-3-3η) were tested using LFT. LFT results were compared to JOINTstat® ELISA measurements for concordance. For whole blood, recombinant 14-3-3η and ELISA-positive serum samples were spiked into whole blood at increasing concentrations (0.4 to 3.2 ng/mL) and tested with LFT. Concordance criteria included visual inspection of test and control lines, with results captured and analyzed using a reference key card. The study was extended to assess 14-3-3η levels in consented patients with 22 matched finger prick and venous serum samples​​. Results In serum testing, LFT demonstrated 100% positivity in detecting 14-3-3η for POS samples. Among NEG samples, 85% tested negative, with 15% positive, indicating a strong concordance between LFT and ELISA. The LFT's ability to semi-quantitatively measure 14-3-3η was confirmed by a significant Kruskal-Wallis test (p<0.0001) across four intensity groups. In whole blood testing, LFT correctly identified all samples spiked at concentrations ≥0.5 ng/mL. The Spearman correlation showed a strong and significant association (r=0.96 to 0.98, p=0.001) between LFT test line intensity and spiked 14-3-3η levels. Finally, the equivalence testing for finger prick and venous serum samples affirmed the LFT’s reliability, with a strong correlation (p<0.0001), underscoring its potential for near-patient testing​​. Conclusions The study validates LFT as a reliable and semi-quantitative method for detecting 14-3-3η in finger prick blood, demonstrating strong concordance with traditional ELISA measurements. The findings support the feasibility of LFT in near-patient testing for early detection, prognosis, and monitoring of autoimmune diseases, paving the way for enhanced patient accessibility. Future research will focus on integrating this technology into routine clinical care and examining its impact on patient management and outcomes.

Correlation between prognosis and peripheral blood levels of NLRP3 and triglyceride-glucose index after myocardial ischemia-reperfusion injury

ObjectiveWe aim to investigate the association between prognosis and outcomes following myocardial ischemia-reperfusion injury, as well as peripheral blood levels of NLRP3 and the triglyceride-glucose index (TyG).MethodsA total of 100 patients who underwent emergency coronary intervention following myocardial infarction confirmed by coronary angiography at our hospital between October 2021 and May 2023 were included in this study. Patients were stratified into two groups based on their prognoses: the control group (n = 73), which did not experience new myocardial infarctions or require hospitalization for heart failure or suffer sudden cardiac death post-interventional treatment; and the observation group (n = 27), which experienced one or more cardiovascular events post-treatment. Patient demographics were obtained from clinical records while biochemical analyses assessed peripheral blood triglycerides, blood glucose levels, and TyG index. Additionally, ELISA measurements determined levels of NLRP3 as well as inflammatory factors IL-6, TNF-α, and CRP in peripheral blood samples. Cardiac function was evaluated according to NYHA standards. Univariable Cox regression analysis identified factors influencing patient prognosis while Pearson correlation analysis examined relationships among prognosis, outcomes following myocardial ischemia-reperfusion injury, TyG index, and peripheral blood NLRP3.ResultsNo significant differences were observed in the general characteristics between the two patient groups (P > 0.05). However, the observation group exhibited higher levels of peripheral blood triglycerides, blood glucose, and TyG index compared to the control group (P < 0.05). Additionally, levels of NLRP3 and inflammatory factors IL-6, TNF-α, and CRP were elevated in the observation group compared to the control group (P < 0.05). Cardiac function impairment was more pronounced in the observation group (P < 0.05). Notably, TyG index and peripheral blood NLRP3 demonstrated higher risk ratios compared to other biomarkers (P < 0.05), indicating their significance in prognosis and outcomes. Elevated levels of NLRP3 and TyG index were associated with poorer recovery of cardiac function, increased rehospitalization rates, and higher mortality (P < 0.05).ConclusionElevated NLRP3 levels and an increased TyG index are strongly associated with impaired cardiac function and heightened risk of cardiovascular events. These findings suggest that these biomarkers may serve as crucial prognostic indicators following myocardial ischemia-reperfusion injury.

