The Role of Cytokines and Chemokines in Severe Acute Respiratory Syndrome Coronavirus 2 Infections

The cellular and molecular cardiac tissue responses in human inflammatory cardiomyopathies after SARS-CoV-2 infection and COVID-19 vaccination

Myocarditis, characterized by inflammatory cell infiltration, can have multiple etiologies, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or, rarely, mRNA-based coronavirus disease 2019 (COVID-19) vaccination. The underlying cellular and molecular mechanisms remain poorly understood. In this study, we performed single-nucleus RNA sequencing on left ventricular endomyocardial biopsies from patients with myocarditis unrelated to COVID-19 (Non-COVID-19), after SARS-CoV-2 infection (Post-COVID-19) and after COVID-19 vaccination (Post-Vaccination). We identified distinct cytokine expression patterns, with interferon-γ playing a key role in Post-COVID-19, and upregulated IL16 and IL18 expression serving as a hallmark of Post-Vaccination myocarditis. Although myeloid responses were similar across all groups, the Post-Vaccination group showed a higher proportion of CD4+ T cells, and the Post-COVID-19 group exhibited an expansion of cytotoxic CD8+ T and natural killer cells. Endothelial cells showed gene expression changes indicative of vascular barrier dysfunction in the Post-COVID-19 group and ongoing angiogenesis across all groups. These findings highlight shared and distinct mechanisms driving myocarditis in patients with and without a history of SARS-CoV-2 infection or vaccination.

Peripheral blood cytokine expression levels and their clinical significance in children with influenza

Background

Cytokine levels in the peripheral blood of children infected with the influenza A virus are significantly associated with disease diagnosis and severity. This study aimed to investigate the correlation between the expression levels of six cytokines in the peripheral blood of pediatric patients with influenza and the diagnosis and severity of their condition.

Methods

The levels of six cytokines were measured using a flow cytometric microsphere array. Statistical analysis was performed using IBM SPSS Statistics 26.0 to compare differences between the groups, with a P value of less than 0.05 considered statistically significant.

Results

Univariate analysis showed that the levels of interferon alpha-2 (IFN-α2), monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), and interleukin-18 (IL-18) were significantly elevated in the influenza group (P≤0.001). IL-18 levels were higher in the H3N2 group than in the H1N1 group (P=0.03), and IFN-α2 levels were higher in the Mycoplasma coinfection group compared to the influenza-only group (P=0.04). Notably, significant differences in IFN-α2 and MCP-1 levels were observed between the mild-moderate and severe influenza A subgroups (P=0.008, P=0.01, respectively). Negative correlations were found between the severity of influenza A and the levels of IFN-α2 and MCP-1 (r=-0.357, P=0.006 and r=-0.329, P=0.01, respectively). Multifactorial logistic regression and receiver operating characteristic (ROC) curve analysis identified IFN-α2 and MCP-1 as independent risk factors for severe influenza A.

Conclusions

Inflammatory cytokine levels are critical in modulating the immune and inflammatory responses of the body. IFN-α2 and MCP-1 could serve as early indicators of severe influenza A. IL-18 levels were significantly higher in the H3N2 group compared to the H1N1 group, this finding may aid in differentiating between influenza subtypes, providing insights for tailored interventions.

Characterizing the diabetes-induced pathological changes of the mouse lung by single-cell RNA sequencing

Pulmonary disorders are exacerbated by high blood sugar, leading to a disordered immune defense and increased susceptibility to infection. Type 2 diabetes mellitus (T2D) is characterized by insulin resistance and inadequate insulin production. Mechanisms leading to pulmonary alternation due to T2D are not clear. The advancements in single-cell RNA sequencing aid in characterizing the effects of T2D on lungs and its altered mechanisms. Our results first revealed that in late-stage diabetic mice, the number of immune cells in the lungs significantly increased, with these immune cells predominantly being immature polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs). At the early stages of diabetes, alveolar cell type I and type II (AT I & II) exhibited a mesenchymal phenotype and showed reduced expression of several key cytokines essential for maintaining lung immunity, including Cxcl15, Cxcl14, and Il34. Additionally, the antigen-presenting cell function of AT II, resulting from the downregulation of several MHC type II proteins, was markedly diminished in diabetic mice. Moreover, decreased expressions of interferon-related genes Ifnar1 and Ifnar2, along with impaired Sftpd expression, compromised lung immunity impairment in diabetic mice. These pathogenic changes contributed to the increased susceptibility and severity of respiratory syncytial virus and tuberculosis in the lung of diabetes. In addition to alveolar cells, pulmonary capillary endothelial cells also exhibited an immature transition phenotype, with a significant increase in angiogenic capacity. Our findings provided a comprehensive exploration of lung pathology under the influence of diabetes and explained the multiple factors impacting lung immunity in diabetic conditions.

Identification of immune-associated genes with altered expression in the spleen of mice enriched with probiotic Lactobacillus species using RNA-seq profiling

OBJECTIVE

Probiotics are living microorganisms that can provide health benefits when consumed. Here, we investigated the effects of probiotics on gene expression in the spleen of mice using RNA-sequencing analysis between negative control and probiotic groups (including 4 Lactobacillus strains: Lactobacillus fermentum, L. casei, L. plantarum, and L. brevis).

METHODS

Mice exposed with probiotic in 4 weeks by intragastric administration. Then, spleen tissues of the control and probiotics groups were collected on days 14 and 28 for RNA sequencing.

RESULTS

In total, 665, 186, and 81 differentially expressed genes (DEGs) were significantly expressed on day 14 vs control, day 28 vs control groups, and probiotics day 28 vs day 14 groups, respectively. On the other hand, 12 toll-like receptor genes underwent additional validation through quantitative real-time polymerase chain reaction (qRT-PCR), affirming the increased alignment between qRT-PCR and RNA-Seq findings. In addition, the Kyoto encyclopedia of genes and genomes and gene ontology analyses revealed that the DEGs were predominantly enriched in defense responses to pathogens, including inflammatory bowel diseases, malaria, leukaemia virus 1, and herpes virus, as well as immune processes related to immune response and signal transduction. This study represents the first investigation into mice's gene expression in the spleen exposed to probiotics using Lactobacillus spp. isolated from a field strain in Vietnam.

CONCLUSION

Our results provide valuable insights into the impacts and functions of probiotics on mammalian development, offering crucial information for the potential therapeutic use of probiotics in defending against pathogens in Vietnam. The findings from this study highlight the potential of probiotics in modulating gene expression in the spleen, which may have implications for immune function and overall health in mice.

Targeting Cytokines: Evaluating the Potential of Mesenchymal Stem Cell Derived Extracellular Vesicles in the Management of COVID-19

The Coronavirus Disease 2019 (COVID-19), caused by virus SARS-CoV-2, is characterized by massive inflammation and immune system imbalance. Despite the implementation of vaccination protocols, the accessibility of treatment remains uneven. Furthermore, the persistent threat of new variants underscores the urgent need for expanded research into therapeutic options for SARS-CoV-2. Mesenchymal stem cells (MSCs) are known for their immunomodulatory potential through the release of molecules into the extracellular space, either as soluble elements or carried by extracellular vesicles (EVs). The aim of this study was to evaluate the anti-inflammatory potential of EVs obtained from human adipose tissue (ASC-EVs) against SARS-CoV-2 infection. ASC-EVs were purified by size-exclusion chromatography, and co-culture assays confirmed that ASC-EVs were internalized by human lung cells and could colocalize with SARS-CoV-2 into early and late endosomes. To determine the functionality of ASC-EVs, lung cells were infected with SARS-CoV-2 in the presence of increasing concentrations of ASC-EVs, and the release of cytokines, chemokines and viruses were measured. While SARS-CoV-2 replication was significantly reduced only at the highest concentrations tested, multiplex analysis highlighted that lower concentrations of ASC-EV sufficed to prevent the production of immune modulators. Importantly, ASC-EVs did not contain detectable inflammatory cytokines, nor did they trigger inflammatory mediators, nor affect cellular viability. In conclusion, this work suggests that ASC-EVs have the potential to attenuate inflammation by decreasing the production of pro-inflammatory cytokines in lung cells following SARS-CoV-2 infection.

TNF/IFN-γ Co-Signaling Induces Differential Cellular Activation in COVID-19 Patients: Implications for Patient Outcomes

TNF and IFN-γ are key proinflammatory cytokines implicated in the pathophysiology of COVID-19. Toll-like receptor (TLR)7 and TLR8 are known to recognize SARS-CoV-2 and induce TNF and IFN-γ production. However, it is unclear whether TNF and IFN-γ levels are altered through TLR-dependent pathways and whether these pathways mediate disease severity during COVID-19. This study aimed to investigate the association between TNF/IFN-γ levels and immune cell activation to understand their role in disease severity better. We enrolled 150 COVID-19 patients, who were classified by their systemic TNF and IFN-γ levels (high (H) or normal-low (N-L)) as TNFHIFNγH, TNFHIFNγN-L, TNFN-LIFNγH, and TNFN-LIFNγN-L. Compared to patients with TNFN-LIFNγN-L, patients with TNFHIFNγH had high systemic levels of pro- and anti-inflammatory cytokines and cytotoxic molecules, and their T cells and monocytes expressed TNF receptor 1 (TNFR1). Patients with TNFHIFNγH presented the SNP rs3853839 to TLR7 and increased levels of MYD88, NFκB, and IRF7 (TLR signaling), FADD, and TRADD (TNFR1 signaling). Moreover, critical patients were observed in the four COVID-19 groups, but patients with TNFHIFNγH or TNFHIFNγN-L most required invasive mechanical ventilation. We concluded that increased TNF/IFN-γ levels are associated with hyperactive immune cells, whereas normal/low levels are associated with hypoactivity, suggesting a model to explain that the pathophysiology of critical COVID-19 may be mediated through different pathways depending on TNF and IFN-γ levels. These findings highlight the potential for exploring the modulation of TNF and IFN-γ as a therapeutic strategy in severe COVID-19.

