Combined chemical synthesis and tailored enzymatic elongation provide fully synthetic and conjugation-ready Neisseria meningitidis serogroup X vaccine antigens

Studies on the polymerization mode of Neisseria meningitidis serogroup X capsular polymerase CsxA recently identified a truncated construct that can be immobilized and used for length controlled on-column production of oligosaccharides. Here, we combined the use of a synthetic acceptor bearing an appendix for carrier protein conjugation and the on-column process to a novel chemo-enzymatic strategy. After protein coupling of the size optimized oligosaccharide produced by the one-pot elongation procedure, we obtained a more homogeneous glycoconjugate compared to the one previously described starting from the natural polysaccharide. Mice immunized with the conjugated fully synthetic oligomer elicited functional antibodies comparable to controls immunized with the current benchmark MenX glycoconjugates prepared from the natural capsule polymer or from fragments of it enzymatically elongated. This pathogen-free technology allows the fast total in vitro construction of predefined bacterial polysaccharide fragments. Compared to conventional synthetic protocols, the procedure is more expeditious and drastically reduces the number of purification steps to achieve the oligomers. Furthermore, the presence of a linker for conjugation in the synthetic acceptor minimizes manipulations on the enzymatically produced glycan prior to protein conjugation. This approach enriches the methods for fast construction of complex bacterial carbohydrates

Synthesis and immunological evaluation of protein conjugates of neisseria meningitidis X capsular polysaccharide fragments

A vaccine to prevent infections from the emerging Neisseria meningitidis X (MenX) is becoming an urgent issue. Recently MenX capsular polysaccharide (CPS) fragments conjugated to CRM197 as carrier protein have been confirmed at preclinical stage as promising candidates for vaccine development. However, more insights about the minimal epitope required for the immunological activity of MenX CPS are needed. We report herein the chemical conjugation of fully synthetic MenX CPS oligomers (monomer, dimer, and trimer) to CRM197. Moreover, improvements in some crucial steps leading to the synthesis of MenX CPS fragments are described. Following immunization with the obtained neoglycoconjugates, the conjugated trimer was demonstrated as the minimal fragment possessing immunogenic activity, even though significantly lower than a pentadecamer obtained from the native polymer and conjugated to the same protein. This finding suggests that oligomers longer than three repeating units are possibly needed to mimic the activity of the native polysaccharide

Therapeutic vulnerability of multiple myeloma to MIR17PTi, a first-in-class inhibitor of pri-mir-17-92

The microRNA cluster miR-17-92 is oncogenic and represents a valuable therapeutic target in c-MYC (MYC)-driven malignancies. Here, we developed novel LNA gapmeR antisense oligonucleotides (ASOs) to induce RNase H-mediated degradation of MIR17HG primary transcripts and, consequently, to prevent biogenesis of miR-17-92 microRNAs (miR-17-92s). The leading LNA-ASO, named MIR17PTi, impaired proliferation of several cancer cell lines (n=48) established from both solid and hematologic tumors by on-target antisense activity, and more effectively as compared to miR-17-92s inhibitors. By focusing on multiple myeloma (MM), we found that MIR17PTi triggers apoptosis via impairment of homeostatic MYC/miR-17-92 feed-forward loops (FFLs) in patient-derived MM cells; and induced MYC-dependent synthetic lethality. We show that alteration of a BIM-centered FFL is instrumental for MIR17PTi to induce cytotoxicity in MM cells. MIR17PTi exerts strong in vivo anti-tumor activity in NOD-SCID mice bearing clinically relevant models of MM, with advantageous safety and pharmacokinetics profiles in non-human primates. Altogether, MIR17PTi is a novel pharmacological tool to be tested in early-phase clinical trials against MM and other MYC-driven malignancies

Synthetic miR-34a mimics as a novel therapeutic agent for Multiple Myeloma : in vitro and in vivo evidence

PURPOSE: Deregulated expression of microRNAs (miRNAs) has been demonstrated in multiple myeloma (MM). A promising strategy to achieve a therapeutic effect by targeting the miRNA regulatory network is to enforce the expression of miRNAs that act as tumor suppressor genes, such as miR-34a EXPERIMENTAL DESIGN: Here, we investigated the therapeutic potential of synthetic miR-34a against human MM cells in vitro and in vivo RESULTS: Either transient expression of miR-34a synthetic mimics or lentivirus-based stable enforced expression of miR-34a gene triggered growth inhibition and apoptosis in MM cells in vitro. Synthetic miR-34a downregulated canonic targets BCL2, CDK6 and NOTCH1 at both the mRNA and protein level. Lentiviral vector-transduced MM xenografts with constitutive miR-34a expression showed high growth inhibition in SCID mice. The anti-MM activity of lipidic-formulated miR-34a was further demonstrated in vivo in two different experimental settings: i) SCID mice bearing non transduced MM xenografts; and ii) SCID-synth-hu mice implanted with synthetic 3D scaffolds reconstituted with human bone marrow stromal cells and then engrafted with human MM cells. Relevant tumor growth inhibition and survival improvement were observed in mice bearing TP53-mutated MM xenografts treated with miR-34a mimics in the absence of systemic toxicity CONCLUSIONS: Our findings provide a proof-of-principle that formulated synthetic miR-34a has therapeutic activity in preclinical models and support a framework for development of miR-34a-based treatment strategies in MM patients

