Safety and immunogenicity of a recombinant protein RBD fusion heterodimer vaccine against SARS-CoV-2.

In response to COVID-19 pandemic, we have launched a vaccine development program against SARS-CoV-2. Here we report the safety, tolerability, and immunogenicity of a recombinant protein RBD fusion heterodimeric vaccine against SARS-CoV-2 (PHH-1V) evaluated in a phase 1-2a dose-escalation, randomized clinical trial conducted in Catalonia, Spain. 30 young healthy adults were enrolled and received two intramuscular doses, 21 days apart of PHH-1V vaccine formulations [10 µg (n = 5), 20 µg (n = 10), 40 µg (n = 10)] or control [BNT162b2 (n = 5)]. Each PHH-1V group had one safety sentinel and the remaining participants were randomly assigned. The primary endpoint was solicited events within 7 days and unsolicited events within 28 days after each vaccination. Secondary endpoints were humoral and cellular immunogenicity against the variants of concern (VOCs) alpha, beta, delta and gamma. All formulations were safe and well tolerated, with tenderness and pain at the site of injection being the most frequently reported solicited events. Throughout the study, all participants reported having at least one mild to moderate unsolicited event. Two unrelated severe adverse events (AE) were reported and fully resolved. No AE of special interest was reported. Fourteen days after the second vaccine dose, all participants had a >4-fold change in total binding antibodies from baseline. PHH-1V induced robust humoral responses with neutralizing activities against all VOCs assessed (geometric mean fold rise at 35 days p < 0.0001). The specific T-cell response assessed by ELISpot was moderate. This initial evaluation has contributed significantly to the further development of PHH-1V, which is now included in the European vaccine portfolio.ClinicalTrials.gov Identifier NCT05007509EudraCT No. 2021-001411-82.

Preclinical evaluation of PHH-1V vaccine candidate against SARS-CoV-2 in non-human primates.

SARS-CoV-2 emerged in December 2019 and quickly spread worldwide, continuously striking with an unpredictable evolution. Despite the success in vaccine production and mass vaccination programs, the situation is not still completely controlled, and therefore accessible second-generation vaccines are required to mitigate the pandemic. We previously developed an adjuvanted vaccine candidate coded PHH-1V, based on a heterodimer fusion protein comprising the RBD domain of two SARS-CoV-2 variants. Here, we report data on the efficacy, safety, and immunogenicity of PHH-1V in cynomolgus macaques. PHH-1V prime-boost vaccination induces high levels of RBD-specific IgG binding and neutralizing antibodies against several SARS-CoV-2 variants, as well as a balanced Th1/Th2 cellular immune response. Remarkably, PHH-1V vaccination prevents SARS-CoV-2 replication in the lower respiratory tract and significantly reduces viral load in the upper respiratory tract after an experimental infection. These results highlight the potential use of the PHH-1V vaccine in humans, currently undergoing Phase III clinical trials.

Immunogenicity and safety in pigs of PHH-1V, a SARS-CoV-2 RBD fusion heterodimer vaccine candidate.

The continuing high global incidence of COVID-19 and the undervaccinated status of billions of persons strongly motivate the development of a new generation of efficacious vaccines. We have developed an adjuvanted vaccine candidate, PHH-1V, based on a protein comprising the receptor binding domain (RBD) of the Beta variant of SARS-CoV-2 fused in tandem with the equivalent domain of the Alpha variant, with its immunogenicity, safety and efficacy previously demonstrated in mouse models. In the present study, we immunized pigs with different doses of PHH-1V in a prime-and-boost scheme showing PHH-1V to exhibit an excellent safety profile in pigs and to produce a solid RBD-specific humoral response with neutralising antibodies to 7 distinct SARS-CoV-2 variants of concern, with the induction of a significant IFNγ+ T-cell response. We conclude that PHH-1V is safe and elicits a robust immune response to SARS-CoV-2 in pigs, a large animal preclinical model.

Exploring FeLV-Gag-Based VLPs as a New Vaccine Platform-Analysis of Production and Immunogenicity.

