Immunopathology and Immunopathogenesis of COVID-19, what we know and what we should learn

Diagnostic Challenges in Fungal Coinfections Associated With Global COVID-19

The early diagnosis of opportunistic infections is a critical concern for patient care worldwide, particularly in the context of the COVID-19 pandemic. This review examines the challenges and advancements in the management and early diagnosis of opportunistic fungal infections, which have become increasingly prominent during the pandemic. Using multiple sources, including curated databases such as PubMed and Scopus, as well as Google Scholar for broader literature searches, we systematically reviewed studies on COVID-19-associated fungal infections, with a focus on candidiasis, mucormycosis, and aspergillosis. The inclusion criteria encompassed peer-reviewed articles, clinical case reports, and cohort studies that discussed diagnostic methods, clinical outcomes, and treatment responses. Data were systematically extracted and analyzed to identify key trends and gaps in current diagnostic practices. Given the significance of opportunistic fungal infections-particularly the selected species-this review provides a comprehensive analysis of diagnostic challenges and advancements in the context of COVID-19 and beyond. Currently, there is no definitive strategy for effectively addressing these opportunistic pathogens, highlighting the need for continued research and innovation. Despite advancements in medical technology, opportunistic fungal infections continue to pose significant challenges to early and accurate diagnosis. The COVID-19 pandemic has exacerbated these challenges, with secondary fungal infections contributing to increased morbidity and mortality rates. This review highlights the complexities of diagnosing fungal coinfections and emphasizes the urgent need for improved diagnostic strategies. Enhancing the early and accurate detection of these infections is critical for effective patient management, particularly during viral pandemics. Addressing the challenges outlined in this review requires innovative diagnostic approaches to improve patient outcomes and reduce the burden of opportunistic infections on global healthcare systems.

Political Affiliation, Policy Measures, and Intention to Receive COVID-19 and Influenza Vaccines

Our study aimed to assess the impact of political affiliation, personal beliefs, and policy measures on the intention to receive routine COVID-19 and influenza vaccines in the coming year. A cross-sectional study of 1256 individuals at Minnesota State and County Fairs was conducted to assess their intention to receive COVID-19 booster and influenza vaccines in the coming year. The association between vaccine intention and political affiliation, belief in collective responsibility, and workplace/school vaccine requirements were analyzed using multinomial logistic regression. Vaccine intention in the coming year was high among our participants; 65% intended to receive both vaccines, 11% intended to receive only the influenza vaccine, 7% intended to receive only the COVID-19 vaccine, and 17% planned to receive neither. Political affiliation was strongly associated with the intention to receive both vaccines. Republicans were far more likely than Democrats to report plans to receive neither vaccine (aOR: 12.8; 95% CI: 6.2-26.6), or only the influenza vaccine in the coming year (aOR: 8.7; 95% CI: 4.2-17.9). Additionally, those who planned to receive both vaccines were significantly more likely to view vaccines as a collective responsibility. This study highlights the significant influence of political affiliation and beliefs in collective responsibility on vaccine intentions.

Efficacy of late-onset antiviral treatment in immunocompromised hosts with persistent SARS-CoV-2 infection

