Phase II prefusion non-stabilised Covid-19 mRNA vaccine randomised study.

ChulaCov19 mRNA vaccine demonstrated promising phase 1 results. Healthy adults aged 18-59 years were double-blind randomised 4:1 to receive two intramuscular doses of ChulaCov19 50 µg or placebo. Primary endpoints were safety and microneutralization antibody against-wild-type (Micro-VNT50) at day 50. One hundred fifty adults with median (IQR) age 37 (30-46) years were randomised. ChulaCov19 was well tolerated, and most adverse events were mild to moderate and temporary. Geometric mean titres (GMT) of neutralizing titre against wild-type for ChulaCov19 on day 50 were 1367 IU/mL. T-cell IFN-γ-ELISpot showed the highest responses at one week (Day29) after dose 2 then gradually declined. ChulaCov19 50 µg is well tolerated and elicited high neutralizing antibodies and strong T-cell responses in healthy adults.Trial registration number: ClinicalTrials.gov Identifier NCT04566276, 28/09/2020.

Aggregation-caused dual-signal response of gold nanoclusters for ratiometric optical detection of cysteine.

Designing ratiometric sensors for cysteine (Cys) monitoring with high accuracy is of great significance for disease diagnosis and biomedical studies. The current ratiometric methods mainly rely on multiplex probes, which not only complicates the operation but also increases the cost, making it difficult for quantitative Cys detection in resource-limited areas. Herein, one-pot prepared gold nanoclusters (Au NCs) that glow red fluorescent were synthesized by employing glutathione as the stabilizer and reducing agent. When Fe3+ is present with Au NCs, the fluorescence is quenched and the scattering is strong because of the aggregation of Au NCs. With introduction of Cys, Cys can efficiently compete with glutathione-modified Au NCs for Fe3+, which leads to increase of fluorescence and decrease of scattering. The ratiometric determination of Cys can be thereby realized by collecting the fluorescence and SRS spectrum simultaneously. The linear range for Cys was 5-30 µM with a detection limit of 1.5 µM. In addition, the sensing system exhibits good selectivity for Cys and shows potential application in biological samples.

Safety and immunogenicity of a prefusion non-stabilized spike protein mRNA COVID-19 vaccine: a phase I trial.

Effective mRNA SARS-CoV-2 vaccines are available but need to be stored in freezers, limiting their use to countries that have appropriate storage capacity. ChulaCov19 is a prefusion non-stabilized SARS-CoV-2 spike-protein-encoding, nucleoside-modified mRNA, lipid nanoparticle encapsulated vaccine that we report to be stable when stored at 2-8 °C for up to 3 months. Here we report safety and immunogenicity data from a phase I open-label, dose escalation, first-in-human trial of the ChulaCov19 vaccine (NCT04566276). Seventy-two eligible volunteers, 36 of whom were aged 18-55 (adults) and 36 aged 56-75 (elderly), were enroled. Two doses of vaccine were administered 21 d apart at 10, 25 or 50 µg per dose (12 per group). The primary outcome was safety and the secondary outcome was immunogenicity. All three dosages of ChulaCov19 were well tolerated and elicited robust dose-dependent and age-dependent B- and T-cell responses. Transient mild/moderate injection site pain, fever, chills, fatigue and headache were more common after the second dose. Four weeks after the second dose, in the adult cohort, MicroVNT-50 geometric mean titre against wild-type SARS-CoV-2 was 848 (95% CI, 483-1,489), 736 (459-1,183) and 1,140 (854-1,522) IU ml-1 at 10, 25 and 50 µg doses, respectively, versus 285 (196-413) IU ml-1 for human convalescent sera. All dose levels elicited 100% seroconversion, with geometric mean titre ratios 4-8-fold higher than for human convalescent sera (P < 0.01), and high IFNγ spot-forming cells per million peripheral blood mononuclear cells. The 50 µg dose induced better cross-neutralization against Alpha, Beta, Gamma and Delta variants than lower doses. ChulaCov19 at 50 µg is well tolerated and elicited higher neutralizing antibodies than human convalescent sera, with strong T-cell responses. These antibodies cross-neutralized four variants of concern. ChulaCov19 has proceeded to phase 2 clinical trials. We conclude that the mRNA vaccine expressing a prefusion non-stabilized spike protein is safe and highly immunogenic.

Phytochemical and antitumor studies on Cynanchum mongolicum (Maxim.) Kom.