Correlation between rs7041 and rs4588 polymorphisms in vitamin D binding protein gene and COVID-19-related severity and mortality

BACKGROUND

The vitamin D binding protein (DBP) plays a critical role in both innate and adaptive immune systems, participating in several clinical conditions, including coronavirus disease 2019 infection severity, and mortality rate. The study aimed to investigate the correlation between rs7041 and rs4588 polymorphisms in the DBP gene and Coronavirus Disease-2019 (COVID-19) severity and mortality, in patients of Suez Canal University Hospitals in Ismailia, Egypt.

METHODS

A case-control study enrolled 220 individuals; 140 COVID-19 patients and 80 healthy controls. Serum 25(OH) vitamin D levels were determined by the enzyme-linked immunosorbent assay (ELISA), and rs7041 and rs4588 polymorphisms of the DBP gene were genotyped using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

The study found that both groups had vitamin D deficiency, which was considerably lower in the COVID-19 patients group compared to controls. Among COVID-19 patients, there was a significant difference in vitamin D levels according to the disease severity indicating that vitamin D levels can be used as predictors of COVID-19 severity. Negative significant correlations between genetic variants rs4588 CA genotype and genetic variants rs7041 TT genotype and COVID-19 prevalence (p = 0.006 and 0.009 respectively) were proved. No significant correlations between all the genetic variants of both rs4588 and rs7041 and COVID-19 severity (p > 0.05). Positive significant correlations between both genetic variants rs4588 CA genotype and genetic variants rs7041 TG genotype and COVID-19 mortality (p = 0.029 and 0.031 respectively).

CONCLUSION

vitamin D deficiency increased the severity of COVID-19. The DBP polymorphism correlated with vitamin COVID-19 prevalence and mortality.

Long-Term Risk of Autoimmune and Autoinflammatory Connective Tissue Disorders Following COVID-19

Importance

Few studies have investigated the association between COVID-19 and autoimmune and autoinflammatory connective tissue disorders; however, research with long-term observation remains insufficient.

Objective

To investigate the long-term risk of autoimmune and autoinflammatory diseases after COVID-19 over an extended observation period.

Design, Setting, and Participants

This retrospective nationwide population-based study investigated the Korea Disease Control and Prevention Agency-COVID-19-National Health Insurance Service (K-COV-N) cohort. Individuals with confirmed COVID-19 from October 8, 2020, to December 31, 2022, and controls identified among individuals who participated in the general health examination in 2018 were included in the analysis.

Exposures

Confirmed COVID-19.

Main Outcomes and Measures

Incidence and risk of autoimmune and autoinflammatory connective tissue disorders in patients after COVID-19. Various covariates, such as demographic characteristics, general health data, socioeconomic status, and comorbidity profiles, were balanced using inverse probability weighting.

Results

A total of 6 912 427 participants (53.6% male; mean [SD] age, 53.39 [20.13] years) consisting of 3 145 388 with COVID-19 and 3 767 039 controls with an observational period of more than 180 days were included. Alopecia areata (adjusted hazard ratio [AHR], 1.11 [95% CI, 1.07-1.15]), alopecia totalis (AHR, 1.24 [95% CI, 1.09-1.42]), vitiligo (AHR, 1.11 [95% CI, 1.04-1.19]), Behçet disease (AHR, 1.45 [95% CI, 1.20-1.74]), Crohn disease (AHR, 1.35 [95% CI, 1.14-1.60]), ulcerative colitis (AHR, 1.15 [95% CI, 1.04-1.28]), rheumatoid arthritis (AHR, 1.09 [95% CI, 1.06-1.12]), systemic lupus erythematosus (AHR, 1.14 [95% CI, 1.01-1.28]), Sjögren syndrome (AHR, 1.13 [95% CI, 1.03-1.25]), ankylosing spondylitis (AHR, 1.11 [95% CI, 1.02-1.20]), and bullous pemphigoid (AHR, 1.62 [95% CI, 1.07-2.45]) were associated with higher risk in the COVID-19 group. Subgroup analyses revealed that demographic factors, including male and female sex, age younger than 40 years, and age 40 years and older, exhibited diverse associations with the risk of autoimmune and autoinflammatory outcomes. In addition, severe COVID-19 infection requiring intensive care unit admission, the Delta period, and not being vaccinated were associated with higher risk.

Conclusions and Relevance

This retrospective cohort study with an extended follow-up period found associations between COVID-19 and the long-term risk of various autoimmune and autoinflammatory connective tissue disorders. Long-term monitoring and care of patients is crucial after COVID-19, considering demographic factors, disease severity, and vaccination status, to mitigate these risks.

Molecular mechanisms of regulation of IL-1 and its receptors

Interleukin 1 (IL-1) is a pro-inflammatory cytokine that plays a key role in the development and regulation of nonspecific defense and specific immunity. However, its regulatory influence extends beyond inflammation and impacts a range of immune and non-immune processes. The involvement of IL-1 in numerous biological processes, including modulation of inflammation, necessitates strict regulation at multiple levels. This review focuses on these regulatory processes and discusses their underlying mechanisms. IL-1 activity is controlled at various levels, including receptor binding, gene transcription, expression as inactive proforms, and regulated post-translational processing and secretion. Regulation at the level of the receptor expression - alternative splicing, tissue-specific isoforms, and gene polymorphism - is also crucial to IL-1 functional activity. Understanding these regulatory features of IL-1 will not only continue to shape future research directions but will also highlight promising therapeutic strategies to modulate the biological effects of IL-1.

Blood Inflammatory Markers and Cytokines in COVID-19 Patients With Bacterial Coinfections

BACKGROUND

Bacterial coinfection in patients with SARS-CoV-2 infection is an important risk factor for death. This study investigated whether there were differences in levels of serum inflammatory markers in COVID-19 patients with bacterial coinfections compared with those without bacterial infection.

METHODS

A total of 235 inpatients with SARS-CoV-2 infection admitted to Qingdao Central Hospital from December 7, 2022, to August 7, 2024, were included. Patients were divided into a bacteria-positive group (115 cases) and a bacteria-negative group (120 cases) according to whether they had bacterial coinfections. PCT, CRP, and 12 kinds of cytokines were compared between groups, and the distribution of bacterial species in the positive group was statistically analyzed.

RESULTS

The serum levels of CRP (Z = 8.94, p < 0.001), PCT (Z = 5.59, p < 0.001), IL-1β (t = 4.863, p < 0.001), IL-2 (t = 5.810, p < 0.001), IL-5 (t = 3.837, p < 0.001), IL-6 (t = 4.910, p < 0.001), IL-8 (t = 3.325, p < 0.001), ILIL-12p70 (t = 4.722, p < 0.001), IL-17 (t = 3.315, p = 0.001) and TNF-α (t = 4.251, p < 0.001) between the two groups were significantly different. IL-4, IL-10, IFN-α, and IFN-γ were not statistically significant (p > 0.05). Among the 115 bacteria-positive patients, 56 patients were positive for one species and 59 patients were multiple infections. Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Haemophilus influenzae were common species.

CONCLUSIONS

Serum PCT and CRP levels in COVID-19 patients with bacterial coinfection are higher than those without bacterial infection. Cytokines such as IL-1β, IL-2, IL-5, IL-6, IL-8, IL-12p70, IL-17, and TNF-α may be involved in the progression of COVID-19 combined with bacterial infection. They can be used as potential markers to evaluate the disease condition and prognosis.

TRIM7 ubiquitinates SARS-CoV-2 membrane protein to limit apoptosis and viral replication

SARS-CoV-2 is a highly transmissible virus that causes COVID-19 disease. Mechanisms of viral pathogenesis include excessive inflammation and viral-induced cell death, resulting in tissue damage. Here we show that the host E3-ubiquitin ligase TRIM7 acts as an inhibitor of apoptosis and SARS-CoV-2 replication via ubiquitination of the viral membrane (M) protein. Trim7-/- mice exhibit increased pathology and virus titers associated with epithelial apoptosis and dysregulated immune responses. Mechanistically, TRIM7 ubiquitinates M on K14, which protects cells from cell death. Longitudinal SARS-CoV-2 sequence analysis from infected patients reveal that mutations on M-K14 appeared in circulating variants during the pandemic. The relevance of these mutations was tested in a mouse model. A recombinant M-K14/K15R virus shows reduced viral replication, consistent with the role of K15 in virus assembly, and increased levels of apoptosis associated with the loss of ubiquitination on K14. TRIM7 antiviral activity requires caspase-6 inhibition, linking apoptosis with viral replication and pathology.

