Role In COVID-19 Pathogenesis Research Articles

Decrease of Tregs cells and increase of exhausted Treg cells as the predictors of COVID19 severity

BackgroundT cells and regulatory T cells (Tregs) play a critical role in viral infectious immunity. Exhaustion of T cells during infection and decreased Tregs both contribute to the exacerbation of the disease. In the present study, we assessed T cells and regulatory T cells of COVID-19 patients and a control group according to the expression of the PD-1 molecule. MethodsForty-two COVID-19 patients and 40 controls were enrolled in the study. In COVID-19 patients, blood samples were collected on the first day of their hospitalization. Regulatory T cells (CD4+, CD25+, FOXP3+), CD4+PD-1+, and PD-1+ regulatory T cells were assessed by flow cytometry. ResultsThe percentage of CD4+PD-1 + T cells in COVID-19 patients was significantly higher compared to the control group (P < 0.0001). The percentage of PD-1+ regulatory T cells was significantly increased in the patient group compared to the control group (P < 0.0001). However, the Treg percentage was significantly decreased in the patient group compared to the control group (P < 0.0001). The frequency of CD4+PD-1 + T cells, Tregs, and PD-1+ Tregs had acceptable sensitivity and specificity for assisting in the diagnosis of severe/critical COVID-19. The declined Tregs and enhanced CD4+CD25+, CD4+PD-1+, and PD-1 + T cells were associated with disease severity. ConclusionThe decrease in Tregs and the increase in exhaustion of these cells and T cells play an important role in COVID-19 pathogenesis. These immune parameters could be used as meaningful indicators for assisting in the diagnosis of severe/critical COVID-19.

The role of ACE2 cause of death between COVID-19 and various complications

The COVID-19 pandemic has affected millions of people worldwide. While the virus primarily targets the respiratory system, it also affects other organs in the body, leading to multiple organ dysfunction syndrome (MODS) and death. Recent studies have shown that angiotensin-converting enzyme 2 (ACE2) plays a crucial role in pathogenesis of COVID-19 and development of MODS.&lt;br /&gt; Since its discovery in 2000, ACE2 has garnered widespread attention for its multiple physiological roles, leading to subsequent interest in the influence of the Renin-angiotensin system (RAS) on SARS-CoV-2 infection and COVID-19 during the pandemic.&lt;br /&gt; ACE2 is both an enzyme and a functional receptor on cell surfaces through which SARS-CoV-2 enters the host cells. Recent research has highlighted the multifaceted impact of the virus on various organs, showcasing its ability to induce severe multi-organ injuries. Understanding the intricate interplay between ACE2, RAS, and the pathophysiological changes associated with COVID-19 is crucial for the development of effective treatment strategies and preventative measures.&lt;br /&gt; This study investigates the differences in causes of death related to COVID-19 and its complications. Data from cumulative records for all age groups across the 50 states of the USA and the District of Columbia was retrospectively analyzed. The results revealed significant differences in the incidence of COVID-19 deaths associated with various medical conditions, with respiratory complications showing notably higher incidence compared to other medical conditions besides COVID-19, circulatory, and diabetes.

S100A9: The Unusual Suspect Connecting Viral Infection and Inflammation.

The study of S100A9 in viral infections has seen increased interest since the COVID-19 pandemic. S100A8/A9 levels were found to be correlated with the severity of COVID-19 disease, cytokine storm, and changes in myeloid cell subsets. These data led to the hypothesis that S100A8/A9 proteins might play an active role in COVID-19 pathogenesis. This review explores the structures and functions of S100A8/9 and the current knowledge on the involvement of S100A8/A9 and its constituents in viral infections. The potential roles of S100A9 in SARS-CoV-2 infections are also discussed.

ADAMTS13 or Caplacizumab Reduces the Accumulation of Neutrophil Extracellular Traps and Thrombus in Whole Blood of COVID-19 Patients under Flow.

