Unlocking the potential of broadly reactive coronavirus monoclonal antibodies (mAbs) and their derivatives offers a transformative therapeutic avenue against severe COVID-19, especially crucial for safeguarding high-risk populations. Novel mAb-based immunotherapies may help address the reduced efficacy of current vaccines and neutralizing mAbs caused by the emergence of variants of concern (VOCs). Using phage display technology, we discovered a pan-SARS-CoV-2 mAb (C10) that targets a conserved region within the receptor-binding domain (RBD) of the virus. Noteworthy, C10 demonstrates exceptional efficacy in recognizing all assessed VOCs, including recent Omicron variants. While C10 lacks direct neutralization capacity, it efficiently binds to infected lung epithelial cells and induces their lysis via natural killer (NK) cell-mediated antibody-dependent cellular cytotoxicity (ADCC). Building upon this pan-SARS-CoV-2 mAb, we engineered C10-based, Chimeric Antigen Receptor (CAR)-T cells endowed with efficient killing capacity against SARS-CoV-2-infected lung epithelial cells. Notably, NK and CAR-T-cell mediated killing of lung infected cells effectively reduces viral titers. These findings highlight the potential of non-neutralizing mAbs in providing immune protection against emerging infectious diseases. Our work reveals a pan-SARS-CoV-2 mAb effective in targeting infected cells and demonstrates the proof-of-concept for the potential application of CAR-T cell therapy in combating SARS-CoV-2 infections. Furthermore, it holds promise for the development of innovative antibody-based and cell-based therapeutic strategies against severe COVID-19 by expanding the array of therapeutic options available for high-risk populations.Trial registration: ClinicalTrials.gov identifier: NCT04093596.

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to pose a significant global public health threat, particularly to older adults, pregnant women, and individuals with underlying chronic conditions. Dysregulated immune responses to SARS-CoV-2 infection are believed to contribute to the progression of COVID-19 in severe cases. Previous studies indicates that a deficiency in type I interferon (IFN-I) immunity accounts for approximately 15 %-20 % of patients with severe pneumonia caused by COVID-19, highlighting the potential therapeutic importance of modulating IFN-I signals. Natural products and their derivatives, due to their structural diversity and novel scaffolds, play a crucial role in drug discovery. Some of these natural products targeting IFN-I have demonstrated applications in infectious diseases and inflammatory conditions. However, the immunomodulatory potential of IFN-I in critical COVID-19 pneumonia and the natural compounds regulating the related signal pathway remain not fully understood. In this review, we offer a comprehensive assessment of the association between IFN-I and severe COVID-19, exploring its mechanisms and integrating information on natural compounds effective for IFN-I regulation. Focusing on the primary targets of IFN-I, we also summarize the regulatory mechanisms of natural products, their impact on IFNs, and their therapeutic roles in viral infections. Collectively, by synthesizing these findings, our goal is to provide a valuable reference for future research and to inspire innovative treatment strategies for COVID-19.

Severe pneumonia, frequently accompanied by cytokine storms, stands as a perilous respiratory condition with alarmingly high mortality rates. Tetrastigma hemsleyanum polysaccharide (THP), a pivotal constituent derived from Tetrastigma hemsleyanum Diels et Gilg (TH), has demonstrated efficacy in treating lung inflammation. However, its precise efficacy and underlying mechanisms in the context of severe pneumonia remain elusive. Our research aims to elucidate THP's protective effects in a "two-hit" severe pneumonia model. Our observations indicate that THP administration markedly shields the lungs from injury, reduces pulmonary apoptosis, balances the formation of immune thrombus and alleviates oxidative stress in pneumonia-induced mice. Furthermore, THP significantly decreases the levels of pro-inflammatory cytokines, suggesting its robust anti-inflammatory capabilities. Notably, THP also plays a crucial role in normalizing gut microbiota imbalance, which is vital in the pathogenesis of severe pneumonia. Metabolomic analysis further validates THP's restorative effects on plasma metabolites, indicating its involvement in regulating energy metabolism and immune homeostasis. Mechanistically, THP targets the TLR4/NF-κB signaling pathway, a core mediator of inflammation, thereby dampening the inflammatory cascade. In summary, our findings underscore that THP, through its multifaceted actions targeting inflammation, oxidative stress, immune thrombus formation, gut microbiota regulation, and metabolic modulation, emerges as a promising therapeutic approach for severe pneumonia. This study provides invaluable insights into the potential applications of natural polysaccharides in treating severe pneumonia and highlights the significance of the TLR4/NF-κB pathway in the disease's progression.

Hypoalbuminemia is commonly observed in patients with severe Coronavirus Disease 2019 (COVID-19) and is independently associated with adverse outcomes. However, the efficacy of albumin administration on the clinical prognosis of these patients remains uncertain.

This multicenter retrospective study enrolled 458 patients with severe COVID-19 in four medical centers from December 1, 2022, to June 1, 2024. Clinical features and laboratory variables were collected through electronic medical records. The cohorts were divided into two groups: albumin administration and non-albumin administration. Propensity score matching (PSM) was used for minimizing confounding effect. Statistical analyses were conducted to assess the relationship between early albumin administration and 28-day mortality.