Integration of nanobiosensors into organ-on-chip systems for monitoring viral infections

The integration of nanobiosensors into organ-on-chip (OoC) models offers a promising advancement in the study of viral infections and therapeutic development. Conventional research methods for studying viral infection, such as two-dimensional cell cultures and animal models, face challenges in replicating the complex and dynamic nature of human tissues. In contrast, OoC systems provide more accurate, physiologically relevant models for investigating viral infections, disease mechanisms, and host responses. Nanobiosensors, with their miniaturized designs and enhanced sensitivity, enable real-time, continuous, in situ monitoring of key biomarkers, such as cytokines and proteins within these systems. This review highlights the need for integrating nanobiosensors into OoC systems to advance virological research and improve therapeutic outcomes. Although there is extensive literature on biosensors for viral infection detection and OoC models for replicating infections, real integration of biosensors into OoCs for continuous monitoring remains unachieved. We discuss the advantages of nanobiosensor integration for real-time tracking of critical biomarkers within OoC models, key biosensor technologies, and current OoC systems relevant to viral infection studies. Additionally, we address the main technical challenges and propose solutions for successful integration. This review aims to guide the development of biosensor-integrated OoCs, paving the way for precise diagnostics and personalized treatments in virological research.

Characterization of the Proinflammatory Cytokine Profile during Acute SARS-CoV-2 Infection in People with Human Immunodeficiency Virus

Persistent inflammation during chronic human immunodeficiency virus (HIV) infection may affect the immune response against severe acute respiratory syndrome-coronavirus 2 (SARS- CoV-2) infection. Plasma levels of multiple proinflammatory cytokines during acute SARS-CoV-2 infection were measured in people with HIV (PWH) with effective combination antiretroviral therapy. There were no significant differences in any of the measured cytokines between severity levels of coronavirus disease 2019 (COVID-19) in PWH, while most were significantly higher in HIV-uninfected individuals with severe COVID-19, suggesting that excess cytokines release by hyperinflammatory responses do not occur in individuals with severe COVID-19 with HIV infection. The strong associations between the cytokines observed in HIV-uninfected individuals, particularly between IFN-α/TNF-α and other cytokines, were lost in PWH. The steady-state plasma levels of IP-10, ICAM-1, and CD62E were significantly higher in PWH, indicating that they were in an enhanced inflammatory state. The absence of several inter-cytokine correlations was observed in in vitro lipopolysaccharide stimulus-driven cytokine production in PWH. These data suggest that inflammatory responses during SARS-CoV-2 infection in PWH are distinct from those in HIV-uninfected individuals, partially because of the underlying inflammatory state and/or impairment of innate immune cells.

Interplay between Lung Diseases and Viral Infections: A Comprehensive Review

The intricate relationship between chronic lung diseases and viral infections is a significant concern in respiratory medicine. We explore how pre-existing lung conditions, including chronic obstructive pulmonary disease, asthma, and interstitial lung diseases, influence susceptibility, severity, and outcomes of viral infections. We also examine how viral infections exacerbate and accelerate the progression of lung disease by disrupting immune responses and triggering inflammatory pathways. By summarizing current evidence, this review highlights the bidirectional nature of these interactions, where underlying lung diseasesincrease vulnerability to viral infections, while these infections, in turn, worsen the clinical course. This review underscores the importance of preventive measures, such as vaccination, early detection, and targeted therapies, to mitigate adverse outcomes in patients with chronic lung conditions. The insights provided aim to inform clinical strategies that can improve patient management and reduce the burden of chronic lung diseases exacerbated by viral infections.

Characterization of Neutrophil Functional Responses to SARS-CoV-2 Infection in a Translational Feline Model for COVID-19

There is a complex interplay between viral infection and host innate immune response regarding disease severity and outcomes. Neutrophil hyperactivation, including excessive release of neutrophil extracellular traps (NETs), is linked to exacerbated disease in acute COVID-19, notably in hospitalized patients. Delineating protective versus detrimental neutrophil responses is essential to developing targeted COVID-19 therapies and relies on high-quality translational animal models. In this study, we utilize a previously established feline model for COVID-19 to investigate neutrophil dysfunction in which experimentally infected cats develop clinical disease that mimics acute COVID-19. Specific pathogen-free cats were inoculated with SARS-CoV-2 (B.1.617.2; Delta variant) (n = 24) or vehicle (n = 6). Plasma, bronchoalveolar lavage fluid, and lung tissues were collected at various time points over 12 days post-inoculation. Systematic and temporal evaluation of the kinetics of neutrophil activation was conducted by measuring markers of activation including myeloperoxidase (MPO), neutrophil elastase (NE), and citrullinated histone H3 (citH3) in SARS-CoV-2-infected cats at 4 and 12 days post-inoculation (dpi) and compared to vehicle-inoculated controls. Cytokine profiling supported elevated innate inflammatory responses with specific upregulation of neutrophil activation and NET formation-related markers, namely IL-8, IL-18, CXCL1, and SDF-1, in infected cats. An increase in MPO-DNA complexes and cell-free dsDNA in infected cats compared to vehicle-inoculated was noted and supported by histopathologic severity in respiratory tissues. Immunofluorescence analyses further supported correlation of NET markers with tissue damage, especially 4 dpi. Differential gene expression analyses indicated an upregulation of genes associated with innate immune and neutrophil activation pathways. Transcripts involved in activation and NETosis pathways were upregulated by 4 dpi and downregulated by 12 dpi, suggesting peak activation of neutrophils and NET-associated markers in the early acute stages of infection. Correlation analyses conducted between NET-specific markers and clinical scores as well as histopathologic scores support association between neutrophil activation and disease severity during SARS-CoV-2 infection in this model. Overall, this study emphasizes the effect of neutrophil activation and NET release in SARS-CoV-2 infection in a feline model, prompting further investigation into therapeutic strategies aimed at mitigating excessive innate inflammatory responses in COVID-19.

Repurposing of antimycobacterium drugs for COVID-19 treatment by targeting SARS CoV-2 main protease: An in-silico perspective

The global mortality rate has been significantly impacted by the COVID-19 pandemic, caused by the SARS CoV-2 virus. Although the pursuit for a potent antiviral is still in progress, experimental therapies based on repurposing of existing drugs is being attempted. One important therapeutic target for COVID-19 is the main protease (Mpro) that cleaves the viral polyprotein in its replication process. Recently minocycline, an antimycobacterium drug, has been successfully implemented for the treatment of COVID-19 patients. But it's mode of action is still far from clear. Furthermore, it remains unresolved whether alternative antimycobacterium drugs can effectively regulate SARS CoV-2 by inhibiting the enzymatic activity of Mpro. To comprehend these facets, eight well-established antimycobacterium drugs were put through molecular docking experiments. Four of the antimycobacterium drugs (minocycline, rifampicin, clofazimine and ofloxacin) were selected by comparing their binding affinities towards Mpro. All of the four drugs interacted with both the catalytic residues of Mpro (His41 and Cys145). Additionally, molecular dynamics experiments demonstrated that the Mpro-minocyline complex has enhanced stability, experiences reduced conformational fluctuations and greater compactness than other three Mpro-antimycobacterium and Mpro-N3/lopinavir complexes. This research furnishes evidences for implementation of minocycline against SARS CoV-2. In addition, our findings also indicate other three antimycobacterium/antituberculosis drugs (rifampicin, clofazimine and ofloxacin) could potentially be evaluated for COVID-19 therapy.

Exploring COVID-19 Pandemic Disparities with Transcriptomic Meta-analysis from the Perspective of Personalized Medicine

Infection with SARS-CoV2, which is responsible for COVID-19, can lead to differences in disease development, severity and mortality rates depending on gender, age or the presence of certain diseases. Considering that existing studies ignore these differences, this study aims to uncover potential differences attributable to gender, age and source of sampling as well as viral load using bioinformatics and multi-omics approaches. Differential gene expression analyses were used to analyse the phenotypic differences between SARS-CoV-2 patients and controls at the mRNA level. Pathway enrichment analyses were performed at the gene set level to identify the activated pathways corresponding to the differences in the samples. Drug repurposing analysis was performed at the protein level, focusing on host-mediated drug candidates to uncover potential therapeutic differences. Significant differences (i.e. the number of differentially expressed genes and their characteristics) were observed for COVID-19 at the mRNA level depending on the sample source, gender and age of the samples. The results of the pathway enrichment show that SARS-CoV-2 can be combated more effectively in the respiratory tract than in the blood samples. Taking into account the different sample sources and their characteristics, different drug candidates were identified. Evaluating disease prediction, prevention and/or treatment strategies from a personalised perspective is crucial. In this study, we not only evaluated the differences in COVID-19 from a personalised perspective, but also provided valuable data for further experimental and clinical efforts. Our findings could shed light on potential pandemics.

Predictive biomarkers of mortality in patients with severe COVID-19 hospitalized in intensive care unit

Objectives

This study was performed to identify predictive markers of worse outcomes in patients with severe COVID-19 in an intensive care unit.

