66 research outputs found
Safety and efficacy of gene therapy for Pompe disease
No full textLa malattia di Pompe è una malattia neuromuscolare grave causata da mutazioni nell’enzima lisosomiale -glucosidasi acida (GAA), le quali determinano l'accumulo patologico di glicogeno in tutti i tessuti. La terapia di sostituzione enzimatica (ERT) è disponibile per la suddetta malattia, ma essa ha solo una limitata efficacia, mentre mostra un’elevata immunogenicità, e non riesce a correggere gruppi di tessuti muscolari e nervosi più refrattari alla cross-csorrezione. Usando l'analisi bioinformatica e ingegnerizzando l’enzima, abbiamo sviluppato transgeni GAA secrenibili per una maggiore cross-correzione della malattia di Pompe tramite virus adeno associati (AAV) attraverso l’espressione epato-specifica della GAA. I topi Pompe sono stati trattati con vettori AAV ottimizzati per l'espressione dei transgeni secrenibili della GAA e fatto un follow-up di 10 mesi. Il trasferimento genico ha evidenziato una correzione dose e tempo dipendente di entrambi i difetti biochimici e funzionali nei muscoli, sistema nervoso centrale e del midollo spinale, con normalizzazione di ipertrofia cardiaca, muscolare e funzione respiratoria, e la sopravvivenza indistinguibile dai topi wild-type. In questi esperimenti, transgeni GAA secernibili hanno mostrato un’efficacia terapeutica superiore e decisamente una bassa immunogenicità rispetto alla loro controparte GAA non secreta. La dimostrazione di un grande potenziale terapeutico e’ evidenziata dal fatto che l’AAV iniettato in primati era in grado di eprimere e secernere discreti livelli di GAA in circolo, ed utilizzando nuovi serotipi di AAV potevamo esprimere la GAA anche in epatociti primari. Considerando che l'immunogenicità della -glucosidasi acida ricombinante (rhGAA) nella terapia enzimatica sostitutiva (ERT) è un problema cosi come l'efficacia nella gestione della malattia di Pompe nei pazienti adulti (LOPD), effetti a lungo termine del ERT sulle risposte umorali e cellulari alla GAA sono ancora poco compresi. Per capire meglio l'impatto dell’immunogenicità del rhGAA sull'efficacia della ERT, dati clinici e campioni di sangue di pazienti LOPD sottoposti a ERT per più di 4 anni o non trattati sono stati raccolti e analizzati. Nei pazienti trattati LOPD, anticorpi anti-GAA avevano un picco entro i primi 1000 giorni di ERT, mentre l'esposizione a lungo termine per rhGAA comportava una clearance degli anticorpi con una produzione residua di IgG non neutralizzanti. Analisi di risposte delle cellule T al rhGAA mostravano una rilevabile reattività delle cellule T solo dopo una ristimolazione in vitro. Incremento di diverse citochine e chemochine era rilevabile sia in soggetti LOPD trattati e non trattati, mentre la secrezione di IL-2 era rilevabile solo nei soggetti che avevano ricevuto ERT. Questi risultati indicano che l’ERT a lungo termine in pazienti LOPD comporta una diminuzione dei titoli anticorpali ed una produzione residua di IgG non inibitorie. Una risposta immunitaria alla GAA a lungo termine in soggetti sottoposti a ERT non sembra influenzare l'efficacia della terapia e sono coerenti con un effetto immunomodulante eventualmente mediata da cellule T regolatorie.Pompe disease is a severe neuromuscular disorder caused by mutations in the lysosomal enzyme acid -glucosidase (GAA), which result in the pathological accumulation of glycogen in all tissues. Enzyme replacement therapy (ERT) is available for Pompe disease, however it has only limited efficacy, high immunogenicity, and fails to correct nervous tissue and muscle groups more refractory to cross-correction. Using bioinformatics analysis and protein engineering, we developed secretable GAA transgenes for enhanced cross-correction of Pompe disease via adeno-associated virus (AAV) vector liver gene transfer. Pompe mice were treated with AAV vectors optimized for hepatic expression of secretable GAA transgenes and followed for up to 10 months post-gene transfer. Gene transfer resulted in dose- and time- dependent whole-body correction of both the biochemical and functional defects in muscle, central nervous system and spinal cord, with normalization of cardiac hypertrophy, muscle and respiratory function, and survival undistinguishable from wild-type littermates. In these experiments, secretable GAA transgenes showed superior therapeutic efficacy and markedly low immunogenicity compared with their native GAA counterpart. Scale up to non-human primates, and modeling of GAA expression in primary hepatocytes using novel AAV vector serotypes, demonstrate the therapeutic potential of AAV vector-mediated liver expression of secretable GAA transgenes, and support the feasibility of the approach in Pompe patients.
