Potential COVID-19 Therapeutic Agents and Vaccines: An Evidence-Based Review

The Role of Cyclodextrins in COVID-19 Therapy-A Literature Review

Coronavirus disease-19 (COVID-19) emerged in December 2019 and quickly spread, giving rise to a pandemic crisis. Therefore, it triggered tireless efforts to identify the mechanisms of the disease, how to prevent and treat it, and to limit and hamper its global dissemination. Considering the above, the search for prophylactic approaches has led to a revolution in the reglementary pharmaceutical pipeline, with the approval of vaccines against COVID-19 in an unprecedented way. Moreover, a drug repurposing scheme using regulatory-approved antiretroviral agents is also being pursued. However, their physicochemical characteristics or reported adverse events have sometimes limited their use. Hence, nanotechnology has been employed to potentially overcome some of these challenges, particularly cyclodextrins. Cyclodextrins are cyclic oligosaccharides that present hydrophobic cavities suitable for complexing several drugs. This review, besides presenting studies on the inclusion of antiviral drugs in cyclodextrins, aims to summarize some currently available prophylactic and therapeutic schemes against COVID-19, highlighting those that already make use of cyclodextrins for their complexation. In addition, some new therapeutic approaches are underscored, and the potential application of cyclodextrins to increase their promising application against COVID-19 will be addressed. This review describes the instances in which the use of cyclodextrins promotes increased bioavailability, antiviral action, and the solubility of the drugs under analysis. The potential use of cyclodextrins as an active ingredient is also covered. Finally, toxicity and regulatory issues as well as future perspectives regarding the use of cyclodextrins in COVID-19 therapy will be provided.

Comparison of hospitalized patients with severe pneumonia caused by COVID-19 and influenza A (H7N9 and H1N1): A retrospective study from a designated hospital

Considerable attention has been focused on the clinical features of coronavirus disease 2019 (COVID-19), but it is also important for clinicians to differentiate it from influenza virus infections. In the present study, the rate of coexisting disease was lower in the severe COVID-19 group than in the influenza A group (p = 0.003). Radiologically, severe COVID-19 patients had fewer instances of pleural effusion (p < 0.001). Clinically, severe COVID-19 patients had relatively better disease severity scores, less secondary bacterial infections, shorter times to beginning absorption on computed tomography, but longer durations of viral shedding from the time of admission (p < 0.05). Although the more severe influenza A patients required noninvasive respiratory support, these two groups ultimately yielded comparable mortalities. Based on the multiple logistic regression analysis, severe COVID-19 infection was associated with a lower risk of severe acute respiratory distress syndrome [odds ratio (OR) 1.016, 95% [confidence interval (CI)] 1.001-1.032, p = 0.041] and a better pneumonia severity index (OR 0.945, 95% [CI] 0.905-0.986, p = 0.009); however, these patients exhibited longer durations of viral shedding (OR 1.192, 95% [CI] 1.047-1.357, p = 0.008) than patients with severe influenza A infection. In conclusion, the conditions of severe influenza A patients appeared to be more critical than that of severe COVID-19 patients. However, relatively lower mortalities of these two severe cases are expected in the context of sufficient medical supplies.

Challenges in evaluating treatments for COVID-19: The case of in-hospital anticoagulant use and the risk of adverse outcomes