Four hundred and fifty-eight severe COVID-19 cases were included in the study, of which 167 (36.5%) received early albumin administration, while 291 (63.5%) did not. Among these patients, 140 experienced in-hospital mortality and 318 survived. Compared to survivors, non-survivors exhibited significantly lower serum albumin levels (29.1g/L vs.33.8g/L, p < 0.05). In comparison to patients with admission albumin levels ≥30 g/L, those with albumin levels <30 g/L had a significantly higher in-hospital mortality (48.4% vs 21.1%, p < 0.001). Prior to PSM, the albumin administration group demonstrated significantly higher 28-day and in-hospital cumulative survival rates compared to the non-albumin group (both p < 0.001). However, no significant differences were observed between the two groups following PSM (p = 0.21 and p = 0.41, respectively).

Hypoalbuminemia was correlated with adverse outcomes in severe COVID-19 patients. However, early albumin administration did not reduce 28-day mortality and in-hospital mortality in these patients, and more relative RCTs were required for validation.

The global impact of SARS-CoV-2 and its associated coronavirus disease (COVID-19) has necessitated urgent characterization of prognostic biomarkers. This study aimed to delineate the epidemiological and clinical predictors of mortality among hospitalized COVID-19 patients.

A retrospective cohort study was conducted on 123 patients with laboratory-confirmed COVID-19 admitted to Huoshenshan Hospital (Wuhan, China) from 1 February 2020 to 30 April 2020. Kaplan-Meier curve and multivariate Cox regression were used to assess the independent factors with survival time. Statistical significance was set at a p-value of <0.05.

The cohort exhibited a mortality rate of 49.6% (61/123), with the critical clinical type (HR = 7.970, p = 0.009), leukocytosis (HR = 3.408, p = 0.006), and lymphopenia (HR = 0.817, p = 0.038) emerging as independent predictors of reduced survival. Critical-type patients demonstrated significantly elevated inflammatory markers (neutrophils: 10.41 ± 6.23 × 109/L; CRP: 104.47 ± 29.18 mg/L) and coagulopathy (D-dimer: 5.21 ± 2.34 μg/ml) compared to non-critical cases. Deceased patients exhibited pronounced metabolic derangements, including hyperglycemia (9.81 ± 2.07 mmol/L) and hepatic dysfunction (ALP: 174.03 ± 30.13 U/L).

We revealed the epidemiological and clinical features of different clinical types of SARS-CoV-2 as summarized in this paper. We found that critical type, leukocyte, and lymphocyte are risk factors that affect survival time, which could be an early and helpful marker to improve management of COVID-19 patients.

Elevated concentrations of IL-10 have been detected in coronavirus disease (COVID-19) patients and are a possible disease severity marker. Single nucleotide variants (SNVs) and their haplotypes can be associated with differences in IL-10 levels and with viral disease susceptibility.

Evaluate the associations of SNVs and their haplotypes in Brazilian patients with COVID-19 severity and outcome.

In this cross-sectional and case-control study, the patients were selected from the University Hospital of State University of Londrina (HU-UEL) (n = 367) and were subdivided into mild (n = 165), moderate (n = 72) and severe (n = 130) groups. The DNA samples of the participants were subjected to real-time PCR for the detection of rs1800896 (A>G), rs1800871 (C>T) and rs1800872 (C>A) genotypes. The haplotypes were inferred with PHASE v2.1.1.

The severe cases of COVID-19 were independently associated with the GG genotype (rs1800896) (P = 0.038, OR 2.522, 95 % CI 1.053-6.038) as well as with the GCC haplotype in homozygosity (P = 0.037, OR 2.767, 95 % CI 1.065-7.191).

These results showed that the GG genotype of rs1800896 or the GCC haplotype are associated with COVID-19 severity in Brazilian patients.

There are studies evaluating the association of serum lactate dehydrogenase (LDH) and albumin levels with mortality in COVID-19 patients. The aim of our study was to evaluate the predictive effect of the LDH/albumin ratio (LAR) on mortality and poor clinical course in COVID-19 patients. A total of 2093 patients for whom LDH and albumin tests were available were included in the study. Demographic data, length of hospitalization, and signs of poor clinical course were recorded and compared with the LAR value at the time of hospitalization. The study included 1010 female (48.3%) and 1083 male (51.7%) patients. Notably, 1408 (67.3%) of the patients had at least 1 comorbidity. Oxygen was required in 860 patients (41.1%) and intensive care unit was required in 215 patients (10.3%). The mortality rate was 8.1% (n: 170). The median LAR value was 8.05. A positive correlation was observed between LAR and length of hospitalization. The LAR value was significantly higher in patients who died compared with those who survived, in patients who required intensive care compared with those who did not, and in patients who required oxygen compared to those who did not. The cutoff value for LAR in predicting mortality was calculated as 10.48. The sensitivity and specificity were determined as 73.5% and 73.7%. In conclusion, serum LAR at the time of admission is predictive of poor clinical course and mortality in COVID-19 patients. Patients with LAR values higher than the cutoff value should be closely monitored for poor clinical course.