Immunocompromised people are at high risk of prolonged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and progression to severe coronavirus disease 2019 (COVID-19). However, the efficacy of late-onset direct-acting antiviral (DAA) therapy with therapeutics in clinical use and experimental drugs to mitigate persistent viral replication is unclear. In this study, we employed an immunocompromised mouse model, which supports prolonged replication of SARS-CoV-2 to explore late-onset treatment options. Tandem immuno-depletion of CD4+ and CD8+ T cells in C57BL/6 mice followed by infection with SARS-CoV-2 variant of concern (VOC) beta B.1.351 resulted in prolonged infection with virus replication for 5 weeks after inoculation. Early-onset treatment with nirmatrelvir/ritonavir (paxlovid) or molnupiravir was only moderately efficacious, whereas the experimental therapeutic 4'-fluorouridine (4'-FlU, EIDD-2749) significantly reduced virus load in the upper and lower respiratory compartments 4 days postinfection (dpi). All antivirals significantly lowered virus burden in a 7-day treatment regimen initiated 14 dpi, but paxlovid-treated animals experienced rebound virus replication in the upper respiratory tract 7 days after treatment end. Viral RNA was detectable 28 dpi in paxlovid-treated animals, albeit not in the molnupiravir or 4'-FlU groups, when treatment was initiated 14 dpi and continued for 14 days. Low-level virus replication continued 35 dpi in animals receiving vehicle but had ceased in all treatment groups. These data indicate that late-onset DAA therapy significantly shortens the duration of persistent virus replication in an immunocompromised host, which may have implications for clinical use of antiviral therapeutics to alleviate the risk of progression to severe disease in highly vulnerable patients.

IMPORTANCE

Four years after the onset of the global coronavirus disease 2019 (COVID-19) pandemic, the immunocompromised are at greatest risk of developing life-threatening severe disease. However, specific treatment plans for this most vulnerable patient group have not yet been developed. Employing a CD4+ and CD8+ T cell-depleted immunocompromised mouse model of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, we explored therapeutic options of persistent infections with standard-of-care paxlovid, molnupiravir, and the experimental therapeutic 4'-fluorouridine (4'-FlU). Late-onset treatment initiated 14 days after infection was efficacious, but only 4'-FlU was rapidly sterilizing. No treatment-experienced viral variants with reduced susceptibility to the drugs emerged, albeit virus replication rebounded in animals of the paxlovid group after treatment end. This study supports the use of direct-acting antivirals (DAAs) for late-onset management of persistent SARS-CoV-2 infection in immunocompromised hosts. However, treatment courses likely require to be extended for maximal therapeutic benefit, calling for appropriately powered clinical trials to meet the specific needs of this patient group.

Factors Influencing the Intention of Chinese Adults to Recommend COVID-19 Vaccination for Specific or Non-Specific Groups

The widespread availability of vaccines has profound implications for sustainable public health. Positive recommendation on vaccination is one of the most effective ways to increase the willingness to vaccinate against COVID-19. This study aims to investigate the factors influencing the intentions to recommend COVID-19 vaccination for specific groups (IRCVSG) and the intentions to recommend COVID-19 vaccination for non-specific groups (IRCVNSG) in China and explore the mediating role of vaccine hesitancy and perception of vaccination information. This study conducted a cross-sectional anonymous online survey of adults (N = 903) in 28 provincial-level administrative regions in China in May 2022. The prevalence of IRCVSG and IRCVNSG was 60.5% and 93.0%, respectively. Health information literacy has a significant direct and indirect impact on IRCVSG through safety hesitancy and the perceived adequacy and usefulness of vaccination information. The relationship between health information literacy and IRCVNSG is entirely mediated via hesitation about the effectiveness and perceived usefulness of vaccination information. Special attention should be paid to the safety hesitation of COVID-19 vaccination for specific groups. This study tests these effects from both theoretical and practical perspectives, helping to address barriers to promoting the vaccination of specific groups for COVID-19 in clinical practice, improving health and sustainability.

Efficacy of late-onset antiviral treatment in immune-compromised hosts with persistent SARS-CoV-2 infection