Neutrophil NETosis and neutrophil extracellular traps (NETs) play a critical role in pathogenesis of coronavirus disease 2019 (COVID-19)-associated thrombosis. However, the extents and reserve of NETosis, and potential of thrombus formation under shear in whole blood of patients with COVID-19 are not fully elucidated. Neither has the role of recombinant ADAMTS13 or caplacizumab on the accumulation of NETs and thrombus in COVID-19 patients' whole blood under shear been investigated. Flow cytometry and microfluidic assay, as well as immunoassays, were employed for the study. We demonstrated that the percentage of H3Cit + MPO+ neutrophils, indicative of NETosis, was dramatically increased in patients with severe but not critical COVID-19 compared with that in asymptomatic or mild disease controls. Upon stimulation with poly [I:C], a double strain DNA mimicking viral infection, or bacterial shigatoxin-2, the percentage of H3Cit + MPO+ neutrophils was not significantly increased in the whole blood of severe and critical COVID-19 patients compared with that of asymptomatic controls, suggesting the reduction in NETosis reserve in these patients. Microfluidic assay demonstrated that the accumulation of NETs and thrombus was significantly enhanced in the whole blood of severe/critical COVID-19 patients compared with that of asymptomatic controls. Like DNase I, recombinant ADAMTS13 or caplacizumab dramatically reduced the NETs accumulation and thrombus formation under arterial shear. Significantly increased neutrophil NETosis, reduced NETosis reserve, and enhanced thrombus formation under arterial shear may play a crucial role in the pathogenesis of COVID-19-associated coagulopathy. Recombinant ADAMTS13 or caplacizumab may be explored for the treatment of COVID-19-associated thrombosis.

What is the actual relationship between neutrophil extracellular traps and COVID-19 severity? A longitudinal study

BackgroundNeutrophil extracellular traps (NETs) have repeatedly been related to COVID-19 severity and mortality. However, there is no consensus on their quantification, and there are scarce data on their evolution during the disease. We studied circulating NET markers in patients with COVID-19 throughout their hospitalization.MethodsWe prospectively included 93 patients (201 blood samples), evaluating the disease severity in 3 evolutionary phases (viral, early, and late inflammation). Of these, 72 had 180 samples in various phases. We also evaluated 55 controls with similar age, sex and comorbidities. We measured 4 NET markers in serum: cfDNA, CitH3, and MPO-DNA and NE-DNA complexes; as well as neutrophil-related cytokines IL-8 and G-CSF.ResultsThe COVID-19 group had higher CitH3 (28.29 vs 20.29 pg/mL, p = 0.022), and cfDNA, MPO-DNA, and NE-DNA (7.87 vs 2.56 ng/mL; 0.80 vs 0.52 and 1.04 vs 0.72, respectively, p < 0.001 for all) than the controls throughout hospitalisation. cfDNA was the only NET marker clearly related to severity, and it remained higher in non-survivors during the 3 phases. Only cfDNA was an independent risk factor for mortality and need for intensive care. Neutrophil count, IL-8, and G-CSF were significantly related to severity. MPO-DNA and NE-DNA showed significant correlations (r: 0.483, p < 0.001), including all 3 phases and across all severity grades, and they only remained significantly higher on days 10–16 of evolution in those who died. Correlations among the other NET markers were lower than expected.ConclusionsThe circulating biomarkers of NETs were present in patients with COVID-19 throughout hospitalization. cfDNA was associated with severity and mortality, but the three other markers showed little or no association with these outcomes. Neutrophil activity and neutrophil count were also associated with severity. MPO-DNA and NE-DNA better reflected NET formation. cfDNA appeared to be more associated with overall tissue damage; previous widespread use of this marker could have overestimated the relationship between NETs and severity. Currently, there are limitations to accurate NET markers measurement that make it difficult to assess its true role in COVID-19 pathogenesis.

Mitochondrial DNA variability and Covid-19 in the Slovak population

Recent studies have shown that mitochondria are involved in the pathogenesis of Covid-19. Mitochondria play a role in production of reactive oxygen species and induction of an innate immune response, both important during infections. Common variability of mitochondrial DNA (mtDNA) can affect oxidative phosphorylation and the risk or lethality of cardiovascular, neurodegenerative diseases and sepsis. However, it is unclear whether susceptibility of severe Covid-19 might be affected by mtDNA variation. Thus, we have analyzed mtDNA in a sample of 446 Slovak patients hospitalized due to Covid-19 and a control population group consisting of 1874 individuals. MtDNA variants in the HVRI region have been analyzed and classified into haplogroups at various phylogenetic levels. Binary logistic regression was used to assess the risk of Covid-19. Haplogroups T1, H11, K and variants 16256C > T, 16265A > C, 16293A > G, 16311 T > C and 16399A > G were associated with an increased Covid-19 risk. On contrary, Haplogroup J1, haplogroup clusters H + U5b and T2b + U5b, and the mtDNA variant 16189 T > C were associated with decreased risk of Covid-19. Following the application of the Bonferroni correction, statistical significance was observed exclusively for the cluster of haplogroups H + U5b. Unsurprisingly, the most significant factor contributing to the mortality of patients with Covid-19 is the age of patients. Our findings suggest that mtDNA haplogroups can play a role in Covid-19 pathogenesis, thus potentially useful in identifying susceptibility to its severe form. To confirm these associations, further studies taking into account the nuclear genome or other non-biological influences are needed.