Considering that immunogenicity of recombinant human acid-alpha glucosidase (rhGAA) in enzyme replacement therapy (ERT) is a safety and efficacy concern in the management of late-onset Pompe disease (LOPD), long-term effects of ERT on humoral and cellular responses to GAA are still poorly understood. To better understand the impact of immunogenicity of rhGAA on the efficacy of ERT, clinical data and blood samples from LOPD patients undergoing ERT for more than 4 years or untreated were collected and analyzed. In treated LOPD patients, anti-GAA antibodies peaked within the first 1000 days of ERT, while long-term exposure to rhGAA resulted in clearance of antibodies with residual production of non-neutralizing IgG. Analysis of T cell responses to rhGAA showed detectable T cell reactivity only after in vitro restimulation. Upregulation of several cytokines and chemokines was detectable both treated and untreated LOPD subjects, while IL2 secretion was detectable only in subjects who received ERT. These results indicate that long-term ERT in LOPD patients results in a decrease in antibody titers and residual production of non-inhibitory IgGs. Immune responses to GAA following long-term ERT do not seem to affect efficacy of ERT and are consistent with an immunomodulatory effect possibly mediated by regulatory T cells
SO2 resistant soot oxidation catalysts based on orthovanadates
No full textMetal orthovanadates based on Fe, Al and Ce were prepared by co-precipitation and their structural,
morphological and reduction properties were characterized by means of XRD, BET and temperature
programmed reduction (H2-TPR). Catalytic soot oxidation was carried out with thermogravimetric analysis
(TGA) and temperature programmed oxidation (TPO), respectively, to study the influence of the soot-catalyst
contact (tight or loose) as well as the influence of SO2 contamination on the catalyst's activity. The catalysts were
compared with CeO2 as reference material. Under tight contact mode, metal orthovanadates were able to oxidize
soot at 466–483 °C while in loose contact mode their activity was close to that of CeO2. However, the former did
not suffer an activity loss due to SO2 poisoning, which is attributed to less adsorptive interactions between SO2
and the vanadates as could be proven by FT-IR and Raman spectroscopy
The carboxyl-terminal region is NOT essential for secreted and functional levels of coagulation factor X
No full textBackground: The homologous coagulation factor X (FX), VII (FVII), IX (FIX) and protein C (PC) display striking differences in the carboxyl-terminus, with that of FX being the most extended. This region is essential for FVII, FIX and PC secretion. Objectives: To provide experimental evidence for the role of the FX carboxyl-terminus. Methods: Recombinant FX (rFX) variants were expressed in multiple eukaryotic cell systems. Protein and activity levels were evaluated by ELISA, coagulant and amidolytic assays. Results and discussion: Expression of a panel of progressively truncated rFX variants in HEK293 cells revealed that the deletion of up to 21 residues in the carboxyl-terminus did not significantly affect secreted protein levels, as confirmed in HepG2 and BHK21 cells. In contrast, chimeric rFX-FVII variants with swapped terminal residues showed severely reduced levels. The truncated rFX variants revealed normal amidolytic activity, suggesting an intact active site. Intriguingly, these variants, which included that resembling the activated FXβ form once cleaved, also displayed remarkable or normal pro-coagulant capacity in PT- and aPTT-based assays. This supports the hypothesis that subjects with nonsense mutations in the FX carboxyl-terminus, so far never identified, would be asymptomatic. Conclusions: For the first time we demonstrate that the FX carboxyl-terminal region downstream of residue K467 is not essential for secretion and provides a modest contribution to pro-coagulant properties. These findings, which might suggest an involvement of the carboxyl-terminal region in the divergence of the homologous FX, FVII, FIX and PC, help to interpret the mutational pattern of FX deficiency
Improved process for the transformation of primary aliphatic alcohols into higher aliphatic alcohols