Capillary mediated vitrification is a novel technique that enables storage of antibody critical reagents at ambient temperature: Impact on binding, structure, and laboratory sustainability

Antibodies and antibody conjugates are essential components of life science research, but their inherent instability necessitates cold storage or lyophilization, posing logistical and sustainability challenges. Capillary-mediated vitrification has shown promise as a tool for improving biomolecule stability. In this study, we assess the feasibility of shipping and storing CMV-stabilized antibody reagents at ambient temperature using a purified rabbit polyclonal as a model system. The conditions tested included a simulated temperature excursion, ambient shipping, and storage for approximately two months at room-temperature. Antibody function was measured by both ELISA and Octet bio-layer interferometry kinetic measurements. Yield, aggregation, and thermal stability were assessed by UV/VIS, Size Exclusion Chromatography (SEC), thermal melting, and thermal aggregation studies. Results indicate >97 % protein yield and no impact on the binding activity. No evidence of aggregation or oligomer formation was detected. Addition of the vitrification buffer to the sample matrix resulted in an increase in the aggregation on-set temperature, indicating enhanced thermostability. A slight shift in both the SEC retention time for the main peak and a difference in aggregation behavior at high temperatures were noted post-vitrification. We hypothesize that these differences are related to the interaction of the protein with the saccharide component of the vitrification matrix and the stabilization mechanism of sugars. The cumulative data supports the use of Capillary Mediated Vitrification as a viable alternative to frozen reagent storage, with the potential to significantly impact reagent stability, assay performance, laboratory operations, and sustainability initiatives.

Identification of Catecholamine and Drug Target α2A-Adrenoceptor in Human Testis and Human Testicular Peritubular Cells.

Background: Clonidine has been used in clinical medicine, e.g., to treat high blood pressure and other conditions. Animal studies have linked its use to impairments of male reproductive functions, and although only a few reports exist for the human species, such actions may exist in man as well. The underlying reasons and, specifically, possible actions of clonidine at the level of the testis are not known. Introduction: Clonidine is an agonist at the α2A-adrenoceptor (ADRA2A), which, as data bank mining indicated, is expressed by several cells of the human testis. The human testis and most of its cells are, however, not readily accessible to experimental testing. Cells from the peritubular wall compartment (human testicular peritubular cells; HTPCs) are the exception. Methods and Results: As shown by immunohistochemical/immunocytochemical and PCR techniques these cells express ADRA2A and retain expression upon isolation and culture. When tested over a concentration range (1-1000 µM) and 24 h, clonidine did not visibly affect HTPC morphology but significantly stimulated IL6 mRNA levels in a concentration-dependent manner. ELISA measurements of cell culture supernatants confirmed a stimulatory action of clonidine (10 µM) on secreted IL6. When examined in collagen gel contraction assays of HTPCs, clonidine (10 µM) exerted a slight relaxing action, while a proteomic study revealed that clonidine (10 µM) did not significantly change cellular protein abundance of HTPCs after 24 h (data available via ProteomeXchange with identifier PXD052220). Conclusion: Thus, ADRA2A-bearing cells in the human testis are targets for catecholamines and drugs such as clonidine. The results of this HTPCs-focused study only show the tip of the iceberg. It is likely that catecholamines/catecholaminergic drugs have the potential to interfere with human testicular functions.

Identification of Pathogenic Pathways for Recurrence of Focal Segmental Glomerulosclerosis after Kidney Transplantation.

Primary focal segmental glomerulosclerosis (FSGS) is a disease of the podocytes and glomerulus, leading to nephrotic syndrome and progressive loss of renal function. One of the most serious aspects is its recurrence of disease in over 30% of patients following allogeneic kidney transplantation, leading to early graft loss. This research investigates the individual genetic predispositions and differences in the immune responses leading to recurrence of FSGS after transplantation. We performed exome sequencing on six patients with recurrent FSGS to identify variants in fifty-one genes and found significant variations in the alpha-2-macroglobulin (A2M). Immunoblotting was used to investigate effects of specific gene variants at the protein level. Further expression analysis identified A2M, exophilin 5 (EXPH5) and plectin (PLEC) as specific proteins linked to podocytes, endothelial cells, and the glomerulus. Subsequent protein array screening revealed the presence of non-HLA-specific antibodies, including TRIM21, after transplantation. Using Metascape for pathway and process enrichment analysis, we focused on the IL-17 signaling and chemotaxis pathways. ELISA measurements showed significantly elevated IL-17 levels in patients with recurrent FSGS (32.30 ± 9.12 pg/mL) compared to individuals with other glomerular diseases (23.16 ± 2.49 pg/mL; p < 0.01) and healthy subjects (22.28 ± 0.94 pg/mL; p < 0.01), with no significant difference in plasma CCL2/MCP-1 levels between groups. This study explores the molecular dynamics underlying recurrence of FSGS after transplantation, offering insights into potential biomarkers and therapeutic targets for the future development of individualized treatments for transplant patients.

