Synthetic Microbial Community Members Interact to Metabolize Caproic Acid to Inhibit Potato Dry Rot Disease.

The potato dry rot disease caused by Fusarium spp. seriously reduces potato yield and threatens human health. However, potential biocontrol agents cannot guarantee the stability and activity of biocontrol. Here, 18 synthetic microbial communities of different scales were constructed, and the synthetic microbial communities with the best biocontrol effect on potato dry rot disease were screened through in vitro and in vivo experiments. The results show that the synthetic community composed of Paenibacillus amylolyticus, Pseudomonas putida, Acinetobacter calcoaceticus, Serratia proteamaculans, Actinomycetia bacterium and Bacillus subtilis has the best biocontrol activity. Metabolomics results show that Serratia protoamaculans interacts with other member strains to produce caproic acid and reduce the disease index to 38.01%. Furthermore, the mycelial growth inhibition after treatment with caproic acid was 77.54%, and flow cytometry analysis showed that the living conidia rate after treatment with caproic acid was 11.2%. This study provides potential value for the application of synthetic microbial communities in potatoes, as well as the interaction mechanisms between member strains of synthetic microbial communities.

A neoadjuvant therapy compatible prognostic staging for resected pancreatic ductal adenocarcinoma.

OBJECTIVE: To improve prediction, the AJCC staging system was revised to be consistent with upfront surgery (UFS) and neoadjuvant therapy (NAT) for PDAC. BACKGROUND: The AJCC staging system was designed for patients who have had UFS for PDAC, and it has limited predictive power for patients receiving NAT. METHODS: We examined 146 PDAC patients who had resection after NAT and 1771 who had UFS at Changhai Hospital between 2012 and 2021. The clinicopathological factors were identified using Cox proportional regression analysis, and the Neoadjuvant Therapy Compatible Prognostic (NATCP) staging was developed based on these variables. Validation was carried out in the prospective NAT cohort and the SEER database. The staging approach was compared to the AJCC staging system regarding predictive accuracy. RESULTS: The NAT cohort's multivariate analysis showed that tumor differentiation and the number of positive lymph nodes independently predicted OS. The NATCP staging simplified the AJCC stages, added tumor differentiation, and restaged the disease based on the Kaplan-Meier curve survival differences. The median OS for NATCP stages IA, IB, II, and III was 31.7 months, 25.0 months, and 15.8 months in the NAT cohort and 30.1 months, 22.8 months, 18.3 months, and 14.1 months in the UFS cohort. Compared to the AJCC staging method, the NATCP staging system performed better and was verified in the validation cohort. CONCLUSIONS: Regardless of the use of NAT, NATCP staging demonstrated greater predictive abilities than the existing AJCC staging approach for resected PDAC and may facilitate clinical decision-making based on accurate prediction of patients' OS.

Cobalt(III)-catalyzed weakly coordinating arylurea-directed regioselective mono-olefination.

Here, we developed an air-stable, earth-abundant cobalt(III)-catalyzed regioselective mono-olefination of arenes directed by urea under mild conditions through a cross-dehydrogenative coupling (CDC) process. Under the optimized conditions, a high regioselectivity of mono-olefination was achieved with various electron-rich and electron-deficient arenes, which afforded E-alkenylated products (with yields of up to 90%). In contrast to the conditions used for noble-metal-catalyzed olefination directed by weakly coordinating groups, our reaction was operated under mild conditions, including mild temperature (40 °C) and non-metallic oxidant.

Screening, Identification, and Growth Promotion of Antagonistic Endophytes Associated with Chenopodium quinoa Against Quinoa Pathogens.