Prognostic significance of serum miR-18a-5p in severe COVID-19 Egyptian patients

BackgroundThe identification of miRNAs as well as characterization of miRNA-mRNA interactions in SARS-CoV-2 infection is important to understand their role in disease pathogenesis. Therefore the aim of the present study was to measure the expression levels of hsa-mir-18a-5p in the sera of severe COVID-19 Egyptian patients admitted to ICU to investigate its roles in the pathogenesis and severity of COVID-19 disease. MethodsA total of 180 unvaccinated severe COVID-19 patients were enrolled in our study. Besides the routine laboratory work, the expression level of hsa-mir-18a-5p was done using reverse transcription quantitative real-time PCR (RTqPCR) technique. Also, target genes of hsa-mir-18a-5p were explored by using online bioinformatics databases. ResultsThe expression level of hsa-mir-18a-5p decreased in nonsurvival severe COVID-19 patients (0.38 ± 0.26) when compared to the survival ones (0.84 ± 0.23). While as a prognostic tool for the prediction of bad prognosis and mortality among severe COVID-19 patients, our results showed that the serum hsa-mir-18a-5p expression level is a good sensitive and specific marker. By using bioinformatics tools, our results revealed that the decreased hsa-mir-18a-5p expression level may have a crucial role in COVID-19 pathogenesis and severity through decreased immunological responses (interpreted as lymphopenia) or increased inflammation (interpreted as increased serum levels of IL-6, CRP, LDH). ConclusionTaken together, the decreased expression level of hsa-mir-18a-5p could be a bad prognostic marker and therapeutic overexpression of hsa-mir-18a-5p could be a novel approach in the treatment of COVID-19 disease.

Purinergic signaling: decoding its role in COVID-19 pathogenesis and promising treatment strategies.

The pathogenesis of coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2), is complex and involves dysregulated immune responses, inflammation, and coagulopathy. Purinergic signaling, mediated by extracellular nucleotides and nucleosides, has emerged as a significant player in the pathogenesis of COVID-19. Extracellular adenosine triphosphate (ATP), released from damaged or infected cells, is a danger signal triggering immune responses. It activates immune cells, releasing pro-inflammatory cytokines, contributing to the cytokine storm observed in severe COVID-19 cases. ATP also promotes platelet activation and thrombus formation, contributing to the hypercoagulability seen in COVID-19 patients. On the other hand, adenosine, an immunosuppressive nucleoside, can impair anti-viral immune responses and promote tissue damage through its anti-inflammatory effects. Modulating purinergic receptors represents a promising therapeutic strategy for COVID-19. Understanding the role of purinergic signaling in COVID-19 pathogenesis and developing targeted therapeutic approaches can potentially improve patient outcomes. This review focuses on the part of purinergic signaling in COVID-19 pathogenesis and highlights potential therapeutic approaches targeting purinergic receptors.

Omics data analysis reveals common molecular basis of small cell lung cancer and COVID-19

The impact of COVID-19 infection on individuals with small cell lung cancer (SCLC) poses a serious threat. Unfortunately, the molecular basis of this severe comorbidity has yet to be elucidated. The present study addresses this gap utilizing publicly available omics data of COVID-19 and SCLC to explore the key molecules and associated pathways involved in the convergence of these diseases. Findings revealed 402 genes, that exhibited differential expression patterns in SCLC patients and also play a pivotal role in COVID-19 pathogenesis. Subsequent functional enrichment analyses identified relevant ontologies and pathways that are significantly associated with these genes, revealing important insights into their potential biological, molecular and cellular functions. The protein-protein interaction network, constructed under four combinatorial topological assessments, highlighted SMAD3, CAV1, PIK3R1, and FN1 as the primary components to this comorbidity. Our results suggest that these components significantly regulate this cross-talk triggering the PI3K-AKT and TGF-β signaling pathways. Lastly, this study made a multi-step computational attempt and identified corylifol A and ginkgetin from natural sources that can potentially inhibit these components. Therefore, the outcomes of this study offer novel perspectives on the common molecular mechanisms underlying SCLC and COVID-19 and present future opportunities for drug development. Communicated by Ramaswamy H. Sarma

Analysis of SARS-CoV-2 isolates, namely the Wuhan strain, Delta variant, and Omicron variant, identifies differential immune profiles.