Unraveling shared molecular signatures and potential therapeutic targets linking psoriasis and acute myocardial infarction

Psoriasis, a chronic inflammatory skin disorder, is associated with comorbidities such as acute myocardial infarction (AMI). However, the molecular mechanisms connecting these conditions are unclear. In this study, we conducted bioinformatics analyses using gene expression datasets to identify differentially expressed genes and hub genes associated with both psoriasis and AMI. Our findings emphasize the involvement of immune-related pathways in the pathogenesis of both conditions. Furthermore, we investigated the expression levels of hub genes in AMI patients and myocardial infarction (MI) mice. ELISA measurements revealed significantly higher levels of CXCL8, IL1B, S100A9, and S100A12 in the serum of AMI patients compared to normal individuals. Immunohistochemical staining of heart tissue from MI mice showed a progressive increase in the expression of CXCL8 and IL-1B as MI advanced, while S100A9 exhibited high expression at day 3 post-MI. mRNA expression analysis validated these findings. Additionally, we explored the skin lesions of psoriasis patients and found significantly higher expression of CXCL8, IL-1B, S100A9, and S100A12 in the affected skin areas compared to unaffected regions. These results highlight the consistent upregulation of hub genes in both AMI and psoriasis patients, as well as in myocardial infarction mice, underscoring their potential as reliable markers for disease diagnosis. Moreover, molecular docking simulations revealed potential interactions between simvastatin and key target proteins, suggesting a potential therapeutic avenue. Overall, our study uncovers shared molecular signatures and potential therapeutic targets, providing a foundation for future investigations targeting common pathways in psoriasis and AMI.

Fc engineering by monoclonal mammalian cell display for improved affinity and selectivity towards FcγRs.

Fc optimization can significantly enhance therapeutic efficacy of monoclonal antibodies. However, existing Fc engineering approaches are sub-optimal with noted limitations, such as inappropriate glycosylation, polyclonal libraries, and utilizing fragment but not full-length IgG display. Applying cell cycle arrested recombinase-mediated cassette exchange, this study constructed high-quality monoclonal Fc libraries in CHO cells, displayed full-length IgG on cell surface, and preformed ratiometric fluorescence activated cell sorting (FACS) with the antigen and individual FcγRs. Identified Fc variants were quantitatively evaluated by flow cytometry, ELISA, kinetic and steady-state binding affinity measurements, and cytotoxicity assays. An error-prone Fc library focusing on the hinge-CH2 region was constructed in CHO cells with a functional diversity of 7.5×106. Panels of novel Fc variants with enhanced affinity and selectivity for FcγRs were isolated. Particularly, clone 2a-10 (G236E/K288R/K290W/K320M) showed increased binding strength towards FcγRIIa-131R and 131H allotypes with kinetic dissociation constants (KD-K) of 140nM and 220nM, respectively, while reduced binding strength towards FcγRIIb compared to WT Fc; clone 2b-1 (K222I/V302E/L328F/K334E) had KD-K of 180nM towards FcγRIIb; clone 3a-2 (P247L/K248E/K334I) exhibited KD-K of 190nM and 100nM towards FcγRIIIa-176F and 176V allotypes, respectively, and improved potency of 2.0ng/ml in ADCC assays. Key mutation hotspots were identified, including P247 for FcγRIIIa, K290 for FcγRIIa, and K334 for FcγRIIb bindings. Discovery of Fc variants with enhanced affinity and selectivity towards individual FcγR and the identification of novel mutation hotspots provide valuable insights for further Fc optimization and serve as a foundation for advancing antibody therapeutics development.