This study aimed to identify possible early biomarkers of mortality among clinical and biochemical parameters, iron metabolism parameters, and cytokines detected within 24 h from admission in hospitalized COVID-19 patients. We enrolled 80 hospitalized patients (40 survivors and 40 non-survivors) with COVID-19 pneumonia and acute respiratory failure. The median time from the onset of COVID-19 symptoms to hospital admission was lower in non-survivors than survivors (p < 0.05). Respiratory failure, expressed as the ratio of arterial oxygen partial pressure to the fraction of inspired oxygen (P/F), was more severe in non-survivors than survivors (p < 0.0001). Comorbidities were similar in both groups. Among biochemical parameters and cytokines, eGFR and interleukin (IL)-1β were found to be significantly lower (p < 0.05), while LDH, IL-10, and IL-8 were significantly higher in non-survivors than in survivors (p < 0.0005, p < 0.05 and p < 0.005, respectively). Among other parameters, LDH values distribution showed the most significant difference between study groups (p < 0.0001). LASSO feature selection combined with Cox proportional hazards and logistic regression models was applied to identify features distinguishing between survivors and non-survivors. Both approaches highlighted LDH as the strongest predictor, with IL-22 and creatinine emerging in the Cox model, while IL-10, eGFR, and creatinine were influential in the logistic model (AUC = 0.744 for Cox, 0.723 for logistic regression). In a similar manner, we applied linear regression for predicting LDH levels, identifying the P/F ratio as the top predictor, followed by IL-10 and eGFR (NRMSE = 0.128). Collectively, these findings underscore LDH's critical role in mortality prediction, with P/F and IL-10 as key determinants of LDH increases in this Italian COVID-19 cohort.

Background and Objectives: We conducted a retrospective observational study to evaluate the impact of elevated blood glucose levels in patients with SARS-CoV-2 infection and a prior diagnosis of diabetes mellitus (DM) or newly diagnosed hyperglycemia. Materials and Methods: This study analyzed 6065 patients admitted to the COVID-19 departments of the "Marius Nasta" National Institute of Pulmonology in Bucharest, Romania, between 26 October 2020 and 5 January 2023. Of these, 813 patients (13.40%) were selected for analysis due to either a pre-existing diagnosis of DM or hyperglycemia at the time of hospital admission. Results: The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels were elevated in patients with blood glucose levels exceeding 300 mg/dL. These elevations correlated with the presence of respiratory failure and increased mortality rates. Additionally, oxygen requirements were significantly higher at elevated blood glucose levels (p < 0.001), with a direct relationship between glycemia and oxygen demand. This was accompanied by lower oxygen saturation levels (p < 0.001). Maximum blood glucose levels were associated with the severity of respiratory failure (AUC 0.6, 95% CI: 0.56-0.63, p < 0.001). We identified cut-off values for blood glucose at admission (217.5 mg/dL) and maximum blood glucose during hospitalization (257.5 mg/dL), both of which were associated with disease severity and identified as risk factors for increased mortality. Conclusions: High blood glucose levels, both at admission and during hospitalization, were identified as risk factors for poor prognosis and increased mortality in patients with SARS-CoV-2 infection, regardless of whether the hyperglycemia was due to a prior diagnosis of DM or was newly developed during the hospital stay. These findings underscore the importance of glycemic control in the management of hospitalized COVID-19 patients.

The impact of anti-Spike monoclonal antibody (mAbs) treatment on the immune response of COVID19-patients is poorly explored. In particular, a comparison of the immunological influence of different therapeutic regimens has not yet been performed. Aim of the study was to compare the kinetic of innate and adaptive immune response as well as the SARS-CoV-2 specific humoral and T cell response in two groups of SARS-CoV-2-infected patients treated with two different mAbs regimens: Bamlanivimab/Etesevimab (BAM/ETE) or Casirivimab/Imdevimab (CAS/IMD). SARS-CoV-2-infected patients (n = 39) with mild/moderate disease were enrolled before (T0) and after 7 days (T7) and 30 day (T30) from mAbs infusion. Patients were divided in two groups on the basis of the mAb regimen: BAM/ETE (n = 15) and CAS/IMD (n = 24). The phenotype/function of immune cell subsets was evaluated by flow-cytometry and by ELISA. The Spike-specific T cell response (IFN-γ) and anti-Nucleocapside IgG were evaluated by chemiluminescence assay. SARS CoV-2 RNA in nasal swabs was evaluated by RT-PCR. Eleven out of the thirty-nine enrolled patients tested negative at T7, among which nine (81.8 %) had been treated with CAS/IMD regimen. A comparable increase in CD4 and CD8 T cells was observed in both treatment groups. Moreover, a reduction of CD38 expression on T (CD4, CD8 and Vδ2) and on NK cells was observed in both groups, as well as a reduction overtime of the perforin expression in T (CD8, Vδ2) and in NK cells reaching significance only in CAS/IMD-treated patients. The SARS-CoV-2-specific T cells response increased at T7 in BAM/ETE-treated patients and at T30 in CAS/IND group. Of note, at T30 SARS-CoV2-specific T cells was higher in CAS/IMD than in BAM/ETE group. Furthermore, the titre of anti-N IgG increased overtime in both groups with a faster kinetic in CAS/IMD group. The spontaneous production of inflammatory cytokines by monocytes and neutrophils was similar the two mAb regimens, as well as the level of plasmatic IL-6. Finally, patients were also analysed according to sex. The male group showed a higher frequency of activated CD4 T cells, NKG2A-expressing CD8 T cells and perforin-expressing Vδ2 T cells compared to female group. Moreover, a higher specific T cell response at T30 was observed in the male compared to female group. In conclusion, these results show similar effects of both mAb regimens in restoring T and NK cell homeostasis and in reducing inflammation. In contrast, CAS/IMD allows a better humoral and cellular SARS-CoV2 specific immunization.