There is an urgent need to better understand the impact of different severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants on immune response and disease dynamics to facilitate better intervention strategies. Here, we show that SARS-CoV-2 variants differentially affect host immune responses. The magnitude and quantity of cytokines and chemokines were comparable in those infected with the Wuhan strain and the Delta variant. However, individuals infected with the Omicron variant had significantly lower levels of these mediators. We also found an elevation of plasma galectins (Gal-3, Gal-8, and Gal-9) in infected individuals, in particular, in those with the original strain. Soluble galectins exert a proinflammatory role in COVID-19 pathogenesis. This was illustrated by their correlation with the plasma levels of sCD14, sCD163, enhanced TNF-α/IL-6 secretion, and increased SARS-CoV-2 infectivity in vitro. Moreover, we observed enhanced CD4+ and CD8+ T cell activation in Wuhan strain-infected individuals. Surprisingly, there was a more pronounced T cell activation in those infected with the Omicron in comparison to the Delta variant. In line with T cell activation status, we observed a more pronounced expansion of T cells expressing different co-inhibitory receptors in patients infected with the Wuhan strain, followed by the Omicron and Delta variants. Individuals infected with the Wuhan strain or the Omicron variant had a similar pattern of plasma soluble immune checkpoints. Our results imply that a milder innate immune response might be beneficial and protective in those infected with the Omicron variant. Our results provide a novel insight into the differential impact of SARS-CoV-2 variants on host immunity. IMPORTANCE There is a need to better understand how different SARS-CoV-2 variants influence the immune system and disease dynamics to facilitate the development of better vaccines and therapies. We compared immune responses in 140 SARS-CoV-2-infected individuals with the Wuhan strain, the Delta variant, or the Omicron variant. All these patients were admitted to the intensive care unit and were SARS-CoV-2 vaccination naïve. We found that SARS-CoV-2 variants differentially affect the host immune response. This was done by measuring soluble biomarkers in their plasma and examining different immune cells. Overall, we found that the magnitude of cytokine storm in individuals infected with the Wuhan strain or the Delta variant was greater than in those infected with the Omicron variant. In light of enhanced cytokine release syndrome in individuals infected with the Wuhan strain or the Delta variant, we believe that a milder innate immune response might be beneficial and protective in those infected with the Omicron variant.

Lipid Mediators and Cytokines/Chemokines Display Differential Profiles in Severe versus Mild/Moderate COVID-19 Patients.

Host immune responses play a key role in COVID-19 pathogenesis. The underlying phenomena are orchestrated by signaling molecules such as cytokines/chemokines and lipid mediators. These immune molecules, including anti-SARS-CoV-2 antibodies, interact with immune cells and regulate host responses, contributing to inflammation that drives the disease. We investigated 48 plasma cytokines/chemokines, 21 lipid mediators, and anti-S protein (RBD) antibodies in COVID-19 patients (n = 56) and non-COVID-19 respiratory disease controls (n = 49), to identify immune-biomarker profiles. Cytokines/chemokines (IL-6, CXCL-10 (IP-10), HGF, MIG, MCP-1, and G-CSF) and lipid mediators (TxB2, 11-HETE, 9-HODE, 13-HODE, 5-HETE, 12-HETE, 15-HETE, 14S-HDHA, 17S-HDHA, and 5-oxo ETE) were significantly elevated in COVID-19 patients compared to controls. In patients exhibiting severe disease, pro-inflammatory cytokines/chemokines (IL-6, CXCL-10, and HGF) and anti-SARS-CoV-2 antibodies were significantly elevated. In contrast, lipid mediators involved in the reduction/resolution of inflammation, in particular, 5-HETE, 11-HETE, and 5-oxoETE, were significantly elevated in mild/moderate disease. Taken together, these immune-biomarker profiles provide insight into immune responses related to COVID-19 pathogenesis. Importantly, our findings suggest that elevation in plasma concentrations of IL-6, CXCL-10, HGF, and anti-SARS-CoV-2 antibodies can predict severe disease, whereas elevation in lipid mediators peaks early (compared to cytokines) and includes induction of mechanisms leading to reduction of inflammation, associated complications, and maintenance of homeostasis.

Tissue plasminogen activator receptor ANXA2 and its complementary regulator anti-inflammatory ANXA1 as prognostic indicators of inflammatory response in COVID-19 pathogenesis

COVID-19 patients demonstrating hyperactive immunologic response appear to have a severe illness with a poor prognosis. This study hypothesizes that the pro-inflammatory Annexin A2 (ANXA2) has role in COVID-19 pathogenesis. In thisobservational study, serum levels of ANXA2 along with interleukin 1 beta (IL1β), IL6, tumour necrosis factor-alpha (TNFα), and anti-inflammatory ANXA1 were determined by sandwich ELISA in 20 each control, mild, moderate, and severe COVID-19 subjects.The ANXA2 levels (130 ng/mL, p < 0.001) were significantly elevated in severe COVID-19 subjects, compared to mild, moderate and controls. Similarly, all the other pro-inflammatory biomarkers levels were also significantly correlated with disease severity (p < 0.0001). However, ANXA1 showed significantly negative correlation with disease severity (p < 0.0001). Furthermore, the pro-inflammatory ANXA2 showed utility in mortality prediction with 86% sensitivity and specificity, and 57% positive predictive value at a serum threshold of 94 ng/mL. Overall,ANXA2 and ANXA1 along with IL1β, IL6, TNFα, would be beneficial biomarkers in assessing the COVID-19 severity and mortality prediction.