Evaluation of antibiofilm activity of metal oxides nanoparticles and carbon nanotubes coated styrofoam on the bacterium Jeotgalicoccus huakuii

The co-existence of metal oxide nanoparticles (MONPs), carbon-based nanomaterials and microplastics (MPs) in the natural environment are expected to be of growing global concern due to their increasing abundance and persistence in the environment worldwide. Knowledge of the interaction of the above compounds particularly under light irradiation in water remains limited. In the present study, the possible individual and combined toxic effects of MONPs, carbon nanotubes (CNTs) through styrofoam (SF) on the environmental bacterium Jeotaglicoccus huakuii were systematically investigated. The fabricated MONPs and CNTs were characterized using the following techniques: FT-IR (functional groups), XRD (crystallinity), SEM, and EDX (topological morphology). The objective of this study was to investigate and identify naturally occurring bacteria capable of mitigating and detoxifying toxic pollutants under adverse conditions. Moreover, the assessment of minimum inhibitory concentration (MIC) was made through an agar well plate method, resazurin (ELISA measurement), growth kinetics and bacterial viability were assessed employing live and dead assay and biofilm combating ability was analyzed using an antibiofilm assay. Further, the biotransformation of f-MWCNTs by J. huakuii was evaluated employing RT-PCR and SEM analysis. The results demonstrated that the toxicity of Pb3O4@f-MWCNTs was comparatively higher than the remaining Pb3O4 NPs and SF coated NPs.. Interestingly, J. huakuii showed resistance against f-MWCNTs at very high concentrations and able to utilize f-MWCNTs as a sole carbon source suggesting J. huakuii as a suitable aquatic bioremediation tool for both MONPs and CNTs transfer via MPs. The results also enhanced our understanding of the affinity of MPs towards MONPs and CNTs under extreme environmental conditions.

Abstract B019: Identification of gene signatures predictive of response to Ad-IFNα/Syn3 in bladder cancer

Abstract Introduction: Interferon α gene therapy (Ad-IFNα/Syn3) is FDA approved for treatment of BCG-unresponsive non-muscle invasive bladder cancer. Ad-IFNα/Syn3 is a non-replicating adenovirus that when transduced into target tissues, produces IFNa2b protein with anti-tumor activity. In the phase 3 multicenter trial, 45.5% of patients with carcinoma-in-situ and 60% of those with Ta/T1 disease who had a complete response to Ad-IFNα/Syn3 at 3 months remained recurrence free at 12 months. Targeting mechanisms of resistance and identifying predictive biomarkers to improve patient selection and overall response rates is a top priority. Towards this, we treated 29 human bladder cancer cell lines with Ad-IFNα/Syn3 and assessed their responses to therapy. We identified sensitive and resistant cell lines and gene signatures predictive of response. Methods: Human bladder cancer cell lines were grown in MEM supplemented with 10% FBS in 96-well plate. After overnight attachment, these were treated with Ad-IFNα/Syn3 (MOI 1000) and cell titre glow assay was performed 72h post-treatment. Cells were also seeded in 6-well plates. and after 24h cell-free supernatants were collected for ELISA and cells were collected for RNA isolation using RNAqueous Total RNA Isolation kit (Thermo Fisher). RNA quality was assessed using Tapestation. RNAseq analysis was carried out using Ion proton Sequencer. Ingenuity pathway analysis (IPA) and gene set enrichment were performed on the sequencing data for the cell lines. ELISA was used to measure IFNα and IL6 protein levels in cell free supernatants. We also tested organoids developed from bladder cancer patients to test drug efficacy and identify gene signatures. Results: Out of the 29 cell lines, we identified that sensitivity to Ad-IFNα/Syn3 was pronounced in luminal cells (8/13 luminal cell lines). Most basal cells were either resistant (&amp;gt;70% viability) or only moderately sensitive to Ad-IFNα/Syn3 (between 70-40% viability) when compared to control. We selected 7 cell lines for sequencing and ELISA measurements: luminal cell lines BV, UC6, Rt4V6 and UC5, and basal cell lines ScaBER, HT1197, and T24. All cell lines mentioned above could be successfully transduced by the adenoviral vector as measured by increased expression of IFNα protein in the cell-free supernatants. Ad-IFNα/Syn3-sensitive luminal cell lines at baseline had lower IFNα and IFNγ scores when compared to resistant basal cell lines. We identified several cell-death pathways enriched in treated cells that were sensitive to Ad-IFNα/Syn3. IL6 measurements in cell free supernatants revealed increased expression of IL6 after treatment in sensitive cells. However, in resistant cells IL6 expression was either high at baseline (ScaBER) or both undetectable at baseline and after treatment (UC5). Conclusion: Our results suggest that the luminal cell lines are more sensitive to Ad-IFNα/Syn3 and that high baseline expression of IFNα and IFNγ in basal cell lines contributes to resistance. IL6 levels are also predictive of response to Ad-IFNα/Syn3. Citation Format: Morgan E. Pierce, Alexis R. Steinmetz, Aruna Nannapaneni, Tanner S. Miest, David J. McConkey, Sharada Mokkapati, Colin P.N. Dinney. Identification of gene signatures predictive of response to Ad-IFNα/Syn3 in bladder cancer [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr B019.