Coronavirus disease 2019 (COVID-19), caused by infection with the enveloped RNA betacoronavirus, SARS-CoV-2, led to a global pandemic involving over 7 million deaths. Macrophage inflammatory responses impact COVID-19 severity; however, it is unclear whether macrophages are infected by SARS-CoV-2. We sought to identify mechanisms regulating macrophage expression of ACE2, the primary receptor for SARS-CoV-2, and to determine if macrophages are susceptible to productive infection. We developed a humanized ACE2 (hACE2) mouse whereby hACE2 cDNA was cloned into the mouse ACE2 locus under control of the native promoter. We validated the susceptibility of hACE2 mice to SARS-CoV-2 infection relative to wild-type mice and an established K18-hACE2 model of acute fulminating disease. Intranasal exposure to SARS-CoV-2 led to pulmonary consolidations with cellular infiltrate, edema, and hemorrhage, consistent with pneumonia, yet unlike the K18-hACE2 model, hACE2 mice survived and maintained stable weight. Infected hACE2 mice also exhibited a unique plasma chemokine, cytokine, and growth factor inflammatory signature relative to K18-hACE2 mice. Infected hACE2 mice demonstrated evidence of viral replication in infiltrating lung macrophages, and infection of macrophages in vitro revealed a transcriptional profile indicative of altered RNA and ribosomal processing machinery as well as activated cellular antiviral defense. Macrophage IL-1β-driven NF-κB transcription of ACE2 was an important mechanism of dynamic ACE2 upregulation, promoting macrophage susceptibility to infection. Experimental models of COVID-19 that make use of native hACE2 expression will allow for mechanistic insight into factors that can either promote host resilience or increase susceptibility to worsening severity of infection.

The human angiotensin converting enzyme 2 (ACE2) gene encodes a type I transmembrane protein, which is homologous to angiotensin I-converting enzyme (ACE) and belongs to the angiotensin-converting enzyme family of dipeptidyl carboxypeptidases. As highlighted by the COVID-19 pandemic, ACE2 is not only crucial for the renin-angiotensin-aldosterone system (RAAS), but also displays great affinity with the SARS-CoV-2 spike protein, representing the major receptor of the virus. Given the significance of ACE2 in COVID-19, especially among cancer patients, the present study aims to explore the transcriptional landscape of ACE2 in human cancer and non-cancerous cell lines through the design and implementation of a custom targeted long-read sequencing approach. Bioinformatics analysis of the massive parallel sequencing data led to the identification of novel ACE2 mRNA splice variants (ACE2 sv.7-sv.12) that demonstrate previously uncharacterized exon-skipping events as well as 5' and/or 3' alternative splice sites. Demultiplexing of the sequencing data elucidated the differential expression profile of the identified splice variants in multiple human cell types, whereas in silico analysis suggests that some of the novel splice variants could produce truncated ACE2 isoforms with altered functionalities, potentially influencing their interaction with the SARS-CoV-2 spike protein. In summary, our study sheds light on the complex alternative splicing landscape of the ACE2 gene in cancer cell lines, revealing novel splice variants that could have significant implications for SARS-CoV-2 susceptibility in cancer patients. These findings contribute to the increased understanding of ACE2's role in COVID-19 and highlight the importance of considering alternative splicing as a key factor in viral pathogenesis. Undoubtably, further research is needed to explore the functional roles of these variants and their potential as therapeutic targets in the ongoing fight against COVID-19.

With the consistent occurrence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the prevalence of various ocular complications has increased over time. SARS-CoV-2 infection has been shown to have neurotropism and therefore to lead to not only peripheral inflammatory responses but also neuroinflammation. Because the receptor for SARS-CoV-2, angiotensin-converting enzyme 2 (ACE2), can be found in many intraocular tissues, coronavirus disease 2019 (COVID-19) may also contribute to persistent intraocular neuroinflammation, microcirculation dysfunction and ocular symptoms. Increased awareness of neuroinflammation and future research on interventional strategies for SARS-CoV-2 infection are important for improving long-term outcomes, reducing disease burden, and improving quality of life. Therefore, the aim of this review is to focus on SARS-CoV-2 infection and intraocular neuroinflammation and to discuss current evidence and future perspectives, especially possible connections between conditions and potential treatment strategies.

The COVID-19 pandemic has disproportionately affected individuals with diabetes mellitus (DM), significantly increasing their risk of adverse outcomes. This retrospective study aimed to explore the underlying factors contributing to the heightened vulnerability of individuals with DM to severe COVID-19. We reviewed medical records of patients diagnosed with DM from August 2020 to August 2022 and identified 60 equally divided into two groups. Group A (n = 30) included those diagnosed with an associated COVID-19 infection, while Group B (n = 30) served as the control group without a COVID-19 infection. Inflammatory biomarkers, venous blood glucose levels, and other parameters were assessed at hospital admission and again after a 14-day treatment period. Statistical analysis confirmed a strong association between diabetes and COVID-19 infection. In COVID-19 patients treated with Empagliflozin, correlations were observed between IL-1, TNF-alpha, IL-6, and blood glucose levels. Patients in Group B did not show significant improvements in inflammatory markers or blood glucose control. In contrast, in the first group, better correlations between interleukin levels and blood glucose were demonstrated, suggesting a higher success rate for that treatment. Our findings indicate that while Empagliflozin had limited efficacy in managing long-term diabetes-related complications, it might offer significant benefits in the acute phase of illness.