Anticoagulants are a potential treatment for the thrombotic complications resulting from COVID-19. We aimed to determine the association between anticoagulant use and adverse outcomes among hospitalized patients with COVID-19. We used data from the COVID-19 International Collaborative Research Project in South Korea from January to June 2020. We defined exposure using an intention-to-treat approach, with person-time classified as use or non-use of anticoagulants at cohort entry, and a time-varying approach. The primary outcome was all-cause, in-hospital mortality; the secondary outcome was a composite including respiratory outcomes, cardiovascular outcomes, venous thromboembolism, major bleeding, and intensive care unit admission. Cox proportional hazards models estimated adjusted hazard ratios (HRs) of the outcomes comparing use versus non-use of anticoagulants. Our cohort included 2,677 hospitalized COVID-19 patients, of whom 24 received anticoagulants at cohort entry. Users were older and had more comorbidities. The crude incidence rate (per 1,000 person-days) of mortality was 5.83 (95% CI: 2.80, 10.72) among anticoagulant users and 1.36 (95% CI: 1.14, 1.59) for non-users. Crude rates of the composite outcome were 3.20 (95% CI: 1.04, 7.47) and 1.80 (95% CI: 1.54, 2.08), respectively. Adjusted HRs for mortality (HR: 1.12, 95% CI: 0.48, 2.64) and the composite outcome (HR: 0.79, 95% CI: 0.28, 2.18) were inconclusive. Although our study was not able to draw conclusions on anticoagulant effectiveness for COVID-19 outcomes, these results can contribute to future knowledge syntheses of this important question. Our study demonstrated that the dynamic pandemic environment may have important implications for observational studies of COVID-19 treatment effectiveness.

Current Treatments for COVID-19: Application of Supercritical Fluids in the Manufacturing of Oral and Pulmonary Formulations

Even though more than two years have passed since the emergence of COVID-19, the research for novel or repositioned medicines from a natural source or chemically synthesized is still an unmet clinical need. In this review, the application of supercritical fluids to the development of novel or repurposed medicines for COVID-19 and their secondary bacterial complications will be discussed. We envision three main applications of the supercritical fluids in this field: (i) drug micronization, (ii) supercritical fluid extraction of bioactives and (iii) sterilization. The supercritical fluids micronization techniques can help to improve the aqueous solubility and oral bioavailability of drugs, and consequently, the need for lower doses to elicit the same pharmacological effects can result in the reduction in the dose administered and adverse effects. In addition, micronization between 1 and 5 µm can aid in the manufacturing of pulmonary formulations to target the drug directly to the lung. Supercritical fluids also have enormous potential in the extraction of natural bioactive compounds, which have shown remarkable efficacy against COVID-19. Finally, the successful application of supercritical fluids in the inactivation of viruses opens up an opportunity for their application in drug sterilization and in the healthcare field.

Current evidence on the use of anakinra in COVID-19

Despite the progressing knowledge in COVID-19 management, remdesivir is the only agent that got approval to inhibit viral replication. However, there are limited data about effective immunomodulatory agents to prevent cytokine release in COVID-19. Cytokine release syndrome in COVID-19 resembles secondary hemophagocytic lymphohistiocytosis, in which interleukin-1 (IL-1) plays a key role. Anakinra is the first recombinant IL-1 receptor antagonist studied for off-label use in COVID-19 treatment. This study reviews the current clinical evidence on the role of interleukin-1 in COVID-19-related cytokine storm, therapeutic effects, significant clinical concerns, and pros and cons of anakinra administration in the management of COVID-19 patients. In this review, four items are shown to be important for achieving the optimal therapeutic effects of anakinra in COVID-19 patients. These items include duration of treatment ≥ 10 days, doses ≥ 100 mg, intravenous administration, and early initiation of therapy. Also, anakinra might be more beneficial in the early stages of the disease when higher levels of cytokines are yet to be observed, which could prevent progression to severe illness and mechanical ventilation. Further studies are required to address the SARS-CoV-2 induced cytokine release syndrome and the role of anakinra in identifying ideal treatment approaches for COVID-19 patients based on their clinical status.

A comprehensive insight into current control of COVID-19: Immunogenicity, vaccination, and treatment