Complement lectin pathway activation is associated with COVID-19 disease severity, independent of MBL2 genotype subgroups.

While complement is a contributor to disease severity in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, all three complement pathways might be activated by the virus. Lectin pathway activation occurs through different pattern recognition molecules, including mannan binding lectin (MBL), a protein shown to interact with SARS-CoV-2 proteins. However, the exact role of lectin pathway activation and its key pattern recognition molecule MBL in COVID-19 is still not fully understood. We therefore investigated activation of the lectin pathway in two independent cohorts of SARS-CoV-2 infected patients, while also analysing MBL protein levels and potential effects of the six major single nucleotide polymorphisms (SNPs) found in the MBL2 gene on COVID-19 severity and outcome. We show that the lectin pathway is activated in acute COVID-19, indicated by the correlation between complement activation product levels of the MASP-1/C1-INH complex (p=0.0011) and C4d (p<0.0001) and COVID-19 severity. Despite this, genetic variations in MBL2 are not associated with susceptibility to SARS-CoV-2 infection or disease outcomes such as mortality and the development of Long COVID. In conclusion, activation of the MBL-LP only plays a minor role in COVID-19 pathogenesis, since no clinically meaningful, consistent associations with disease outcomes were noted.

Immune and ionic mechanisms mediating the effect of dexamethasone in severe COVID-19.

Severe COVID-19 is characterized by cytokine storm, an excessive production of proinflammatory cytokines that contributes to acute lung damage and death. Dexamethasone is routinely used to treat severe COVID-19 and has been shown to reduce patient mortality. However, the mechanisms underlying the beneficial effects of dexamethasone are poorly understood. We conducted transcriptomic analysis of peripheral blood mononuclear cells (PBMCs) from COVID-19 patients with mild disease, and patients with severe COVID-19 with and without dexamethasone treatment. We then treated healthy donor PBMCs in vitro with dexamethasone and investigated the effects of dexamethasone treatment ion channel abundance (by RT-qPCR and flow cytometry) and function (by electrophysiology, Ca2+ influx measurements and cytokine release) in T cells. We observed that dexamethasone treatment in severe COVID-19 inhibited pro-inflammatory and immune exhaustion pathways, circulating cytotoxic and Th1 cells, interferon (IFN) signaling, genes involved in cytokine storm, and Ca2+ signaling. Ca2+ influx is regulated by Kv1.3 potassium channels, but their role in COVID-19 pathogenesis remains elusive. Kv1.3 mRNA was increased in PBMCs of severe COVID-19 patients, and was significantly reduced in the dexamethasone-treated group. In agreement with these findings, in vitro treatment of healthy donor PBMCs with dexamethasone reduced Kv1.3 abundance in T cells and CD56dimNK cells. Furthermore, functional studies showed that dexamethasone treatment significantly reduced Kv1.3 activity, Ca2+ influx and IFN-g production in T cells. Our findings suggest that dexamethasone attenuates inflammatory cytokine release via Kv1.3 suppression, and this mechanism contributes to dexamethasone-mediated immunosuppression in severe COVID-19.

Human Endogenous Retrovirus (HERV) Transcriptome Is Dynamically Modulated during SARS-CoV-2 Infection and Allows Discrimination of COVID-19 Clinical Stages.