The immunocompromised are at high risk of prolonged SARS-CoV-2 infection and progression to severe COVID-19. However, efficacy of late-onset direct-acting antiviral (DAA) therapy with therapeutics in clinical use and experimental drugs to mitigate persistent viral replication is unclear. In this study, we employed an immunocompromised mouse model, which supports prolonged replication of SARS-CoV-2 to explore late-onset treatment options. Tandem immuno-depletion of CD4 + and CD8 + T cells in C57BL/6 mice followed by infection with SARS-CoV-2 variant of concern (VOC) beta B.1.351 resulted in prolonged infection with virus replication for five weeks after inoculation. Early-onset treatment with nirmatrelvir/ritonavir (paxlovid) or molnupiravir was only moderately efficacious, whereas the experimental therapeutic 4'-fluorourdine (4'-FlU, EIDD-2749) significantly reduced virus load in upper and lower respiratory compartments four days post infection (dpi). All antivirals significantly lowered virus burden in a 7-day treatment regimen initiated 14 dpi, but paxlovid-treated animals experienced rebound virus replication in the upper respiratory tract seven days after treatment end. Viral RNA was detectable 28 dpi in paxlovid-treated animals, albeit not in the molnupiravir or 4'-FlU groups, when treatment was initiated 14 dpi and continued for 14 days. Low-level virus replication continued 35 dpi in animals receiving vehicle but had ceased in all treatment groups. These data indicate that late-onset DAA therapy significantly shortens the duration of persistent virus replication in an immunocompromised host, which may have implications for clinical use of antiviral therapeutics to alleviate the risk of progression to severe disease in highly vulnerable patients.

Importance

Four years after the onset of the global COVID-19 pandemic, the immunocompromised are at greatest risk of developing life-threatening severe disease. However, specific treatment plans for this most vulnerable patient group have not yet been developed. Employing a CD4 + and CD8 + T cell-depleted immunocompromised mouse model of SARS-CoV-2 infection, we explored therapeutic options of persistent infections with standard-of-care paxlovid, molnupiravir, and the experimental therapeutic 4'-FlU. Late-onset treatment initiated 14 days after infection was efficacious, but only 4'-FlU was rapidly sterilizing. No treatment-experienced viral variants with reduced susceptibility to the drugs emerged, albeit virus replication rebounded in animals of the paxlovid group after treatment end. This study supports the use of direct-acting antivirals for late-onset management of persistent SARS-CoV-2 infection in immunocompromised hosts. However, treatment courses likely require to be extended for maximal therapeutic benefit, calling for appropriately powered clinical trials to meet the specific needs of this patient group.

Relative effectiveness of bivalent COVID-19 vaccine: a systematic review and meta-analysis

Objective

The rapid development of COVID-19 bivalent vaccines (BVs) has encompassed both the original virus strains and the variant strain. However, the effectiveness of BVs is largely unknown. Therefore, we conducted a systematic review and meta-analysis of the effectiveness of BVs.

Methods

Literature research was conducted through PubMed, Cochrane Library, Embase, and Web of Science up until November 4, 2023. Both randomized control trials and observational studies were considered for inclusion. Pooled estimates were calculated using a random effects model. The Newcastle-Ottawa Scale (NOS) was used to assess the risk of bias in cohort and case-control studies.

Results

A total of 1,174 articles were reviewed and 22 eligible studies were included. All included studies were observational (15 cohort studies, 7 case-control studies). The total number of participants was 39,673,160, and the number of people vaccinated with BVs as an intervention group was 11,585,182. Two mRNA BVs were mainly involved, including the ancestral strain and the BA.1 or BA.4-5 variants. Meta-analysis results showed, compared with the monovalent vaccines (MVs), the relative effectiveness (rVE) of the BVs in COVID-19-associated infections/symptomatic infections, illnesses, hospitalizations, and deaths was 30.90% [95% confidence interval (CI), 8.43-53.37], 39.83% (95% CI, 27.34-52.32), 59.70% (95% CI, 44.08-75.32), and 72.23% (95% CI, 62.08-82.38), respectively. For those aged 50 years and older, BVs provided an additional 49.69% (95% CI, 41.44-57.94) effective protection compared with MVs. During the dominance period of the omicron XBB variant strain, BVs provided an additional 47.63% (95% CI, 27.45-67.82) effective protection compared with MVs.

Conclusion

Our findings show that the rVE of BVs in preventing COVID-19-associated infections, symptomatic infections, illnesses, hospitalizations, and deaths is higher compared to MVs. Particularly for people over 50 years of age and during the Omicron variant XBB dominance phase, BVs provided superior protection. Therefore, BVs may have a broader application in the prevention and control of coronaviruses variant.

