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INTRODUCTION: Type 1 (T1D) and type 2 diabetes (T2D) are associated with an elevated incidence of infectious diseases and a higher risk of infections-related hospitalization and death. In this study, we delineated the "vaccinome" landscape obtained with a large immunization schedule offered by the Regional Government of Lombardy in a cohort of 618,396 patients with diabetes (T1D and T2D). METHODS: Between September 2021 and September 2022, immunization coverage for influenza, meningococcus, pneumococcus, and herpes zoster was obtained from the public computerized registry of the healthcare system of Lombardy Region (Italy) in 618,396 patients with diabetes and in 9,534,087 subjects without diabetes. Type of diabetes, age, mortality, and hospitalizations were retrospectively analyzed in vaccinated and unvaccinated patients. RESULTS: Among patients with diabetes (T1D and T2D), 44.6% received the influenza vaccine, 10.9% the pneumococcal vaccine, 2.5% the anti-meningococcus vaccine and 0.7% the anti-zoster vaccine. Patients with diabetes immunized for influenza, zoster and meningococcus showed a 2-fold overall reduction in mortality risk and a decrease in hospitalizations. A 3-fold lower risk of mortality and a decrease in hospitalizations for both cardiac and pulmonary causes were also observed after influenza, zoster, and meningococcus immunization in older patients with diabetes. CONCLUSIONS: Immunization coverage is still far from the recommended targets in patients with diabetes. Despite this, influenza vaccination protected nearly 3,800 per 100,000 patients with diabetes from risk of death. The overall impressive decrease in mortality and hospitalizations observed in vaccinated patients strengthens the need for scaling up the "vaccinome" landscape in patients with diabetes.
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Pancreatic beta cells replenishment is considered the next therapeutic option for type 1 diabetes; while stimulating endogenous beta cells proliferation is the "holy grail" for those patients with exhausted beta cell mass. Here we are demonstrating that the pro-apoptotic receptor TMEM219 is expressed in fetal pancreas, in beta cell precursors and in in vitro embryonic-derived endocrine progenitors. TMEM219 signaling negatively regulates beta cells at early stages and induces Caspase 8-mediated cell death. Pharmacological blockade of TMEM219 further rescued beta cell precursor and proliferation markers, and decreased cell death, both in islets and in in vitro-derived endocrine progenitors, allowing for beta cell preservation. While addressing the upstream controlling TMEM219 expression, we determined the TMEM219 miRNet; indeed, one of those miRNAs, miR-129-2, is highly expressed in human islets, particularly in patients at risk or with established type 1 diabetes. miR-129-2 mimic downregulated TMEM219 expression in islets, in in vitro embryonic-derived endocrine progenitors and in highly proliferating insulinoma-derived cells. Moreover, miR-129-2 inhibitor induced a TMEM219 overexpression in insulinoma-derived cells, which restored cell proliferation and functional markers, thus acting as endogenous regulator of TMEM219 expression. The TMEM219 upstream regulator miR129-2 controls the fate of beta cell precursors and may unleash their regenerative potentials to replenish beta cells in type 1 diabetes.
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Diabetes Mellitus Tipo 1 , Células Secretoras de Insulina , Insulinoma , MicroARNs , Neoplasias Pancreáticas , Humanos , Proliferación Celular , Diabetes Mellitus Tipo 1/metabolismo , Células Secretoras de Insulina/metabolismo , Insulinoma/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Neoplasias Pancreáticas/metabolismo , Factores de Transcripción/metabolismoRESUMEN
AIMS: The use of advanced hybrid closed loop systems is spreading due to the beneficial effects on glycometabolic control obtained in patients with type 1 diabetes. However, hypoglycemic episodes can be sometimes a matter of concern. We aim to compare the hypoglycemic risk of an advanced hybrid closed loop system and a predictive low glucose suspend sensor augmented pump. METHODS: In this retrospective three months observational study, we included 30 patients using Medtronic Minimed™ 780G advanced hybrid closed loop system and 30 patients using a Medtronic Minimed™ predictive low glucose suspend sensor augmented pump. RESULTS: The advanced hybrid closed loop system reduced the time spent above 180 mg/dL threshold and increased the time in range as compared to the predictive low glucose suspend. No severe hypoglycemia occurred in both groups and no differences were observed in the percentage of time spent below 70 mg/dl and 54 mg/dl glucose threshold. Nevertheless, more hypoglycemic episodes were recorded during daytime, but not in nighttime, with the use of the advanced hybrid closed loop system. CONCLUSIONS: Our results confirmed the general improvement of glycemic outcomes obtained with the advanced hybrid closed loop system; however more hypoglycemic episodes during daytime were evident.