SARS-CoV-2 infection is known to trigger an important inflammatory response, which has a major role in COVID-19 pathogenesis. In infectious and inflammatory contexts, the modulation of human endogenous retroviruses (HERV) has been broadly reported, being able to further sustain innate immune responses due to the expression of immunogenic viral transcripts, including double-stranded DNA (dsRNA), and eventually, immunogenic proteins. To gain insights on this poorly characterized interplay, we performed a high-throughput expression analysis of ~3,300 specific HERV loci in the peripheral blood mononuclear cells (PBMCs) of 10 healthy controls and 16 individuals being either convalescent after the infection (6) or retesting positive after convalescence (10) (Gene Expression Onmibus [GEO] data set GSE166253). Results showed that the exposure to SARS-CoV-2 infection modulates HERV expression according to the disease stage and reflecting COVID-19 immune signatures. The differential expression analysis between healthy control (HC) and COVID-19 patients allowed us to identify a total of 282 differentially expressed HERV loci (deHERV) in the individuals exposed to SARS-CoV-2 infection, independently from the clinical form. In addition, 278 and 60 deHERV loci that were specifically modulated in individuals convalescent after COVID19 infection (C) and patients that retested positive to SARS-CoV-2 after convalescence (RTP) as individually compared to HC, respectively, as well as 164 deHERV loci between C and RTP patients were identified. The identified HERV loci belonged to 36 different HERV groups, including members of all three classes. The present study provides an exhaustive picture of the HERV transcriptome in PBMCs and its dynamic variation in the presence of COVID-19, revealing specific modulation patterns according to the infection stage that can be relevant to the disease clinical manifestation and outcome. IMPORTANCE We report here the first high-throughput analysis of HERV loci expression along SARS-CoV-2 infection, as performed with peripheral blood mononuclear cells (PBMCs). Such cells are not directly infected by the virus but have a crucial role in the plethora of inflammatory and immune events that constitute a major hallmark of COVID-19 pathogenesis. Results provide a novel and exhaustive picture of HERV expression in PBMCs, revealing specific modulation patterns according to the disease condition and the concomitant immune activation. To our knowledge, this is the first set of deHERVs whose expression is dynamically modulated across COVID-19 stages, confirming a tight interplay between HERV and cellular immunity and revealing specific transcriptional signatures that can have an impact on the disease clinical manifestation and outcome.

Sars-Cov-2-Specific CD4+ and CD8+ T Cell Responses Can Originate from Cross-Reactive CMV-Specific T Cells

Introduction: SARS-CoV-2-specific CD4+ and CD8+ T cells play an important role in COVID-19 pathogenesis. In addition to de novo SARS-CoV-2-specific T cell responses in infected individuals, SARS-CoV-2-specific T cells have also been identified in samples frozen down before the pandemic. So far, pre-existing SARS-CoV-2 specific T cell responses has mostly been ascribed to cross-reactive T cells that were initially primed by other coronaviruses. The presence of these cross-reactive T cells is not surprising considering these human coronaviruses share a relatively high sequence homology. However, T cells are also able to cross-react towards dissimilar pathogens, called heterologous immunity. Given the high prevalence and magnitudes of pre-pandemic SARS-CoV-2-specific T cells, we hypothesized that pre-pandemic SARS-CoV-2 T cell immunity could be explained by cross-reactive cytomegalovirus (CMV)-specific T cells. Methods & Results: PBMCs from CMV seropositive and seronegative donors that were cryopreserved before the pandemic were incubated with SARS-CoV-2 peptide pools. To detect SARS-CoV-2-specific T cells using flow cytometry, CD4+ T cell responses were identified by upregulation of CD154 and CD137 whereas CD8+ T cell responses were identified by upregulation of CD137 and IFN-γ production. In the CMV seropositive group, clear CD4+ T cell responses against SARS-CoV-2 membrane and CD8+ T cell responses against SARS-CoV-2 spike were detected whilst this was not observed in CMV seronegative donors. To investigate whether these T cells were reactive against both SARS-CoV-2 and CMV, the SARS-CoV-2 reactive T cells were single cell sorted, clonally expanded, and tested in co-culture assays in which stimulator cells expressing the relevant human leukocyte antigen (HLA) alleles were pulsed with overlapping peptide pools, peptide libraries or single peptides. The results demonstrated that the pre-pandemic SARS-CoV-2 membrane-specific CD4+ T cells recognized both SARS-CoV-2 membrane and CMV-pp65 peptide pools in HLA-DRB3*02:02, and specifically recognized AGILRNLVPM peptide of CMV-pp65. The pre-pandemic SARS-CoV-2 spike-specific CD8+ T cells recognized spike peptide FVSNGTHWF (FVS) and, interestingly, dissimilar CMV-pp65 peptide IPSINVHHY (IPS) both presented by HLA-B*35:01. Importantly, these FVS/IPS-cross-reactive T cells displayed a higher avidity for CMV compared to SARS-CoV-2, which illustrates that these cells were originally primed against CMV since repeated antigen exposure results in a selection for high avidity T cell clonotypes. This selection cannot have occurred in response to SARS-CoV-2-specific peptides in SARS-CoV-2-unexposed individuals. PBMCs from pre-pandemic CMV-seropositive donors that express HLA-B*35:01 were screened for the presence of these dual IPS/FVS-specific CD8+ T cells by peptide-HLA tetramer technology. In multiple donors these cross-reactive T cells were detected, and isolation followed by direct T cell receptor (TCR) sequencing of the IPS/FVS-tetramer positive cells showed that these T cells express an amino acid-identical TCR, illustrating that this SARS-CoV-2/CMV cross-reactivity of the IPS/FVS T cells is caused by a public TCR. To investigate the potential of the IPS/FVS-specific T cells to kill virus-infected cells, and thereby reducing spreading of SARS-CoV-2, the T cells were incubated with SARS-CoV-2-infected airway epithelial Calu-3 cells. Intracellular SARS-CoV-2 RNA was reduced at low virus titers in IPS/FVS-specific T cell co-cultures, indicating that the cross-reactive T cells are killing SARS-CoV-2-infected cells and thereby reduce spreading of SARS-CoV-2 during initial infection. Circulating IPS/FVS-specific T cells were not phenotypically activated in two patients with advanced COVID-19, as measured by flow cytometry analysis of CD38 and HLA-DR expression, indicating that cross-reactive T cells may more likely play a role during early stage of infection. Conclusion: CMV-specific T cells cross-react with SARS-CoV-2, despite low sequence homology between the two viruses, and may contribute to the pre-pandemic immunity against SARS-CoV-2. Pre-print link: https://www.biorxiv.org/content/10.1101/2022.07.31.502203v1