Feline leukemia virus (FeLV) is one of the most prevalent infectious diseases in domestic cats. Although different commercial vaccines are available, none of them provides full protection. Thus, efforts to design a more efficient vaccine are needed. Our group has successfully engineered HIV-1 Gag-based VLPs that induce a potent and functional immune response against the HIV-1 transmembrane protein gp41. Here, we propose to use this concept to generate FeLV-Gag-based VLPs as a novel vaccine strategy against this retrovirus. By analogy to our HIV-1 platform, a fragment of the FeLV transmembrane p15E protein was exposed on FeLV-Gag-based VLPs. After optimization of Gag sequences, the immunogenicity of the selected candidates was evaluated in C57BL/6 and BALB/c mice, showing strong cellular and humoral responses to Gag but failing to generate anti-p15E antibodies. Altogether, this study not only tests the versatility of the enveloped VLP-based vaccine platform but also sheds light on FeLV vaccine research.

Preclinical evaluation of a COVID-19 vaccine candidate based on a recombinant RBD fusion heterodimer of SARS-CoV-2.

Current COVID-19 vaccines have been associated with a decline in infection rates, prevention of severe disease, and a decrease in mortality rates. However, SARS-CoV-2 variants are continuously evolving, and development of new accessible COVID-19 vaccines is essential to mitigate the pandemic. Here, we present data on preclinical studies in mice of a receptor-binding domain (RBD)-based recombinant protein vaccine (PHH-1V) consisting of an RBD fusion heterodimer comprising the B.1.351 and B.1.1.7 SARS-CoV-2 variants formulated in SQBA adjuvant, an oil-in-water emulsion. A prime-boost immunisation with PHH-1V in BALB/c and K18-hACE2 mice induced a CD4+ and CD8+ T cell response and RBD-binding antibodies with neutralizing activity against several variants, and also showed a good tolerability profile. Significantly, RBD fusion heterodimer vaccination conferred 100% efficacy, preventing mortality in SARS-CoV-2 infected K18-hACE2 mice, but also reducing Beta, Delta and Omicron infection in lower respiratory airways. These findings demonstrate the feasibility of this recombinant vaccine strategy.

Phosphorylation disrupts long-distance electron transport in cytochrome c.

It has been recently shown that electron transfer between mitochondrial cytochrome c and the cytochrome c1 subunit of the cytochrome bc1 can proceed at long-distance through the aqueous solution. Cytochrome c is thought to adjust its activity by changing the affinity for its partners via Tyr48 phosphorylation, but it is unknown how it impacts the nanoscopic environment, interaction forces, and long-range electron transfer. Here, we constrain the orientation and separation between cytochrome c1 and cytochrome c or the phosphomimetic Y48pCMF cytochrome c, and deploy an array of single-molecule, bulk, and computational methods to investigate the molecular mechanism of electron transfer regulation by cytochrome c phosphorylation. We demonstrate that phosphorylation impairs long-range electron transfer, shortens the long-distance charge conduit between the partners, strengthens their interaction, and departs it from equilibrium. These results unveil a nanoscopic view of the interaction between redox protein partners in electron transport chains and its mechanisms of regulation.

Catalytic Diastereo- and Enantioselective Synthesis of Tertiary Trifluoromethyl Carbinols through a Vinylogous Aldol Reaction of Alkylidenepyrazolones with Trifluoromethyl Ketones.

A diastereo- and enantioselective organocatalytic aldol reaction between alkylidenepyrazolones and trifluoromethyl ketones leading to chiral tertiary alcohols bearing a trifluoromethyl group is presented. The methodology is based on the use of a bifunctional organocatalyst in order to activate the γ-hydrogen atoms of the alkylidenepyrazolone nucleophile and the carbonyl group of the trifluoromethylarylketone providing highly functionalized trifluoromethyl alcohols with moderate yields, excellent diastereoselectivity, and moderate to good enantioselectivity. Experiments monitoring the conversion by 1H NMR and the enantiomeric excess by HPLC with the reaction time showed that full conversion of the starting materials is not achieved and that the enantiomeric excess decreases upon extended times, probably due to the reversibility of the reaction.

Evaluation of changes in pediatric healthcare activity during the Covid-19 state of alarm in the Canary Islands.