Fungal disease is one of the important reasons for crop yield reduction. Isolation of important endophytes with biocontrol and growth-promoting effects is of great significance for the exploitation of beneficial microbial resources and the biological control of crop fungal diseases. In this study, endophytes from roots, stems, and leaves of quinoa at different growth and development stages were isolated and purified; then the antagonistic activity and growth-promoting characteristics of antagonistic endophytes were determined. Finally, the antagonistic endophytes were identified by morphological characteristics and ITS/16S rRNA sequence analysis. Our results showed that 122 endophytic fungi and 371 endophytic bacteria were isolated from quinoa, of which three endophytic fungi and seven endophytic bacteria were screened that had inhibitory activity against quinoa pathogenic fungi. Most of the antagonistic strains could produce indole-3 acetic acid and had the ability to dissolve organic phosphorus. In addition, the bacterial suspension of endophytic bacteria had the ability to promote the seed germination and plant growth of quinoa. The endophytic fungi with antagonistic activity were identified as Penicillium raperi and P. pulvillorum; the endophytic bacteria were identified as Bacillus paralicheniformis, B. tequilensis, and B. velezensis, respectively. The strains of quinoa endophytes in this study can provide rich microbial resources and a theoretical basis for biological control of plant fungal diseases and agricultural production.

First Report of Colletotrichum spinaciae Causing Leaf Anthracnose on Quinoa in China.

Quinoa (Chenopodium quinoa Willd.) is a traditional food originally from the Andes Mountains in South America. It was first planted in China in 1987 and is grown in Tibet, Gansu, and Qinghai provinces. In May 2021, 40% of 2-month-old quinoa plants in the 3.4 hm² experimental base of Qinghai University (36.7262° N, 101.7487° E) were found to have leaves with grey-brown subcircular spots (about 0.4 to 0.7 cm) with black dots (acervuli). Severely infected plants exhibited symptoms such as withered and stunted growth. The diseased-healthy junctions of infected leaves (0.5 cm) were cut out, disinfected with 3% NaClO for 1.5 min, washed three times with sterile water, dried, placed on water agar, and incubated at 25°C for 48 h. After sporulation was seen on the leaf surface, spore suspensions were prepared by placing conidia in sterile water using a pipette. Next, 200 µl of each spore suspension was spread on the surface of water agar and incubated at 25°C for 12 h. Single spores were selected under a stereomicroscope and cultured on potato dextrose agar (PDA) (Qi et al. 2022). The mycelium of two representative isolates (20DLMF-5-4-1 and 20DLMF-7-4-1) was grey-black with white edges and included a fluffy aerial mycelium. Conidia were unicellular, colorless, long ellipsoid or curved moon shaped, averaging 14.3 × 1.8 to 20.2 × 2.2 µm (n=100). The light brown appressoria were ovoid, averaging 8.5 × 5.2 to 7.7 × 4.1 µm (n=20). Spherical, dark brown acervuli were observed on the leaves, averaging 160 to 200 µm (n=20), and there were dark brown spiny bristles. The ITS, partial ACT, CHS, GAPDH and TUB2 genes were amplified from genomic DNA of the two isolates (Weir et al. 2012). Sequences were deposited in GenBank (accession no. OQ871595 to OQ871602 for ACT, CHS, GAPDH, and TUB2, and OQ860235 to OQ860236 for ITS) and showed over 99% identities with the corresponding sequences of C. spinaciae CBS125347 and CBS128.57 (Vu et al. 2019; Damm et al. 2009). Both isolates clustered with the type culture of C. spinaciae (CBS125347, CBS128.57), with 100% bootstrap support in the phylogenetic tree. Thus, according to the morphological and molecular characteristics, the two isolates were identified as C. spinaciae. Pathogenicity tests were conducted on 24 healthy, tender leaves of six 1-month-old quinoa plants, with three replicates (Yang et al. 2021). The leaves were gently scratched in 3-4 areas with a sterile needle. A conidial suspension (105 conidia/ml) of the two isolates was sprayed on these wounds. The control group was unscratched and sprayed with sterile water. The plants were incubated in a greenhouse at 25°C for 24 h in the dark and 7 days in the light. Tiny grey-brown spots appeared on day 3 (about 0.4 to 0.6 cm) and continued to enlarge until perforations and ruptures developed on day 7. Subsequently, acervuli were observed on the surface of the leaves. The control leaves remained healthy. Isolates were reisolated from the symptomatic leaves and they had the same morphological and molecular characteristics as the original isolates, confirming Koch's postulates. To our knowledge, this is the first report of C. spinaciae causing quinoa leaf anthracnose in China. C. spinaciae seriously affects the yield and quality of quinoa and has been previously reported to cause anthracnose of Vicia sativa in China (Wang et al. 2019). The results provide a basis for the study and control of quinoa leaf anthracnose.