The healthy immune system eliminates pathogens and maintains tissue homeostasis through extraordinarily complex networks with feedback systems while avoiding potentially massive tissue destruction. Many parameters influence humoral and cellular vaccine responses, including intrinsic and extrinsic, environmental, and behavioral, nutritional, perinatal and administrative parameters. The relative contributions of persisting antibodies and immune memory as well as the determinants of immune memory induction, to protect against specific diseases are the main parameters of long-term vaccine efficacy. Natural and vaccine-induced immunity and monoclonal antibody immunotherapeutic, may be evaded by SARS-CoV-2 variants. Besides the complications of the production of COVID-19 vaccinations, there is no effective single treatment against COVID-19. However, administration of a combined treatment at different stages of COVID-19 infection may offer some cure assistance. Combination treatment of antiviral drugs and immunomodulatory drugs may reduce inflammation in critical COVID-19 patients with cytokine release syndrome. Molnupiravir, remdesivir and paxlovid are the approved antiviral agents that may reduce the recovery time. In addition, immunomodulatory drugs such as lactoferrin and monoclonal antibodies are used to control inflammatory responses in their respective auto-immune conditions. Therefore, the widespread occurrence of highly transmissible variants like Delta and Omicron indicates that there is still a lot of work to be done in designing efficient vaccines and medicines for COVID-19. In this review, we briefly discussed the immunological response against SARS-CoV-2 and the vaccines approved by the World Health Organization (WHO) for COVID-19, their mechanisms, and side effects. Moreover, we mentioned various treatment trials and strategies for COVID-19.

Comprehensive review on molnupiravir in COVID-19: a novel promising antiviral to combat the pandemic

Despite the progress in the management of COVID-19, effective oral antiviral agents are still lacking. In the present review, the potential beneficial effects of molnupiravir in the management of COVID-19 are discussed. A literature search in Google Scholar, Scopus, PubMed and clinicaltrials.gov for the relevant articles regarding the pharmacokinetics, pharmacodynamics and clinical trials of molnupiravir in the management of COVID-19 is conducted. Most of the preclinical studies and available clinical trials showed a favorable short-term safety profile of molnupiravir; however, given its possible genotoxic effects, further trials are required to confirm the long-term efficacy and safety of molnupiravir in patients with COVID-19.

Liposomal Formulation of a PLA2-Sensitive Phospholipid-Allocolchicinoid Conjugate: Stability and Activity Studies In Vitro

To assess the stability and efficiency of liposomes carrying a phospholipase A2-sensitive phospholipid-allocolchicinoid conjugate (aC-PC) in the bilayer, egg phosphatidylcholine and 1-palmitoyl-2-oleoylphosphatidylglycerol-based formulations were tested in plasma protein binding, tubulin polymerization inhibition, and cytotoxicity assays. Liposomes L-aC-PC10 containing 10 mol. % aC-PC in the bilayer bound less plasma proteins and were more stable in 50% plasma within 4 h incubation, according to calcein release and FRET-based assays. Liposomes with 25 mol. % of the prodrug (L-aC-PC25) were characterized by higher storage stability judged by their hydrodynamic radius evolution yet enhanced deposition of blood plasma opsonins on their surface according to SDS-PAGE and immunoblotting. Notably, inhibition of tubulin polymerization was found to require that the prodrug should be hydrolyzed to the parent allocolchicinoid. The L-aC-PC10 and L-aC-PC25 formulations demonstrated similar tubulin polymerization inhibition and cytotoxic activities. The L-aC-PC10 formulation should be beneficial for applications requiring liposome accumulation at tumor or inflammation sites.

Factors associated with admission to the intensive care unit and mortality in patients with COVID-19, Colombia

Introduction

Coronavirus disease 2019 (COVID-19) has affected millions of people worldwide, and several sociodemographic variables, comorbidities and care variables have been associated with complications and mortality.

Objective

To identify the factors associated with admission to intensive care units (ICUs) and mortality in patients with COVID-19 from 4 clinics in Colombia.

Methods

This was a follow-up study of a cohort of patients diagnosed with COVID-19 between March and August 2020. Sociodemographic, clinical (Charlson comorbidity index and NEWS 2 score) and pharmacological variables were identified. Multivariate analyses were performed to identify variables associated with the risk of admission to the ICU and death (p<0.05).