It would be highly valuable to possess a tool for evaluating disease progression and identifying patients at risk of experiencing a more severe clinical course and potentially worse outcomes. The concept of allostatic load, which represents the overall strain on the body from repeated stress responses, has been recognized as a precursor to the development of chronic illnesses. It functions as a cumulative measure of the body's capacity to adapt to stress. Numerous studies have demonstrated that elevated allostatic load levels are associated with various negative health outcomes, both physical and mental, and are more predictive of mortality than individual biomarkers. Leveraging the unique circumstances presented by the COVID-19 pandemic, we evaluated different clinical and laboratory parameters in hospitalised COVID-19 patients to assess allostatic load. Our results indicated that allostatic load acts as a strong predictor of prolonged hospitalisation, increased ICU days, and mortality. This highlights its efficacy as a precise gauge of biological dysregulation linked to the response to COVID-19 during disease progression. Allostatic load is easily obtainable and provides an early, cost-effective indication of disease prognosis. Additionally, it has the potential to forecast the necessity for ICU admission. As a result, this parameter, indicative of the comprehensive physiological disruption in response to stress, emerges as a promising prognostic marker for hospitalised patients, extending beyond COVID-19.

The severity of COVID-19 is influenced by uncontrolled hyper-inflammatory response with excessive release of many cytokines and chemokines. The understanding of the temporal change in the cytokine levels that underlies the diverse clinical presentations of COVID-19 can help in the prediction of the disease outcome and in the design of proper treatment strategies.

Data were collected from children (<18 years old) hospitalised with severe COVID-19 or severe MIS-C who were compared to a group of healthy control children. Patient demographics, clinical, laboratory data and cytokines profiles were evaluated. Blood samples were collected within 24 h of admission for all enrolled children and on Day 14.

Twenty-five children with severe COVID-19 and 23 cases with severe MIS-C were included in the study. The biochemical and inflammatory markers tend to be elevated in MIS-C group. There was a significant difference between studied cases and the control group in the following cytokines: G-CSF, IL-10, HMGB1, TNF-α, IL-6, IL-8 and INF-gamma (P < 0.05). While there was a significant difference between severe COVID-19 and MIS-C groups in the following cytokines at Day 1 of admission; IL-10, IL-6, IL-8 and INF-gamma; while at Day 14, there was a significant difference only for G-CSF, IL-10 and IL-6, all other cytokines were comparable.

Our study underpinned patterns of cytokine response in severe COVID-19 and MIS-C. There is a significant upregulation in pro-inflammatory cytokines (mainly G-CSF, IL-10, HMGB1, TNF-α, IL-6, IL-8 and INF-gamma). These biomarkers that could imply on the severity rating and treatment strategies, should be preferentially assessed in SARS-CoV-2 associated immunological events.

The COVID-19 pandemic has caused significant morbidity and mortality worldwide. The emergence of the Alpha and Delta variants of SARS-CoV-2 has led to a renewed interest in using interferon therapy as a potential treatment option. Interferons are a group of signaling proteins produced by host cells in response to viral infections. They play a critical role in the innate immune response to viral infections by inducing an antiviral state in infected and neighboring cells. Interferon therapy has shown promise as a potential treatment option for COVID-19. In this review paper, we review the current knowledge regarding interferon therapy in the context of the Alpha and Delta variants of SARS-CoV-2 and discuss the challenges that must be overcome to translate laboratory findings into effective clinical treatments.

To elicit optimal immune responses, messenger RNA vaccines require intracellular delivery of the mRNA and the careful use of adjuvants. Here we report a multiply adjuvanted mRNA vaccine consisting of lipid nanoparticles encapsulating an mRNA-encoded antigen, optimized for efficient mRNA delivery and for the enhanced activation of innate and adaptive responses. We optimized the vaccine by screening a library of 480 biodegradable ionizable lipids with headgroups adjuvanted with cyclic amines and by adjuvanting the mRNA-encoded antigen by fusing it with a natural adjuvant derived from the C3 complement protein. In mice, intramuscular or intranasal administration of nanoparticles with the lead ionizable lipid and with mRNA encoding for the fusion protein (either the spike protein or the receptor-binding domain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)) increased the titres of antibodies against SARS-CoV-2 tenfold with respect to the vaccine encoding for the unadjuvanted antigen. Multiply adjuvanted mRNA vaccines may improve the efficacy, safety and ease of administration of mRNA-based immunization.

Numerous hematological abnormalities have been documented in COVID-19 patients. We conducted an analysis of 82 articles from PubMed, focusing on the hematological characteristics observed in survivors (S) and non-survivors (NS) with moderate and severe COVID-19 symptoms, respectively. Our review underlines neutrophilia, lymphopenia, and thrombocytopenia as hallmark features of the disease. In severe cases, blood cell microscopy revealed the following abnormalities: i) an increased number of neutrophils, often displaying granularity, toxic granulation, and vacuolization; ii) lymphocytes with a notably blue cytoplasm; iii) several monocytes that contain vacuoles; iv) platelet aggregation; and v) basophilic stippling in red blood cells. Furthermore, scattergram analysis of COVID-19 patients revealed two common features: i) an increased neutrophil population and ii) the presence of a distinctive "sandglass pattern". This review underscores the critical role of hematochemical and cytomorphological blood cell analysis in COVID-19 patients, aiding clinicians in better recognizing and understanding the indicators of disease severity.