Methods

Sixty patients with severe COVID-19, hospitalized in the Intensive Care Unit (ICU) between March and July 2021, were stratified into two groups according to the outcome survivors and non-survivors. After admission to the ICU, blood samples were collected directly for biomarker analysis. Routine hematological and biochemical biomarkers, as well as serum levels of cytokines, chemokines, and immunoglobulins, were investigated.

Results

Lymphopenia, neutrophilia, and thrombocytopenia were more pronounced in non-surviving patients, while the levels of CRP, AST, creatinine, ferritin, AST, troponin I, urea, magnesium, and potassium were higher in the non-surviving group than the survival group. In addition, serum levels of IL-10, CCL2, CXCL9, and CXCL10 were significantly increased in patients who did not survive. These changes in the biomarkers evaluated were associated with increased mortality in patients with severe COVID-19.

Conclusion

The present study confirmed and expanded the validity of laboratory biomarkers as indicators of mortality in severe COVID-19.

Cytokine and chemokine profiles in the sera of COVID-19 patients with different stages of severity

INTRODUCTION

COVID-19 is a viral infection that disturbs the host's immune system and causes an overproduction of cytokines leading to a cytokine storm. The present study aimed to evaluate the serum levels of 27 protein biomarkers to determine their association with COVID-19 disease severity.

METHODS

The serum levels of 89 patients with different degrees of COVID-19 disease severity [asymptomatic (n = 14), moderate (n = 14), severe (n = 30), and critical (n = 31)] and 14 healthy individuals were tested for a panel of 27 cytokines and chemokines using Luminex assay (27 Bio‑Plex Pro Human Cytokine, Bio-rad™).

RESULTS

IL-12, IL-2 and IL-13, as well as IL-17 and GM-CSF were clearly undetectable in asymptomatic patients. IL-8 levels were higher in asymptomatic compared with other groups. Very high levels of IL-6, IL-10 and the chemokines MIP-1α, MCP-1 and IP10 were associated with disease progression, while IL-4 tends to decrease with disease severity.

CONCLUSION

Our study provides more evidence that excessive cytokine synthesis is linked to the disease progression.

The Impact of Chemical Modifications on the Interferon-Inducing and Antiproliferative Activity of Short Double-Stranded Immunostimulating RNA

A short 19 bp dsRNA with 3'-trinucleotide overhangs acting as immunostimulating RNA (isRNA) demonstrated strong antiproliferative action against cancer cells, immunostimulatory activity through activation of cytokines and Type-I IFN secretion, as well as anti-tumor and anti-metastatic effects in vivo. The aim of this study was to determine the tolerance of chemical modifications (2'-F, 2'-OMe, PS, cholesterol, and amino acids) located at different positions within this isRNA to its ability to activate the innate immune system. The obtained duplexes were tested in vivo for their ability to activate the synthesis of interferon-α in mice, and in tumor cell cultures for their ability to inhibit their proliferation. The obtained data show that chemical modifications in the composition of isRNA have different effects on its individual functions, including interferon-inducing and antiproliferative effects. The effect of modifications depends not only on the type of modification but also on its location and the surrounding context of the modifications. This study made it possible to identify leader patterns of modifications that enhance the properties of isRNA: F2/F2 and F2_S/F2 for interferon-inducing activity, as well as F2_S5/F2_S5, F2-NH2/F2-NH2, and Ch-F2/Ch-F2 for antiproliferative action. These modifications can improve the pharmacokinetic and pharmacodynamic properties, as well as increase the specificity of isRNA action to obtain the desired effect.

TRIM7 ubiquitinates SARS-CoV-2 membrane protein to limit apoptosis and viral replication

SARS-CoV-2 is a highly transmissible virus that causes COVID-19 disease. Mechanisms of viral pathogenesis include excessive inflammation and viral-induced cell death, resulting in tissue damage. We identified the host E3-ubiquitin ligase TRIM7 as an inhibitor of apoptosis and SARS-CoV-2 replication via ubiquitination of the viral membrane (M) protein. Trim7 -/- mice exhibited increased pathology and virus titers associated with epithelial apoptosis and dysregulated immune responses. Mechanistically, TRIM7 ubiquitinates M on K14, which protects cells from cell death. Longitudinal SARS-CoV-2 sequence analysis from infected patients revealed that mutations on M-K14 appeared in circulating variants during the pandemic. The relevance of these mutations was tested in a mouse model. A recombinant M-K14/K15R virus showed reduced viral replication, consistent with the role of K15 in virus assembly, and increased levels of apoptosis associated with the loss of ubiquitination on K14. TRIM7 antiviral activity requires caspase-6 inhibition, linking apoptosis with viral replication and pathology.

Evaluation of bovine coronavirus in Korean native calves challenged through different inoculation routes

Bovine coronavirus (BCoV) is a pneumoenteric virus that can infect the digestive and respiratory tracts of cattle, resulting in economic losses. Despite its significance, information regarding BCoV pathogenesis is limited. Hence, we investigated clinical signs, patterns of viral shedding, changes in antibody abundance, and cytokine/chemokine production in calves inoculated with BCoV via intranasal and oral. Six clinically healthy Korean native calves (< 30 days old), initially negative for BCoV, were divided into intranasal and oral groups and monitored for 15 days post-infection (dpi). BCoV-infected calves exhibited clinical signs such as nasal discharge and diarrhea, starting at 3 dpi and recovering by 12 dpi, with nasal discharge being the most common symptoms. Viral RNA was detected in nasal and fecal samples from all infected calves. Nasal shedding occurred before fecal shedding regardless of the inoculation route; however, fecal shedding persisted longer. Although the number of partitions was very few, viral RNA was identified in the blood of two calves in the oral group at 7 dpi and 9 dpi using digital RT-PCR analysis. The effectiveness of maternal antibodies in preventing viral replication and shedding appeared limited. Our results showed interleukin (IL)-8 as the most common and highly induced chemokine. During BCoV infection, the levels of IL-8, monocyte chemoattractant protein-1, and macrophage inflammatory protein-1β were significantly affected, suggesting that these emerge as potential and reliable biomarkers for predicting BCoV infection. This study underscores the importance of BCoV as a major pathogen causing diarrhea and respiratory disease.

IFNAR(-/-) Mice Constitute a Suitable Animal Model for Epizootic Hemorrhagic Disease Virus Study and Vaccine Evaluation

Epizootic hemorrhagic disease (EHD), caused by Epizootic hemorrhagic disease virus (EHDV), is an emerging and severe livestock disease. Recent incursion and distribution of EHDV in Europe have outlined the emerging character of EHD. Despite its worldwide impact, numerous knowledge gaps exist. A range of inconveniences restricts utilization of natural hosts of EHDV. Here, we show that adult mice deficient in type I IFN receptor (IFNAR(-/-)) are highly susceptible to EHDV-6 and EHDV-8 infection when the virus is administered subcutaneously. Disease was characterized by ruffled hair, reluctance to move, dehydration and conjunctivitis, with viraemia detected from day 5 post-infection. A deeper characterization of EHDV-8 infection showed viral replication in the lung, liver, spleen, kidney, testis and ovaries. Importantly, increased expression levels of pro-inflammatory cytokines IL-1β, IL-6 and CXCL2 were observed in spleen after EHDV-8 infection. Furthermore, IFNAR(-/-) adult mice immunized with a EHDV-8 inactivated vaccine elicited neutralizing antibodies specific of EHDV-8 and full protection against challenge with a lethal dose of this virus. This study also explores the possibilities of this animal model for study of BTV and EHDV coinfection. In summary, the IFNAR(-/-) mouse model faithfully recapitulates EHD and can be applied for vaccine testing, which can facilitate progress in addressing the animal health challenge posed by this virus.

Sex differences in immune protection in mice conferred by heterologous vaccines for pneumonic plague

Background

Yersinia pestis is the etiological agent of plague, which can manifest as bubonic, septicemic, and/or pneumonic disease. Plague is a severe and rapidly progressing illness that can only be successfully treated with antibiotics initiated early after infection. There are no FDA-approved vaccines for plague, and some vaccine candidates may be less effective against pneumonic plague than bubonic plague. Y. pestis is not known to impact males and females differently in mechanisms of pathogenesis or severity of infection. However, one previous study reported sex-biased vaccine effectiveness after intranasal Y. pestis challenge. As part of developing a safe and effective vaccine, it is essential that potential sex differences are characterized.

Methods

In this study we evaluated novel vaccines in male and female BALB/c mice using a heterologous prime-boost approach and monitored survival, bacterial load in organs, and immunological correlates. Our vaccine strategy consisted of two subcutaneous immunizations, followed by challenge with aerosolized virulent nonencapsulated Y. pestis. Mice were immunized with a combination of live Y. pestis pgm- pPst-Δcaf1, live Y. pestis pgm- pPst-Δcaf1/ΔyopD, or recombinant F1-V (rF1-V) combined with adjuvants.

Results

The most effective vaccine regimen was initial priming with rF1-V, followed by boost with either of the live attenuated strains. However, this and other strategies were more protective in female mice. Males had higher bacterial burden and differing patterns of cytokine expression and serum antibody titers. Male mice did not demonstrate synergy between vaccination and antibiotic treatment as repeatedly observed in female mice.