Efficacy of Coxsackievirus A5 Vaccine Candidates in an Actively Immunized Mouse Model.

Coxsackievirus A5 (CV-A5) has recently emerged as a main hand, foot, and mouth disease (HFMD) pathogen. Following a large-scale vaccination campaign against enterovirus 71 (EV-71) in China, the number of HFMD-associated cases with EV-71 was reduced, especially severe and fatal cases. However, the total number of HFMD cases remains high, as HFMD is also caused by other enterovirus serotypes. A multivalent HFMD vaccine containing 4 or 6 antigens of enterovirus serotypes is urgently needed. A formaldehyde-inactivated CV-A5 vaccine derived from Vero cells was used to inoculate newborn Kunming mice on days 3 and 10. The mice were challenged on day 14 with a mouse-adapted CV-A5 strain at a dose that was lethal for 14-day-old suckling mice. Within 14 days postchallenge, groups of mice immunized with three formulations, empty particles (EPs), full particles (FPs), and a mixture of the EP and FP vaccine candidates, all survived, while 100% of the mock-immunized mice died. Neutralizing antibodies (NtAbs) were detected in the sera of immunized mice, and the NtAb levels were correlated with the survival rate of the challenged mice. The virus loads in organs were reduced, and pathological changes and viral protein expression were weak or not observed in the immunized mice compared with those in alum-inoculated control mice. Another interesting finding was the identification of CV-A5 dense particles (DPs), facilitating morphogenesis study. These results demonstrated that the Vero cell-adapted CV-A5 strain is a promising vaccine candidate and could be used as a multivalent HFMD vaccine component in the future.IMPORTANCE The vaccine candidate strain CV-A5 was produced with a high infectivity titer and a high viral particle yield. Three particle forms, empty particles (EPs), full particles (FPs), and dense particles (DPs), were obtained and characterized after purification. The immunogenicities of EP, FP, and the EP and FP mixture were evaluated in mice. Mouse-adapted CV-A5 was generated as a challenge strain to infect 14-day-old mice. An active immunization challenge mouse model was established to evaluate the efficacy of the inactivated vaccine candidate. This animal model mimics vaccination, similar to immune responses of the vaccinated. The animal model also tests protective efficacy in response to the vaccine against the disease. This work is important for the preparation of multivalent vaccines against HFMD caused by different emerging strains.

Establishment and evaluation of glucose-modified nanocomposite liposomes for the treatment of cerebral malaria.

Cerebral malaria (CM) is a life-threatening neurological complication caused by Plasmodium falciparum. About 627,000 patients died of malaria in 2020. Currently, artemisinin and its derivatives are the front-line drugs used for the treatment of cerebral malaria. However, they cannot target the brain, which decreases their effectiveness. Therefore, increasing their ability to target the brain by the nano-delivery system with brain-targeted materials is of great significance for enhancing the effects of antimalarials and reducing CM mortality. This study used glucose transporter 1 (GLUT1) on the blood-brain barrier as a target for a synthesized cholesterol-undecanoic acid-glucose conjugate. The molecular dynamics simulation found that the structural fragment of glucose in the conjugate faced the outside the phospholipid bilayers, which was conducive to the recognition of brain-targeted liposomes by GLUT1. The fluorescence intensity of the brain-targeted liposomes (na-ATS/TMP@lipoBX) in the mouse brain was significantly higher than that of the non-targeted liposomes (na-ATS/TMP@lipo) in vivo (P < 0.001) after intranasal administration. The infection and recurrence rate of the mice receiving na-ATS/TMP@lipoBX treatment were significantly decreased, which had more advantages than those of other administration groups. The analysis of pharmacokinetic data showed that na-ATS/TMP@lipoBX could enter the brain in both systemic circulation and nasal-brain pathway to treat malaria. Taken together, these results in this study provide a new approach to the treatment of cerebral malaria.

Development of artesunate intelligent prodrug liposomes based on mitochondrial targeting strategy.