Huashi Baidu Granule (HSBDG), a traditional Chinese medicine (TCM), is used for treating coronavirus disease 2019 (COVID-19). Porcine reproductive and respiratory syndrome (PRRS) is considered the "COVID-19" for swine. According to the TCM theory, "dampness" is the main pathogenic factor in COVID-19 and PRRS, and "Huashi" means that this formula is good at removing "dampness". Studies have demonstrated that HSBDG's effect in COVID-19; but the mechanism of removing "dampness" remains elusive.

We aimed to assess the effect of HSBDG on PRRS, and elucidate its potential mechanism in removing "dampness".

We established a PRRS-virus (PRRSV)-infected Marc-145 cells model, and performed qRT-PCR, Western blot analysis, and indirect immunofluorescence assay to examine the anti-PRRSV effects of HSBDG in vitro. PRRSV-infected pig model was established and used to investigate HSBDG's effect in PRRS and explore underlying mechanisms in removing "dampness" using ELISA and immunohistochemistry assay methods.

HSBDG exhibited anti-PRRSV activity and suppressed the viral replication and release phases. HSBDG treatment alleviated PRRS, lowered rectal temperature, reduced histopathological changes and viral load in lung tissues, and ameliorated organ lesions. Moreover, IL-1β, IL-6, IL-8, and TNF-α expressions were decreased in lung tissues. Mechanistically, HSBDG inhibited the NLRP3/Caspase-1/GSDMD-N pathway to reduce the inflammatory response and upregulated AQP1, AQP5, α-ENaC, and Na-K-ATPase expressions to promote lung fluid clearance.

HSBDG exerted anti-PRRSV effects and could attenuate PRRS. HSBDG potentially removes "dampness" by attenuating inflammation by suppressing the NLRP3/Caspase-1/GSDMD-N pathway and inhibiting pulmonary edema by upregulating the expression of AQP1, AQP5, α-ENaC, and Na-K-ATPase.

Accurate in silico determination of CD8+ T cell epitopes would greatly enhance T cell-based vaccine development, but current prediction models are not reliably successful. Here, motivated by recent successes applying machine learning to complex biology, we curated a dataset of 651,237 unique human leukocyte antigen class I (HLA-I) ligands and developed MUNIS, a deep learning model that identifies peptides presented by HLA-I alleles. MUNIS shows improved performance compared with existing models in predicting peptide presentation and CD8+ T cell epitope immunodominance hierarchies. Moreover, application of MUNIS to proteins from Epstein-Barr virus led to successful identification of both established and novel HLA-I epitopes which were experimentally validated by in vitro HLA-I-peptide stability and T cell immunogenicity assays. MUNIS performs comparably to an experimental stability assay in terms of immunogenicity prediction, suggesting that deep learning can reduce experimental burden and accelerate identification of CD8+ T cell epitopes for rapid T cell vaccine development.

SARS-CoV-2 infection and the resultant COVID-19 pneumonia cause significant damage to the airway and lung epithelium. This damage manifests as mucus hypersecretion, pulmonary inflammation and fibrosis, which often lead to long-term complications collectively referred to as long COVID or post-acute sequelae of COVID-19 (PASC). The airway epithelium, as the first line of defence against respiratory pathogens, depends on airway basal stem cells (BSCs) for regeneration. Alterations in BSCs are associated with impaired epithelial repair and may contribute to the respiratory complications observed in PASC. Given the critical role of BSCs in maintaining epithelial integrity, understanding their alterations in COVID-19 is essential for developing effective therapeutic strategies. This study investigates the intrinsic properties of BSCs derived from COVID-19 patients and evaluates the modulatory effects of mesenchymal stem cells (MSCs). Through a combination of functional assessments and transcriptomic profiling, we identified key phenotypic and molecular deviations in COVID-19 patient-derived BSCs, including goblet cell hyperplasia, inflammation and fibrosis, which may underlie their contribution to PASC. Notably, MSC co-culture significantly mitigated these adverse effects, potentially through modulation of the interferon signalling pathway. This is the first study to isolate BSCs from COVID-19 patients in the Chinese population and establish a COVID-19 BSC-based xenograft model. Our findings reveal critical insights into the role of BSCs in epithelial repair and their inflammatory alterations in COVID-19 pathology, with potential relevance to PASC and virus-induced respiratory sequelae. Additionally, our study highlights MSC-based therapies as a promising strategy to address respiratory sequelae and persistent symptoms.

We aimed to understand the potential therapeutic and anti-inflammatory effects of the phosphodiesterase-4 (PDE4) inhibitor roflumilast in models of pulmonary infection caused by betacoronaviruses.

Mice were infected intranasally with murine hepatitis virus (MHV-3) or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Roflumilast was given to MHV-3-infected mice therapeutically at doses of 1 mg/kg or 10 mg/kg, or prophylactically at 10 mg/kg. In SARS-CoV-2-infected mice, roflumilast was given therapeutically at a dose of 10 mg/kg. Lung histopathology, chemokines (CXCL-1 and CCL2), cytokines (IL-1β, IL-6, TNF, IFN-γ, IL-10 and TGFβ), neutrophil immunohistochemical staining (Ly6G+ cells), macrophage immunofluorescence staining (F4/80+ cells), viral titration plaque assay, real-time PCR virus detection, and blood cell counts were examined.

Therapeutic treatment with roflumilast at 10 mg/kg reduced lung injury in SARS-CoV-2 or MHV-3-infected mice without compromising viral clearance. In MHV-3-infected mice, reduced lung injury was associated with decreased chemokines levels, prevention of neutrophil aggregates and reduced macrophage accumulation in the lung tissue. However, the prophylactic treatment strategy with roflumilast increased lung injury in MHV-3-infected mice.