Results

A total of 780 patients were analyzed, with a median age of 57.0 years; 61.2% were male. On admission, 54.9% were classified as severely ill, 65.3% were diagnosed with acute respiratory distress syndrome, 32.4% were admitted to the ICU, and 26.0% died. The factors associated with a greater likelihood of ICU admission were severe pneumonia (OR: 9.86; 95%CI:5.99–16.23), each 1-point increase in the NEWS 2 score (OR:1.09; 95%CI:1.002–1.19), history of ischemic heart disease (OR:3.24; 95%CI:1.16–9.00), and chronic obstructive pulmonary disease (OR:2.07; 95%CI:1.09–3.90). The risk of dying increased in those older than 65 years (OR:3.08; 95%CI:1.66–5.71), in patients with acute renal failure (OR:6.96; 95%CI:4.41–11.78), admitted to the ICU (OR:6.31; 95%CI:3.63–10.95), and for each 1-point increase in the Charlson comorbidity index (OR:1.16; 95%CI:1.002–1.35).

Conclusions

Factors related to increasing the probability of requiring ICU care or dying in patients with COVID-19 were identified, facilitating the development of anticipatory intervention measures that favor comprehensive care and improve patient prognosis.

A multi-center, adaptive, randomized, platform trial to evaluate the effect of repurposed medicines in outpatients with early coronavirus disease 2019 (COVID-19) and high-risk for complications: the TOGETHER master trial protocol

Background: There remains a need for an effective and affordable outpatient treatment for early COVID-19. Multiple repurposed drugs have shown promise in treating COVID-19. We describe a master protocol that will assess the efficacy of different repurposed drugs as treatments for early COVID-19 among outpatients at a high risk for severe complications. Methods: The TOGETHER Trial is a multi-center platform adaptive randomized, placebo-controlled, clinical trial. Patients are included if they are at least 18 years of age, have a positive antigen test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and have an indication for high risk of disease severity, including co-morbidities, older age, or high body mass index. Eligible patients are randomized with equal chance to an investigational product (IP) or to placebo.The primary endpoint is hospitalization defined as either retention in a COVID-19 emergency setting for greater than 6 hours or transfer to tertiary hospital due to COVID-19. Secondary outcomes include mortality, adverse events, adherence, and viral clearance. Scheduled interim analyses are conducted and reviewed by the Data and Safety Monitoring Committee (DSMC), who make recommendations on continuing or stopping each IP. The platform adaptive design go-no-go decision rules are extended to dynamically incorporate external evidence on COVID-19 interventions from ongoing independent randomized clinical trials. Discussion: Results from this trial will assist in the identification of therapeutics for the treatment of early diagnosed COVID-19. The novel methodological extension of the platform adaptive design to dynamically incorporate external evidence is one of the first of its kind and may provide highly valuable information for all COVID-19 trials going forward. Clinicaltrials.gov registration: NCT04727424 (27/01/2021)

Drug Interactions for Patients with Respiratory Diseases Receiving COVID-19 Emerged Treatments

Pandemic of coronavirus disease (COVID-19) is still pressing the healthcare systems worldwide. Thus far, the lack of available COVID-19-targeted treatments has led scientists to look through drug repositioning practices and exploitation of available scientific evidence for potential efficient drugs that may block biological pathways of SARS-CoV-2. Till today, several molecules have emerged as promising pharmacological agents, and more than a few medication protocols are applied during hospitalization. On the other hand, given the criticality of the disease, it is important for healthcare providers, especially those in COVID-19 clinics (i.e., nursing personnel and treating physicians), to recognize potential drug interactions that may lead to adverse drug reactions that may negatively impact the therapeutic outcome. In this review, focusing on patients with respiratory diseases (i.e., asthma or chronic obstructive pulmonary disease) that are treated also for COVID-19, we discuss possible drug interactions, their underlying pharmacological mechanisms, and possible clinical signs that healthcare providers in COVID-19 clinics may need to acknowledge as adverse drug reactions due to drug-drug interactions.