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Diabetes Mellitus Tipo 1 , Hipoglucemia , Humanos , Glucemia , Estudios Retrospectivos , Insulina/uso terapéutico , Sistemas de Infusión de Insulina , Hipoglucemia/prevención & control , Hipoglucemia/inducido químicamente , Hipoglucemiantes/uso terapéutico , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Glucosa/uso terapéutico , Automonitorización de la Glucosa SanguíneaRESUMEN
Diabetic kidney disease (DKD) is the first cause of end-stage kidney disease in patients with diabetes and its prevalence is increasing worldwide. It encompasses histological alterations that mainly affect the glomerular filtration unit, which include thickening of the basement membrane, mesangial cell proliferation, endothelial alteration, and podocyte injury. These morphological abnormalities further result in a persistent increase of urinary albumin-to-creatinine ratio and in a reduction of the estimated glomerular filtration rate. Several molecular and cellular mechanisms have been recognized, up to date, as major players in mediating such clinical and histological features and many more are being under investigation. This review summarizes the most recent advances in understanding cell death mechanisms, intracellular signaling pathways and molecular effectors that play a role in the onset and progression of diabetic kidney damage. Some of those molecular and cellular mechanisms have been already successfully targeted in preclinical models of DKD and, in some cases, strategies have been tested in clinical trials. Finally, this report sheds light on the relevance of novel pathways that may become therapeutic targets for future applications in DKD.
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Diabetes Mellitus , Nefropatías Diabéticas , Podocitos , Humanos , Nefropatías Diabéticas/metabolismo , Podocitos/patología , Transducción de Señal , Tasa de Filtración Glomerular , Diabetes Mellitus/metabolismoRESUMEN
Patients with type 1 diabetes (T1D) may develop severe outcomes during coronavirus disease 2019 (COVID-19), but their ability to generate an immune response against the SARS-CoV-2 mRNA vaccines remains to be established. We evaluated the safety, immunogenicity, and glycometabolic effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccines in patients with T1D. A total of 375 patients (326 with T1D and 49 subjects without diabetes) who received two doses of the SARS-CoV-2 mRNA vaccines (mRNA-1273, BNT162b2) between March and April 2021 at ASST Fatebenefratelli Sacco were included in this monocentric observational study. Local and systemic adverse events were reported in both groups after SARS-CoV-2 mRNA vaccination, without statistical differences between them. While both patients with T1D and subjects without diabetes exhibited a parallel increase in anti-SARS-CoV-2 spike titers after vaccination, the majority of patients with T1D (70% and 78%, respectively) did not show any increase in the SARS-CoV-2-specific cytotoxic response compared with the robust increase observed in all subjects without diabetes. A reduced secretion of the T-cell-related cytokines interleukin-2 and tumor necrosis factor-α in vaccinated patients with T1D was also observed. No glycometabolic alterations were evident in patients with T1D using continuous glucose monitoring during follow-up. Administration of the SARS-CoV-2 mRNA vaccine is associated with an impaired cellular SARS-CoV-2-specific cytotoxic immune response in patients with T1D.