Breast cancer is the leading cause of cancer-related deaths in women and remains a formidable therapeutic challenge. Mitochondria participate in a myriad of essential cellular processes, such as metabolism, and are becoming an ideal target for cancer therapy. Artemisinin and its derivatives have demonstrated multiple activities in the context of various cancers. Mitochondrial autophagy(mitophagy) is one of the important anti-tumor mechanisms of artemisinin drugs. However, the lack of specific tumor targeting ability limits the anti-tumor efficacy of artemisinin drugs. In this study, a GSH-sensitive artesunate smart conjugate (TPP-SS-ATS) was synthesized and liposomes (TPP-SS-ATS-LS) that target tumor cells and mitochondria were further prepared. The advantages of TPP-SS-ATS-LS targeting to the breast tumor were verified by in vivo and in vitro evaluations. In our study, the cytotoxicity was obviously enhanced in vitro and tumor growth inhibition rate was increased from 37.7% to 56.4% at equivalent artesunate dosage in breast cancer orthotopic implanted mice. Meanwhile, mitochondrial dysfunction, suppression of ATP production and respiratory capacity were detected in breast cancer cells. We further discovered that TPP-SS-ATS-LS inhibited tumor cells proliferation through mitophagy by regulating PHB2 and PINK1 expression. These results provide new research strategies for the development of new artemisinin-based anti-tumor drugs.

[Research of preparation quality markers of Yulian Tang with anti-inflammatory activity].

The lipopolysaccharide(LPS)-indused RAW264.7 cells inflammation model was used as a carrier to investigated the effects of the preparation quality markers of Yulian Tang with anti-inflammatory activity in vitro. RAW264.7 cells were treated with LPS(50 ng·mL~(-1)) or/and different concentrations(low dose 0.1 µmol·L~(-1); medium dose 1 µmol·L~(-1); high dose 10 µmol·L~(-1)) of 18 chemical components in Yulian Tang for 24 h. Then the activity of RAW264.7 cell was detected using Cell Counting Kit-8(CCK-8) and the concentrations of inflammatory factors TNF-α and IL-6 in the supernatant of RAW264.7 cell were detected by ELISA assay. As the concentrations of chemical components in Yulian Tang increased, berberine, coptisine, magnoflorine, epiberberine, columbamine and costunolide had stronger inhibitory effects on TNF-α, whereas limonin, dehydroevodiamine, chlorogenic acid, neochlorogenic acid, groenlandicine, evodiamine, rutaecarpine and phellodendrine showed weakened inhibitory effects on TNF-α. The concentrations of palmatine, jatrorrhizine, dehydrocostus lactone and cryptochlorogenic acid had no significant effect on their inhibitory effect on TNF-α. Furthermore, dehydrorutaecarpine, chlorogenic acid, neochlorogenic acid, evodiamine, rutaecarpine, costunolide, phellodendrine and cryptochlorogenic acid showed stronger inhibitory effect on IL-6 as their concentrations increased; berberine, coptisine, magnoflorine, epiberberine, limonin, columbamine, groenlandicine and dehydrocostus lactone had no changes in their inhibitory effects on IL-6 as the concentrations increased. Palmatine and jatrorrhizine had the best inhibitory effect on IL-6. Combining the previous analysis of qualitative and quantitative preparation quality markers of Yulian Tang with the above result of dose-response relationship, we finally identified 15 preparation quality markers of Yulian Tang with anti-inflammatory activity, namely berberine, coptisine, palmatine, magnoflorine, epiberberine, limonin, columbamine, jatrorrhizine, neochlorogenic acid, chlorogenic acid, groenlandicine, evodiamine, rutaecarpine, dehydrocostus lactone and costunolide. In conclusion, our study provides a quick strategy for screening the qualitative preparation quality markers of Yulian Tang with anti-inflammatory activity. Moreover, it also provides an explicit route for the determination of preparation quality markers of Yulian Tang with other activities.

Amino acid substitutions in VP2, VP1, and 2C attenuate a Coxsackievirus A16 in mice.