Safety and Efficacy of Convalescent Plasma in COVID-19: An Overview of Systematic Reviews

Convalescent plasma (CP) from patients recovered from COVID-19 is one of the most studied anti-viral therapies against SARS-COV-2 infection. The aim of this study is to summarize the evidence from the available systematic reviews on the efficacy and safety of CP in COVID-19 through an overview of the published systematic reviews (SRs). A systematic literature search was conducted up to August 2021 in Embase, PubMed, Web of Science, Cochrane and Medrxiv databases to identify systematic reviews focusing on CP use in COVID-19. Two review authors independently evaluated reviews for inclusion, extracted data and assessed quality of evidence using AMSTAR (A Measurement Tool to Assess Reviews) and GRADE tools. The following outcomes were analyzed: mortality, viral clearance, clinical improvement, length of hospital stay, adverse reactions. In addition, where possible, subgroup analyses were performed according to study design (e.g., RCTs vs. non-RCTs), CP neutralizing antibody titer and timing of administration, and disease severity. The methodological quality of included studies was assessed using the checklist for systematic reviews AMSTAR-2 and the GRADE assessment. Overall, 29 SRs met the inclusion criteria based on 53 unique primary studies (17 RCT and 36 non-RCT). Limitations to the methodological quality of reviews most commonly related to absence of a protocol (11/29) and funding sources of primary studies (27/29). Of the 89 analyses on which GRADE judgements were made, effect estimates were judged to be of high/moderate certainty in four analyses, moderate in 38, low in 38, very low in nine. Despite the variability in the certainty of the evidence, mostly related to the risk of bias and inconsistency, the results of this umbrella review highlight a mortality reduction in CP over standard therapy when administered early and at high titer, without increased adverse reactions.

Dissecting Tumor Antigens and Immune Subtypes of Glioma to Develop mRNA Vaccine

Background

Nowadays, researchers are leveraging the mRNA-based vaccine technology used to develop personalized immunotherapy for cancer. However, its application against glioma is still in its infancy. In this study, the applicable candidates were excavated for mRNA vaccine treatment in the perspective of immune regulation, and suitable glioma recipients with corresponding immune subtypes were further investigated.

Methods

The RNA-seq data and clinical information of 702 and 325 patients were recruited from TCGA and CGGA, separately. The genetic alteration profile was visualized and compared by cBioPortal. Then, we explored prognostic outcomes and immune correlations of the selected antigens to validate their clinical relevance. The prognostic index was measured via GEPIA2, and infiltration of antigen-presenting cells (APCs) was calculated and visualized by TIMER. Based on immune-related gene expression, immune subtypes of glioma were identified using consensus clustering analysis. Moreover, the immune landscape was visualized by graph learning-based dimensionality reduction analysis.

Results

Four glioma antigens, namely ANXA5, FKBP10, MSN, and PYGL, associated with superior prognoses and infiltration of APCs were selected. Three immune subtypes IS1-IS3 were identified, which fundamentally differed in molecular, cellular, and clinical signatures. Patients in subtypes IS2 and IS3 carried immunologically cold phenotypes, whereas those in IS1 carried immunologically hot phenotype. Particularly, patients in subtypes IS3 and IS2 demonstrated better outcomes than that in IS1. Expression profiles of immune checkpoints and immunogenic cell death (ICD) modulators showed a difference among IS1-IS3 tumors. Ultimately, the immune landscape of glioma elucidated considerable heterogeneity not only between individual patients but also within the same immune subtype.

Conclusions

ANXA5, FKBP10, MSN, and PYGL are identified as potential antigens for anti-glioma mRNA vaccine production, specifically for patients in immune subtypes 2 and 3. In summary, this study may shed new light on the promising approaches of immunotherapy, such as devising mRNA vaccination tailored to applicable glioma recipients.