OBJECTIVE: During the SARS-CoV-2 state of alarm (SoA), a 30-70% reduction was observed in the number of visits to Pediatric Emergency Departments (ED), as well as frequent delay in diagnosis or difficulty accessing healthcare services. Here we evaluate modifications observed in pediatric healthcare activity during the SoA. STUDY DESIGN: Descriptive retrospective observational study of the hospital pediatric activity. METHOD: We compared the use of pediatric healthcare services during the SoA (March 11th - June 25th, 2020) versus the use during the equivalent periods of years 2018 and 2019, in the "Complejo Hospitalario Universitario Insular Materno Infantil de Canarias" (Mother and Child University Hospital of the Canary Islands). RESULTS: The number of patients visiting the pediatric ED decreased by 66.75% on average (95%CI: -65.6; - 67.7; p < 0.001), with a peak reduction (70.4%; 95%CI: -69.0; -71.7; p < 0.001) during the lockdown. We observed an increase in the number of cases of psychiatric disorders, foreign body ingestions and intoxications, as well as a decrease in respiratory conditions. Hospital admissions decreased by 45.5% (95%CI: - 38.9; -51.3; p < 0.001), while the ratio and duration of hospital stay increased. A proportion of 3.95% of admitted patients experienced complications caused by delayed visit to the ED. CONCLUSIONS: The study shows that more patient education campaigns are needed to improve the efficiency of emergency services. It is important to reinforce the message that adequate healthcare service management is necessary.

Catalytic Diastereo- and Enantioselective Vinylogous Mannich Reaction of Alkylidenepyrazolones to Isatin-Derived Ketimines.

A valuable organocatalytic vinylogous Mannich reaction between alkylidenepyrazolones and isatin-derived ketimines has been successfully established. Squaramide organocatalyst, prepared from quinine, catalyzed the diastereo- and enantioselective vinylogous Mannich addition, affording a range of aminooxindole-pyrazolone adducts (24 examples) with excellent outcomes: up to 98% yield with complete diastereoselectivity and excellent enantioselectivity (up to 99% ee). Additionally, different synthetic transformations were performed with the chiral pyrazolone-oxindole adducts.

Reference Intervals of Thyroid Function Tests Assessed by Immunoassay and Mass Spectrometry in Healthy Pregnant Women Living in Catalonia.

BACKGROUND: Recent guidelines recommend establishing a local reference interval (RI) for thyroid function. We aimed to establish trimester-specific RIs for thyrotropin (TSH) and free thyroxine (FT4) in a cohort of healthy pregnant women in Catalonia (Spain). METHODS: A prospective observational study was conducted with 332 healthy pregnant women, from the first trimester (1T) to delivery. TSH was measured using an Architect® immunoassay (Abbott) and FT4 by two immunoassays, Architect® (Abbott) and Cobas® (Roche), in the three trimesters. FT4 was also measured by liquid chromatography mass spectrometry (LC/MS/MS) in the 1T. RESULTS: TSH (µUI/mL) increased throughout pregnancy (1T: 0.03-3.78; 2T: 0.51-3.53; 3T: 0.50-4.32; p < 0.0001) and FT4 (pmol/L) progressively decreased (Architect® 1T: 10.42-15.96; 2T: 8.37-12.74; 3T: 8.24-12.49; p < 0.0001; and Cobas®: 1T: 11.46-19.05; 2T: 9.65-14.67; 3T: 8.88-14.54; p < 0.0067). The FT4 RI during 1T determined LC/MS/MS was 8.75-18.27. Despite the 1T FT4 results measured by LC/MS/MS and with the two immunoassays being significantly correlated, the results obtained by the three methods were found to be non-interchangeable. CONCLUSIONS: We established trimester-specific RIs for TSH and for FT4 with immunoassays in our population. We also validated the 1T FT4 using LC/MS/MS to confirm the results of FT4 lower than the 2.5th percentile or higher than the 97.5th percentile.

Design of vesicle prototissues as a model for cellular tissues.

Synthesizing biomimetic prototissues with predictable physical properties is a promising tool for the study of cellular tissues, as they would enable to test systematically the role of individual physical mechanisms on complex biological processes. The aim of this study is to design a biomimetic cohesive tissue with tunable mechanical properties by the controlled assembly of giant unillamelar vesicles (GUV). GUV-GUV specific adhesion is mediated by the inclusion of the streptavidin-biotin pair, or DNA complementary strands. Using a simple assembly protocol, we are capable of synthesizing vesicle prototissues of spheroidal or sheet-like morphologies, with predictable cell-cell adhesion strengths, typical sizes, and degree of compaction.

Automatic multicommuted flow systems applied in sample treatment for radionuclide determination in biological and environmental analysis.

