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Journal of Immunological Methods Jun 2024When the membrane protein CD40 ligand (CD40L) on activated T cells binds the receptor CD40 on B-cells, it provides a co-stimulatory signal for B cell activation....
When the membrane protein CD40 ligand (CD40L) on activated T cells binds the receptor CD40 on B-cells, it provides a co-stimulatory signal for B cell activation. Dysregulation of the CD40L:CD40 axis is associated with inflammatory and autoimmune diseases. The presence of soluble CD40L (sCD40L) in plasma is implicated in several diseases, from cardiovascular and autoimmune diseases to different types of cancer, and sCD40L has been suggested as a valuable marker of disease. If sCD40L is to be used as a biomarker, being able to precisely measure and quantify the levels of sCD40L in human blood samples is of utmost importance. We demonstrate the development of a sandwich-type time-resolved immunofluorometric assay for quantification of sCD40L in plasma or serum samples. For this, we generate 29 monoclonal anti-CD40L antibodies, and from these, we select the optimal combination of capture antibody and detection antibody. A number of variables were tested: the influence of the type of sample (comparing 3 different blood collection tubes for serum sampling and 4 different types of tubes for plasma sampling), the influence of freeze-thaw cycles, the influence of sampling time during night and day, and the influence of centrifugation of the samples. We found a very similar level of sCD40L in paired EDTA plasma and serum samples. Out of 100 healthy blood donor samples 61 had a level of sCD40L below the detection level of the assay, whereas the remaining 39 samples had ranging levels of sCD40L from 1.14 to 33.14 ng/mL. In summary, we present a time-resolved immunofluorometric assay based on paired monoclonal antibodies, ensuring high specificity, sensitivity, and homogeneity. The Eu-based assay additionally provides consistent assay readouts due to the extended decay time not seen in standard enzyme-linked immunosorbent assays. The assay paves the way for specific and consistent quantification of sCD40L in human plasma and serum samples.
PubMed: 38871279
DOI: 10.1016/j.jim.2024.113710 -
Pathology, Research and Practice Jun 2024Expression and function of TRPC3 and TRPC6 in the pancreas is a controversial topic. Investigation in human tissue is seldom. We aimed to provide here a detailed...
BACKGROUND
Expression and function of TRPC3 and TRPC6 in the pancreas is a controversial topic. Investigation in human tissue is seldom. We aimed to provide here a detailed description of the distribution of TRPC3 and TRPC6 in the human exocrine and endocrine pancreas.
METHODS
We collected healthy samples from cadavers (n = 4) and visceral surgery (n = 4) to investigate the respective expression profiles using immunohistochemical tracing with knockout-validated antibodies.
RESULTS
TRPC3- and TRPC6-proteins were detected in different pancreatic structures including acinar cells, as well as epithelial ductal cells from intercalate, intralobular, and interlobular ducts. Respective connective tissue layers appeared unstained. Endocrine islets of Langerhans were clearly and homogenously immunolabeled by the anti-TRPC3 and anti-TRPC6 antibodies. Insular α, β, γ, and δ cells were conclusively stained, although no secure differentiation of cell types was performed.
CONCLUSIONS
Due to aforementioned antibody specificity verification, protein expression in the immunolabeled localizations can be accepted. Our study in human tissue supports previous investigations especially with respect to acinar and insular α and β cells, while other localizations are here reported for the first time to express TRPC3 and TRPC6, ultimately warranting further research.
PubMed: 38870712
DOI: 10.1016/j.prp.2024.155403 -
Pulmonary Circulation Apr 2024A blood test identifying patients at increased risk of pulmonary hypertension (PH) could streamline the investigative pathway. The prospective, multicenter CIPHER study...
