Structural mapping of antibody landscapes to human betacoronavirus spike proteins.

Preexisting immunity against seasonal coronaviruses (CoVs) represents an important variable in predicting antibody responses and disease severity to severe acute respiratory syndrome CoV-2 (SARS-CoV-2) infections. We used electron microscopy-based polyclonal epitope mapping (EMPEM) to characterize the antibody specificities against ß-CoV spike proteins in prepandemic (PP) sera or SARS-CoV-2 convalescent (SC) sera. We observed that most PP sera had antibodies specific to seasonal human CoVs (HCoVs) OC43 and HKU1 spike proteins while the SC sera showed reactivity across all human ß-CoVs. Detailed molecular mapping of spike-antibody complexes revealed epitopes that were differentially targeted by preexisting antibodies and SC serum antibodies. Our studies provide an antigenic landscape to ß-HCoV spikes in the general population serving as a basis for cross-reactive epitope analyses in SARS-CoV-2-infected individuals.

Inhibitory effects and mechanisms of the anti-covid-19 traditional Chinese prescription, Keguan-1, on acute lung injury.

ETHNOPHARMACOLOGICAL RELEVANCE: Keguan-1, a new traditional Chinese medicine (TCM) prescription contained seven Chinese herbs, is developed to treat coronavirus disease 19 (COVID-19). The first internationally registered COVID-19 randomised clinical trial on integrated therapy demonstrated that Keguan-1 significantly reduced the incidence of ARDS and inhibited the severe progression of COVID-19. AIM OF THE STUDY: To investigate the protective mechanism of Keguan-1 on ARDS, a lipopolysaccharide (LPS)-induced acute lung injury (ALI) model was used to simulate the pathological state of ARDS in patients with COVID-19, focusing on its effect and mechanism on ALI. MATERIALS AND METHODS: Mice were challenged with LPS (2 mg/kg) by intratracheal instillation (i.t.) and were orally administered Keguan-1 (low dose, 1.25 g/kg; medium dose, 2.5 g/kg; high dose, 5 g/kg) after 2 h. Bronchoalveolar lavage fluid (BALF) and lung tissue were collected 6 h and 24 h after i.t. administration of LPS. The levels of inflammatory factors tumour necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-1ß, keratinocyte-derived chemokine (KC or mCXCL1), macrophage inflammatory protein 2 (MIP2 or mCXCL2), angiotensin II (Ang II), and endothelial cell junction-associated proteins were analysed using ELISA or western blotting. RESULTS: Keguan-1 improved the survival rate, respiratory condition, and pathological lung injury; decreased the production of proinflammatory factors (TNF-α, IL-6, IL-1ß, KC, and MIP2) in BALF and the number of neutrophils in the lung tissues; and ameliorated inflammatory injury in the lung tissues of the mice with LPS-induced ALI. Keguan-1 also reduced the expression of Ang II and the adhesion molecule ICAM-1; increased tight junction proteins (JAM-1 and claudin-5) and VE-cadherin expression; and alleviated pulmonary vascular endothelial injury in LPS-induced ALI. CONCLUSION: These results demonstrate that Keguan-1 can improve LPS-induced ALI by reducing inflammation and pulmonary vascular endothelial injury, providing scientific support for the clinical treatment of patients with COVID-19. Moreover, it also provides a theoretical basis and technical support for the scientific use of TCMs in emerging infectious diseases.

Exploring an Integrative Therapy for Treating COVID-19: A Randomized Controlled Trial.

OBJECTIVES: To develop a new Chinese medicine (CM)-based drug and to evaluate its safety and effect for suppressing acute respiratory distress syndrome (ARDS) in COVID-19 patients. METHODS: A putative ARDS-suppressing drug Keguan-1 was first developed and then evaluated by a randomized, controlled two-arm trial. The two arms of the trial consist of a control therapy (alpha interferon inhalation, 50 µg twice daily; and lopinavir/ritonavir, 400 and 100 mg twice daily, respectively) and a testing therapy (control therapy plus Keguan-1 19.4 g twice daily) by random number table at 1:1 ratio with 24 cases each group. After 2-week treatment, adverse events, time to fever resolution, ARDS development, and lung injury on newly diagnosed COVID-19 patients were assessed. RESULTS: An analysis of the data from the first 30 participants showed that the control arm and the testing arm did not exhibit any significant differences in terms of adverse events. Based on this result, the study was expanded to include a total of 48 participants (24 cases each arm). The results show that compared with the control arm, the testing arm exhibited a significant improvement in time to fever resolution (P=0.035), and a significant reduction in the development of ARDS (P=0.048). CONCLUSIONS: Keguan-1-based integrative therapy was safe and superior to the standard therapy in suppressing the development of ARDS in COVID-19 patients. (Trial registration No. NCT04251871 at www.clinicaltrials.gov ).

[Rapid establishment of traditional Chinese medicine prevention and treatment of 2019-nCoV based on clinical experience and molecular docking].

The coronavirus disease 2019(COVID-19) is raging in China and more than 20 other countries and regions since the middle of December 2019. Currently, there is no specific drug or vaccine besides symptomatic supportive therapy. Taking full advantage of the clinical experience of traditional Chinese medicine(TCM) in preventing and controlling major epidemics such as SARS, it is an important mission for TCM to propose effective formula with immediate response and solid evidence by using modern biomedical knowledge and techniques(molecular docking assisted TCM formulation for short). In view of the high homology between the gene sequences of the novel coronavirus and SARS virus, and the similarities between the two in terms of pathogenic mechanism and clinical manifestations, our team established a rapid screening and optimization model for the prevention and treatment of the novel coronavirus based on clinical experience and molecular docking technology. Firstly, the clinical team and the research team pre-developed and screened TCM formula by using "back-to-back" manner. Then, the formula was optimized and determined by comparing and analyzing the results of the two groups. The results showed that the research team screened out 46 active ingredients from candidate TCMs that could act on the novel coronavirus S-protein-binding site of human ACE2 protein, which were mainly attributed to 7 herbs such as Lonicerae Japonicae Flos and Mori Folium. The result was largely consistent with the formula raised by the clinical group, verifying and supporting its rationality. This provides evidence for the scientific and potential efficacy of the TCM prescription from the perspective of treatment target analysis, and also suggests that the TCM prescription has the potential to directly inhibit viral infection in addition to improving clinical symptoms or syndromes. Based on this, our team optimized and formed a new anti-coronavirus TCM prescription "Keguan Yihao", immediately providing the TCM prescription with certain clinical experience and objective evidence support for the prevention and treatment of new emergent infectious diseases in our hospital. The TCM prescription was combined with modern medicine symptomatic supportive treatment for clinical treatment, preliminary results showed better effect than symptomatic supportive therapy alone. This research has innovated the method mode in clinical practice and basic research integration of traditional Chinese medicine for the prevention and control of new emerging infectious diseases. It is of great significance to further improve the rapid response mechanism of TCM in face of major epidemics, and further improve the capability level of TCM to prevent and treat new emerging infectious diseases.