Correlation between D-dimer and HRCT in Covid-19

Background: To retrospectively determine the correlation between CT severity score &amp; D-dimer. Methodology: This is a retrospective original research of 227 patients (IPD &amp; OPD) during April 1 to May 31, 2021 for Covid-19. Patients CT severity scores, HRCT Thorax findings, D-dimer, Platelet count and Demographic variables were recorded. The correlation between CT severity score &amp; D-dimer were determined. Results: Between the mentioned dates, 227 patients are taken into study which includes 146 Males &amp; 81 Females. Mean of CT severity score was 6.7, D-dimer was 0.46mg/l. Higher CT score is seen in males (mean -7.1) as compare to females (mean -6.12).D-dimer are seen higher in males (mean =0.52mg/l) as compare to females (median=0.37mg/l). The study of 227 patients has shown positive correlation between CT score &amp; D-dimer (r=0.38, p&lt;0.05). Males showed relatively stronger positive correlation(r=0.4, p&lt;0 .05) than females(r=0.3, p&lt;0.05).Patients with age less than equal to 45 has shown relatively stronger positive correlation between CT score &amp; D-dimer (r=0.4, p&lt;0.05) than patients with age more than 45 (r=0.35, p&lt;0.05). Conclusion: Pulmonary lesion induced by SARS-CoV-2 infection was associated with raised inflammatory response, impairment in exchange of gases, and end organ damage. In study, we can conclude that lung lesion may exert important role in COVID-19 pathogenesis &amp; clinical presentation.

Coronavirus infection and psoriasis: relationship and consequences

As numerous scientific data show, despite the fact that patients with severe psoriasis have a high risk of coronavirus infection, COVID-19 in this group proceeds quite easily. However, many specialists have encountered an unusual exacerbation of the psoriatic process already after the infection, the reasons for which may be several. On the one hand, the skin is one of the target organs for SARS-CoV-2, on the other hand, exacerbations may be caused by the immune system response to the infection. The influence of specific therapy on the course of the psoriatic process is also not excluded. But interleukin status of patients with psoriasis is of the greatest interest. It is known that interleukin-6 (IL-6) plays an active role in pathogenesis of COVID-19 and cytokine storm arising at infection. It is also regarded as an indicator of inflammatory activity in psoriasis. In addition, IL-6 is involved in lipid and hepatobiliary disorders in this group of patients. It is also associated with IL-17, the role of which has been well studied in psoriasis and autoimmune hepatitis. Patients with psoriasis often have changes in biochemical blood parameters, similar to those seen with COVID-19. Combinations of all these factors can lead to exacerbation of psoriasis with predominance of erythroderma and toxic component. In our opinion, in such cases it is necessary to include in the therapy a systemic hepatoprotective drug containing glycyrrhizic acid. It has a pronounced anti-inflammatory effect, inhibits IL-6 production and allows to achieve significant improvement of psoriatic process in a short time.

LipoxinA4 as a Potential Prognostic Marker of COVID-19.

This pilot study aimed to determine early changes of LXA4 levels among the hospitalized patients confirmed as COVID-19 cases following the clinical management and its correlation with commonly used inflammatory markers, including erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), and ferritin. Thirty-one adult hospitalized patients infected with the non-severe COVID-19 were included. LXA4 levels were measured at the baseline and 48-72 hours after hospitalization. Accordingly, ESR and CRP levels were collected on the first day of hospitalization. Moreover, the maximum serum ferritin levels were determined during the five days. LXA4 levels significantly increased at 48-72 hours compared to the baseline. ESR, CRP, and ferritin levels were positively correlated with the increased LXA4. In contrast, aging was shown to negatively correlate with the increased LXA4 levels. LXA4 may be known as a valuable marker to assess the treatment response among non-elderly patients with non-severe COVID-19. Furthermore, LXA4 could be considered as a potential treatment option under inflammatory conditions. Further studies are necessary to clarify LXA4 role in COVID-19 pathogenesis, as well as the balance between such pro-resolving mediators and inflammatory parameters.