A blood test identifying patients at increased risk of pulmonary hypertension (PH) could streamline the investigative pathway. The prospective, multicenter CIPHER study aimed to develop a microRNA-based signature for detecting PH in breathless patients and enrolled adults with a high suspicion of PH who had undergone right heart catheterization (RHC). The CIPHER-MRI study was added to assess the performance of this CIPHER signature in a population with low probability of having PH who underwent cardiac magnetic resonance imaging (cMRI) instead of RHC. The microRNA signature was developed using a penalized linear regression (LASSO) model. Data were modeled both with and without N-terminal pro-brain natriuretic peptide (NT-proBNP). Signature performance was assessed against predefined thresholds (lower 98.7% CI bound of ≥0.73 for sensitivity and ≥0.53 for specificity, based on a meta-analysis of echocardiographic data), using RHC as the true diagnosis. Overall, 926 CIPHER participants were screened and 888 were included in the analysis. Of 688 RHC-confirmed PH cases, approximately 40% were already receiving PH treatment. Fifty microRNA (from 311 investigated) were algorithmically selected to be included in the signature. Sensitivity [97.5% CI] of the signature was 0.85 [0.80-0.89] for microRNA-alone and 0.90 [0.86-0.93] for microRNA+NT-proBNP, and the corresponding specificities were 0.33 [0.24-0.44] and 0.28 [0.20-0.39]. Of 80 CIPHER-MRI participants with evaluable data, 7 were considered PH-positive by cMRI whereas 52 were considered PH-positive by the microRNA signature. Due to low specificity, the CIPHER miRNA-based signature for PH (either with or without NT-proBNP in model) did not meet the prespecified diagnostic threshold for the primary analysis.
PubMed: 38868397
DOI: 10.1002/pul2.12386 -
Access Microbiology 2024Leptospirosis is a zoonotic disease that is prevalent worldwide. Leptospiral 3-hydroxyacyl-CoA dehydrogenase (3-HADH) is excreted in the urine of infected individuals....
Leptospirosis is a zoonotic disease that is prevalent worldwide. Leptospiral 3-hydroxyacyl-CoA dehydrogenase (3-HADH) is excreted in the urine of infected individuals. However, the potential use of 3-HADH as a biomarker for the diagnosis of leptospirosis using enzyme-linked immunosorbent assay (ELISA) has not been investigated. A technique that identifies in a patient in urine sample will be valuable in regular diagnostics and epidemic scenarios, as opposed to existing serological approaches. This study aimed to develop and evaluate an ELISA that can detect 3-HADH in the urine of patients with confirmed acute leptospirosis and to assess its potential as a screening test for leptospirosis. Laboratory confirmation of acute leptospirosis was done by -nested polymerase chain reaction (PCR) of plasma samples from suspected patients. ELISA-based determination of the presence of 3-HADH in the urine of PCR-positive patients versus PCR-negative patients matched for fever date was performed by coating ELISA plates with urine supernatants and using rabbit anti-3-HADH as the primary antibody. Receiver operating characteristic curve analysis was used to determine the cutoff values for the ELISA. The diagnostic measures between the PCR-positive and PCR-negative patients were compared using the Mann-Whitney U test. In total, 158 febrile patients were assessed, of whom 121 (76.6 %) were male. Of the 15 nested PCR-positive patients, 12 were in the acute phase of the febrile illness. The best cutoff was an average optical density (OD) value of 0.2200 for febrile patients. Sensitivity and specificity were 83.33% [95 % confidence interval (CI), 51.59-97.91 %) and 83.33 % (95 % CI, 76.05-89.13 %), respectively. The OD values for PCR-positive patients in the acute phase of the disease (≤7 days of fever) were significantly higher than those for PCR-negative patients (<0.001, =114.0, =-4.946). Detection of 3-HADH in urine by ELISA appears to be promising for the screening of acute leptospirosis in suspected patients.
PubMed: 38868371
DOI: 10.1099/acmi.0.000651.v4 -
Parasitology Research Jun 2024Rat lungworm disease or neuroangiostrongyliasis is a cerebral parasitic infection that affects humans and animals alike. Its clinical signs and symptoms can range from...