Conclusions

This study provides new knowledge about heterologous vaccine strategies, sex differences in plague-vaccine efficacy, and the immunological factors that differ between male and female mice.

Exposure to urban particulate matter alters responses of olfactory mucosal cells to SARS-CoV-2 infection

Respiratory viruses have a significant impact on health, as highlighted by the COVID-19 pandemic. Exposure to air pollution can contribute to viral susceptibility and be associated with severe outcomes, as suggested by recent epidemiological studies. Furthermore, exposure to particulate matter (PM), an important constituent of air pollution, is linked to adverse effects on the brain, including cognitive decline and Alzheimer's disease (AD). The olfactory mucosa (OM), a tissue located at the rooftop of the nasal cavity, is directly exposed to inhaled air and in direct contact with the brain. Increasing evidence of OM dysfunction related to neuropathogenesis and viral infection demonstrates the importance of elucidating the interplay between viruses and air pollutants at the OM. This study examined the effects of subacute exposure to urban PM 0.2 and PM 10-2.5 on SARS-CoV-2 infection using primary human OM cells obtained from cognitively healthy individuals and individuals diagnosed with AD. OM cells were exposed to PM and subsequently infected with the SARS-CoV-2 virus in the presence of pollutants. SARS-CoV-2 entry receptors and replication, toxicological endpoints, cytokine release, oxidative stress markers, and amyloid beta levels were measured. Exposure to PM did not enhance the expression of viral entry receptors or cellular viral load in human OM cells. However, PM-exposed and SARS-CoV-2-infected cells showed alterations in cellular and immune responses when compared to cells infected only with the virus or pollutants. These changes are highly pronounced in AD OM cells. These results suggest that exposure of human OM cells to PM does not increase susceptibility to SARS-CoV-2 infection in vitro, but it can alter cellular immune responses to the virus, particularly in AD. Understanding the interplay of air pollutants and COVID-19 can provide important insight for the development of public health policies and interventions to reduce the negative influences of air pollution exposure.

Porcine cis-acting lnc-CAST positively regulates CXCL8 expression through histone H3K27ac

The chemokine CXCL8, also known as the neutrophil chemotactic factor, plays a crucial role in mediating inflammatory responses and managing cellular immune reactions during viral infections. Porcine reproductive and respiratory syndrome virus (PRRSV) primarily infects pulmonary alveolar macrophages (PAMs), leading to acute pulmonary infections. In this study, we explored a novel long non-coding RNA (lncRNA), termed lnc-CAST, situated within the Cxcl8 gene locus. This lncRNA was found to be highly expressed in porcine macrophages. We observed that both lnc-CAST and CXCL8 were significantly upregulated in PAMs following PRRSV infection, and after treatments with lipopolysaccharide (LPS) or lipoteichoic acid (LTA). Furthermore, we noticed a concurrent upregulation of lnc-CAST and CXCL8 expression in lungs of PRRSV-infected pigs. We then determined that lnc-CAST positively influenced CXCL8 expression in PAMs. Overexpression of lnc-CAST led to an increase in CXCL8 production, which in turn enhanced the migration of epithelial cells and the recruitment of neutrophils. Conversely, inhibiting lnc-CAST expression resulted in reduced CXCL8 production in PAMs, leading to decreased migration levels of epithelial cells and neutrophils. From a mechanistic perspective, we found that lnc-CAST, localized in the nucleus, facilitated the enrichment of histone H3K27ac in CXCL8 promoter region, thereby stimulating CXCL8 transcription in a cis-regulatory manner. In conclusion, our study underscores the pivotal critical role of lnc-CAST in regulating CXCL8 production, offering valuable insights into chemokine regulation and lung damage during PRRSV infection.

Laboratory parameters related to disease severity and physical performance after reconvalescence of acute COVID-19 infection

Research into the molecular basis of disease trajectory and Long-COVID is important to get insights toward underlying pathophysiological processes. The objective of this study was to investigate inflammation-mediated changes of metabolism in patients with acute COVID-19 infection and throughout a one-year follow up period. The study enrolled 34 patients with moderate to severe COVID-19 infection admitted to the University Clinic of Innsbruck in early 2020. The dynamics of multiple laboratory parameters (including inflammatory markers [C-reactive protein (CRP), interleukin-6 (IL-6), neopterin] as well as amino acids [tryptophan (Trp), phenylalanine (Phe) and tyrosine (Tyr)], and parameters of iron and vitamin B metabolism) was related to disease severity and patients' physical performance. Also, symptom load during acute illness and at approximately 60 days (FU1), and one year after symptom onset (FU2) were monitored and related with changes of the investigated laboratory parameters: During acute infection many investigated laboratory parameters were elevated (e.g., inflammatory markers, ferritin, kynurenine, phenylalanine) and enhanced tryptophan catabolism and phenylalanine accumulation were found. At FU2 nearly all laboratory markers had declined back to reference ranges. However, kynurenine/tryptophan ratio (Kyn/Trp) and the phenylalanine/tyrosine ratio (Phe/Tyr) were still exceeding the 95th percentile of healthy controls in about two thirds of our cohort at FU2. Lower tryptophan concentrations were associated with B vitamin availability (during acute infection and at FU1), patients with lower vitamin B12 levels at FU1 had a prolonged and more severe impairment of their physical functioning ability. Patients who had fully recovered (ECOG 0) presented with higher concentrations of iron parameters (ferritin, hepcidin, transferrin) and amino acids (phenylalanine, tyrosine) at FU2 compared to patients with restricted ability to work. Persistent symptoms at FU2 were tendentially associated with IFN-γ related parameters. Women were affected by long-term symptoms more frequently. Conclusively, inflammation-mediated biochemical changes appear to be related to symptoms of patients with acute and Long Covid.

From Detection to Protection: Antibodies and Their Crucial Role in Diagnosing and Combatting SARS-CoV-2

Understanding the antibody response to SARS-CoV-2, the virus responsible for COVID-19, is crucial to comprehending disease progression and the significance of vaccine and therapeutic development. The emergence of highly contagious variants poses a significant challenge to humoral immunity, underscoring the necessity of grasping the intricacies of specific antibodies. This review emphasizes the pivotal role of antibodies in shaping immune responses and their implications for diagnosing, preventing, and treating SARS-CoV-2 infection. It delves into the kinetics and characteristics of the antibody response to SARS-CoV-2 and explores current antibody-based diagnostics, discussing their strengths, clinical utility, and limitations. Furthermore, we underscore the therapeutic potential of SARS-CoV-2-specific antibodies, discussing various antibody-based therapies such as monoclonal antibodies, polyclonal antibodies, anti-cytokines, convalescent plasma, and hyperimmunoglobulin-based therapies. Moreover, we offer insights into antibody responses to SARS-CoV-2 vaccines, emphasizing the significance of neutralizing antibodies in order to confer immunity to SARS-CoV-2, along with emerging variants of concern (VOCs) and circulating Omicron subvariants. We also highlight challenges in the field, such as the risks of antibody-dependent enhancement (ADE) for SARS-CoV-2 antibodies, and shed light on the challenges associated with the original antigenic sin (OAS) effect and long COVID. Overall, this review intends to provide valuable insights, which are crucial to advancing sensitive diagnostic tools, identifying efficient antibody-based therapeutics, and developing effective vaccines to combat the evolving threat of SARS-CoV-2 variants on a global scale.

Inhibitory effect of food-functioned phytochemicals on dysregulated inflammatory pathways triggered by SARS-CoV-2: a mechanistic review

Inflammatory cascades of the dysregulated inflammatory pathways in COVID-19 can cause excessive production of pro-inflammatory cytokines and chemokines leading to cytokine storm syndrome (CSS). The molecular cascades involved in the pathways may be targeted for discovery of new anti-inflammatory agents. Many plant extracts have been used clinically in the management of COVID-19, however, their immunosuppressive activities were mainly investigated based on in silico activity. Dietary flavonoids of the extracts such as quercetin, luteolin, kaempferol, naringenin, isorhamnetin, baicalein, wogonin, and rutin were commonly identified as responsible for their inhibitory effects. The present review critically analyzes the anti-inflammatory effects and mechanisms of phytochemicals, including dietary compounds against cytokine storm (CS) and hyperinflammation via inhibition of the altered inflammatory pathways triggered by SARS-CoV-2, published since the emergence of COVID-19 in December 2019. Only a few phytochemicals, mainly dietary compounds such as nanocurcumin, melatonin, quercetin, 6-shagoal, kaempferol, resveratrol, andrographolide, and colchicine have been investigated either in in silico or preliminary clinical studies to evaluate their anti-inflammatory effects against COVID-19. Sufficient pre-clinical studies on safety and efficacy of anti-inflammatory effects of the phytochemicals must be performed prior to proper clinical studies to develop them into therapeutic adjuvants in the prevention and treatmemt of COVID-19 symptoms.