A multi-center, adaptive, randomized, platform trial to evaluate the effect of repurposed medicines in outpatients with early coronavirus disease 2019 (COVID-19) and high-risk for complications: the TOGETHER master trial protocol

Background: Although vaccines are currently available for coronavirus disease 2019 (COVID-19), there remains a need for an effective and affordable outpatient treatment for early COVID-19. Multiple repurposed drugs have shown promise in treating COVID-19. We describe a master protocol that will assess the efficacy of different repurposed drugs as treatments for early COVID-19 among outpatients at a high risk for severe complications. Methods: The TOGETHER Trial is an international (currently in Brazil and Africa), multi-center platform adaptive randomized, placebo-controlled, clinical trial. Patients are included if they are at least 18 years of age, have a positive antigen test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and have an indication for high risk of disease severity, including co-morbidities, older age, or high body mass index. Eligible patients are randomized with equal chance to an investigational product (IP) or to placebo. The primary endpoint is hospitalization due to clinical worsening of COVID-19 or emergency room required observation for more than 6 hours up to 28 days after randomization. Key secondary endpoints include viral clearance, clinical improvement, hospitalization for any cause, mortality for any cause, and safety and tolerability of each IP. Scheduled interim analyses are conducted and reviewed by the Data and Safety Monitoring Committee (DSMC), who make recommendations on continuing or stopping each IP. The platform adaptive design go-no-go decision rules are extended to dynamically incorporate external evidence on COVID-19 interventions from ongoing independent randomized clinical trials. Discussion: Results from this trial will assist in the identification of therapeutics for COVID-19 that can easily be scaled in low- and middle-income settings. The novel methodological extension of the platform adaptive design to dynamically incorporate external evidence is one of the first of its kind and may provide highly valuable information for all COVID-19 trials going forward. Clinicaltrials.gov registration: NCT04727424 (27/01/2021)

COVID‑19 vaccination and IgG and IgA antibody dynamics in healthcare workers

Given the current outbreak of coronavirus disease 2019 (COVID‑19) and the development and implementation of mass vaccination, data are being obtained by analyzing vaccination campaigns. In the present study, 69 healthcare workers who were exposed to patients with severe acute respiratory syndrome coronavirus‑2 were monitored for specific immunoglobulin (Ig)G and IgA levels at different time periods. Prior to vaccination, after the first round of vaccination at 21 days (when the second dose of vaccine was administrated) and 24 days after the second round of vaccination, with an mRNA‑based vaccine. The basal IgG and IgA levels in previously infected subjects and non‑infected subjects notably differed. Vaccination increased the IgG and IgA levels after the first dose in most subjects from both groups, the levels of which further increased following the second round of vaccination. The associations between IgG and IgA levels following the first and second rounds of vaccination demonstrated that in the entire vaccination group, regardless of prior exposure to the infectious agent, the increment and levels of IgG and IgA were similar. Thus, the levels upon vaccination were statistically similar irrespective of the starting base line prior to vaccination. In the present study, seroconversion was achieved in all subjects following the second round of vaccination, with similar antibodies levels.

Emergent Inpatient Administration of Casirivimab and Imdevimab Antibody Cocktail for the Treatment of COVID-19 Pneumonia

Infection by severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) is known to have the highest mortality rate among the elderly and those with pre-existing medical conditions. Viral load has been directly correlated with increased risk of mortality in hospitalized patients. Once infected, symptoms first arise approximately six to seven days later followed by immunoglobulin M (IgM) antibodies appearing 8-12 days after onset of clinical symptoms. Recent studies have noted that the monoclonal antibody combination of casirivimab and imdevimab (REGN-COV2) effectively reduces viral load in infected seronegative non-hospitalized patients. However, research supporting the use of REGN-COV2 in an inpatient setting is limited. We present the case of a 45-year-old male with confirmed SARS-CoV-2 infection with moderate dyspnea and progressive worsening of his symptoms over a week period. The patient showed drastic improvement of his symptoms after a single low-dose regimen of REGN-COV2 infusion while admitted to the hospital and was subsequently discharged without further medical complications.

[Salvianolic acid B and its magnesium salt inhibit SARS-CoV-2 infection of Vero-E6 cells by blocking spike protein-mediated membrane fusion]

OBJECTIVE

The investigate the inhibitory effects of the traditional Chinese medicine (TCM) monomer salvianolic acid B (Sal-B) and its magnesium salt Salvia Miltiorrhiza Polyphenolate Injection (ZDDY) against SARS-CoV-2 infection in vitro and explore the molecular mechanism.