Rat lungworm disease or neuroangiostrongyliasis is a cerebral parasitic infection that affects humans and animals alike. Its clinical signs and symptoms can range from mild self-resolving to serious life-threatening conditions. Studies suggest therapeutic interventions during the early stages of infection to be more effective than in later stages. However, early diagnosis of infection is usually problematic without the knowledge of exposure and/or detection of the parasite's DNA or antibody against the parasite in the cerebrospinal fluid. This requires a lumbar puncture, which is an invasive procedure that generally requires hospitalization. This study evaluates an affordable and less invasive alternative to detect parasitic DNA by PCR from the peripheral blood of potentially infected animals. Blood samples from 58 animals (55 dogs and 3 cats) with clinical suspicion of infection were submitted to our lab between February 2019 and August 2022 by local, licensed veterinarians. DNA was extracted from whole blood, plasma, serum, and/or packed cells using the Qiagen DNeasy Blood & Tissue Kit as per the manufacturer's protocol. All 58 animals were tested by real-time PCR using the AcanITS1 assay and 32 of these animals (31dogs; 1 cat) were also tested using the AcanR3990 assay. The PCR results for both assays were classified into strongly positive > positive > weakly positive > negative, and equivocal for ambiguous results, based on the strength of the signal. The percent infection detected using the AcanITS1 and AcanR3990 assays was 12.72% (7/55) and 20.68% (6/29), respectively. The overall percent infection detected was 34.37% (11/32), with only two animals testing positive by both assays. The three cats involved in this study tested negative by both assays. These results are promising and warrant further investigations to increase sensitivity including variables that might affect detection in the blood, such as parasite load, and laboratory methodologies.
Topics: Animals; Angiostrongylus cantonensis; Strongylida Infections; Real-Time Polymerase Chain Reaction; Cats; Cat Diseases; Dogs; Dog Diseases; Sensitivity and Specificity; DNA, Helminth
PubMed: 38862687
DOI: 10.1007/s00436-024-08251-9 -
Scientific Reports Jun 2024Cardiotrophin-like cytokine factor 1 (CLCF1) is an IL-6 family cytokine with neurotrophic and immuno-modulating functions. CLCF1 mRNA has been detected in primary and...
Cardiotrophin-like cytokine factor 1 (CLCF1) is an IL-6 family cytokine with neurotrophic and immuno-modulating functions. CLCF1 mRNA has been detected in primary and secondary lymphoid organs, and up-regulation of CLCF1 mRNA levels has been associated with the T helper (Th) 17 polarization. However, information regarding CLCF1 expression by immune cells at the protein level remains scarce. We have developed a methodology that uses a monoclonal antibody (mAb) directed against CLCF1 for the detection of human and mouse CLCF1 by flow cytometry. We have successfully detected CLCF1 protein expression in cells from the mouse pro-B cell line Ba/F3 that were transduced with CLCF1 cDNA. Interestingly, we found that the anti-CLCF1 mAb inhibits CLCF1 biological activity in vitro by binding to an epitope that encompasses site III of the cytokine. Moreover, we have detected CLCF1 expression in mouse splenic T cells, as well as in vitro differentiated Th1 cells. The specificity of the fluorescence signal was demonstrated using Clcf1-deficient lymphocytes generated using a conditional knock-out mouse model. The detection of CLCF1 protein by flow cytometry will be a valuable tool to study CLCF1 expression during normal and pathological immune responses.
Topics: Animals; Flow Cytometry; Mice; Humans; Antibodies, Monoclonal; Cytokines; Mice, Knockout; Cell Line; Th1 Cells
PubMed: 38858477
DOI: 10.1038/s41598-024-64101-9 -
Journal of Feline Medicine and Surgery Jun 2024The aim of the present study was to evaluate minimally invasive diagnostic techniques, such as the semi-quantitative indirect IgG antibody enzyme immunoassay (EIA) using...
OBJECTIVES
The aim of the present study was to evaluate minimally invasive diagnostic techniques, such as the semi-quantitative indirect IgG antibody enzyme immunoassay (EIA) using blood serum and the urinary lateral flow assay (LFA), for the detection of in cats with histoplasmosis.