Coxsackievirus A16 (CVA16) is one of the major etiological agents of hand, foot and mouth disease (HFMD), a common acute infectious disease affecting infants and young children. Severe symptoms of the central nervous system may develop and even lead to death. Here, a plaque-purified CVA16 strain, L731-P1 (P1), was serially passaged in Vero cells for six times and passage 6 (P6) stock became highly attenuated in newborn mice. Genomic sequencing of the P1 and P6 revealed seven nucleotide substitutions at positions 1434 (C to U), 2744 (A to G), 2747 (A to G), 3161 (G to A), 3182 (A to G), 4968 (C to U), and 6064 (C to U). Six of these substitutions resulted in amino acid changes at VP2-T161 M, VP1-N102D, VP1-T103A, VP1-E241K, VP1-T248A, and 2C-S297F, respectively. P1-based infectious cDNA was generated to further investigate these virulent determinants. Independent reverse transcription-polymerase chain reaction (RT-PCR) amplifications for mutant constructions and plaque-purification of the P6 for isolation of variants were performed to determine dominant mutations and strains more related to attenuation. The virulent P1, attenuated P6, as well as a plaque purified strain (PP) and other four recombinant mutants, were inoculated into one-day-old BALB/c mice and the 50% lethal dose of each strain was determined. Comparison of virulence among these strains indicated that amino acid changes of VP1-N102D, VP1-E241K and 2C-S297F might be associated more closely with a high level attenuation of CVA16-L731-P6 than other mutations. Identification of novel residues associated with virulence may contribute to understanding of molecular basis of virulence of CVA16 and other enteroviruses.

Comparison of 4- and 4 plus-courses S-1 administration as adjuvant chemotherapy for pancreatic ductal adenocarcinoma.

PURPOSE: The study aimed to investigate the potential benefit of more than 4 courses of S1 adjuvant chemotherapy for patients with pancreatic ductal adenocarcinoma (PDAC) after surgery. METHOD: Data were retrospectively collected from consecutive patients who underwent S-1 adjuvant chemotherapy following curative pancreatectomy between January 2016 and December 2018. Four-courses and > 4 courses cohorts were compared for overall survival (OS) as a primary outcome, and relapse-free survival (RFS) and adverse event incidence as secondary outcomes. RESULTS: Four-courses and > 4 courses cohorts comprised 99 patients and 64 ones, respectively. TNM stage (stage II vs. I: HR, 2.125; 95% CI, 1.164-4.213; P = 0.015), duration of S-1 administration (4 vs. > 4 courses: HR, 3.113; 95% CI, 1.531-6.327; P = 0.002) and tumor grade (G3 vs. G1/2: HR, 3.887; 95% CI, 1.922-7.861; P < 0.001) were independent prognostic factors. Under the condition of patients' survival time beyond 8 months, the OS of patients in > 4 courses cohort was significantly prolonged compared with that of 4 courses cohort (4 vs. > 4 courses: HR, 2.284; 95% CI, 1.197-4.358; P = 0.012), especially for patients in TNM stageII (4 vs. > 4 courses: HR, 2.906; 95% CI, 1.275-6.623; P = 0.011).RFS and adverse events incidence did not signifcantly difer between both cohorts. CONCLUSION: Prolonged duration of S-1 intake is beneficial to prognosis of patients with PDAC resection.

Assessment of potential, cost, and environmental benefits of CCS-EWR technology for coal-fired power plants in Yellow River Basin of China.

As an effective emission reduction approach, CO2 capture and storage (CCS) combined with enhanced water recovery (EWR) technology can not only reduce CO2 emissions, but can also recover deep saline water resources to relieve pressure on regional water resources, and can ensure the energy supply and both social and economic development. However, the environmental benefits and application costs of CCS-EWR are uncertain, and are determined by the technology level, geological conditions, and other physical factors. In this study, an optimal source-sink matching model and a techno-economic assessment model were developed to evaluate the contributions of CCS-EWR to carbon emission reduction and the increase of the water supply by considering various uncertain factors, as well as the corresponding costs. In addition, the Yellow River Basin (YRB) in China was selected as the research region because, while there are abundant coal-fired power plants (CFPPs) in the YRB, the water resources are scarce. The results revealed the following. (1) The maximum CO2 capture capacity of the 236 CFPPs in the YRB is about 738.77 Mt/a, and nearly 13.14 Gt of fresh water could be provided until the 236 CFPPs in the YRB retire, which can partially relieve the pressure on the supply of water resources. (2) With the consideration of the CCS-EWR benefits, the average cost of the 236 CFPPs in the YRB in their residual lifetime to reduce their CO2 emissions by 90% will be no more than 180 CNY/t. (3) The incentive effect of the increase of the industrial water price on the profits of CCS-EWR projects is not significant. CCS-EWR technology has better application prospects in China under the dual constraints of carbon-neutral targets and water shortages, and more policy support is required for its deployment.