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Vacuna nCoV-2019 mRNA-1273 , Vacuna BNT162 , Diabetes Mellitus Tipo 1 , Vacuna nCoV-2019 mRNA-1273/efectos adversos , Vacuna nCoV-2019 mRNA-1273/inmunología , Anticuerpos Antivirales , Vacuna BNT162/efectos adversos , Vacuna BNT162/inmunología , Glucemia , Automonitorización de la Glucosa Sanguínea , COVID-19/prevención & control , Estudios de Cohortes , Diabetes Mellitus Tipo 1/inmunología , HumanosRESUMEN
The present work is a preliminary study on the potential of low-frequency ultrasound irradiation coupled with O3 process for the disinfection of a primary effluent from a municipal wastewater treatment plant preserving nutrient levels (in particular nitrogen and phosphorous), for its possible reuse in civil, industrial, and agricultural sectors. The treated water could be reused, after appropriate dilution, contributing to the circular economy perspective and reducing the need for both chemical fertilizer addition and freshwater supply. The effect of different specific ultrasonic energies and ozone doses was assessed on a bench-top system, composed of an ultrasonic reactor and a semi-batch ozonation vessel. The results showed that the combined US-O3 process produces a good removal efficiency regarding soluble Chemical Oxygen Demand, sCOD (ca. 60%), anionic surfactants (ca. 50%), and formaldehyde (ca. 50%), and an optimal abatement for Methylene Blue Active Substances (MBAS, > 90%). The process also reached high disinfection performances, obtaining 4 logs for E. coli and 5 log abatement for Total Coliforms. The high removal efficiency is matched by an outstanding retention of nutrients (total nitrogen and orthophosphate) highlighting a high potential value for agricultural reuse of the treated primary effluent, with possible significant saving of chemical fertilizers. It was concluded that low-frequency ultrasound pre-treatment, combined with ozonation, could be a useful process for primary effluent recovery for several purposes. Further studies are expected to be planned and executed to evaluate system scale-up feasibility.
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Ozono , Contaminantes Químicos del Agua , Purificación del Agua , Escherichia coli , Aguas Residuales , Contaminantes Químicos del Agua/análisisRESUMEN
We provide a dataset of 3D coordinate time series of 37 continuous GNSS stations installed for stability monitoring purposes on onshore and offshore industrial settlements along a NW-SE-oriented and ~100-km-wide belt encompassing the eastern Italian coast and the Adriatic Sea. The dataset results from the analysis performed by using different geodetic software (Bernese, GAMIT/GLOBK and GIPSY) and consists of six raw position time series solutions, referred to IGb08 and IGS14 reference frames. Time series analyses and comparisons evidence that the different solutions are consistent between them, despite the use of different software, models, strategy processing and frame realizations. We observe that the offshore stations are subject to significant seasonal oscillations probably due to seasonal environmental loads, seasonal temperature-induced platform deformation and hydrostatic pressure variations. Many stations are characterized by non-linear time series, suggesting a complex interplay between regional (long-term tectonic stress) and local sources of deformation (e.g. reservoirs depletion, sediment compaction). Computed raw time series, logs files, phasor diagrams and time series comparison plots are distributed via PANGAEA ( https://www.pangaea.de ).
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BACKGROUND: Mitochondria play a role in type 1 diabetes (T1D) particularly in the treatment and prevention of disorder consequences. Due to their demonstrated role in diabetes pathology, mitochondrial proteins can be an interesting starting point to study candidate antigens in T1D. We investigated the role of relevant post-translational modifications (PTM) on a synthetic mitochondrial peptide as putative antigen. METHODS: The antibody response in T1D was evaluated by solid phase-ELISA using a collection of synthetic peptides bearing different PTMs. We investigated the role of lipoylation, phosphorylation, and glycosylation. The PTMs were introduced at position 173 of the mitochondrial pyruvate dehydrogenase E2 complex peptide PDC-E2(167-184) and at position 7 of a structure-based designed ß-turn peptide as an irrelevant sequence to investigate the role of the specific PDC-E2 peptide sequence. RESULTS: IgM titres in 31 T1D patients were higher than IgGs to all the synthetic PTM peptides. Results demonstrated the crucial role of lysine lipoamide, serine O-phosphorylation, and O-glycosylation into the PDC-E2(167-184) peptide sequence for IgM antibody recognition. CONCLUSIONS: Results highlight the importance of immune dysregulation in T1D, furthermore, if confirmed in a large number of patients, they will contribute to add novel diagnostic markers for the understanding the physiopathology of the disease.