METHODS
Eight client-owned domestic cats diagnosed with histoplasmosis were selected based on cytological, histopathological, mycological, molecular or antigenic techniques. The blood serum of these animals was tested in a semi-quantitative indirect IgG antibody EIA for the detection of . Urine samples were tested for antigen using LFA.
RESULTS
Five cats were seropositive on IgG EIA (5/8, with diagnostic sensitivity equal to 62.5%; 95% confidence interval [CI] 24.5-91.5) and five cats were positive on antigen LFA (5/7, with diagnostic sensitivity equal to 71.4%; 95% CI 29.0-96.3). The combined diagnostic sensitivity when interpreted in parallel was 87.5% (7/8, 95% CI 47.3-99.7). The specificity for the anti- IgG EIA was 100% (95% CI 71.5-100) and for the antigen LFA it was also 100% (95% CI 71.5-100).
CONCLUSIONS AND RELEVANCE
The semi-quantitative indirect IgG antibody EIA for the detection of in blood serum and the urinary LFA for the detection of the same agent emerge as new minimally invasive diagnostic techniques that can assist in the approach to disseminated and pulmonary feline histoplasmosis, especially when both techniques are considered together.
Topics: Cats; Animals; Histoplasmosis; Cat Diseases; Histoplasma; Sensitivity and Specificity; Male; Female; Antibodies, Fungal; Immunoenzyme Techniques; Immunoglobulin G
PubMed: 38857445
DOI: 10.1177/1098612X241248984 -
PloS One 2024Traumatic brain injury has faced numerous challenges in drug development, primarily due to the difficulty of effectively delivering drugs to the brain. However, there is...
Traumatic brain injury has faced numerous challenges in drug development, primarily due to the difficulty of effectively delivering drugs to the brain. However, there is a potential solution in targeted drug delivery methods involving antibody-drug conjugates or nanocarriers conjugated with targeting antibodies. Following a TBI, the blood-brain barrier (BBB) becomes permeable, which can last for years and allow the leakage of harmful plasma proteins. Consequently, an appealing approach for TBI treatment involves using drug delivery systems that utilize targeting antibodies and nanocarriers to help restore BBB integrity. In our investigation of this strategy, we examined the efficacy of free antibodies and nanocarriers targeting a specific endothelial surface marker called vascular cell adhesion molecule-1 (VCAM-1), which is known to be upregulated during inflammation. In a mouse model of TBI utilizing central fluid percussion injury, free VCAM-1 antibody did not demonstrate superior targeting when comparing sham vs. TBI brain. However, the administration of VCAM-1-targeted nanocarriers (liposomes) exhibited a 10-fold higher targeting specificity in TBI brain than in sham control. Flow cytometry and confocal microscopy analysis confirmed that VCAM-1 liposomes were primarily taken up by brain endothelial cells post-TBI. Consequently, VCAM-1 liposomes represent a promising platform for the targeted delivery of therapeutics to the brain following traumatic brain injury.
Topics: Animals; Brain Injuries, Traumatic; Vascular Cell Adhesion Molecule-1; Mice; Blood-Brain Barrier; Nanoparticles; Liposomes; Male; Drug Delivery Systems; Mice, Inbred C57BL; Disease Models, Animal; Endothelial Cells
PubMed: 38857220
DOI: 10.1371/journal.pone.0297451 -
Theranostics 2024Myocardial infarction (MI) as a consequence of atherosclerosis-associated acute thrombosis is a leading cause of death and disability globally. Antiplatelet and...
Platelet-targeted thromboprophylaxis with a human serum albumin fusion drug: Preventing thrombosis and reducing cardiac ischemia/reperfusion injurywithout bleeding complications.