Our findings indicate that therapeutic treatment with roflumilast reduced lung injury in MHV-3 and SARS-CoV-2 lung infections. Given the protection induced by roflumilast in inflammation, PDE4 targeting could be a promising therapeutic avenue worth exploring following severe viral infections of the lung.

Despite the fact that an increasing number of studies have focused on developing therapies for acute lung injury, managing acute respiratory distress syndrome (ARDS) remains a challenge in intensive care medicine. Whether the pathology of animal models with acute lung injury in prior studies differed from clinical symptoms of ARDS, resulting in questionable management for human ARDS. To evaluate precisely the therapeutic effect of transplanted stem cells or medications on acute lung injury, we developed an animal model of severe ARDS with lower lung function, capable of keeping the experimental animals survive with consistent reproducibility. Establishing this animal model could help develop the treatment of ARDS with higher efficiency.

In this approach, we intratracheally delivered bleomycin (BLM, 5 mg/rat) into rats' left trachea via a needle connected with polyethylene tube, and simultaneously rotated the rats to the left side by 60 degrees. Within seven days after the injury, we found that arterial blood oxygen saturation (SpO2) significantly decreased to 83.7%, partial pressure of arterial oxygen (PaO2) markedly reduced to 65.3 mmHg, partial pressure of arterial carbon dioxide (PaCO2) amplified to 49.2 mmHg, and the respiratory rate increased over time. Morphologically, the surface of the left lung appeared uneven on Day 1, the alveoli of the left lung disappeared on Day 2, and the left lung shrank on Day 7. A histological examination revealed that considerable cell infiltration began on Day 1 and lasted until Day 7, with a larger area of cell infiltration. Serum levels of IL-5, IL-6, IFN-γ, MCP-1, MIP-2, G-CSF, and TNF-α substantially rose on Day 7.

This modified approach for BLM-induced lung injury provided a severe, stable, and one-sided (left-lobe) ARDS animal model with consistent reproducibility. The physiological symptoms observed in this severe ARDS animal model are entirely consistent with the characteristics of clinical ARDS. The establishment of this ARDS animal model could help develop treatment for ARDS.

This study identifies the secondary metabolites from Alternaria alternate and evaluates their ACE-2: Spike RBD (SARS-CoV-2) inhibitory activity confirmed via immunoblotting in human lung microvascular endothelial cells. In addition, their in vitro anti-inflammatory potential was assessed using a cell-based assay in LPS-treated RAW 264.7 macrophage cells. Two novel compounds, altenuline (1), phthalic acid bis (7'/7'' pentyloxy) isohexyl ester (2), along with 1-deoxyrubralactone (3) alternariol-5-O-methyl ether (4) and alternariol (5) were identified. Molecular docking and in vitro studies showed that compounds 2 and 4 were promising to counteract SARS-CoV-2 attachment to human ACE-2. Thus, they are considered promising natural anti-viral agents. SwissADME in silico analysis was conducted to predict the drug-like potential. Immunoblotting analysis confirmed that the tested compounds (1-4) demonstrated downregulation of ACE-2 expression in the endothelial cells from the lungs with variable degrees. Furthermore, the tested compounds (1-4) showed promising anti-inflammatory activities through TNF-α: TNFR2 inhibitory activity and their inhibitory effect on the proinflammatory cytokines (TNF-α and IL-6) in LPS-stimulated monocytes. In conclusion, our study, for the first time, provides beneficial experimental confirmation for the efficiency of the A. alternate secondary metabolites for the treatment of COVID-19 as they hinder SARS-CoV-2 infection and lower inflammatory responses initiated by SARS-CoV-2. A. alternate and its metabolites are considered in developing preventative and therapeutic tactics for COVID-19.

Background and Objectives: Immune checkpoint inhibitors such as PD-1 and TIM-3 play an important role in regulating the host immune response and are proposed as potential prognostic markers and therapeutic targets in severe cases of COVID-19. We evaluated the expression of PD-1 and TIM-3 on T cells, as well as the concentration of sPD-1 in plasma, to clarify the role of these molecules in patients infected with SARS-CoV-2. Materials and Methods: In this retrospective observational study, we analysed the expression of PD-1 and TIM-3 on CD4+ and CD8+ T cells upon admission and after 7 days of hospitalisation in 770 adult patients. We also evaluated sPD-1 levels in the plasma of 145 patients at different stages of COVID-19 and of 11 control subjects. Molecules were determined using conventional flow cytometry and ELISA and the data were statistically processed. Results: We observed a significantly higher expression of PD-1 on CD4+ cells in deceased patients than in those with mild-to-moderate disease. All patients with COVID-19 exhibited a significantly higher expression of TIM-3 on both CD4+ and CD8+ T cells compared to controls. After 1 week of hospitalisation, there was no significant change in PD-1 or TIM-3 expression on CD4+ or CD8+ T cells across the studied groups. sPD-1 concentrations were not significantly different between survivors and non-survivors. Plasma sPD-1 levels did not correlate with PD-1 expression on T cells, but a significant correlation was observed between CD4+ PD-1 and CD8+ PD-1. Using machine-learning algorithms, we supported our observations and confirmed immunological variables capable of predicting survival, with AUC = 0.786. Conclusions: Analysis of the immune response may be useful for monitoring and predicting the course of COVID-19 upon admission. However, it is essential to evaluate complex immune parameters in conjunction with other key clinical and laboratory indicators.

