pH-Sensitive and Biodegradable Mn3(PO4)2·3H2O Nanoparticles as an Adjuvant of Protein-Based Bivalent COVID-19 Vaccine to Induce Potent and Broad-Spectrum Immunity.

Developing a novel and potent adjuvant with great biocompatibility for immune response augmentation is of great significance to enhance vaccine efficacy. In this work, we prepared a long-term stable, pH-sensitive, and biodegradable Mn3(PO4)2·3H2O nanoparticle (nano-MnP) by simply mixing MnCl2/NaH2PO4/Na2HPO4 solution for the first time and employed it as an immune stimulant in the bivalent COVID-19 protein vaccine comprised of wild-type S1 (S1-WT) and Omicron S1 (S1-Omicron) proteins as antigens to elicit a broad-spectrum immunity. The biological experiments indicated that the nano-MnP could effectively activate antigen-presenting cells through the cGAS-STING pathway. Compared with the conventional Alum-adjuvanted group, the nano-MnP-adjuvanted bivalent vaccine elicited approximately 7- and 8-fold increases in IgG antibody titers and antigen-specific IFN-γ secreting T cells, respectively. Importantly, antisera of the nano-MnP-adjuvanted group could effectively cross-neutralize the SARS-CoV-2 and its five variants of concern (VOCs) including Alpha, Beta, Gamma, Delta, and Omicron, demonstrating that this bivalent vaccine based on S1-WT and S1-Omicron proteins is an effective vaccine design strategy to induce broad-spectrum immune responses. Collectively, this nano-MnP material may provide a novel and efficient adjuvant platform for various prophylactic and therapeutic vaccines and provide insights for the development of the next-generation manganese adjuvant.

Novel sialoglycan linkage for constructing adjuvant-protein conjugate as potent vaccine for COVID-19.

Self-adjuvanting protein vaccines have been proved to be highly immunogenic with efficient codelivery of adjuvant and antigen. Current protein vaccines with built-in adjuvants are all modified at the peptide backbone of antigen protein, which could not achieve minor epitope interference and adjuvant multivalency at the same time. Herein, we developed a new conjugate strategy to construct effective adjuvant-protein vaccine with adjuvant cluster effect and minimal epitope interference. The toll-like receptor 7 agonist (TLR7a) is covalently conjugated on the terminal sialoglycans of SARS-CoV-2-S1 protein, leading to intracellular release of the small-molecule stimulators with greatly reduced risks of systemic toxicity. The resulting TLR7a-S1 conjugate elicited strong activation of immune cells in vitro, and potent antibody and cellular responses with a significantly enhanced Th1-bias in vivo. TLR7a-S1-induced antibody also effectively cross-neutralized all variants of concern. This sialoglycoconjugation approach to construct protein conjugate vaccines will have more applications to combat SARS-CoV-2 and other diseases.

Simultaneous determination of twenty-nine active compounds in fuzhengjiedu granules by HPLC-QQQ-MS/MS.

As an empirical medicine of traditional Chinese medicine, Fuzhengjiedu Granules have shown an effect against COVID-19 in clinical and inflammatory animal models. It is formulated with eight herbs, including Aconiti Lateralis Radix Praeparata, Zingiberis Rhizoma, Glycyrrhizae Radix Et Rhizoma, Lonicerae Japonicae Flos, Gleditsiae Spina, Fici Radix, Pogostemonis Herba, and Citri Reticulatae Pericarpium. This study established a high-performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-QQQ-MS/MS) method by simultaneously determining 29 active compounds in the granules with significant content differences. Separation by gradient elution using acetonitrile and water (0.1% formic acid) as mobile phases was performed on a Waters Acquilty UPLC T3 column (2.1 mm × 100 mm, 1.7 µm). A triple quadrupole mass spectrometer, operating in positive and negative ionization modes, was used for multiple reaction monitoring to detect the 29 compounds. All calibration curves showed good linear regression (r2 > 0.998). RSDs of precision, reproducibility, and stability of active compounds were all lower than 5.0%. The recovery rates were 95.4-104.9%, with RSDs< 5.0%. This method was successfully used to analyze the samples, and the results showed that 26 representative active components from 8 herbs were detected in the granules. While aconitine, mesaconitine, and hypaconitine were not detected, indicating that the existing samples were safe. The granules had the maximum and minimum content of hesperidin (27.3 ± 0.375 mg/g) and benzoylaconine (38.2 ± 0.759 ng/g). To conclude, a fast, accurate, sensitive, and reliable HPLC-QQQ-MS/MS method was established, which can simultaneously detect 29 active compounds that have a considerable difference in the content of Fuzhengjiedu Granules. This study can be used to control the quality and safety of Fuzhengjiedu Granules and provide a basis and guarantee for further experimental research and clinical application.