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Anticuerpos/inmunología , Diabetes Mellitus Tipo 1/inmunología , Proteínas Mitocondriales/química , Fragmentos de Péptidos/inmunología , Fragmentos de Péptidos/metabolismo , Procesamiento Proteico-Postraduccional , Adulto , Diabetes Mellitus Tipo 1/metabolismo , Femenino , Glicosilación , Humanos , Masculino , Fosforilación , Estereoisomerismo , Ácido Tióctico/análogos & derivados , Ácido Tióctico/química , Ácido Tióctico/metabolismoRESUMEN
The design of molecules that mimic biologically relevant glycans is a significant goal for understanding important biological processes and may lead to new therapeutic and diagnostic agents. In this study we focused our attention on the trisaccharide human natural killer cell-1 (HNK-1), considered the antigenic determinant of myelin-associated glycoprotein and the target of clinically relevant auto-antibodies in autoimmune neurological disorders such as IgM monoclonal gammopathy and demyelinating polyneuropathy. We describe a structure-activity relationship study based on surface plasmon resonance binding affinities aimed at the optimization of a peptide that mimics the HNK-1 minimal epitope. We developed a cyclic heptapeptide that shows an affinity of 1.09×10-7 m for a commercial anti-HNK1 mouse monoclonal antibody. Detailed conformational analysis gave possible explanations for the good affinity displayed by this novel analogue, which was subsequently used as an immunological probe. However, preliminary screening indicates that patients' sera do not specifically recognize this peptide, showing that murine monoclonal antibodies cannot be used as a guide to select immunological probes for the detection of clinically relevant human auto-antibodies.
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Antígenos CD57/química , Epítopos/química , Células Asesinas Naturales/química , Oligosacáridos/química , Oligosacáridos/inmunología , Péptidos/química , Péptidos/inmunología , Resonancia por Plasmón de Superficie , Animales , Anticuerpos Monoclonales/inmunología , Reacciones Antígeno-Anticuerpo , Antígenos CD57/inmunología , Epítopos/inmunología , Humanos , Células Asesinas Naturales/inmunología , Ratones , Conformación Proteica , Relación Estructura-ActividadRESUMEN
In autoimmune diseases, there have been proposals that exogenous "molecular triggers", i.e., specific 'non-self antigens' accompanying infectious agents, might disrupt control of the adaptive immune system resulting in serious pathologies. The etiology of multiple sclerosis (MS) remains unclear. However, epidemiologic data suggest that exposure to infectious agents may be associated with increased MS risk and progression may be linked to exogenous, bacterially-derived, antigenic molecules, mimicking mammalian cell surface glycoconjugates triggering autoimmune responses. Previously, antibodies specific to a gluco-asparagine (N-Glc) glycopeptide, CSF114(N-Glc), were identified in sera of an MS patient subpopulation. Since the human glycoproteome repertoire lacks this uniquely modified amino acid, we turned our attention to bacteria, i.e., Haemophilus influenzae, expressing cell-surface adhesins including N-Glc, to establish a connection between H. influenzae infection and MS. We exploited the biosynthetic machinery from the opportunistic pathogen H. influenzae (and the homologous enzymes from A. pleuropneumoniae) to produce a unique set of defined glucosylated adhesin proteins. Interestingly we revealed that a hyperglucosylated protein domain, based on the cell-surface adhesin HMW1A, is preferentially recognized by antibodies from sera of an MS patient subpopulation. In conclusion the hyperglucosylated adhesin is the first example of an N-glucosylated native antigen that can be considered a relevant candidate for triggering pathogenic antibodies in MS.
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Adhesinas Bacterianas/inmunología , Anticuerpos/inmunología , Haemophilus influenzae/inmunología , Esclerosis Múltiple/inmunología , Adulto , Anciano , Antígenos Bacterianos/inmunología , Asparagina/inmunología , Proteínas de la Membrana Bacteriana Externa/inmunología , Femenino , Glicoconjugados/inmunología , Glicopéptidos/inmunología , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
Surface plasmon resonance (SPR) technique is extremely interesting in immunology because it has the potential to directly visualize biomolecular interactions in real-time monitoring antibody affinity, one of the parameters affecting pathogenicity in autoimmune diseases. Herein we describe the affinity evaluation of anti-citrullinated peptide antibodies (ACPA) to a peptide-based biosensor by SPR. The method describes the purification of ACPA isolated from rheumatoid arthritis (RA) patients using affinity columns, the strategy employed for the immobilization of citrullinated peptides onto a sensor chip, and the evaluation of the specific binding of purified ACPA to immobilized peptides.