A systematic two-sample and bidirectional MR process highlights a unidirectional genetic causal effect of allergic diseases on COVID-19 infection/severity

BACKGROUND

Allergic diseases (ADs) such as asthma are presumed risk factors for COVID-19 infection. However, recent observational studies suggest that the assumed correlation contradicts each other. We therefore systematically investigated the genetic causal correlations between various ADs and COVID-19 infection/severity.

METHODS

We performed a two-sample, bidirectional Mendelian randomization (MR) study for five types of ADs and the latest round of COVID-19 GWAS meta-analysis datasets (critically ill, hospitalized, and infection cases). We also further validated the significant causal correlations and elucidated the potential underlying molecular mechanisms.

RESULTS

With the most suitable MR method, asthma consistently demonstrated causal protective effects on critically ill and hospitalized COVID-19 cases (OR < 0.93, p < 2.01 × 10-2), which were further confirmed by another validated GWAS dataset (OR < 0.92, p < 4.22 × 10-3). In addition, our MR analyses also observed significant causal correlations of food allergies such as shrimp allergy with the risk of COVID-19 infection/severity. However, we did not find any significant causal effect of COVID-19 phenotypes on the risk of ADs. Regarding the underlying molecular mechanisms, not only multiple immune-related cells such as CD4+ T, CD8+ T and the ratio of CD4+/CD8+ T cells showed significant causal effects on COVID-19 phenotypes and various ADs, the hematology traits including monocytes were also significantly correlated with them. Conversely, various ADs such as asthma and shrimp allergy may be causally correlated with COVID-19 infection/severity by affecting multiple hematological traits and immune-related cells.

CONCLUSIONS

Our systematic and bidirectional MR analyses suggest a unidirectional causal effect of various ADs, particularly of asthma on COVID-19 infection/severity, but the reverse is not true. The potential underlying molecular mechanisms of the causal effects call for more attention to clinical monitoring of hematological cells/traits and may be beneficial in developing effective therapeutic strategies for allergic patients following infection with COVID-19.

Safety of multiple intravenous infusions of adipose-derived mesenchymal stem cells for hospitalized cases of COVID-19: a randomized controlled trial

Objective

The purpose of the study was to assess the safety of allogeneic, Hope Biosciences Adipose Derived Mesenchymal Stem Cells (HB-adMSCs) for the treatment of hospitalized subjects with COVID-19.

Methods

N = 48 patients were randomly assigned to HB-adMSC (100 MM) or placebo group. Four intravenous infusions of HB-adMSCs or saline were administered at days 0, 3, 7, 10. The primary safety endpoint was incidence of adverse and serious adverse events (AE/SAEs); secondary endpoints were incidence of specific AEs and alterations in hematology, biochemistry, and coagulation parameters.

Results

Majority of AEs were mild in severity. HB-adMSC group showed a higher incidence of cardiopulmonary failure, anemia, anxiety, and diarrhea, while placebo group showed a higher incidence of headaches, fatigue, and chest discomfort (posterior probabilities ≥80%). Deaths were attributed to severe complications due to COVID-19 and were unrelated to study drug. No AEs were attributed to the treatment. Hematology and coagulation panel alterations were not associated with HB-adMSCs. Analyses of inflammatory markers showed increased levels of interleukin-6 and C-reactive protein over time in HB-adMSC group (posterior probabilities ≥78%).

Conclusion

Multiple infusions of 100MM allogeneic HB-adMSCs were considered safe for the study population. More research is needed to determine the safety of MSC therapy.

Clinical trial registration

(www.ClinicalTrials.gov) identifier NCT04362189.