Relationship Between Cerebrospinal Fluid Alzheimer's Disease Biomarker Values Measured via Lumipulse Assays and Conventional ELISA: Single-Center Experience and Systematic Review.

Although Lumipulse assays and conventional ELISA are strongly correlated, the precise relationship between their measured values remains undetermined. To determine the relationship between Lumipulse and ELISA measurement values. Patients who underwent cerebrospinal fluid (CSF) Alzheimer's disease (AD) biomarker measurements and consented to biobanking between December 2021 and June 2023 were included. The relationship between values measured via Lumipulse assays and conventional ELISA were evaluated by Passing-Bablok analyses for amyloid-β 1-42 (Aβ42), total tau (t-tau), and phospho-tau 181 (p-tau 181). Studies using both assays were systematically searched for in PubMed and summarized after quality assessment. Regression line slopes and intercepts were 1.41 (1.23 to 1.60) and -77.8 (-198.4 to 44.5) for Aβ42, 0.94 (0.88 to 1.01) and 98.2 (76.9 to 114.4) for t-tau, and 1.60 (1.43 to 1.75) and -21.1 (-26.9 to -15.6) for p-tau181. Spearman's correlation coefficients were 0.90, 0.95, and 0.95 for Aβ42, t-tau, and p-tau181, respectively. We identified 13 other studies that included 2,117 patients in total. Aβ42 slope varied among studies, suggesting inter-lab difference of ELISA. The slope and intercept of t-tau were approximately 1 and 0, respectively, suggesting small proportional and systematic differences. Conversely, the p-tau181 slope was significantly higher than 1, distributed between 1.5-2 in most studies, with intercepts significantly lower than 0, suggesting proportional and systematic differences. We characterized different relationship between measurement values for each biomarker, which may be useful for understanding the differences in CSF biomarker measurement values on different platforms and for future global harmonization.

Association between blood procollagen III N-terminal propeptide, granulocyte-macrophage colony-stimulating factor and triple therapy in single inhaler efficacy for chronic obstructive pulmonary disease re-exacerbation prevention

Triple therapy with inhaled corticosteroid (ISC) / long-acting β2 agonist (LABA) / long-acting muscarinic antagonist (LAMA) in single inhaler expanded the possibilities for prevention of chronic obstructive pulmonary disease (COPD) exacerbations. Heterogeneity of COPD determines the needs in search of target population and efficacy markers for each existing therapy. Disease phenotype depends on a complex of factors, with respiratory viral infection among the most significant. Aim of the study was to assess the efficacy of triple therapy with ICS/LABA/LAMA in single inhaler for subsequent COPD exacerbations prevention and to search molecular markers of the efficacy depending the etiology of index exacerbation. Material and methods. It was a prospective observational study of three COPD patients’ strata: after COPD exacerbation required hospitalization with viral (n = 60), bacterial (n = 60) and viral-bacterial (n = 60) infection. Triple therapy in single inhaler (n = 104) or in free combinations (n = 76) were prescribed in real clinical practice. COPD was diagnosed according to spirography criteria. To establish the COPD exacerbation etiology the real time PCR of sputum or bronchoalveolar lavage fluid, standard cultural method, blood procalcitonin, as well as marker blood proteins, hyaluronic acid by ELISA measurement were done. Associations were revealed using Cox regression. Results. Triple therapy in single inhaler in comparison with free combinations decreased time to first re-exacerbation, hazard ratio (HR) in viral-associated index exacerbation strata was 0.38 (95% confidence interval (95% CI) 1.15–0.40), in bacterial – 0.47 (0.39–0.72), in viral-bacterial – 0.39 (0.14–0.39). In strata of COPD patients after viral and viral-bacterial exacerbations, in subgroups treated with triple therapy in single inhaler blood procollagen III N-terminal propeptide (PIIINP) (HR for group after viral index exacerbations was 1.03, 95 % CI 1.02–1.28, HR for group after viral-bacterial exacerbations was 1.04, 95 % CI 1.02–1.28), granulocyte-macrophage colony-stimulating factor (GM-CSF) (HR 1.03, 95 % CI 1.02–1.32, 1.01, 95 % CI 1.00–1.35, respectively) content was associated with time of re-exacerbations. Conclusions. Blood PIIINP and GM-CSF during COPD exacerbation are perspective markers of subsequent exacerbations within 1 year in patients after virus-associated or viral-bacterial index exacerbation. In these groups of patients triple therapy in single inhaler is more effective than free combination for subsequent exacerbations prevention.