Myocardial infarction (MI) as a consequence of atherosclerosis-associated acute thrombosis is a leading cause of death and disability globally. Antiplatelet and anticoagulant drugs are standard therapies in preventing and treating MI. However, all clinically used drugs are associated with bleeding complications, which ultimately limits their use in patients with a high risk of bleeding. We have developed a new recombinant drug, targ-HSA-TAP, that combines targeting and specific inhibition of activated platelets as well as anticoagulation. This drug is designed and tested for a prolonged circulating half-life, enabling unique thromboprophylaxis without bleeding complications. Targ-HSA-TAP combines a single-chain antibody (scFv) that targets activated glycoprotein IIb/IIIa on activated platelets, human serum albumin (HSA) for prolonged circulation, and tick anticoagulant peptide (TAP) for coagulation FX inhibition. A non-binding scFv is employed as a non-targeting control (non-targ-HSA-TAP). Its efficacy was investigated using murine models of acute thrombosis and cardiac ischemia-reperfusion (I/R) injury. Our experiments confirmed the targeting specificity of targ-HSA-TAP to activated platelets and demonstrated effective prevention of platelet aggregation and thrombus formation, as well as FXa inhibition . Thromboprophylactic administration of targ-HSA-TAP subcutaneously in mice prevented occlusion of the carotid artery after ferric chloride injury as compared to non-targ-HSA-TAP and PBS-control treated mice. By comparing the therapeutic outcomes between targ-TAP and targ-HSA-TAP, we demonstrate the significant improvements brought by the HSA fusion in extending the drug's half-life and enhancing its therapeutic window for up to 16 h post-administration. Importantly, tail bleeding time was not prolonged with targ-HSA-TAP in contrast to the clinically used anticoagulant enoxaparin. Furthermore, in a murine model of cardiac I/R injury, mice administered targ-HSA-TAP 10 h before injury demonstrated preserved cardiac function, with significantly higher ejection fraction and fractional shortening, as compared to the non-targ-HSA-TAP and PBS control groups. Advanced strain analysis revealed reduced myocardial deformation and histology confirmed a reduced infarct size in targ-HSA-TAP treated mice compared to control groups. The inclusion of HSA represents a significant advancement in the design of targeted therapeutic agents for thromboprophylaxis. Our activated platelet-targeted targ-HSA-TAP is a highly effective antithrombotic drug with both anticoagulant and antiplatelet effects while retaining normal hemostasis. The long half-life of targ-HSA-TAP provides the unique opportunity to use this antithrombotic drug for more effective, long-lasting and safer anti-thrombotic prophylaxis. In cases where MI occurs, this prophylactic strategy reduces thrombus burden and effectively reduces cardiac I/R injury.
Topics: Animals; Serum Albumin, Human; Mice; Thrombosis; Humans; Hemorrhage; Blood Platelets; Disease Models, Animal; Male; Anticoagulants; Single-Chain Antibodies; Myocardial Reperfusion Injury; Myocardial Infarction; Mice, Inbred C57BL; Recombinant Fusion Proteins
PubMed: 38855181
DOI: 10.7150/thno.97517 -
Journal of Molecular Biology Jun 2024The FLAG-tag/anti-FLAG system is a widely used biochemical tool for protein detection and purification. Anti-FLAG M2 is the most popular antibody against the FLAG-tag,...
The FLAG-tag/anti-FLAG system is a widely used biochemical tool for protein detection and purification. Anti-FLAG M2 is the most popular antibody against the FLAG-tag, due to its ease of use, versatility, and availability in pure form or as bead conjugate. M2 binds N-terminal, C-terminal and internal FLAG-tags and binding is calcium-independent, but the molecular basis for the FLAG-tag specificity and recognition remains unresolved. Here we present an atomic resolution (1.17 Å) structure of the FLAG peptide in complex with the Fab of anti-FLAG M2, revealing key binding determinants. Five of the eight FLAG peptide residues form direct interactions with paratope residues. The FLAG peptide adopts a 3 helix conformation in complex with the Fab. These structural insights allowed us to rationally introduce point mutations on both the peptide and antibody side. We tested these by surface plasmon resonance, leading us to propose a shorter yet equally binding version of the FLAG-tag for the M2 antibody.
PubMed: 38852931
DOI: 10.1016/j.jmb.2024.168649