The Immunomodulatory Role of Cell-Free Approaches in SARS-CoV-2-Induced Cytokine Storm-A Powerful Therapeutic Tool for COVID-19 Patients

Currently, there is still no effective and definitive cure for the coronavirus disease 2019 (COVID-19) caused by the infection of the novel highly contagious severe acute respiratory syndrome virus (SARS-CoV-2), whose sudden outbreak was recorded for the first time in China in late December 2019. Soon after, COVID-19 affected not only the vast majority of China's population but the whole world and caused a global health public crisis as a new pandemic. It is well known that viral infection can cause acute respiratory distress syndrome (ARDS) and, in severe cases, can even be lethal. Behind the inflammatory process lies the so-called cytokine storm (CS), which activates various inflammatory cytokines that damage numerous organ tissues. Since the first outbreak of SARS-CoV-2, various research groups have been intensively trying to investigate the best treatment options; however, only limited outcomes have been achieved. One of the most promising strategies represents using either stem cells, such as mesenchymal stem cells (MSCs)/induced pluripotent stem cells (iPSCs), or, more recently, using cell-free approaches involving conditioned media (CMs) and their content, such as extracellular vesicles (EVs) (e.g., exosomes or miRNAs) derived from stem cells. As key mediators of intracellular communication, exosomes carry a cocktail of different molecules with anti-inflammatory effects and immunomodulatory capacity. Our comprehensive review outlines the complex inflammatory process responsible for the CS, summarizes the present results of cell-free-based pre-clinical and clinical studies for COVID-19 treatment, and discusses their future perspectives for therapeutic applications.

SARS-CoV-2 in brief: from virus to prevention

The recent outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), ahighly transmissible virus with a likely animal origin, has posed major and unprecedentedchallenges to millions of lives across the affected nations of the world. This outbreak firstoccurred in China, and despite massive regional and global attempts shortly thereafter, itspread to other countries and caused millions of deaths worldwide. This review presents keyinformation about the characteristics of SARS-CoV-2 and its associated disease (namely,coronavirus disease 2019) and briefly discusses the origin of the virus. Herein, we also brieflysummarize the strategies used against viral spread and transmission.

Early Access to Oral Antivirals in High-Risk Outpatients: Good Weapons to Fight COVID-19

INTRODUCTION

Molnupiravir and Nirmatrelvir/r (NMV-r) have been proven to reduce severe Coronavirus Disease 2019 (COVID-19) in unvaccinated high-risk individuals. Data regarding their impact in fully vaccinated vulnerable subjects with mild-to-moderate COVID-19 are still limited, particularly in the era of Omicron and sub-variants.

METHODS

Our retrospective study aimed to compare the safety profile and effectiveness of the two antivirals in all consecutive high-risk outpatients between 11 January and 10 July 2022. A logistic regression model was carried out to assess factors associated with the composite outcome defined as all-cause hospitalization and/or death at 30 days.

RESULTS

A total of 719 individuals were included: 554 (77%) received Molnupiravir, whereas 165 (23%) were NMV-r users. Overall, 43 all-cause hospitalizations (5.9%) and 13 (1.8%) deaths were observed at 30 days. A composite outcome occurred in 47 (6.5%) individuals. At multivariate analysis, male sex [OR 3.785; p = 0.0021], age ≥ 75 [OR 2.647; p = 0.0124], moderate illness [OR 16.75; p < 0.001], and treatment discontinuation after medical decision [OR 8.148; p = 0.0123] remained independently associated with the composite outcome.

CONCLUSIONS

No differences between the two antivirals were observed. In this real-life setting, the early use of both of the oral antivirals helped limit composite outcome at 30 days among subjects who were at high risk of disease progression.