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Anticuerpos/química , Anticuerpos/inmunología , Afinidad de Anticuerpos/inmunología , Citrulina/química , Péptidos/química , Péptidos/inmunología , Resonancia por Plasmón de Superficie/métodos , Anticuerpos/aislamiento & purificación , Cromatografía de Afinidad , Concentración de Iones de Hidrógeno , CinéticaRESUMEN
Adalimumab (ADA) is a TNF-α blocker drug antibody fully humanized and thus indistinguishable in structure and function from natural human IgG1, used in the juvenile idiopathic arthritis (JIA) treatment. Immunogenicity against the drug has been frequently detected in treated patients, and the presence of anti-ADA antibodies is correlated to treatment failure or lower clinical remission. Herein, we measured by surface plasmon resonance (SPR) both the binding and the affinity of anti-ADA antibodies to the ADA-immobilized biosensor. The binding of anti-ADA antibodies was evaluated by testing sera from ADA-treated patients (n = 30), untreated patients (n = 9), and healthy donors (n = 20) in the SPR biosensor. The optimal cut-off point was defined using the receiver operating characteristic curve (ROC-curve) analysis with 79 % (60.28 to 92.01 %, 95 % CI) sensitivity, 99 % (88.06 to 100.0 %, 95 % CI) specificity, and a positive likelihood ratio of 23. The area under the curve was 0.9298 (p < 0.0001). The apparent affinity of anti-ADA antibodies from pediatric patients' sera was measured, analyzing the interaction of anti-drug antibodies using whole sera, enriched IgG fractions, and isolated anti-ADA antibodies. The immobilized drug ADA interacted with purified antibodies at low affinities (10(-6) M > K D > 10(-9) M). Graphical Abstract Adalimumab immobilized on the biosensor chip surface detects specific anti-drug antibodies in treated patients' sera.
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Adalimumab/inmunología , Resonancia por Plasmón de Superficie/métodos , Adolescente , Niño , Preescolar , Femenino , Humanos , Cinética , MasculinoRESUMEN
Surface plasmon resonance technique is particularly interesting in immunology because it has the potential to visualize label-free antigen-antibody interactions in real-time, thus enabling antibody detection and monitoring. Herein we release the guidelines for the correct use of a method to detect specific antibodies directly in Multiple Sclerosis patients' sera using a glucopeptide-based label-free biosensor. The protocol describes the strategy employed for the immobilization of glucopeptide antigen onto a gold sensor chip and the evaluation of the specific binding of serum antibodies to the immobilized antigen. â¢Label-free method for the real time screening of disease-specific antibodies within a few minutes;â¢The described protocol employs small quantities of glucopeptide antigen and blood serum samples saving method-cost;â¢Stability of the immobilized glucopeptide antigen guarantees the regeneration of the surface allowing re-use the immunosensor with high automated throughput. The antibodies detected using the described methodology can be evaluated as biomarkers of Multiple Sclerosis. The SPR detection system is able to characterize antibodies significantly different from those evaluated in the classical enzyme-linked immunosorbent assays (ELISA).