[Screening of quantitative preparation quality markers of Yulian Decoction].

On the basis of the qualitative preparation quality markers of Yulian Decoction, we screened out the quantitative markers and explored a general strategy for analyzing the component migration in Chinese herbal pieces, preparations, and plasma. A method capable of simultaneously determining 28 chemical components in Yulian Decoction was established based on HPLC-MS/MS. This method was used to determine the migrated components in herbal pieces-lyophilized powder preparations-rat plasma after administration of Yulian Decoction. Liquid chromatography was performed under the following conditions: C_(18)-reversed phase chromatographic column(2.1 mm × 100 mm, 1.8 µm); acetonitrile-water(containing 0.1% formic acid) as the mobile phase for gradient elution; the flow rate of 0.2 mL·min~(-1). Electrospray ionization source was adopted for mass spectrometry detection, in which positive and negative ion modes and multiple reaction monitoring were applied. Confirmed by the methodological investigation in linear range, recovery(95.48%-103.4%), precision(RSD, 0.45%-3.8%), stability, and repeatability(RSD, 5.6%-14%), the established method was suitable for the detection and quantification of the components in Yulian Decoction. The results showed that in the lyophilized powder of Yulian Decoction, berberine was greater than 5% in mass fraction, magnoflorine, epiberberine, coptisine, palmatine, and limonin in the range of 1%-5%, and dehydroevodiamine, evodiamine, rutaecarpine, costunolide, and dehydrocostus lactone in the range of 0.002%-1%. Of the 28 components detected in pieces, 27 were found to migrate to the lyophilized powder, and 11 were detected in rat plasma. Fifteen components were preliminarily determined as quantitative preparation quality markers for Yulian Decoction, including berberine, epiberberine, coptisine, palmatine, evodiamine, rutaecarpine, limonin, costunolide, dehydrocostus lactone, magnoflorine, jatrorrhizine, columbamine, groenlandicine, chlorogenic acid, and neochlorogenic acid. In conclusion, the HPLC-MS/MS general strategy was established for analyzing the migration of multiple components in Chinese herbal pieces, preparations, and plasma, which can provide the basis for the screening of quantitative preparation quality markers and multi-index quality control of Yulian Decoction.

Preoperative detection of KRAS G12D mutation in ctDNA is a powerful predictor for early recurrence of resectable PDAC patients.

BACKGROUND: About 25-37% of resectable pancreatic ductal adenocarcinoma (PDAC) had a great chance of early recurrence after radical resection, which is mainly due to preoperative micrometastasis. We herein demonstrated the profiles of ctDNA in resectable PDAC and use of ctDNA to identify patients with potential micrometastasis. METHODS: A total of 113 and 44 resectable PDACs were enrolled in discovery and validation cohorts, separately. A panel containing 50 genes was used to screen ctDNA by an NGS-based assessment with high specificity. RESULTS: In the discovery cohort, the overall detection rate was 38.05% (43/113). Among positive ctDNA, KRAS mutation had the highest detection rate (23.01%, 26/113), while the others were <5%. Survival analysis showed that plasma KRAS mutations, especially KRAS G12D mutation, had significant association with OS and RFS of resectable PDAC. Plasma KRAS G12D mutation showed a strong correlation with early distant metastasis. In the validation cohort, survival analysis showed similar association between plasma KRAS G12D mutation and poor outcomes. CONCLUSIONS: This study demonstrated that plasma KRAS mutations, especially KRAS G12D mutation, served as a useful predictive biomarker for prognosis of resectable PDAC. More importantly, due to high correlation with micrometastasis, preoperative detection of plasma KRAS G12D mutation helps in optimising surgical selection of resectable PDAC.

Effect of an Inactivated Vaccine Against SARS-CoV-2 on Safety and Immunogenicity Outcomes: Interim Analysis of 2 Randomized Clinical Trials.