Assessing T-Cell Immunity in Kidney Transplant Recipients with Absent Antibody Production after a 3rd Dose of the mRNA-1273 Vaccine

The vulnerable population of kidney transplant recipients (KTRs) are low responders to COVID-19 vaccines, so specific immune surveillance is needed. The interferon-gamma (IFN-γ) release assay (IGRA) is effective in assessing T cell-mediated immunity. We assessed SARS-CoV-2-directed T cell responses in KTRs with absent antibody production after a third dose of the mRNA-1273 vaccine, using two different IGRAs. A cohort of 57 KTRs, who were actively followed up, received a third dose of the mRNA-1273 vaccine. After the evaluation of humoral immunity to SARS-CoV-2, 14 seronegative patients were tested with two commercial IGRAs (SD Biosensor and Euroimmun). Out of 14 patients, one and three samples were positive by IGRAs with Euroimmun and SD Biosensor, respectively. The overall agreement between the two assays was 85.7% (κ = 0.444). In addition, multivariate linear regression analysis showed no statistically significant association between the IFN-γ concentration, and the independent variables analyzed (age, gender, years since transplant, total lymphocytes cells/mcl, CD3+ cells/mcl, CD3+ CD4+ cells/mcl, CD3+ CD8+ cells/mcl, CD19+ cells/mcl, CD3-CD16+CD56+ cells/mcl) (p > 0.01). In a vulnerable setting, assessing cellular immune response to complement the humoral response may be advantageous. Since the two commercial IGRAs showed a good agreement on negative samples, the three discordant samples highlight the need for further investigations.

In Vitro Stimulation with Live SARS-CoV-2 Suggests Th17 Dominance In Virus-Specific CD4+ T Cell Response after COVID-19

The SARS-CoV-2 and influenza viruses are the main causes of human respiratory tract infections with similar disease manifestation but distinct mechanisms of immunopathology and host response to the infection. In this study, we investigated the SARS-CoV-2-specific CD4+ T cell phenotype in comparison with H1N1 influenza-specific CD4+ T cells. We determined the levels of SARS-CoV-2- and H1N1-specific CD4+ T cell responses in subjects recovered from COVID-19 one to 15 months ago by stimulating PBMCs with live SARS-CoV-2 or H1N1 influenza viruses. We investigated phenotypes and frequencies of main CD4+ T cell subsets specific for SARS-CoV-2 using an activation induced cell marker assay and multicolor flow cytometry, and compared the magnitude of SARS-CoV-2- and H1N1-specific CD4+ T cells. SARS-CoV-2-specific CD4+ T cells were detected 1-15 months post infection and the frequency of SARS-CoV-2-specific central memory CD4+ T cells was increased with the time post-symptom onset. Next, SARS-CoV-2-specific CD4+ T cells predominantly expressed the Th17 phenotype, but the level of Th17 cells in this group was lower than in H1N1-specific CD4+ T cells. Finally, we found that the lower level of total Th17 subset within total SARS-CoV-2-specific CD4+ T cells was linked with the low level of CCR4+CXCR3- 'classical' Th17 cells if compared with H1N1-specific Th17 cells. Taken together, our data suggest the involvement of Th17 cells and their separate subsets in the pathogenesis of SARS-CoV-2- and influenza-induced pneumonia; and a better understanding of Th17 mediated antiviral immune responses may lead to the development of new therapeutic strategies.

Lessons from SARS-CoV, MERS-CoV, and SARS-CoV-2 Infections: What We Know So Far

Within past decades, human infections with emerging and reemerging zoonotic viral pathogens have raised the eminent public health concern. Since November 2002, three highly pathogenic and major deadly human coronaviruses of the βετα-genera (β-hCoVs), namely, severe acute respiratory distress syndrome-coronavirus (SARS-CoV), middle east respiratory syndrome-coronavirus (MERS-CoV), and SARS-CoV-2, have been globally emerged and culminated in the occurrence of SARS epidemic, MERS outbreak, and coronavirus disease 19 (COVID-19) pandemic, respectively. The global emergence and spread of these three major deadly β-hCoVs have extremely dreadful impacts on human health and become an economic burden. Unfortunately, clear specific and highly efficient medical countermeasures for these three β-hCoVs and their underlying fatal illnesses remain under development. Although they belong to the same family and share many features and convergent evolution, these three deadly β-hCoVs have some important and obvious differences. By utilizing their lessons and gaining a deeper understanding of these β-hCoVs, we can identify areas of improvement and provide preparedness plans for fighting and controlling the future reemerging human infections that might arise from them or from other potential pathogenic hCoVs. Therefore, this review summarizes the state-of-the-art information and compares the similarities and dissimilarities between SARS-CoV, MERS-CoV, and SARS-CoV-2, in terms of their evolution trait, genome organization, host cell entry mechanisms, tissue infectivity tropisms, transmission routes and contagiousness, and the clinical characteristics, laboratory features, and immunological abnormalities of their related illnesses. It also provides an overview of the emerging SARS-CoV-2 variants. Additionally, it discusses the challenges of the most proposed treatment options for SARS-CoV-2 infections.