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Antibody detection in autoimmune disorders, such as multiple sclerosis (MS) and Rett syndrome (RTT) can be achieved more efficiently using synthetic peptides. The previously developed synthetic antigenic probe CSF114(Glc), a type I' ß-turn N-glucosylated peptide structure, is able to recognize antibodies in MS and RTT patients' sera as a sign of immune system derangement. We report herein the design, synthesis, conformational analysis, and immunological evaluation of a collection of glycopeptide analogs of CSF114(Glc) to characterize the specific role of secondary structures in MS and RTT antibody recognition. Therefore, we synthesized a series of linear and cyclic short glucosylated sequences, mimicking different ß-turn conformations, which were evaluated in inhibition enzyme-linked immunosorbent assays (ELISA). Calculated IC50 ranking analysis allowed the selection of the candidate octapeptide containing two (S)-2-amino-4-pentynoic acid (L-Pra) residues Ac-Pra-RRN(Glc)GHT-Pra-NH2 , with an IC50 in the nanomolar range. This peptide was adequately modified for solid-phase ELISA (SP-ELISA) and surface plasmon resonance (SPR) experiments. Pra-RRN(Glc)GHT-Pra-NH2 peptide was modified with an alkyl chain linked to the N-terminus, favoring immobilization on solid phase in SP-ELISA and differentiating IgG antibody recognition between patients and healthy blood donors with a high specificity. However, this peptide displayed a loss in IgM specificity and sensitivity. Moreover, an analog was obtained after modification of the octapeptide candidate Ac-Pra-RRN(Glc)GHT-Pra-NH2 to favor immobilization on SPR sensor chips. SPR technology allowed us to determine its affinity (KD = 16.4 nM), 2.3 times lower than the affinity of the original glucopeptide CSF114(Glc) (KD = 7.1 nM).
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Glicoconjugados/química , Esclerosis Múltiple/inmunología , Síndrome de Rett/inmunología , Especificidad de Anticuerpos , Ensayo de Inmunoadsorción Enzimática , Humanos , Concentración 50 Inhibidora , Conformación ProteicaRESUMEN
Rett syndrome (RTT), a neurodevelopmental disorder affecting exclusively (99%) female infants, is associated with loss-of-function mutations in the gene encoding methyl-CpG binding protein 2 (MECP2) and, more rarely, cyclin-dependent kinase-like 5 (CDKL5) and forkhead box protein G1 (FOXG1). In this study, we aimed to evaluate the function of the immune system by measuring serum immunoglobulins (IgG and IgM) in RTT patients (n = 53) and, by comparison, in age-matched children affected by non-RTT pervasive developmental disorders (non-RTT PDD) (n = 82) and healthy age-matched controls (n = 29). To determine immunoglobulins we used both a conventional agglutination assay and a novel ELISA based on antibody recognition by a surrogate antigen probe, CSF114(Glc), a synthetic N-glucosylated peptide. Both assays provided evidence for an increase in IgM titer, but not in IgG, in RTT patients relative to both healthy controls and non-RTT PDD patients. The significant difference in IgM titers between RTT patients and healthy subjects in the CSF114(Glc) assay (P = 0.001) suggests that this procedure specifically detects a fraction of IgM antibodies likely to be relevant for the RTT disease. These findings offer a new insight into the mechanism underlying the Rett disease as they unveil the possible involvement of the immune system in this pathology.
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Sistema Inmunológico/inmunología , Inmunoglobulina G/inmunología , Inmunoglobulina M/inmunología , Síndrome de Rett/inmunología , Adolescente , Pruebas de Aglutinación/métodos , Niño , Preescolar , Ensayo de Inmunoadsorción Enzimática , Femenino , Factores de Transcripción Forkhead/genética , Glicopéptidos/inmunología , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Proteína 2 de Unión a Metil-CpG/genética , Mutación , Proteínas del Tejido Nervioso/genética , Proteínas Serina-Treonina Quinasas/genética , Síndrome de Rett/sangre , Síndrome de Rett/genética , Adulto JovenRESUMEN
Multiple sclerosis (MS) is a chronic auto-immune disease characterized by a damage to the myelin component of the central nervous system. Self-antigens created by aberrant glycosylation have been described to be a key component in the formation of auto-antibodies. CSF114(Glc) is a synthetic glucopeptide detecting in vitro MS-specific auto-antibodies, and it is actively used in diagnostics and research to monitor and quantify MS-associated Ig levels. We reasoned that antibodies raised against this probe could have been relevant for MS. We therefore screened a human Domain Antibody library against CSF114(Glc) using magnetic separation as a panning method. We obtained and described several clones, and the one with the highest signals was produced as a 6×His-tagged protein to properly study the binding properties as a soluble antibody. By surface plasmon resonance measurements, we evidenced that our clone recognized CSF114(Glc) with high affinity and specific for the glucosylated peptide. Kinetic parameters of peptide-clone interaction were calculated obtaining a value of KD in the nanomolar range. Harboring a human framework, this antibody should be very well tolerated by human immune system and may represent a valuable tool for MS diagnosis and therapy, paving the way to new research strategies.