No full textA process for obtaining higher aliphatic alcohols starting from aliphatic primary alcohols by condensation reactions is disclosed. Specifically, the process comprises a step in which an aliphatic primary alcohol is contacted in a 5 homogeneous phase with a catalyst mixture comprising a transition metal, a base and an additive; specifically, this additive can be selected from the classes of compounds of the isoquinolines N-oxide, quinolines N-oxide, pyridines N-oxide, benzoquinones, naphthoquinones, or TEMPO. In particular, the process can be carried out by contacting said aliphatic primary alcohol with a catalyst of a 10 recycled transition metal, with a freshly added base and with a recycled additive of the aforementioned type
Stacking the Nanochemistry Deck: Structural and Compositional Diversity in One-Dimensional Photonic Crystals
No full textOne-dimensional photonic structures, known as Bragg stacks reflectors or Bragg mirrors, represent a well-developed subject in the field of optical science. However, because of a lack of dynamic tunablity and their dependence on complex top-down techniques for their fabrication, they have received little attention from the materials science community present recent and ongoing developments on the way to fun dimensional photonic structures obtained from simple botton-up techniques. We focus on the versatility of this new approach, which allows the incorporation of a wide range of materials into photonic structures
Procedimento migliorato per la trasformazione di alcoli alifatici primari in alcoli alifatici superiori
No full textViene descritto un procedimento per l’ottenimento di alcoli alifatici superiori a partire da alcoli primari alifatici tramite reazioni di condensazione. Nello specifico il procedimento comprende un passaggio in cui si mette a contatto in fase omogenea un alcol primario alifatico con un catalizzatore contenente un metallo di transizione, una base ed un additivo; nello specifico tale additivo può essere scelto fra le classi di composti delle isochinoline N-ossido, chinoline N-ossido, piridine N-ossido, benzochinoni, naftochinoni o TEMPO. In particolare, il procedimento può essere effettuato mettendo a contatto detto alcol primario alifatico con un catalizzatore di un metallo di transizione di riciclo, con una base aggiunta di fresco e con un additivo di riciclo del tipo suddetto
A New Process for Maleic Anhydride Synthesis from a Renewable Building Block: The Gas-Phase Oxidehydration of Bio-1-butanol
No full textWe investigated the synthesisofmaleic anhydride by oxidehydration of abio-alcohol, 1-butanol,asapossible alternative to the classical process of n-butane oxidation. Avanadyl pyrophosphate catalystwas used to explore the one-pot reaction, which involved two sequential steps:1)1-butanol dehydration to 1-butene, catalysed by acid sites, and 2) the oxidation of butenes to maleic anhydride,catalysed by redox sites. Anon-negligible amount of phthalic anhydride wasalso formed. The effect of different experimentalparameters was investigated
with chemically sourced1-butanol,and the results werethen confirmed by using genuinely bio-sourced 1-butanol. In the case of bio-1-butanol, however,the purity of the product remarkably affected the yield of maleic anhydride. It was found that the reactionmechanism includes the oxidation of butenes to crotonaldehyde and the oxidation of the latter to either furan or maleic acid, both of which are transformed to produce maleic anhydride
Procedimento migliorato per la trasformazione di alcoli alifatici primari in alcoli alifatici superiori
No full textViene descritto un procedimento per l’ottenimento di alcoli alifatici superiori a partire da alcoli primari alifatici tramite reazioni di condensazione. Nello specifico il procedimento comprende un passaggio in cui si mette a contatto in fase omogenea un alcol primario alifatico con un catalizzatore contenente un metallo di transizione, una base ed un additivo; nello specifico tale additivo può essere scelto fra le classi di composti delle isochinoline N-ossido, chinoline N-ossido, piridine N-ossido, benzochinoni, naftochinoni o TEMPO. In particolare, il procedimento può essere effettuato mettendo a contatto detto alcol primario alifatico con un catalizzatore di un metallo di transizione di riciclo, con una base aggiunta di fresco e con un additivo di riciclo del tipo suddetto
Industry 4.0 and Human Resource Management Processes: A Qualitative Study.
No full textIndustry 4.0 and Human Resource Management Processes: A Qualitative Study
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