Importance: A vaccine against coronavirus disease 2019 (COVID-19) is urgently needed. Objective: To evaluate the safety and immunogenicity of an investigational inactivated whole-virus COVID-19 vaccine in China. Interventions: In the phase 1 trial, 96 participants were assigned to 1 of the 3 dose groups (2.5, 5, and 10 µg/dose) and an aluminum hydroxide (alum) adjuvant-only group (n = 24 in each group), and received 3 intramuscular injections at days 0, 28, and 56. In the phase 2 trial, 224 adults were randomized to 5 µg/dose in 2 schedule groups (injections on days 0 and 14 [n = 84] vs alum only [n = 28], and days 0 and 21 [n = 84] vs alum only [n = 28]). Design, Setting, and Participants: Interim analysis of ongoing randomized, double-blind, placebo-controlled, phase 1 and 2 clinical trials to assess an inactivated COVID-19 vaccine. The trials were conducted in Henan Province, China, among 96 (phase 1) and 224 (phase 2) healthy adults aged between 18 and 59 years. Study enrollment began on April 12, 2020. The interim analysis was conducted on June 16, 2020, and updated on July 27, 2020. Main Outcomes and Measures: The primary safety outcome was the combined adverse reactions 7 days after each injection, and the primary immunogenicity outcome was neutralizing antibody response 14 days after the whole-course vaccination, which was measured by a 50% plaque reduction neutralization test against live severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Results: Among 320 patients who were randomized (mean age, 42.8 years; 200 women [62.5%]), all completed the trial up to 28 days after the whole-course vaccination. The 7-day adverse reactions occurred in 3 (12.5%), 5 (20.8%), 4 (16.7%), and 6 (25.0%) patients in the alum only, low-dose, medium-dose, and high-dose groups, respectively, in the phase 1 trial; and in 5 (6.0%) and 4 (14.3%) patients who received injections on days 0 and 14 for vaccine and alum only, and 16 (19.0%) and 5 (17.9%) patients who received injections on days 0 and 21 for vaccine and alum only, respectively, in the phase 2 trial. The most common adverse reaction was injection site pain, followed by fever, which were mild and self-limiting; no serious adverse reactions were noted. The geometric mean titers of neutralizing antibodies in the low-, medium-, and high-dose groups at day 14 after 3 injections were 316 (95% CI, 218-457), 206 (95% CI, 123-343), and 297 (95% CI, 208-424), respectively, in the phase 1 trial, and were 121 (95% CI, 95-154) and 247 (95% CI, 176-345) at day 14 after 2 injections in participants receiving vaccine on days 0 and 14 and on days 0 and 21, respectively, in the phase 2 trial. There were no detectable antibody responses in all alum-only groups. Conclusions and Relevance: In this interim report of the phase 1 and phase 2 trials of an inactivated COVID-19 vaccine, patients had a low rate of adverse reactions and demonstrated immunogenicity; the study is ongoing. Efficacy and longer-term adverse event assessment will require phase 3 trials. Trial Registration: Chinese Clinical Trial Registry Identifier: ChiCTR2000031809.

Shikonin inhibits cancer cell cycling by targeting Cdc25s.

BACKGROUND: Shikonin, a natural naphthoquinone, is abundant in Chinese herb medicine Zicao (purple gromwell) and has a wide range of biological activities, especially for cancer. Shikonin and its analogues have been reported to induce cell-cycle arrest, but target information is still unclear. We hypothesized that shikonin, with a structure similar to that of quinone-type compounds, which are inhibitors of cell division cycle 25 (Cdc25) phosphatases, will have similar effects on Cdc25s. To test this hypothesis, the effects of shikonin on Cdc25s and cell-cycle progression were determined in this paper. METHODS: The in vitro effects of shikonin and its analogues on Cdc25s were detected by fluorometric assay kit. The binding mode between shikonin and Cdc25B was modelled by molecular docking. The dephosphorylating level of cyclin-dependent kinase 1 (CDK1), a natural substrate of Cdc25B, was tested by Western blotting. The effect of shikonin on cell cycle progression was investigated by flow cytometry analysis. We also tested the anti-proliferation activity of shikonin on cancer cell lines by MTT assay. Moreover, in vivo anti-proliferation activity was tested in a mouse xenograft tumour model. RESULTS: Shikonin and its analogues inhibited recombinant human Cdc25 A, B, and C phosphatase with IC50 values ranging from 2.14 ± 0.21 to 13.45 ± 1.45 µM irreversibly. The molecular modelling results showed that shikonin bound to the inhibitor binding pocket of Cdc25B with a favourable binding mode through hydrophobic interactions and hydrogen bonds. In addition, an accumulation of the tyrosine 15-phosphorylated form of CDK1 was induced by shikonin in a concentration-dependent manner in vitro and in vivo. We also confirmed that shikonin showed an anti-proliferation effect on three cancer cell lines with IC50 values ranging from 6.15 ± 0.46 to 9.56 ± 1.03 µM. Furthermore, shikonin showed a promising anti-proliferation effect on a K562 mouse xenograph tumour model. CONCLUSION: In this study, we provide evidence for how shikonin induces cell cycle arrest and functions as a Cdc25s inhibitor. It shows an anti-proliferation effect both in vitro and in vivo by mediating Cdc25s.