The presence of artificial and natural radioactivity in the environment is currently a topic of great relevance and ecological interest, even in human health issue, due to the increase of different anthropogenic activities. The use of multicommuted flow analysis techniques (e.g. Multi-Syringe Flow Injection Analysis - MSFIA, Lab-On-Valve - LOV and Lab-In-Syringe - LIS) has allowed the automation of radiochemical procedures to separate and preconcentrate radionuclides in environmental and biological samples. In comparison with the manual approach commonly used in routine analysis for radioactivity monitoring, the automation has enabled the development of highly reproducible methodologies with a great analysis frequency. Moreover, during the analytical procedure, the intervention of the analyst is drastically reduced, minimizing the radiological risk. The automation also offers significant advantages such as minimum consumption of time and reagents, reducing the cost and the generation of waste, contributing to the green chemistry. In this review, several multicommuted flow analysis techniques (MSFIA, LOV and LIS) reported in the last decade applied for the development of automatic sample treatment methodologies, used to separate, preconcentrate and quantify 90Sr, 99Tc, natural U and 226Ra in biological and environmental samples are described and critically compared.

SIVA-1 regulates apoptosis and synaptic function by modulating XIAP interaction with the death receptor antagonist FAIM-L.

The long isoform of Fas apoptosis inhibitory molecule (FAIM-L) is a neuron-specific death receptor antagonist that modulates apoptotic cell death and mechanisms of neuronal plasticity. FAIM-L exerts its antiapoptotic action by binding to X-linked inhibitor of apoptosis protein (XIAP), an inhibitor of caspases, which are the main effectors of apoptosis. XIAP levels are regulated by the ubiquitin-proteasome pathway. FAIM-L interaction with XIAP prevents the ubiquitination and degradation of the latter, thereby allowing it to inhibit caspase activation. This interaction also modulates non-apoptotic functions of caspases, such as the endocytosis of AMPA receptor (AMPAR) in hippocampal long-term depression (LTD). The molecular mechanism of action exerted by FAIM-L is unclear since the consensus binding motifs are still unknown. Here, we performed a two-hybrid screening to discover novel FAIM-L-interacting proteins. We found a functional interaction of SIVA-1 with FAIM-L. SIVA-1 is a proapoptotic protein that has the capacity to interact with XIAP. We describe how SIVA-1 regulates FAIM-L function by disrupting the interaction of FAIM-L with XIAP, thereby promoting XIAP ubiquitination, caspase-3 activation and neuronal death. Furthermore, we report that SIVA-1 plays a role in receptor internalization in synapses. SIVA-1 is upregulated upon chemical LTD induction, and it modulates AMPAR internalization via non-apoptotic activation of caspases. In summary, our findings uncover SIVA-1 as new functional partner of FAIM-L and demonstrate its role as a regulator of caspase activity in synaptic function.

Fast-response flow-based method for evaluating 131I from biological and hospital waste samples exploiting liquid scintillation detection.

This paper presents a fast and automatic flow-based method to extract 131I from biological samples and hospital waste, previous to liquid scintillation detection. 131I is a radionuclide extensively used in Nuclear Medicine due to their beta and gamma disintegrations, whereby hospitals have to manage the associated waste generation. The automatic developed system is based on Lab-On-Valve (LOV) flow-technique exploiting Cl-resin (135 mg per extraction). This methodology allows performing sample extractions and measurements on the same day, since the extraction frequency takes 1.4-4 h-1, depending on the analysed sample volume, plus up to 2 h of measurement for each vial. 131I is retained as iodine ion and eluted with sodium sulphide 0.2 mol L-1. The maximum sample volume that can be preconcentrated is 20 mL, reaching an extraction efficiency of 85 ±â€¯5%. The minimum detectable activity (MDA) is 0.05 Bq, showing a precision of 7% RSD (n = 5). Both, biological samples (urine and saliva) and hospital waste samples can be satisfactorily analysed by the proposed system, obtaining recoveries between 90 and 110%. The developed method is then suitable to implement in hospitals, improving the surveillance of the 131I environmental release.

Organocatalytic enantioselective aminoalkylation of pyrazol-3-ones with aldimines generated in situ from α-amido sulfones.

Herein, an efficient asymmetric aminoalkylation of pyrazolones with α-amido sulfones catalyzed by a quinine-derived squaramide in dichloromethane/aqueous media has been established. A variety of chiral amines were obtained with high yields (up to 98%) and excellent enantioselectivities (up to 99% ee). The corresponding products are transformed into optically active acetylated pyrazoles after treatment with Ac2O/Et3N, because of the instability of some adducts. The reaction tolerates a wide range of α-amido sulfones and different pyrazolones.

Flow-through magnetic-stirring assisted system for uranium(VI) extraction: First 3D printed device application.