OBJECTIVE

The anti-SARS-CoV-2 activity of Sal-B and ZDDY was assessed using the authentic and pseudotyped SARS-CoV-2 infection assay. The antiviral targets of Sal-B were identified by molecular docking and molecular dynamics simulation. Circular dichroism spectroscopy was used to examine the structural characteristics of HR1 and HR2 regions of SARS-CoV-2 S protein, and the S protein-mediated cell-cell fusion assay was used to evaluate the effect of Sal-B on virus-cell membrane fusion. Flow cytometry was carried out to analyze the effect of Sal-B on the binding of SARS-CoV-2 RBD to hACE2 receptor.

OBJECTIVE

The median effective concentrations (EC50) of Sal-B and ZDDY against SARSCoV-2 infection in Vero-E6 cells were 55.47 μmol/L and 36.07 μg/mL, respectively. Both Sal-B and ZDDY successfully inhibited the entry of SARS-CoV-2 pseudovirus into the cells that stably expressed human ACE2 (ACE2/293T), with half maximal inhibitory concentrations (IC50) of 1.69 μmol/L and 24.81 μg/mL, respectively. Sal-B showed a binding affinity of -8.2 kcal/mol to the 6-helix bundle (6-HB) of SARS-CoV-2 S protein. Molecular dynamics simulation showed stable binding between Sal-B and the 6-HB of SARS-CoV-2 S protein at the predicted binding site. Sal-B disturbed the formation of the secondary structure of 6-HB in HR1P/HR2P mixture, resulting in a significantly lowered α-helicity (P < 0.05). Sal-B dose-dependently inhibited SARS-CoV-2 S protein-mediated cell-cell fusion, with an IC50 of 3.33 μmol/L. Sal-B showed no effect on RBD-Fc protein binding to the ACE2 receptor.

OBJECTIVE

Sal-B and its magnesium salt ZDDY can inhibit the entry of SARS-CoV-2 in Vero-E6 cells in vitro by blocking SARS-CoV-2 spike protein-mediated virus-cell membrane fusion.

Identification of tumor antigens and immune subtypes of cholangiocarcinoma for mRNA vaccine development

BACKGROUND

The mRNA-based cancer vaccine has been considered a promising strategy and the next hotspot in cancer immunotherapy. However, its application on cholangiocarcinoma remains largely uncharacterized. This study aimed to identify potential antigens of cholangiocarcinoma for development of anti-cholangiocarcinoma mRNA vaccine, and determine immune subtypes of cholangiocarcinoma for selection of suitable patients from an extremely heterogeneous population.

METHODS

Gene expression profiles and corresponding clinical information were collected from GEO and TCGA, respectively. cBioPortal was used to visualize and compare genetic alterations. GEPIA2 was used to calculate the prognostic index of the selected antigens. TIMER was used to visualize the correlation between the infiltration of antigen-presenting cells and the expression of the identified antigens. Consensus clustering analysis was performed to identify the immune subtypes. Graph learning-based dimensionality reduction analysis was conducted to visualize the immune landscape of cholangiocarcinoma.

RESULTS

Three tumor antigens, such as CD247, FCGR1A, and TRRAP, correlated with superior prognoses and infiltration of antigen-presenting cells were identified in cholangiocarcinoma. Cholangiocarcinoma patients were stratified into two immune subtypes characterized by differential molecular, cellular and clinical features. Patients with the IS1 tumor had immune "hot" and immunosuppressive phenotype, whereas those with the IS2 tumor had immune "cold" phenotype. Interestingly, patients with the IS2 tumor had a superior survival than those with the IS1 tumor. Furthermore, distinct expression of immune checkpoints and immunogenic cell death modulators was observed between different immune subtype tumors. Finally, the immune landscape of cholangiocarcinoma revealed immune cell components in individual patient.

CONCLUSIONS

CD247, FCGR1A, and TRRAP are potential antigens for mRNA vaccine development against cholangiocarcinoma, specifically for patients with IS2 tumors. Therefore, this study provides a theoretical basis for the anti-cholangiocarcinoma mRNA vaccine and defines suitable patients for vaccination.