Characterization of a Norovirus-specific monoclonal antibody that exhibits wide spectrum binding activities.

Noroviruses (NoVs) are increasingly recognized as the leading cause of acute non-bacterial gastroenteritis worldwide. To screen for NoV-specific monoclonal antibodies (mAbs) with wide spectrum binding activities that could be used for the development of NoV-related detection reagents, we immunized mice with a combination of virus like particles (VLPs) derived from eight different genotypes (two from genogroup I and six from genogroup II), of which two (GI.7 and GII.2) were newly produced VLPs. Indirect enzyme-linked immunosorbent assay (ELISA) confirmed that two mAbs (8D8 and 10B11) bound to all eight major capsid proteins (VP1) with varied binding abilities. Epitope mapping using short peptides covering the N-terminal half of GII.3 VP1 indicated that the binding site of mAb 8D8 was located between amino acid 31 and 60. Multiple amino acid sequence alignment of VP1 suggested that this site harbors conservative sequences across all genogroups. Indirect and sandwich ELISA indicated that mAb 8D8 was unable bind intact VLPs. In summary, we successfully produced GI.7 and GII.2 VLPs using recombinant baculovirus expression system and a cross-reactive mAb by immunizing mice with eight different VLPs that might be useful in the studying and detecting NoVs.

Chimeric GII.3/GII.6 norovirus capsid (VP1) proteins: characterization by electron microscopy, trypsin sensitivity and binding to histo-blood group antigens.

GII.3 and GII.6 noroviruses (NoVs) are similar in several aspects, including the presence of a short sequence insertion in the P2 domain of the major capsid protein (VP1) and trypsin susceptibility of VP1-containing virus-like particles (VLPs). In this study, we generated two constructs with the S or P domains of VP1 from GII.3 and GII.6 NoV strains exchanged (GII.3S/GII.6P and GII.6S/GII.3P), and the resultant chimeric capsid proteins were expressed from recombinant baculoviruses. The assembly of VLPs was confirmed by electron microscopy, and the susceptibility of assembled VLPs to trypsin digestion was analyzed by SDS-PAGE. Salivary histo-blood group antigen (HBGA) binding and binding blockade assays were performed to determine the binding characteristics of chimeric VP1-containing VLPs with and without trypsin digestion. Our results indicated that both expressed GII.3S/GII.6P and GII.6S/GII.3P chimeric proteins successfully assembled into VLPs. Trypsin digestion of VLPs assembled from both chimeric proteins led to the generation of two fragments with molecular sizes similar to those of wild-type VP1-containing VLPs. An in vitro salivary HBGA binding assay demonstrated that VLPs assembled from both chimeric proteins exhibited enhanced binding after trypsin cleavage. An HBGA binding blockade assay indicated that the binding of GII.3S/GII.6P and GII.6S/GII.3P VLPs against salivary HBGAs could only be blocked by GII.3 and GII.6 NoV VLP-specific hyperimmune sera, respectively. For GII.6 and GII.3S/GII.6P VLPs, a difference in binding enhancement after trypsin cleavage was observed. Our results demonstrate that the S domains of GII.3 and GII.6 NoV VP1 are interchangeable and that the S domain affects the binding of the P domain to HBGAs.