Taxi Utilization Rate Maximization by Dynamic Demand Prediction: A Case Study in the City of Chicago

The explosive popularity of transportation network companies (TNCs) in the last decade has imposed dramatic disruptions on the taxi industry, but not all the impacts are beneficial. For instance, studies have shown taxi capacity utilization rate is lower than 50% in five major U.S. cities. With the availability of taxi data, this study finds the taxi utilization rate is around 40% in June 2019 (normal scenario) and 35% in June 2020 (COVID 19 scenario) in the city of Chicago, U.S. Powered by recent advances in the deep learning of capturing non-linear relationships and the availability of datasets, a real-time taxi trip optimization strategy with dynamic demand prediction was designed using long short-term memory (LSTM) architecture to maximize the taxi utilization rate. The algorithms are tested in both scenarios?normal time and COVID 19 time?and promising results have been shown by implementing the strategy, with around 19% improvement in mileage utilization rate in June 2019 and 74% in June 2020 compared with the baseline without any optimizations. Additionally, this study investigated the impacts of COVID 19 on the taxi service in Chicago.

Novel sialoglycan linkage for constructing adjuvant-protein conjugate as potent vaccine for COVID-19.

Self-adjuvanting protein vaccines have been proved to be highly immunogenic with efficient codelivery of adjuvant and antigen. Current protein vaccines with built-in adjuvants are all modified at the peptide backbone of antigen protein, which could not achieve minor epitope interference and adjuvant multivalency at the same time. Herein, we developed a new conjugate strategy to construct effective adjuvant-protein vaccine with adjuvant cluster effect and minimal epitope interference. The toll-like receptor 7 agonist (TLR7a) is covalently conjugated on the terminal sialoglycans of SARS-CoV-2-S1 protein, leading to intracellular release of the small-molecule stimulators with greatly reduced risks of systemic toxicity. The resulting TLR7a-S1 conjugate elicited strong activation of immune cells in vitro, and potent antibody and cellular responses with a significantly enhanced Th1-bias in vivo. TLR7a-S1-induced antibody also effectively cross-neutralized all variants of concern. This sialoglycoconjugation approach to construct protein conjugate vaccines will have more applications to combat SARS-CoV-2 and other diseases.

Self-Adjuvanting Protein Vaccine Conjugated with a Novel Synthetic TLR4 Agonist on Virus-Like Liposome Induces Potent Immunity against SARS-CoV-2.

Exploring potent adjuvants and new vaccine strategies is crucial for the development of protein vaccines. In this work, we synthesized a new TLR4 agonist, structurally simplified lipid A analogue GAP112, as a potent built-in adjuvant to improve the immunogenicity of SARS-CoV-2 spike RBD protein. The new TLR4 agonist GAP112 was site-selectively conjugated on the N-terminus of RBD to construct an adjuvant-protein conjugate vaccine in a liposomal formulation. It is the first time that a TLR4 agonist is site-specifically and quantitatively conjugated to a protein antigen. Compared with an unconjugated mixture of GAP112/RBD, a two-dose immunization of the GAP112-RBD conjugate vaccine strongly activated innate immune cells, elicited a 223-fold increase in RBD-specific antibodies, and markedly enhanced T-cell responses. Antibodies induced by GAP112-RBD also effectively cross-neutralized SARS-CoV-2 variants (Delta/B.1.617.2 and Omicron/B.1.1.529). This conjugate strategy provides an effective method to greatly enhance the immunogenicity of antigen in protein vaccines against SARS-CoV-2 and other diseases.