Herpes Simplex Virus 1 (HSV-1) Reactivation in Critically Ill COVID-19 Patients: A Brief Narrative Review

Systemic or pulmonary reactivations of herpes simplex virus 1 (HSV-1) have been reported in critically ill patients with COVID-19, posing a dilemma for clinicians in terms of their diagnostic and clinical relevance. Prevalence of HSV-1 reactivation may be as high as > 40% in this population, but with large heterogeneity across studies, likely reflecting the different samples and/or cut-offs for defining reactivation. There is frequently agreement on the clinical significance of HSV-1 reactivation in the presence of severe manifestations clearly attributable to the virus. However, the clinical implications of HSV-1 reactivations in the absence of manifest signs and symptoms remain controversial. Our review aims at providing immunological background and at reviewing clinical findings on HSV-1 reactivations in critically ill patients with COVID-19.

Mechanistic Understanding of Lung Inflammation: Recent Advances and Emerging Techniques

Acute respiratory distress syndrome (ARDS) is a life-threatening lung injury characterized by an acute inflammatory response in the lung parenchyma. Hence, it is considered as the most appropriate clinical syndrome to study pathogenic mechanisms of lung inflammation. ARDS is associated with increased morbidity and mortality in the intensive care unit (ICU), while no effective pharmacological treatment exists. It is very important therefore to fully characterize the underlying pathobiology and the related mechanisms, in order to develop novel therapeutic approaches. In vivo and in vitro models are important pre-clinical tools in biological and medical research in the mechanistic and pathological understanding of the majority of diseases. In this review, we will present data from selected experimental models of lung injury/acute lung inflammation, which have been based on clinical disorders that can lead to the development of ARDS and related inflammatory lung processes in humans, including ventilation-induced lung injury (VILI), sepsis, ischemia/reperfusion, smoke, acid aspiration, radiation, transfusion-related acute lung injury (TRALI), influenza, Streptococcus (S.) pneumoniae and coronaviruses infection. Data from the corresponding clinical conditions will also be presented. The mechanisms related to lung inflammation that will be covered are oxidative stress, neutrophil extracellular traps, mitogen-activated protein kinase (MAPK) pathways, surfactant, and water and ion channels. Finally, we will present a brief overview of emerging techniques in the field of omics research that have been applied to ARDS research, encompassing genomics, transcriptomics, proteomics, and metabolomics, which may recognize factors to help stratify ICU patients at risk, predict their prognosis, and possibly, serve as more specific therapeutic targets.

Multi-Level Biological Network Analysis and Drug Repurposing Based on Leukocyte Transcriptomics in Severe COVID-19: In Silico Systems Biology to Precision Medicine