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Anticuerpos/química , Esclerosis Múltiple/inmunología , Proteínas Recombinantes/química , Secuencia de Aminoácidos , Ensayo de Inmunoadsorción Enzimática , Humanos , Cinética , Modelos Moleculares , Datos de Secuencia Molecular , Esclerosis Múltiple/diagnóstico , Péptidos/química , Péptidos/inmunología , Proteínas Recombinantes/inmunología , Análisis de Secuencia de Proteína , Resonancia por Plasmón de SuperficieRESUMEN
Anti-citrullinated protein/peptide antibodies (ACPAs) are detected in rheumatoid arthritis (RA) sera and because of their strict association with the disease are considered marker antibodies, probably endowed with pathogenic potential. Antibody affinity is one of the parameters affecting pathogenicity. Three diagnostic citrullinated peptides-viral citrullinated peptide 1 (VCP1) and VCP2 derived from Epstein-Barr virus (EBV)-encoded proteins and histone citrullinated peptide 1 (HCP1) derived from histone H4-were synthesized as tetrameric multiple antigen peptides and immobilized on sensor chips CM5 type in a Biacore T100 instrument. Specific binding of purified antibodies from RA patients to the three peptides was analyzed by surface plasmon resonance using two arginine-containing sequences as controls. Employing a 1:1 binding model for affinity constant calculation, ACPAs interacted with VCP1 and VCP2 with lower apparent affinity (10(-6) M>KD>10(-7) M) and interacted with HCP1 with higher apparent affinity (KD=10(-8) M). The results indicate that the binding to citrullinated peptides is characterized by wide differences in affinity, with slower association and faster dissociation rates in the case of antibodies to viral citrullinated peptides as compared with antibodies specific for the histone peptide. This biosensor analysis shows the high cross-reactivity of purified ACPAs that bind other citrullinated peptides besides the one used for purification.
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Anticuerpos Antivirales/química , Afinidad de Anticuerpos , Bioensayo/métodos , Herpesvirus Humano 4/química , Modelos Químicos , Fragmentos de Péptidos/análisis , Proteínas Virales/análisis , Anticuerpos Antivirales/inmunología , Reacciones Cruzadas , Herpesvirus Humano 4/inmunología , Humanos , Fragmentos de Péptidos/química , Proteínas Virales/químicaRESUMEN
A series of ultrasonic assisted acid washing and thermal desorption tests were performed on sludge and other solid matrices with the aim to assay these removal technologies and to determine if the application of low frequency ultrasound was effective to enhance mercury removal. Unpolluted dredging sludge, 820 K calcinated dredging sludge, silica and alumina were characterized, polluted with a known concentration of mercury and treated both by acid washing and thermal desorption with and without low frequency ultrasound application. The acid washing was carried out by a 4% HNO(3) acid solution and the thermal desorption was performed in a 370-620K range. X-ray semi-quantitative analysis of dredging sludge before and after acid washing and granulometric curves of the matrices after the ultrasonic treatment were considered in order to evidence chemical or physical changes during these treatments. Total residual mercury measurements were carried out before and after sonication. Results showed not measurable acid washing extraction from polluted dredging sludge, a little (3%) extraction from 820K heat-treated sludge and a significant (10-20%) extraction from alumina and silica within 120 min of treatment. The ultrasound application gave generally poor improvement of the mercury removal. On the contrary thermal desorption of mercury was somewhat effective for alumina, silica and heat-treated dredging sludge samples in which mercury removal was 30-40% at 370 K and 90-99% at 570 K. Likewise ultrasound application did not improve desorption. Instead, the thermal treatment of dredging sludge had a negligible amount of mercury desorption at 370 K but it reached 95% at 570 K. The application of ultrasound improved the thermal extraction of 25% in the 470-520 K range of temperature.