A 3D printed solid-phase extraction (SPE) device for uranium(VI) extraction has been fabricated using stereolithographic 3D printing. The 3D printed device is shaped as a stirred reactor chamber containing a network of small cubes, which were impregnated with TEVA resin for the extraction of U(VI) from water matrices without doing any previous pretreatment. A flow-through system was combined with off-line ICP-MS detection for the accurate and rapid determination of U(VI) at trace levels. The automatic system was satisfactorily optimized using experimental design, obtaining 0.03 and 0.09 ng U(VI) of detection and quantification limits, respectively, and a durability of 11 consecutive extractions. The reliability of the proposed system was confirmed through the analysis of a reference water material (CSN/CIEMAT 2011), and to water samples (tap, mineral and groundwater) by addition/recovery assays obtaining recoveries between 95 and 106%. This study present for the first time the design of a 3D printing SPE device impregnated with TEVA resin for the on-line extraction of U(VI), showing that 3D printing is a powerful tool for simplifying the construction of complex experimental devices and its operation in analytical procedures for pretreatment applications in water matrices.

3D printed resin-coated device for uranium (VI) extraction.

Laser-based stereolithography (SLA) 3D printing has been applied to construct a 3D printed device as support for uranium(VI) extraction, using a quaternary ammonium salt in liquid and solid form. As proof of concept, a simple process was carried out to immobilize a selective and commercial resin (TEVA resin), in all the surface area of the non-cured SLA 3D printed device, becoming immobilized after UV photocuring. Besides, a coat of Aliquat®336 covering the surface of the cured SLA 3D printed device was tested. Both 3D printed devices as supported for liquid and solid extractant were characterized. Better results in terms of precision were obtained by using TEVA resin (RSD 2.9%), which was satisfactory optimized, reaching a LOD of 0.03 ng U(VI), and a durability of 10 consecutive extractions, maintaining a recovery of 90% with 5% RSD. The 3D printed device is able to preconcentrate up to a sample volume of 30 mL, without any additional pretreatment. The uranium detection was performed with an ICP-MS. Satisfactorily results were obtained analyzing reference material, e.g. phosphogypsum and water matrices from intercomparison exercises, at a confidence level of 95%.

Enamel remineralization therapies for treating postorthodontic white-spot lesions: A systematic review.

BACKGROUND: One of the adverse effects of orthodontic treatment is the appearance of white-spot lesions (WSLs) resulting from enamel demineralization. The objective of this systematic review was to investigate the effectiveness of remineralization therapies on WSLs after orthodontic treatment. TYPES OF STUDIES REVIEWED: In this systematic review, the authors identified relevant articles listed in 5 databases-PubMed, the Cochrane Library, Scopus, Embase, and Web of Science-by using a combination of search terms referring to orthodontics, demineralization, and treatment. Ten articles on the efficacy of WSL remineralization therapies met the inclusion criteria. RESULTS: Among the studies of remineralizing therapy, neither fluoride mouthrinses nor phosphopeptide toothpastes with or without fluoride had any positive effect in addition to oral hygiene maintenance with fluoride toothpaste. A 5% sodium fluoride varnish was the only therapy to show a statistically significant improvement compared with results in the control group. The authors found large variations in results among the studies reviewed because of the different methods used. CONCLUSIONS AND PRACTICAL IMPLICATIONS: None of the treatments was capable of remineralizing WSLs. A 5% sodium fluoride varnish could improve remineralization of WSLs.

Are functional fillers improving environmental behavior of plastics? A review on LCA studies.

The use of functional fillers can be advantageous in terms of cost reduction and improved properties in plastics. There are many types of fillers used in industry, organic and inorganic, with a wide application area. As a response to the growing concerns about environmental damage that plastics cause, recently fillers have started to be considered as a way to reduce it by decreasing the need for petrochemical resources. Life cycle assessment (LCA) is identified as a proper tool to evaluate potential environmental impacts of products or systems. Therefore, in this study, the literature regarding LCA of plastics with functional fillers was reviewed in order to see if the use of fillers in plastics could be environmentally helpful. It was interesting to find out that environmental impacts of functional fillers in plastics had not been studied too often, especially in the case of inorganic fillers. Therefore, a gap in the literature was identified for the future works. Results of the study showed that, although there were not many and some differences exist among the LCA studies, the use of fillers in plastics industry may help to reduce environmental emissions. In addition, how LCA methodology was applied to these materials was also investigated.