A vaccine delivery system promotes strong immune responses against SARS-CoV-2 variants.

Global coronavirus disease 2019 (COVID-19) pandemics highlight the need of developing vaccines with universal and durable protection against emerging SARS-CoV-2 variants. Here we developed an extended-release vaccine delivery system (GP-diABZI-RBD), consisting the original SARS-CoV-2 WA1 strain receptor-binding domain (RBD) as the antigen and diABZI stimulator of interferon genes (STING) agonist in conjunction with yeast ß-glucan particles (GP-diABZI) as the platform. GP-diABZI-RBD could activate STING pathway and inhibit SARS-CoV-2 replication. Compared to diABZI-RBD, intraperitoneal injection of GP-diABZI-RBD elicited robust cellular and humoral immune responses in mice. Using SARS-CoV-2 GFP/ΔN transcription and replication-competent virus-like particle system (trVLP), we demonstrated that GP-diABZI-RBD-prototype vaccine exhibited the strongest and durable humoral immune responses and antiviral protection; whereas GP-diABZI-RBD-Omicron displayed minimum neutralization responses against trVLP. By using pseudotype virus (PsVs) neutralization assay, we found that GP-diABZI-RBD-Prototype, GP-diABZI-RBD-Delta, and GP-diABZI-RBD-Gamma immunized mice sera could efficiently neutralize Delta and Gamma PsVs, but had weak protection against Omicron PsVs. In contrast, GP-diABZI-RBD-Omicron immunized mice sera displayed the strongest neutralization response to Omicron PsVs. Taken together, the results suggest that GP-diABZI can serve as a promising vaccine delivery system for enhancing durable humoral and cellular immunity against broad SARS-CoV-2 variants. Our study provides important scientific basis for developing SARS-CoV-2 VOC-specific vaccines.

Adjuvant-Protein Conjugate Vaccine with Built-In TLR7 Agonist on S1 Induces Potent Immunity against SARS-CoV-2 and Variants of Concern.

With the global pandemic of the new coronavirus disease (COVID-19), a safe, effective, and affordable mass-produced vaccine remains the current focus of research. Herein, we designed an adjuvant-protein conjugate vaccine candidate, in which the TLR7 agonist (TLR7a) was conjugated to S1 subunit of SARS-CoV-2 spike protein, and systematically compared the effect of different numbers of built-in TLR7a on the immune activity for the first time. As the number of built-in TLR7a increased, a bell-shaped reaction was observed in three TLR7a-S1 conjugates, with TLR7a(10)-S1 (with around 10 built-in adjuvant molecules on one S1 protein) eliciting a more potent immune response than TLR7a(2)-S1 and TLR7a(18)-S1. This adjuvant-protein conjugate strategy allows the built-in adjuvant to provide cluster effects and prevents systemic toxicity and facilitates the co-delivery of adjuvant and antigen. Vaccination of mice with TLR7a(10)-S1 triggered a potent humoral and cellular immunity and a balanced Th1/Th2 immune response. Meanwhile, the vaccine induces effective neutralizing antibodies against SARS-CoV-2 and all variants of concern (B.1.1.7/alpha, B.1.351/beta, P.1/gamma, B.1.617.2/delta, and B.1.1.529/omicron). It is expected that the adjuvant-protein conjugate strategy has great potential to construct a potent recombinant protein vaccine candidate against various types of diseases.

NLRP3 Inflammasome: Mechanism of Action, Role, and Therapeutics in Liver Diseases (preprint)

Liver inflammation is a universal characteristic of chronic liver diseases. NLRP3 is an intracellular sensor that recognizes various endogenous danger signals and environmental irritants, contributing to the formation and activation of the NLRP3 inflammasome. NLRP3 inflammasome is closely related to the progression of various liver diseases and is strongly associated with replicating COVID-19, which is still spreading globally. The assembly and activation of NLRP3 inflammasome in the liver diseases aggravate inflammation and subsequent fibrosis, and this effect is abolished by genetic or pharmacologic deletion of NLRP3 inflammasome. Here, we summarized the latest advances in the critical regulatory role of NLRP3 inflammasome in a variety of liver diseases, including COVID-19 induced liver diseases, NAFLD, ALD, and ischemia-reperfusion (I/R) injury. Additionally, we also discuss small-molecule inhibitors identifying the NLRP3 inflammasome signaling are novel therapeutic targets in treating liver diseases. Our review provides novel insights into the underlying mechanisms of NLRP3 inflammasome in liver diseases and may offer a potential therapeutic strategy for treating liver diseases by targeting NLRP3 inflammasome.