A cell-adapted SARS-CoV-2 mutant, showing a deletion in the spike protein spanning the furin cleavage site, has reduced virulence at the lung level in K18-hACE2 mice

Here we investigated the virulence properties of a unique cell-adapted SARS-CoV-2 mutant showing a ten-amino acid deletion encompassing the furin cleavage site of the spike protein (Δ680SPRAARSVAS689; Δ680-689-B.1) in comparison to its parental strain (wt-B.1) and two Delta variants (AY.122 and AY.21) of concern. After intranasal inoculation, transgenic K18-hACE2 mice were monitored for 14 days for weight change, lethality, and clinical score; oral swabs were daily collected and tested for the presence of N protein subgenomic RNA. At 3 and 7 dpi mice were also sacrificed and organs collected for molecular, histopathological, and immune response profile investigations. The Δ680-689-B.1-infected mice exhibited reduced shedding, lower virulence at the lung level, and milder pulmonary lesions. In the lung, infection with Δ680-689-B.1 was associated with a significant lower expression of some cytokines at 3 dpi (IL-4, IL-27, and IL-28) and 7 dpi (IL-4, IL-27, IL-28, IFN-γ and IL-1α).

Nanomedicine at the Pulmonary Frontier: Immune-Centric Approaches for Respiratory Disease Treatment

Respiratory diseases (RD) are a group of common ailments with a rapidly increasing global prevalence, posing a significant threat to humanity, especially the elderly population, and imposing a substantial burden on society and the economy. RD represents an unmet medical need that requires the development of viable pharmacotherapies. While various promising strategies have been devised to advance potential treatments for RD, their implementation has been hindered by difficulties in drug delivery, particularly in critically ill patients. Nanotechnology offers innovative solutions for delivering medications to the inflamed organ sites, such as the lungs. Although this approach is enticing, delivering nanomedicine to the lungs presents complex challenges that require sophisticated techniques. In this context, we review the potential of novel nanomedicine-based immunomodulatory strategies that could offer therapeutic benefits in managing this pressing health condition.

A Comparative Investigation on Cytokine Expression in Pulmonary Tuberculosis and Comorbidity with Type 2 Diabetes Mellitus

BACKGROUND

Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis (TB), with a high global prevalence and mortality rate. To control the gruesome pathogen, a deep understanding of pathophysiology and host-pathogen interaction is essential for early diagnosis and novel drug development. Cytokines play a crucial role in infection and susceptibility, and their expressions could serve as potential biomarkers to enhance our understanding of Mtb pathophysiology for improved therapeutic approaches. This cross-sectional study investigates the levels of four important T-cell immune-mediated cytokines: interleukins (IL-6 and IL-10), interferon-gamma (IFN-γ), and tumor necrosis factor-alpha in 80 cohort samples, with 20 people in each group.

METHODS

Following proper ethics and patient consent, we collected blood samples and isolated serum from all four groups: TB, type 2 diabetes mellitus (T2DM), type 2 diabetes-TB comorbidity (T2DM + TB), and a healthy individual as a control group (C). Furthermore, cytokine expression was measured in individual serum samples through the enzyme-linked immunosorbent assay method using commercial kits (Diaclone, French). Statistical significance was observed by analyzing triplicate data using t-tests and the one-way ANOVA method with GraphPad Prism 10.

RESULTS

The results showed that all four cytokine levels were higher (P ≤ 0.0001) than the control, especially IL-6, IL-10, and IFN-γ, which were found to be upregulated in T2DM + TB samples (P ≤ 0.0001) than individual TB or T2DM samples.

CONCLUSION

The high levels of cytokines in comorbidity cases raise the risk of insulin resistance and the severity of TB infection. These levels of expression could be used to keep track of the Mtb infection status or severity, aid in early diagnosis as a possible biomarker, and suggest possible treatment plans.

Risk prediction for severe COVID-19 progressing to critical illness and death in the ICU and efficacy analysis of using traditional Chinese medicine

To reveal the key factors influencing the progression of severe COVID-19 to critical illness and death in the intensive care unit (ICU) and to accurately predict the risk, as well as to validate the efficacy of treatment using traditional Chinese medicine (TCM), thus providing valuable recommendations for the clinical management of patients. A total of 189 patients with COVID-19 in 25 ICUs in Chongqing, China, were enrolled, and 16 eventually died. Statistical models shown that factors influencing the progression of COVID-19 to critical illness include the severity of illness at diagnosis, the mode of respiratory support, and the use of TCM. Risk factors for death include a history of metabolic disease, the use of antiviral drugs and TCM, and invasive endotracheal intubation. The area under curve of the noncollinearity model predicted the risk of progression to critical illness and the risk of death reached 0.847 and 0.876, respectively. The use of TCM is an independent protective factor for the prevention of the progression of severe COVID-19, while uncorrectable hypoxemia and invasive respiratory support are independent risk factors, and antiviral drugs can help reduce mortality. The multifactorial prediction model can assess the risk of critical illness and death in ICU COVID-19 patients, and inform clinicians in choosing the treatment options and medications.

IRF1 Mediates Growth Arrest and the Induction of a Secretory Phenotype in Alveolar Epithelial Cells in Response to Inflammatory Cytokines IFNγ/TNFα

In COVID-19, cytokine release syndrome can cause severe lung tissue damage leading to acute respiratory distress syndrome (ARDS). Here, we address the effects of IFNγ, TNFα, IL-1β and IL-6 on the growth arrest of alveolar A549 cells, focusing on the role of the IFN regulatory factor 1 (IRF1) transcription factor. The efficacy of JAK1/2 inhibitor baricitinib has also been tested. A549 WT and IRF1 KO cells were exposed to cytokines for up to 72 h. Cell proliferation and death were evaluated with the resazurin assay, analysis of cell cycle and cycle-regulator proteins, LDH release and Annexin-V positivity; the induction of senescence and senescence-associated secretory phenotype (SASP) was evaluated through β-galactosidase staining and the quantitation of secreted inflammatory mediators. While IL-1 and IL-6 proved ineffective, IFNγ plus TNFα caused a proliferative arrest in A549 WT cells with alterations in cell morphology, along with the acquisition of a secretory phenotype. These effects were STAT and IRF1-dependent since they were prevented by baricitinib and much less evident in IRF1 KO than in WT cells. In alveolar cells, STATs/IRF1 axis is required for cytokine-induced proliferative arrest and the induction of a secretory phenotype. Hence, baricitininb is a promising therapeutic strategy for the attenuation of senescence-associated inflammation.

Do chemokine/chemokine receptor axes play paramount parts in trafficking and oriented locomotion of monocytes/macrophages toward the lungs of COVID-19 infected patients? A systematic review

The COVID-19 (coronavirus disease 2019) is a well-defined viral infection, resulting from SARS-CoV-2 (severe acute respiratory syndrome- coronavirus-2). The innate immune system serves as the first line of defense to limit viral spreading and subsequently stimulate adaptive immune responses by the prominent aids of its cellular and molecular arms. Monocytes are defined as the most prominent innate immune cells (IICs) that are reactive against invading pathogens. These cells support host protection against the virus that is mediated by several non-specific mechanisms such as phagocytosis, producing antiviral enzymes, and recruitment of immune cells toward and into the infected tissues. They have the ability to egress from blood and migrate to the SARS-CoV-2 infected regions by the aid of some defense-related functions like chemotaxis, which is mediated by chemical compounds, e.g., chemokines. Chemokines, in addition to their related ligands are categorized within the most important and deserved agents involved in oriented trafficking of monocytes/macrophages towards and within the lung parenchyma in both steady state and pathological circumstances, including COVID-19-raised infection. However, the overexpression of chemokines could have deleterious effects on various organs through the induction of cytokine storm and may be the most important leading mechanisms in the pathogenesis of COVID-19. Authors have aimed the current review article to describe present knowledge about the interplay between monocytes/macrophages and SARS-CoV-2 with a focus on the ability of IICs to migrate and home into the lung of COVID-19 patients through various chemokine-chemokine receptor axes to promote our understanding regarding this disease.

Autoimmune response after SARS-CoV-2 infection and SARS-CoV-2 vaccines

The complicated relationships between autoimmunity, COVID-19, and COVID-19 vaccinations are described, giving insight into their intricacies. Antinuclear antibodies (ANA), anti-Ro/SSA, rheumatoid factor, lupus anticoagulant, and antibodies against interferon (IFN)-I have all been consistently found in COVID-19 patients, indicating a high prevalence of autoimmune reactions following viral exposure. Furthermore, the discovery of human proteins with structural similarities to SARS-CoV-2 peptides as possible autoantigens highlights the complex interplay between the virus and the immune system in initiating autoimmunity. An updated summary of the current status of COVID-19 vaccines is presented. We present probable pathways underpinning the genesis of COVID-19 autoimmunity, such as bystander activation caused by hyperinflammatory conditions, viral persistence, and the creation of neutrophil extracellular traps. These pathways provide important insights into the development of autoimmune-related symptoms ranging from organ-specific to systemic autoimmune and inflammatory illnesses, demonstrating the wide influence of COVID-19 on the immune system.