A chemical investigation of Cynanchum mongolicum (Maxim.) Kom. identified 8 compounds. On the basis of spectroscopic data, they were determined to be 3 alkaloids and 5 sinapoyl esters, among which were two previously undescribed compounds (1 and 2). The inhibitory effects of the isolated compounds against four human tumor cell lines were evaluated in vitro by MTT assays, which revealed moderate inhibitory effects with IC50 values < 50 mM, in particularly, three antofine analogues have showed significant antitumor activities with IC50 values < 0.1 mM, which was obviously better than the 5-fluorouracil and potential to be used as cancer drugs.

Comparative Analysis of Chemical Composition, Anti-Inflammatory Activity and Antitumor Activity in Essential Oils from Siegesbeckiaorientalis, S. glabrescens and S. pubescens with an ITS Sequence Analysis.

Herba Siegesbeckiae (HS), derived from the aerial parts of three plants, Siegesbeckia orientalis (SO), S. glabrescens (SG), and S. pubescens (SP), has been used for the treatment of inflammatory diseases in China for centuries. In the present study, hydrodistillation was applied to extract essential oils from dried SO, SG, and SP aerial parts, and chemical composition analysis by gas chromatography⁻mass spectrometry (GC-MS) led to the identification of a total of 148 compounds (56 in SO, 62 in SG, and 59 in SP). The main components in the essential oils of SO, SG, and SP differed significantly. In vitro anti-inflammatory activity assays showed that SP essential oils (IC50, 0.97 µg/mL) significantly reduced the ability of lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages to release NO, and the SO essential oil (IC50, 14.99 µg/mL) was better than the others at inhibiting the LPS-induced release of cytokine IL-6. Furthermore, the essential oils exhibited antitumor activities (IC50, 37.72⁻123.16 µg/mL) against Hep3B (liver) and Hela (cervical) cells. Linear regression analysis showed that, caryophyllene oxide peak area percentages showed remarkably high negative correlation coefficients with IC50 values of Hep3B and Hela cytotoxicity, which suggested the contribution of this compound on the cancer cell cytotoxicity of three essential oils. Finally, the ITS1-5.8S-ITS2 region was amplified and sequenced in order to generate genomic reference sequences for each plant. These can be used to identify the origins of the plants, and will assist other research studies related to these three plants.

Crystal structures of IL-2-inducible T cell kinase complexed with inhibitors: insights into rational drug design and activity regulation.

IL-2-inducible T cell kinase plays an essential role in T cell receptor signaling and is considered a drug target for the treatment of Th2-mediated inflammatory diseases. By applying high-throughput protein engineering and crystallization, we have determined the X-ray crystal structures of IL-2-inducible T cell kinase in complex with its selective inhibitor BMS-509744 and the broad-spectrum kinase inhibitors sunitinib and RO5191614. Sunitinib uniquely stabilizes IL-2-inducible T cell kinase in the helix C-in conformation by inducing side chain conformational changes in the ATP-binding site. This preference of sunitinib to bind to an active kinase conformation is reflective of its broad-spectrum kinase activity. BMS-509744 uniquely stabilizes the activation loop in a substrate-blocking inactive conformation, indicating that structural changes described for Src family kinases are also involved in the regulation of IL-2-inducible T cell kinase activity. The observed BMS-509744 binding mode allows rationalization of structure-activity relationships reported for this inhibitor class and facilitates further structure-based drug design. Sequence-based analysis of this binding mode provides guidance for the rational design of inhibitor selectivity.

Cellular and antitumor activity of a new diethylene glycol benzoporphyrin derivative (lemuteporfin).

A newly synthesized diethylene glycol functionalized chlorin-type photosensitizer, lemuteporfin, was characterized for use in photodynamic therapy (PDT) in a panel of in vitro and in vivo test systems. The photosensitizer was highly potent, killing cells at low nanomolar concentrations upon exposure to activating light. The cellular uptake of lemuteporfin was rapid, with maximum levels reached within 20 min. Mitogen-activated lymphoid cells accumulated more of the lemuteporfin than their quiescent equivalents, supporting selectivity. Photosensitizer fluorescence in the skin increased rapidly within the first few minutes following intravenous administration to mice, then decreased over the next 24 h. Skin photosensitivity reactions indicated rapid clearance of the photosensitizer. Intravenous doses as low as 1.4 micromol/kg combined with exposure to 50 J/cm2 red light suppressed tumor growth in a mouse model. In conclusion, this new benzoporphyrin was found to be an effective photosensitizer, showing rapid uptake and clearance both in vitro and in vivo. This rapid photosensitization of tumors could be useful in therapies requiring a potent, rapidly accumulating photosensitizer, while minimizing the potential for skin photosensitivity reactions to sunlight following treatment.