Risk of COVID-19 infection in MS and neuromyelitis optica spectrum disorders.

OBJECTIVE: Disease-modifying drugs (DMDs) may alter the immune status and thus increase the susceptibility to coronavirus disease 2019 (COVID-19) in patients with MS or neuromyelitis optica spectrum disorders (NMOSD). However, evidence supporting this notion is currently lacking. In this study, we conducted a survey on the risk of COVID-19 in patients with MS and NMOSD. METHODS: The survey was conducted through the Chinese Medical Network for Neuroinflammation. Patients in 10 MS centers from 8 cities including Wuhan were included. Information about MS and NMOSD disease duration and the usage of DMDs were collected. Data of suspected cases of COVID-19 were obtained from hospital visits, questionnaires, and patient self-reporting. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was confirmed through clinical evaluation by a panel of experts in conjunction with chest CT and viral RNA detection. RESULTS: Eight hundred eighty-two of 1,804 (48.89%) patients with MS and 2,129 of 3,060 (69.58%) patients with NMOSD were receiving DMDs. There were no alterations in the patients' DMD regimen during January 15, 2020, to March 15, 2020, the 3-month period. None of the patients with MS treated with DMDs had COVID-19. However, 2 patients with relapsing NMOSD were diagnosed with COVID-19-related pneumonia. After treatment, both patients recovered from pneumonia and neither patient experienced new attacks due to predisposing SARS-CoV-2 infection in the following 2 months. CONCLUSIONS: No increased risk of COVID-19 infection was observed in patients with MS or NMOSD, irrespective of whether these patients received DMDs. A battery of stringent preventive measures adopted by neurologists to reduce COVID-19 infection in these patients may have contributed to low risk of COVID-19 infection.

Factors associated with prolonged viral shedding and impact of Lopinavir/Ritonavir treatment in patients with SARS-CoV-2 infection (preprint)

Background: The duration of viral shedding is central to guide decisions around isolation precautions and antiviral treatment. However, studies about risk factors associated with prolonged SARS-CoV-2 shedding and the potential impact of Lopinavir/Ritonavir (LPV/r) treatment remain scarce. Methods: In this retrospective study, data were collected from all SARS-CoV-2 infected patients who were admitted to isolation wards and had RT-PCR conversion at the NO.3 People's hospital of Hubei province between 31 January and 09 March 2020. We compared clinical features and SARS-CoV-2 RNA shedding between patients with LPV/r treatment and those without. Logistic regression analysis was employed to evaluate risk factors associated with prolonged viral shedding. Results: Of 120 patients, the median age was 52 years, 54 (45%) were male and 78 (65%) received LPV/r treatment. The median duration of SARS-CoV-2 RNA detection from symptom onset was 23 days (IQR, 18-32 days). Older age (odd ratio [OR] 1.03, 95% confidence interval [CI] 1.00-1.05, p=0.03) and lack of LPV/r treatment (OR 2.42, 95% CI 1.10-5.36, p=0.029) were independent risk factors for prolonged SARS-CoV-2 RNA shedding in multivariate logistic regression analysis. The median duration of viral shedding was shorter in the LPV/r treatment group (n=78) than that in no LPV/r treatment group (n=42) (median, 22 days vs. 28.5 days, p=0.02). Only earlier administration of LPV/r treatment ([≤]10 days from symptom onset) could shorten the duration of viral shedding. Conclusions: Older age and lack of LPV/r treatment were independently associated with prolonged SARS-CoV-2 RNA shedding in patients with COVID-19. Earlier administration of LPV/r treatment could shorten viral shedding.