State of the Art Nanotechnology to Combat Current COVID-19 Outbreak

COVID-19 has lately emerged as the most severe pandemics of the 20 century, with lethal consequences and ahigher rate of propagation. More than 6.3 million individuals have died around the world as of this writing (June 10, 2022), while around 11.9 billion people have been vaccinated worldwide by June 06, 2022.1 Since noeffective drug against COVID-19 has been approved to date, it highlights the crucial need for developing newertherapeutic targets, vaccines, and antibodies to eliminate COVID-19 viral load and associated side effects.2Though, delivering these agents in a tailored manner that avoids off-targeting and excessive drug absorption isextremely difficult. It is commonly known that nanotechnology-based drug delivery systems improveconventional therapies, up till now, their application in viral infections remains underdeveloped andunderutilized, as seen by the COVID-19 epidemic.3 Nanotechnology enhances the pharmacological propertiesof drug by allowing the use of nano-systems such as organic (micelles, liposomes, polymers) and inorganic(metallic, quantum dots, carbon nano-tubes) nanoparticles for encapsulation. Nanotechnology has the highpotential to combat against COVID-19 in a number of ways, for instance, prevention of viral contamination byspraying and developing personal protective equipment (PPE), as well as developing appropriate antiviraldisinfectants.4 Numerous nanocarriers have been used for drug delivery to address issues such as inadequatesolubility, permeability, and target ability, all of which contribute to drug molecules failing to exert the desiredtherapeutic impact.5 To identify COVID-19 infection or immune response, various nanomaterials can beemployed as extremely accurate and sensitive nano-based biosensors.6 A nanotechnology research group atUniversity of Georgia developed a rapid test based on optical sensors designed for COVID-19 detection inAugust 2020. In March 2022, they filed a patent application on rapid COVID-19 detection, using an optical nanosensor, developed based on human angiotensin-converting enzyme 2 protein (ACE2) functionalized silvernanotriangle arrays.7 Nanomedicine possess several characteristics that can be used to accurately transporttherapeutic agents to the target cells, and the specific ligand conjugated nanoparticle connects with epitopes ofthe virus, causing the virus to be inactivated and unable to enter the cells. As a result, nanomedicine-basedtechniques that target COVID-19 binding, entry, replication, and budding can be used to neutralize theinfection.8 A number of products based on nanotechnology, like nano-silver is on the market currently due totheir ability to combat viruses. Remdesivir is one of nanomedicine's greatest accomplishments in themanagement of COVID-19 infection. Furthermore, plasmonic nanoparticles (silver, gold and their hybridnanostructures) have anti-infective properties against COVID-19 and have been useful in the development ofdiagnostic assays. For this reason, nanomedicine has shown to be critical in combating the COVID-19 epidemic.5Several nanocarriers have been explored in designing and delivering vaccines such as lipid nanoparticles beable to deliver mRNA into the cytoplasm which directly translate in to the target protein.9 In 2020, UK regulatorsapproved the COVID-19 mRNA encapsulated lipid nanoparticles based vaccine created by Pfizer and BioNTechfor emergency use, followed by authorization of Moderna's vaccine.10 Recently, both of these nanoparticlebased vaccines have been fully approved by the FDA.11 The licensing of the COVID-19 mRNA vaccines wasunquestionably a huge milestone in nanotechnology. Currently ten innovative technologies based on lipidnanoparticles are in clinical pipelines for COVID-19 vaccines.11In conclusion, nanoparticles may play a vital role in COVID-19 pathogenesis at several phases during viral entry.Nano-encapsulated drugs may also be more effective at triggering intracellular pathways that produceirreversible virus damage and limit viral transcription, translation, and reproduction.Going forward, nanoparticle-based vaccines will play mounting role in enhancing vaccination outcomes againstCOVID-19. Scholars may use state-of-the-art nanomedicine as a platform to examine their involvement inmanaging the COVID-19 pandemic with greater efficacy.How to cite this: Awan UA, Saeed RF, Naeem M, Mumtaz S, Qazi AS. State of the Art Nanotechnology to Combat Current COVID-19 Outbreak. Life and Science. 2022; 3(3): 141-142.doi: http://doi.org/10.37185/LnS.1.1.229&#x0D;