Synthetic miR-34a mimics as a novel therapeutic agent for Multiple Myeloma : in vitro and in vivo evidence

PURPOSE: Deregulated expression of microRNAs (miRNAs) has been demonstrated in multiple myeloma (MM). A promising strategy to achieve a therapeutic effect by targeting the miRNA regulatory network is to enforce the expression of miRNAs that act as tumor suppressor genes, such as miR-34a EXPERIMENTAL DESIGN: Here, we investigated the therapeutic potential of synthetic miR-34a against human MM cells in vitro and in vivo RESULTS: Either transient expression of miR-34a synthetic mimics or lentivirus-based stable enforced expression of miR-34a gene triggered growth inhibition and apoptosis in MM cells in vitro. Synthetic miR-34a downregulated canonic targets BCL2, CDK6 and NOTCH1 at both the mRNA and protein level. Lentiviral vector-transduced MM xenografts with constitutive miR-34a expression showed high growth inhibition in SCID mice. The anti-MM activity of lipidic-formulated miR-34a was further demonstrated in vivo in two different experimental settings: i) SCID mice bearing non transduced MM xenografts; and ii) SCID-synth-hu mice implanted with synthetic 3D scaffolds reconstituted with human bone marrow stromal cells and then engrafted with human MM cells. Relevant tumor growth inhibition and survival improvement were observed in mice bearing TP53-mutated MM xenografts treated with miR-34a mimics in the absence of systemic toxicity CONCLUSIONS: Our findings provide a proof-of-principle that formulated synthetic miR-34a has therapeutic activity in preclinical models and support a framework for development of miR-34a-based treatment strategies in MM patients

Space Telescope and Optical Reverberation Mapping Project. VII. Understanding the Ultraviolet Anomaly in NGC 5548 with X-Ray Spectroscopy

During the Space Telescope and Optical Reverberation Mapping Project observations of NGC 5548, the continuum and emission-line variability became decorrelated during the second half of the six-month-long observing campaign. Here we present Swift and Chandra X-ray spectra of NGC 5548 obtained as part of the campaign. The Swift spectra show that excess flux (relative to a power-law continuum) in the soft X-ray band appears before the start of the anomalous emission-line behavior, peaks during the period of the anomaly, and then declines. This is a model-independent result suggesting that the soft excess is related to the anomaly. We divide the Swift data into on- and off-anomaly spectra to characterize the soft excess via spectral fitting. The cause of the spectral differences is likely due to a change in the intrinsic spectrum rather than to variable obscuration or partial covering. The Chandra spectra have lower signal-to-noise ratios, but are consistent with the Swift data. Our preferred model of the soft excess is emission from an optically thick, warm Comptonizing corona, the effective optical depth of which increases during the anomaly. This model simultaneously explains all three observations: the UV emission-line flux decrease, the soft-excess increase, and the emission-line anomaly

Hepatitis E in Italy : 5 years of national epidemiological, virological and environmental surveillance, 2012 to 2016

Increasing numbers of hepatitis E cases are being reported in several European countries, including Italy, but the burden of hepatitis E virus (HEV) infection is largely unknown in the latter. To gain a better understanding of HEV epidemiology at national level in Italy, we piloted a strengthened and integrated human (epi-demiological and virological) and environmental HEV surveillance system between 2012 and 2016. Over the 5-year period, 169 confirmed hepatitis E cases were identified, with a national annual incidence of 0.72 cases per 1,000,000. Of 65 HEV-RNA positive samples of sufficient quality for molecular analysis, 66% were genotype HEV3, 32% HEV1 and 1% HEV4. The most frequent risk factor reported by all HEV3 infected cases, was the consumption of undercooked pork and sausage. For the environmental surveillance, 679 urban sewage samples were collected from 53 wastewater treatment plants and HEV-RNA was detected in 38/679 of the samples. Among these, 25 (66%) were genotype HEV3 and the remaining were HEV1. We demonstrate that autochthonous transmission and environmental circulation of genotype HEV3 is adding to travel-related HEV transmission in Italy. We recommend the \u2018One Health\u2019 approach to integrated surveillance, and to include HEV-related messages within health information campaigns focussing on food security

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele