There is an urgent need for vaccines against coronavirus disease 2019 (COVID-19) because of the ongoing SARS-CoV-2 pandemic. Among all approaches, a messenger RNA (mRNA)-based vaccine has emerged as ...a rapid and versatile platform to quickly respond to this challenge. Here, we developed a lipid nanoparticle-encapsulated mRNA (mRNA-LNP) encoding the receptor binding domain (RBD) of SARS-CoV-2 as a vaccine candidate (called ARCoV). Intramuscular immunization of ARCoV mRNA-LNP elicited robust neutralizing antibodies against SARS-CoV-2 as well as a Th1-biased cellular response in mice and non-human primates. Two doses of ARCoV immunization in mice conferred complete protection against the challenge of a SARS-CoV-2 mouse-adapted strain. Additionally, ARCoV is manufactured as a liquid formulation and can be stored at room temperature for at least 1 week. ARCoV is currently being evaluated in phase 1 clinical trials.
Display omitted
•Development of LNP-encapsulated mRNA vaccine (ARCoV) targeting the RBD of SARS-CoV-2•ARCoV induces neutralizing antibodies and T cell immunity in mice and NHPs•ARCoV vaccination confers full protection against SARS-CoV-2 challenge in mice•ARCoV is a thermostable vaccine candidate for phase I studies
ARCoV is an LNP-encapsulated mRNA vaccine platform that is highly immunogenic and safe in mice and non-human primates, conferring protection against challenge with a SARS-CoV-2 mouse-adapted strain.
The re-emergence of Zika virus (ZIKV) in the Western Hemisphere has resulted in global public health crisis since 2015. ZIKV preferentially infects and targets human neural progenitor cells (hNPCs) ...and causes fetal microcephaly upon maternal infection. hNPCs not only play critical roles during fetal brain development, but also persist in adult brain throughout life. Yet the mechanism of innate antiviral immunity in hNPCs remains largely unknown. Here, we show that ZIKV infection triggers the abundant production of virus-derived small interfering RNAs in hNPCs, but not in the more differentiated progenies or somatic cells. Ablation of key RNAi machinery components significantly enhances ZIKV replication in hNPCs. Furthermore, enoxacin, a broad-spectrum antibiotic that is known as an RNAi enhancer, exerts potent anti-ZIKV activity in hNPCs and other RNAi-competent cells. Strikingly, enoxacin treatment completely prevents ZIKV infection and circumvents ZIKV-induced microcephalic phenotypes in brain organoid models that recapitulate human fetal brain development. Our findings highlight the physiological importance of RNAi-mediated antiviral immunity during the early stage of human brain development, uncovering a novel strategy to combat human congenital viral infections through enhancing RNAi.
Zika virus (ZIKV) has become a public health threat due to its global transmission and link to severe congenital disorders. The host immune responses to ZIKV infection have not been fully elucidated, ...and effective therapeutics are not currently available. Herein, we demonstrated that cholesterol-25-hydroxylase (CH25H) was induced in response to ZIKV infection and that its enzymatic product, 25-hydroxycholesterol (25HC), was a critical mediator of host protection against ZIKV. Synthetic 25HC addition inhibited ZIKV infection in vitro by blocking viral entry, and treatment with 25HC reduced viremia and conferred protection against ZIKV in mice and rhesus macaques. 25HC suppressed ZIKV infection and reduced tissue damage in human cortical organoids and the embryonic brain of the ZIKV-induced mouse microcephaly model. Our findings highlight the protective role of CH25H during ZIKV infection and the potential use of 25HC as a natural antiviral agent to combat ZIKV infection and prevent ZIKV-associated outcomes, such as microcephaly.
Display omitted
•CH25H and its enzymatic product, 25HC, inhibit ZIKV entry in vitro•25HC attenuates ZIKV-associated viremia and disease in mice and non-human primates•25HC prevents ZIKV infection in human cortical organoids•25HC protects fetal mice from microcephaly caused by ZIKV infection
Zika virus (ZIKV) presents a major challenge to the global health system. Li et al. find that 25-hydroxycholesterol (25HC) inhibits ZIKV infection in monkeys and human cortical organoids and protects mice from microcephaly. 25HC has potential as a first-line antiviral agent to combat a broad array of pathogenic species, including ZIKV.
Recent outbreaks of Zika virus （ZIKV） highlight an urgent need for therapeutics. The protease complex NS2B- NS3 plays essential roles during flaviviral polyprotein processing, and thus represents an ...attractive drug target. Here, we developed a split luciferase complementation-based high-throughput screening assay to identify orthosteric inhibitors that directly target flavivirus NS2B-NS3 interactions. By screening a total of 2 816 approved and investigational drugs, we identified three potent candidates, temoporfin, niclosamide, and nitazoxanide, as flavivirus NS2B- NS3 interaction inhibitors with nanomolar potencies. Significantly, the most potent compound, temoporfin, not only inhibited ZIKV replication in human placental and neural progenitor cells, but also prevented ZIKV-induced viremia and mortality in mouse models. Structural docking suggests that temoporfin potentially binds NS3 pockets that hold critical NS2B residues, thus inhibiting flaviviral polyprotein processing in a non-competitive manner. As these drugs have already been approved for clinical use in other indications either in the USA or other countries, they represent promising and easily developed therapies for the management of infections by ZIKV and other flaviviruses.
Glioma is the common highly malignant primary brain tumor. However, the molecular pathways that result in the pathogenesis of glioma remain elusive. In this study, we found that microRNA-103 ...(miR-103), microRNA-195 (miR-195), or microRNA-15b (miR-15b), which all have the same 5' "seed" miRNA portion and share common binding sites in the SALL4 3'-untranslated region (UTR), were downregulated in glioma tissues and cell lines. These miRNAs suppressed glioma cell proliferation, migration, and invasion, induced cell apoptosis, and decreased the level of the SALL4 protein, but not that of SALL4 mRNA, which was identified as a direct target of all three miRNAs. The caspase-3/7 activity expression in U251 cells overexpressing these miRNAs was rescued during SALL4 upregulation. An obvious inverse correlation was observed between SALL4 and miR-103 or miR-195 expression levels in clinical glioma samples. Moreover, enforced expression of SALL4 stimulated cell proliferation, migration, and invasion. In conclusion, these data suggest that miR-103, miR-195, and miR-15b post-transcriptionally downregulated the expression of SALL4 and suppressed glioma cell growth, migration, and invasion, and increased cell apoptosis. These results provide a potential therapeutic target that may downregulate SALL4 in glioma.
The ongoing coronavirus disease 2019 (COVID-19) pandemic has prioritized the development of small-animal models for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We adapted a clinical ...isolate of SARS-CoV-2 by serial passaging in the respiratory tract of aged BALB/c mice. The resulting mouse-adapted strain at passage 6 (called MASCp6) showed increased infectivity in mouse lung and led to interstitial pneumonia and inflammatory responses in both young and aged mice after intranasal inoculation. Deep sequencing revealed a panel of adaptive mutations potentially associated with the increased virulence. In particular, the N501Y mutation is located at the receptor binding domain (RBD) of the spike protein. The protective efficacy of a recombinant RBD vaccine candidate was validated by using this model. Thus, this mouse-adapted strain and associated challenge model should be of value in evaluating vaccines and antivirals against SARS-CoV-2.
Since December 2019, a novel coronavirus SARS-CoV-2 has emerged and rapidly spread throughout the world, resulting in a global public health emergency. The lack of vaccine and antivirals has brought ...an urgent need for an animal model. Human angiotensin-converting enzyme II (ACE2) has been identified as a functional receptor for SARS-CoV-2. In this study, we generated a mouse model expressing human ACE2 (hACE2) by using CRISPR/Cas9 knockin technology. In comparison with wild-type C57BL/6 mice, both young and aged hACE2 mice sustained high viral loads in lung, trachea, and brain upon intranasal infection. Although fatalities were not observed, interstitial pneumonia and elevated cytokines were seen in SARS-CoV-2 infected-aged hACE2 mice. Interestingly, intragastric inoculation of SARS-CoV-2 was seen to cause productive infection and lead to pulmonary pathological changes in hACE2 mice. Overall, this animal model described here provides a useful tool for studying SARS-CoV-2 transmission and pathogenesis and evaluating COVID-19 vaccines and therapeutics.
Display omitted
•Human ACE2 knockin mice were generated by using CRISPR/Cas9 technology•SARS-CoV-2 leads to robust replication in lung, trachea, and brain•SARS-CoV-2 causes interstitial pneumonia and elevated cytokine in aged hACE2 mice•High dose of SARS-CoV-2 can establish infection via intragastric route in hACE2 mice
The COVID-19 pandemic has brought an urgent need for small animal models. Here, Sun et al. established an ACE2 humanized mouse by CRISPR/Cas9 knockin technology. These hACE2 mice are susceptible to SARS-CoV-2 infection upon intranasal inoculation, and the resulting pulmonary infection and pathological changes resemble those observed in COVID-19 patients.
Microplastics have been widely detected in the environment and marine organisms. However, few studies have investigated the presence of microplastics in humans. This preliminary study identified and ...quantified the microplastic content in human feces.
A total of 26 young male students aged 18–25 years were recruited from Beijing, China. A self-administered 7-day 24-h fluid intake record was used to document fluid intake, and food intake was recorded for 3 days. Feces were collected by participants using a sterile fecal collector. Microplastics in the remaining fecal residues were measured and identified using fourier transform infrared micro-spectroscopy.
Eventually, twenty-four participants completed the study. The fecal samples of 23 (95.8%) participants tested positive for microplastics. In these 23 samples, the abundance of microplastics varied from 1 particle/g to 36 particles/g (size 20 to 800 μm). The summed mass of all microplastic particles per participant ranged from 0.01 to 14.6 mg. Qualitative analysis of the microplastics indicated the presence of one to eight types of microplastics in each sample, with polypropylene (PP) being the most abundant; it was found in 95.8% of fecal samples. We examined associations between water intake habits and the abundance of microplastics in their feces. A moderate correlation was observed between packaged water and beverage intake and microplastic abundance in feces (r = 0.445, P = 0.029).
Various types of microplastics were detected in human feces, with PP being found in the highest proportion. There may be an association between water intake habits and microplastic abundance in feces.
Display omitted
•Microplastics have been found in human feces.•The highest proportion of microplastic components was polypropylene.•Sources of water intake may one of the influencing factors on the content of microplastics in the human gastrointestinal tract.•More attention should be paid to the widespread existence of microplastics and its health effects.
Solar‐driven overall water splitting is an ideal way to generate renewable energy while still challenging. For the first time, this work combined covalent organic frameworks (COFs) and piezoelectric ...material by covalent linkages to form Z‐scheme core@shell heterostructure for overall water splitting. Benefiting from the synergistic effect between the polarized electric field and photo‐generated charges, as well as the precise adjustment of shell thickness, the carrier separation and utilization efficiency is greatly improved. The optimal BiFeO3@TpPa‐1‐COF photocatalyst revealed hydrogen (H2) and oxygen (O2) production rates of 1416.4 and 708.2 μmol h−1 g−1 under the excitation of ultrasonication coupled with light irradiation, which is the best performance among various piezo‐ and COF‐based photocatalysts. This provides a new sight for the practical application of highly efficient photocatalytic overall water splitting.
We combined covalent organic frameworks (COFs) and piezoelectric material by covalent bonds to form a Z‐scheme core@shell heterostructure piezo‐photocatalyst with tunable shell thickness for overall water splitting. The optimal sample reveals the unprecedented H2 and O2 production rates of 1416.4 and 708.2 μmol h−1 g−1 under the excitation of ultrasonication coupled with visible light irradiation.
PDF