Rapid analysis of wheat gluten composition using a triple ELISA.

Gluten composition is an important quality parameter of wheat flour. Reversed-phase high-performance liquid chromatography (RP-HPLC) is a state-of-the-art method for its analysis. As this is a very labour-intensive and time-consuming procedure, alternative faster methods are desirable. Enzyme-linked immunosorbent assay (ELISA) is a high-throughput method often used for the analysis of gluten traces in gluten-free products. In this proof-of-principle study, we introduce an experimental triple ELISA for the relative quantitation of gliadins, high-molecular-weight glutenin subunits (HMW-GS) and low-molecular-weight glutenin subunits (LMW-GS) of one wheat flour extract. The results of 80 common wheat flour samples obtained from the triple ELISA and RP-HPLC were correlated. The results for gliadins (r = 0.69) and HMW-GS (r = 0.81) showed a medium and high correlation, respectively. Only a very weak correlation of ELISA and RP-HPLC results was observed for LMW-GS (r = 0.49). Results for glutenins (r = 0.69) and gluten (r = 0.72) had a medium correlation. The gliadin/glutenin ratio (r = 0.47) and LMW-GS/HMW-GS ratio (r = 0.40) showed a weak or no correlation. The gliadin, LMW-GS and gluten contents were lower and the HMW-GS content was higher in the ELISA measurement compared to RP-HPLC. The quantitation of gliadins and HMW-GS by the experimental triple ELISA showed comparable results to RP-HPLC, whereas no strong correlation between the results from the two methods was found for LMW-GS. Overall, the experimental triple ELISA is suitable for relative gluten quantitation, especially for the analysis of large sample sets. Further work will focus on improving the experimental procedure of the ELISA. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Decreased circulating CTRP3 levels in acute and chronic cardiovascular patients

C1q/TNF-related protein 3 (CTRP3) represents an adipokine with various metabolic and immune-regulatory functions. While circulating CTRP3 has been proposed as a potential biomarker for cardiovascular disease (CVD), current data on CTRP3 regarding coronary artery disease (CAD) remains partially contradictory. This study aimed to investigate CTRP3 levels in chronic and acute settings such as chronic coronary syndrome (CCS) and acute coronary syndrome (ACS). A total of 206 patients were classified into three groups: CCS (n = 64), ACS having a first acute event (ACS-1, n = 75), and ACS having a recurrent acute event (ACS-2, n = 67). The control group consisted of 49 healthy individuals. ELISA measurement in peripheral blood revealed decreased CTRP3 levels in all patient groups (p < 0.001) without significant differences between the groups. This effect was exclusively observed in male patients. Females generally exhibited significantly higher CTRP3 plasma levels than males. ROC curve analysis in male patients revealed a valuable predictive potency of plasma CTRP3 in order to identify CAD patients, with a proposed cut-off value of 51.25 ng/mL. The sensitivity and specificity of prediction by CTRP3 were congruent for the subgroups of CCS, ACS-1, and ACS-2 patients. Regulation of circulating CTRP3 levels in murine models of cardiovascular pathophysiology was found to be partly opposite to the clinical findings, with male mice exhibiting higher circulating CTRP3 levels than females. We conclude that circulating CTRP3 levels are decreased in both male CCS and ACS patients. Therefore, CTRP3 might be useful as a biomarker for CAD but not for distinguishing an acute from a chronic setting.Key messagesCTRP3 levels were found to be decreased in both male CCS and ACS patients compared to healthy controls. Plasma CTRP3 has a valuable predictive potency in order to identify CAD patients among men and is therefore proposed as a biomarker for CAD but not for distinguishing between acute and chronic settings.Regulation of circulating CTRP3 levels in murine models of cardiovascular pathophysiology was found to be partly opposite to the clinical findings in men.