The coronavirus disease 2019 (COVID-19) pandemic causes many morbidity and mortality cases. Despite several developed vaccines and antiviral therapies, some patients experience severe conditions that need intensive care units (ICU); therefore, precision medicine is necessary to predict and treat these patients using novel biomarkers and targeted drugs. In this study, we proposed a multi-level biological network analysis framework to identify key genes via protein–protein interaction (PPI) network analysis as well as survival analysis based on differentially expressed genes (DEGs) in leukocyte transcriptomic profiles, discover novel biomarkers using microRNAs (miRNA) from regulatory network analysis, and provide candidate drugs targeting the key genes using drug–gene interaction network and structural analysis. The results show that upregulated DEGs were mainly enriched in cell division, cell cycle, and innate immune signaling pathways. Downregulated DEGs were primarily concentrated in the cellular response to stress, lysosome, glycosaminoglycan catabolic process, and mature B cell differentiation. Regulatory network analysis revealed that hsa-miR-6792-5p, hsa-let-7b-5p, hsa-miR-34a-5p, hsa-miR-92a-3p, and hsa-miR-146a-5p were predicted biomarkers. CDC25A, GUSB, MYBL2, and SDAD1 were identified as key genes in severe COVID-19. In addition, drug repurposing from drug–gene and drug–protein database searching and molecular docking showed that camptothecin and doxorubicin were candidate drugs interacting with the key genes. In conclusion, multi-level systems biology analysis plays an important role in precision medicine by finding novel biomarkers and targeted drugs based on key gene identification.

Immunotherapy and CRISPR Cas Systems: Potential Cure of COVID-19?

The COVID-19 has plunged the world into a pandemic that affected millions. The continually emerging new variants of concern raise the question as to whether the existing vaccines will continue to provide sufficient protection for individuals from SARS-CoV-2 during natural infection. This narrative review aims to briefly outline various immunotherapeutic options and discuss the potential of clustered regularly interspaced short palindromic repeat (CRISPR Cas system technology against COVID-19 treatment as specific cure. As the development of vaccine, convalescent plasma, neutralizing antibodies are based on the understanding of human immune responses against SARS-CoV-2, boosting human body immune responses in case of SARS-CoV-2 infection, immunotherapeutics seem feasible as specific cure against COVID-19 if the present challenges are overcome. In cell based therapeutics, apart from the high costs, risks and side effects, there are technical problems such as the production of sufficient potent immune cells and antibodies under limited time to treat the COVID-19 patients in mild conditions prior to progression into a more severe case. The CRISPR Cas technology could be utilized to refine the specificity and safety of CAR-T cells, CAR-NK cells and neutralizing antibodies against SARS-CoV-2 during various stages of the COVID-19 disease progression in infected individuals. Moreover, CRISPR Cas technology are proposed in hypotheses to degrade the viral RNA in order to terminate the infection caused by SARS-CoV-2. Thus personalized cocktails of immunotherapeutics and CRISPR Cas systems against COVID-19 as a strategy might prevent further disease progression and circumvent immunity escape.

Potential Role of Colchicine in Combating COVID-19 Cytokine Storm and Its Ability to Inhibit Protease Enzyme of SARS-CoV-2 as Conferred by Molecular Docking Analysis

Despite the advance in the management of Coronavirus disease 2019 (COVID-19), the global pandemic is still ongoing with a massive health crisis. COVID-19 manifestations may range from mild symptoms to severe life threatening ones. The hallmark of the disease severity is related to the overproduction of pro-inflammatory cytokines manifested as a cytokine storm. Based on its anti-inflammatory activity through interfering with several pro and anti-inflammatory pathways, colchicine had been proposed to reduce the cytokine storm and subsequently improve clinical outcomes. Molecular docking analysis of colchicine against RNA-dependent RNA polymerase (RdRp) and protease enzymes of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) revealed that colchicine provided a grid-based molecular docking method, C-DOCKER interaction energy 64.26 and 47.53 (Kcal/mol) with protease and RdRp, respectively. This finding indicated higher binding stability for colchicine–protease complexes than the colchicine–RdRp complex with the involvement of seven hydrogen bonds, six hydrogen acceptors with Asn142, Gly143, Ser144, and Glu166 and one hydrogen-bond donors with Cys145 of the protease enzyme. This is in addition to three hydrophobic interactions with His172, Glu166, and Arg188. A good alignment with the reference compound, Boceprevir, indicated high probability of binding to the protease enzyme of SARS-CoV-2. In conclusion, colchicine can ameliorate the destructive effect of the COVID-19 cytokine storm with a strong evidence of antiviral activity by inhibiting the protease enzyme of SARS-CoV-2.