Immunological disturbances (anti-type I IFN auto-antibody production, cytokine storm, lymphopenia, T-cell hyperactivation and exhaustion) are responsible for disease exacerbation during severe COVID-19 infections.

In this study, we set up a prospective, randomised clinical trial (ClinicalTrials.gov ID: NCT04751643) and performed therapeutic plasma exchange (TPE) in severe COVID-19 patients in order to decrease excess cytokines and auto-antibodies and to assess whether adding TPE to the standard treatment (ST, including corticosteroids plus high-flow rate oxygen) could help restore immune parameters and limit the progression of acute respiratory distress syndrome (ARDS).

As expected, performing TPE decreased the amount of anti-type I IFN auto-antibodies and improved the elimination or limited the production of certain inflammatory mediators (IL-18, IL-7, CCL2, CCL3, etc.) circulating in the blood of COVID-19 patients, compared to ST controls. Interestingly, while TPE did not influence changes in ARDS parameters throughout the protocol, it proved more effective than ST in reversing lymphopenia, preventing T-cell hyperactivation and reducing T-cell exhaustion, notably in a fraction of TPE patients who had an early favourable respiratory outcome. TPE also restored appropriate numbers of CD4+ and CD8+ T-cell memory populations and increased the number of circulating virus-specific T cells in these patients.

Our results therefore indicate that the addition of TPE sessions to the standard treatment accelerates immune cell recovery and contributes to the development of appropriate antiviral T-cell responses in some patients with severe COVID-19 disease.

The interactions between viruses and the host immune response are nuanced and intricate. The cytokine response arguably plays a central role in dictating the outcome of virus infection, balancing inflammation, and healing, which is crucial to resolving infection without destructive immunopathologies.

Early innate immune responses are key to the generation of a beneficial or detrimental immune response. These initial responses are regulated by a plethora of surface bound, endosomal, and cytoplasmic innate immune receptors known as pattern recognition receptors. Of these, the Toll-like receptors (TLRs) play an important role in the induction of cytokines during virus infection. Recognizing pathogen-associated molecular patterns (PAMPs) such as viral proteins and/or nucleotide sequences, the TLRs act as sentinels for the initiation and propagation of immune responses.

TLRs are important receptors for initiating the innate response to single-stranded RNA (ssRNA) viruses like influenza A virus (IAV), severe acute respiratory syndrome coronavirus-1 (SARS-CoV-1), SARS-CoV-2, Middle East respiratory syndrome coronavirus, dengue virus, and Ebola virus. Infection with these viruses is also associated with aberrant expression of proinflammatory cytokines that contribute to a harmful cytokine storm response. Herein we discuss the connections between these ssRNA viruses, cytokine storm, and the roles of TLRs.

The interactions between viruses and the host immune response are nuanced and intricate. The cytokine response arguably plays a central role in dictating the outcome of virus infection, balancing inflammation, and healing, which is crucial to resolving infection without destructive immunopathologies.

Early innate immune responses are key to the generation of a beneficial or detrimental immune response. These initial responses are regulated by a plethora of surface bound, endosomal, and cytoplasmic innate immune receptors known as pattern recognition receptors. Of these, the Toll-like receptors (TLRs) play an important role in the induction of cytokines during virus infection. Recognizing pathogen-associated molecular patterns (PAMPs) such as viral proteins and/or nucleotide sequences, the TLRs act as sentinels for the initiation and propagation of immune responses.

TLRs are important receptors for initiating the innate response to single-stranded RNA (ssRNA) viruses like influenza A virus (IAV), severe acute respiratory syndrome coronavirus-1 (SARS-CoV-1), SARS-CoV-2, Middle East respiratory syndrome coronavirus, dengue virus, and Ebola virus. Infection with these viruses is also associated with aberrant expression of proinflammatory cytokines that contribute to a harmful cytokine storm response. Herein we discuss the connections between these ssRNA viruses, cytokine storm, and the roles of TLRs.

The apoptotic molecule Fas and its ligand FasL are involved in the process of T-lymphocyte death, which may lead to lymphopenia, a characteristic of severe coronavirus disease 2019 (COVID-19). In this study, we investigated the influence of polymorphisms in the FAS and FASL genes, FAS and FASL gene expression, and plasma cytokine levels on COVID-19 severity and long COVID occurrence. A total of 116 individuals with severe COVID-19 and 254 with the non-severe form of the disease were evaluated. In the post-COVID-19 period, samples from 196 individuals with long COVID and 67 from people who did not have long COVID were included. Genotyping and quantification of gene expression were performed via real-time PCR, and cytokine measurement was performed via flow cytometry. The AA genotype for FAS rs1800682 (A/G) and the TT genotype for FASL rs763110 (C/T) were associated with increased FAS and FASL gene expression, respectively (p < 0.005). Higher plasma IFN-γ levels were associated with higher FAS and FASL gene expression (p < 0.05). Among individuals with non-severe COVID-19, carriers of the AA genotype for FAS rs1800682 (A/G) had higher levels of FAS expression, more symptoms, and higher IFN-γ levels (p < 0.05). No association of the evaluated markers with long COVID were observed. The AA genotype of FAS rs1800682 (A/G) and the TT genotype of FASL rs763110 (C/T) influence the levels of FAS and FASL gene expression. Higher gene expression of FAS and FASL may lead to greater inflammation in COVID-19 patients, with higher levels of IFN-γ and T lymphocyte death.