COVID-19 in patients with anemia and haematological malignancies: risk factors, clinical guidelines, and emerging therapeutic approaches

Extensive research in countries with high sociodemographic indices (SDIs) to date has shown that coronavirus disease 2019 (COVID-19) may be directly associated with more severe outcomes among patients living with haematological disorders and malignancies (HDMs). Because individuals with moderate to severe immunodeficiency are likely to undergo persistent infections, shed virus particles for prolonged periods, and lack an inflammatory or abortive phase, this represents an overall risk of morbidity and mortality from COVID-19. In cases suffering from HDMs, further investigation is needed to achieve a better understanding of triviruses and a group of related variants in patients with anemia and HDMs, as well as their treatment through vaccines, drugs, and other methods. Against this background, the present study aimed to delineate the relationship between HDMs and the novel COVID-19, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Besides, effective treatment options for HDM cases were further explored to address this epidemic and its variants. Therefore, learning about how COVID-19 manifests in these patients, along with exploiting the most appropriate treatments, may lead to the development of treatment and care strategies by clinicians and researchers to help patients recover faster. Video Abstract.

Isolation and characterization of a pangolin-borne HKU4-related coronavirus that potentially infects human-DPP4-transgenic mice

We recently detected a HKU4-related coronavirus in subgenus Merbecovirus (named pangolin-CoV-HKU4-P251T) from a Malayan pangolin1. Here we report isolation and characterization of pangolin-CoV-HKU4-P251T, the genome sequence of which is closest to that of a coronavirus from the greater bamboo bat (Tylonycteris robustula) in Yunnan Province, China, with a 94.3% nucleotide identity. Pangolin-CoV-HKU4-P251T is able to infect human cell lines, and replicates more efficiently in cells that express human-dipeptidyl-peptidase-4 (hDPP4)-expressing and pangolin-DPP4-expressing cells than in bat-DPP4-expressing cells. After intranasal inoculation with pangolin-CoV-HKU4-P251, hDPP4-transgenic female mice are likely infected, showing persistent viral RNA copy numbers in the lungs. Progressive interstitial pneumonia developed in the infected mice, characterized by the accumulation of macrophages, and increase of antiviral cytokines, proinflammatory cytokines, and chemokines in lung tissues. These findings suggest that the pangolin-borne HKU4-related coronavirus has a potential for emerging as a human pathogen by using hDPP4.

"When," "Where," and "How" of SARS-CoV-2 Infection Affects the Human Cardiovascular System: A Narrative Review

Coronavirus disease 2019 (COVID-19) is caused by the novel severe acute respiratory coronavirus-2 (SARS-CoV-2). Several explanations for the development of cardiovascular complications during and after acute COVID-19 infection have been hypothesized. The COVID-19 pandemic, caused by SARS-CoV-2, has emerged as one of the deadliest pandemics in modern history. The myocardial injury in COVID-19 patients has been associated with coronary spasm, microthrombi formation, plaque rupture, hypoxic injury, or cytokine storm, which have the same pathophysiology as the three clinical variants of Kounis syndrome. The angiotensin-converting enzyme 2 (ACE2), reninaldosterone system (RAAS), and kinin-kallikrein system are the main proposed mechanisms contributing to cardiovascular complications with the COVID-19 infection. ACE receptors can be found in the heart, blood vessels, endothelium, lungs, intestines, testes, neurons, and other human body parts. SARS-CoV-2 directly invades the endothelial cells with ACE2 receptors and constitutes the main pathway through which the virus enters the endothelial cells. This causes angiotensin II accumulation downregulation of the ACE2 receptors, resulting in prothrombotic effects, such as hemostatic imbalance via activation of the coagulation cascade, impaired fibrinolysis, thrombin generation, vasoconstriction, endothelial and platelet activation, and pro-inflammatory cytokine release. The KKS system typically causes vasodilation and regulates tissue repair, inflammation, cell proliferation, and platelet aggregation, but SARS-CoV-2 infection impairs such counterbalancing effects. This cascade results in cardiac arrhythmias, cardiac arrest, cardiomyopathy, cytokine storm, heart failure, ischemic myocardial injuries, microvascular disease, Kounis syndrome, prolonged COVID, myocardial fibrosis, myocarditis, new-onset hypertension, pericarditis, postural orthostatic tachycardia syndrome, pulmonary hypertension, stroke, Takotsubo syndrome, venous thromboembolism, and thrombocytopenia. In this narrative review, we describe and elucidate when, where, and how COVID-19 affects the human cardiovascular system in various parts of the human body that are vulnerable in every patient category, including children and athletes.

Combination therapy with oral antiviral and anti-inflammatory drugs improves the efficacy of delayed treatment in a COVID-19 hamster model

BACKGROUND

Pulmonary infection with SARS-CoV-2 stimulates host immune responses and can also result in the progression of dysregulated and critical inflammation. Throughout the pandemic, the management and treatment of COVID-19 has been continuously updated with a range of antiviral drugs and immunomodulators. Monotherapy with oral antivirals has proven to be effective in the treatment of COVID-19. However, treatment should be initiated in the early stages of infection to ensure beneficial therapeutic outcomes, and there is still room for further consideration on therapeutic strategies using antivirals.

METHODS

We studied the therapeutic effects of monotherapy with the oral antiviral ensitrelvir or the anti-inflammatory corticosteroid methylprednisolone and combination therapy with ensitrelvir and methylprednisolone in a delayed dosing model of hamsters infected with SARS-CoV-2.

FINDINGS

Combination therapy with ensitrelvir and methylprednisolone improved respiratory conditions and reduced the development of pneumonia in hamsters even when the treatment was started after 2 days post-infection. The combination therapy led to a differential histological and transcriptomic pattern in comparison to either of the monotherapies, with reduced lung damage and down-regulation of expression of genes involved in the inflammatory response. Furthermore, we found that the combination treatment is effective in case of infection with either the highly pathogenic delta or circulating omicron variants.

INTERPRETATION

Our results demonstrate the advantage of combination therapy with antiviral and corticosteroid drugs in COVID-19 treatment from the perspective of lung pathology and host inflammatory responses.

FUNDING

Funding bodies are described in the Acknowledgments section.

Can alpha‐linolenic acid be a modulator of “cytokine storm,” oxidative stress and immune response in SARS‐CoV‐2 infection?

Alpha‐linolenic acid (ALA) is a long‐chain polyunsaturated essential fatty acid of the Ω3 series found mainly in vegetables, especially in the fatty part of oilseeds, dried fruit, berries, and legumes. It is very popular for its preventive use in several diseases: It seems to reduce the risk of the onset or decrease some phenomena related to inflammation, oxidative stress, and conditions of dysregulation of the immune response. Recent studies have confirmed these unhealthy situations also in patients with severe coronavirus disease 2019 (COVID‐19). Different findings (in vitro, in vivo, and clinical ones), summarized and analyzed in this review, have showed an important role of ALA in other various non‐COVID physiological and pathological situations against “cytokines storm,” chemokines secretion, oxidative stress, and dysregulation of immune cells that are also involved in the infection of the 2019 novel coronavirus. According to the effects of ALA against all the aforementioned situations (also present in patients with a severe clinical picture of severe acute respiratory syndrome‐(CoV‐2) infection), there may be the biologic plausibility of a prophylactic effect of this compound against COVID‐19 symptoms and fatality.

SARS-CoV-2 Causes Brain Damage: Therapeutic Intervention with AZD8797

Elevated CX3CL1 is associated with severe COVID-19 and neurologic symptoms. We aimed to investigate the potential protective effects of selective CX3CR1 antagonist AZD8797 on SARS-CoV-2-induced neuronal damage, and to identify the underlying mechanisms. K18-hACE2 transgenic mice (n = 37) were randomly divided into control groups and SARS-CoV-2 groups, with and without intraperitoneal administration of vehicle or AZD8797 (2.5 mg/mL/day), following exposure to either a single dose of SARS-CoV-2 inhalation or no exposure. Object recognition and hole board tests were performed to assess memory function. Postinfection 8 days, brain tissues were analyzed for histopathological changes, viral, glial, apoptotic, and other immunohistochemical markers, along with measuring malondialdehyde, glutathione, and myeloperoxidase activities. Serum samples were analyzed for proinflammatory cytokines. The SARS-CoV-2 group showed significant weight loss, neuronal damage, oxidative stress, and impaired object recognition memory, while AZD8797 treatment mitigated some of these effects, especially in weight, apoptosis, glutathione, and MCP-1. Histopathological analyses supported the protective effects of AZD8797 against SARS-CoV-2-induced damage. The CX3CL1-CX3CR1 signaling pathway could offer a promising target for reducing SARS-CoV-2's neurological impact, but additional research is needed to confirm these findings in combination with other therapies and assess the clinical significance.

A bioinformatic analysis: Previous allergen exposure may support anti- SARS-CoV-2 immune response

COVID-19, caused by infection with the SARS-CoV-2 has become a global health problem due to significant mortality rates; the exact pathophysiological mechanism remains uncertain. Articles reporting patient data are quite heterogeneous and have several limitations. Surviving patients develop a CD4 and CD8 T-cell response to the virus SARS-CoV-2 during COVID-19. Interestingly, pre-existing virus-reactive T-cells have been found in patients that were not infected before, suggesting some form of cross-reactivity or immunological mimicry. To better understand this phenomenon, we performed a bioinformatic study, which was aimed to identify antigenic structures that may explain the presence of such "reactive" T-cells, which may support or modulate the immune response to SARS-CoV-2 infections. Seven different common environmental allergen epitopes identical to the SARS-CoV-2 S-protein were identified that share affinity to 8 MHCI-specific epitope regions. Pollen showed the greatest similarity with the S protein epitope. In the epitope similarity analysis between the S protein and MHC-II / T helper epitopes, the highest similarity was determined for mites. When S-protein that stimulates B cells and identical epitope antigens are examined, the most common allergens were hornbeam and wheat. The high epitope similarity observed for the allergens examined and S protein epitopes suggest that these allergens may be a reason for pre-existing SARS-CoV-2 - reactive T-cells in previously non-infected subjects and such a previous exposure may affect the course of the disease in COVID-19 infection. It remains to be determined whether such a previous existence of SARS-CoV-2 reactive cells can support the clearance of the virus or if they, in contrast, may even aggravate the disease course. (Table 4, Ref 54).

Antiphospholipid antibodies are enriched post-acute COVID-19 but do not modulate the thrombotic risk

BACKGROUND AND OBJECTIVES

COVID-19-associated coagulopathy, shown to increase the risk for the occurrence of thromboses and microthromboses, displays phenotypic features of the antiphospholipid syndrome (APS), a prototype antibody-mediated autoimmune disease. Several groups have reported elevated levels of criteria and non-criteria antiphospholipid antibodies (aPL), assumed to cause APS, during acute or post-acute COVID-19. However, disease heterogeneity of COVID-19 is accompanied by heterogeneity in molecular signatures, including aberrant cytokine profiles and an increased occurrence of autoantibodies. Moreover, little is known about the association between autoantibodies and the clinical events. Here, we first aim to characterise the antiphospholipid antibody, anti-SARS-CoV-2 antibody, and the cytokine profiles in a diverse collective of COVID-19 patients (disease severity: asymptomatic to intensive care), using vaccinated individuals and influenza patients as comparisons. We then aim to assess whether the presence of aPL in COVID-19 is associated with an increased incidence of thrombotic events in COVID-19.

METHODS AND RESULTS

We conducted anti-SARS-CoV-2 IgG and IgA microELISA and IgG, IgA, and IgM antiphospholipid line immunoassay (LIA) against 10 criteria and non-criteria antigens in 155 plasma samples of 124 individuals, and we measured 16 cytokines and chemokines in 112 plasma samples. We additionally employed clinical and demographic parameters to conduct multivariable regression analyses within multiple paradigms. In line with recent results, we find that IgM autoantibodies against annexin V (AnV), β2-glycoprotein I (β2GPI), and prothrombin (PT) are enriched upon infection with SARS-CoV-2. There was no evidence for seroconversion from IgM to IgG or IgA. PT, β2GPI, and AnV IgM as well as cardiolipin (CL) IgG antiphospholipid levels were significantly elevated in the COVID-19 but not in the influenza or control groups. They were associated predominantly with the strength of the anti-SARS-CoV-2 antibody titres and the major correlate for thromboses was SARS-CoV-2 disease severity.

CONCLUSION

While we have recapitulated previous findings, we conclude that the presence of the aPL, most notably PT, β2GPI, AnV IgM, and CL IgG in COVID-19 are not associated with a higher incidence of thrombotic events.

[Bone/cartilage immunomodulating hydrogels: construction strategies and applications]

Objective

To review the research progress in the construction strategy and application of bone/cartilage immunomodulating hydrogels.

Methods

The literature related to bone/cartilage immunomodulating hydrogels at home and abroad in recent years was reviewed and summarized from the immune response mechanism of different immune cells, the construction strategy of immunomodulating hydrogels, and their practical applications.

Results

According to the immune response mechanism of different immune cells, the biological materials with immunoregulatory effect is designed, which can regulate the immune response of the body and thus promote the regeneration of bone/cartilage tissue. Immunomodulating hydrogels have good biocompatibility, adjustability, and multifunctionality. By regulating the physical and chemical properties of hydrogel and loading factors or cells, the immune system of the body can be purposively regulated, thus forming an immune microenvironment conducive to osteochondral regeneration.

Conclusion

Immunomodulating hydrogels can promote osteochondral repair by affecting the immunomodulation process of host organs or cells. It has shown a wide application prospect in the repair of osteochondral defects. However, more data support from basic and clinical experiments is needed for this material to further advance its clinical translation process.

Impairment of platelet function in both mild and severe COVID-19 patients

Abnormalities of platelet function were reported in patients with severe COVID-19 (severe-C), but few data are available in patients with mild COVID-19 (mild-C) and after COVID-19 recovery. The aim of this study was to investigate platelet parameters in mild-C patients (n = 51), with no evidence of pneumonia, and severe-C patients (n = 49), during the acute phase and after recovery, compared to 43 healthy controls. Both mild-C and severe-C patients displayed increased circulating activated platelets, low δ-granule content (ADP, serotonin), impaired platelet activation by collagen (light transmission aggregometry) and impaired platelet thrombus formation on collagen-coated surfaces under controlled flow conditions (300/s shear rate). The observed abnormalities were more marked in severe-C patients than in mild-C patients. Overall, 61% (30/49) of mild-C and 73% (33/45) of severe-C patients displayed at least one abnormal platelet parameter. In a subgroup of just 13 patients who showed no persisting signs/symptoms of COVID-19 and were re-evaluated at least 1 month after recovery, 11 of the 13 subjects exhibited normalization of platelet parameters. In conclusion, mild abnormalities of platelet parameters were present not only in severe-C but also, albeit to a lesser extent, in mild-C patients during the acute phase of COVID-19 and normalized in most tested patients after clinical recovery.

CXCL10 May Be Responsible for Susceptibility to Pulmonary Embolism in COVID-19 Patients

Background

Although the potential of coronavirus disease 2019 (COVID-19) patients to develop pulmonary embolism (PE) is widely recognized, the underlying mechanism has not been completely elucidated. This study aimed to identify genes common to COVID-19 and PE to reveal the underlying pathogenesis of susceptibility to PE in COVID-19 patients.

Methods

COVID-19 genes were obtained from the GEO database and the OMIM, CTD, GeneCards, and DisGeNET databases; PE genes were obtained from the OMIM, CTD, GeneCards, and DisGeNET databases. We overlapped the genes of COVID-19 and PE to obtain common genes for additional analysis, including functional enrichment, protein-protein interaction, and immune infiltration analysis. Hub genes were identified using cytoHubba, a plugin of Cytoscape, and validated using the independent datasets GSE167000 and GSE13535. The genes validated by the above datasets were further validated in clinical samples.

Results

We obtained 36 genes shared by PE and COVID-19. Functional enrichment and immune infiltration analyses revealed the involvement of cytokines and immune activation. Five genes (CCL2, CXCL10, ALB, EGF, and MKI67) were identified as hub genes common to COVID-19 and PE. CXCL10 was validated in both independent datasets (GSE167000 and GSE13535). Serum levels of CXCL10 in the COVID-19 group and the COVID-19 combined with PE group were significantly higher than those in the healthy control group (P<0.001). In addition, there were significant differences between the COVID-19 group and the COVID-19 combined with PE group (P<0.01).

Conclusion

Our study reveals common genes shared by PE and COVID-19 and identifies CXCL10 as a possible cause of susceptibility to PE in COVID-19 patients.

On fine particulate matter and COVID-19 spread and severity: An in vitro toxicological plausible mechanism

COVID-19 pandemic had a significant impact on global public health. The spread of the disease was related to the high transmissibility of SARS-CoV-2 virus but incidence and mortality rate suggested a possible relationship with environmental factors. Air pollution has been hypothesized to play a role in the transmission of the virus and the resulting severity of the disease. Here we report a plausible in vitro toxicological mode of action by which fine particulate matter (PM2.5) could promote a higher infection rate of SARS-CoV-2 and severity of COVID-19 disease. PM2.5 promotes a 1.5 fold over-expression of the angiotensin 2 converting enzyme (ACE2) which is exploited by viral particles to enter human lung alveolar cells (1.5 fold increase in RAB5 protein) and increases their inflammatory state (IL-8 and NF-kB protein expression). Our results provide a basis for further exploring the possible synergy between biological threats and air pollutants and ask for a deeper understanding of how air quality could influence new pandemics in the future.

Spatiotemporally organized immunomodulatory response to SARS-CoV-2 virus in primary human broncho-alveolar epithelia

The COVID-19 pandemic continues to be a health crisis with major unmet medical needs. The early responses from airway epithelial cells, the first target of the virus regulating the progression toward severe disease, are not fully understood. Primary human air-liquid interface cultures representing the broncho-alveolar epithelia were used to study the kinetics and dynamics of SARS-CoV-2 variants infection. The infection measured by nucleoprotein expression, was a late event appearing between day 4-6 post infection for Wuhan-like virus. Other variants demonstrated increasingly accelerated timelines of infection. All variants triggered similar transcriptional signatures, an "early" inflammatory/immune signature preceding a "late" type I/III IFN, but differences in the quality and kinetics were found, consistent with the timing of nucleoprotein expression. Response to virus was spatially organized: CSF3 expression in basal cells and CCL20 in apical cells. Thus, SARS-CoV-2 virus triggers specific responses modulated over time to engage different arms of immune response.