The shed P2X7 receptor is an index of adverse clinical outcome in COVID-19 patients.

Introduction: The pathophysiology of the Corona Virus Disease 2019 (COVID-19) is incompletely known. A robust inflammatory response caused by viral replication is a main cause of the acute lung and multiorgan injury observed in critical patients. Inflammasomes are likely players in COVID-19 pathogenesis. The P2X7 receptor (P2X7R), a plasma membrane ATP-gated ion channel, is a main activator of the NLRP3 inflammasome, of the ensuing release of inflammatory cytokines and of cell death by pyroptosis. The P2X7R has been implicated in COVID-19-dependent hyperinflammation and in the associated multiorgan damage. Shed P2X7R (sP2X7R) and shed NLRP3 (sNLRP3) have been detected in plasma and other body fluids, especially during infection and inflammation. Methods: Blood samples from 96 patients with confirmed SARS-CoV-2 infection with various degrees of disease severity were tested at the time of diagnosis at hospital admission. Standard haematological parameters and IL-6, IL-10, IL-1ß, sP2X7R and sNLRP3 levels were measured, compared to reference values, statistically validated, and correlated to clinical outcome. Results: Most COVID-19 patients included in this study had lymphopenia, eosinopenia, neutrophilia, increased inflammatory and coagulation indexes, and augmented sNLRP3, IL-6 and IL-10 levels. Blood concentration of sP2X7R was also increased, and significantly positively correlated with lymphopenia, procalcitonin (PCT), IL-10, and alanine transaminase (ALT). Patients with increased sP2X7R levels at diagnosis also showed fever and respiratory symptoms, were more often transferred to Pneumology division, required mechanical ventilation, and had a higher likelihood to die during hospitalization. Conclusion: Blood sP2X7R was elevated in the early phases of COVID-19 and predicted an adverse clinical outcome. It is suggested that sP2X7R might be a useful marker of disease progression.

The specialized pro-resolving lipid mediator Protectin D1 affects macrophages differentiation and activity in Adult-onset Still's disease and COVID-19, two hyperinflammatory diseases sharing similar transcriptomic profiles.

Introduction: COVID-19 and autoinflammatory diseases, such as Adult-onset Still's Disease (AOSD), are characterized by hyperinflammation, in which it is observed massive production and uncontrolled secretion of pro-inflammatory cytokines. The specialized pro-resolving lipid mediators (SPMs) family is one the most important processes counteracting hyperinflammation inducing tissue repair and homeostasis restoration. Among SPMs, Protectin D1 (PD1) is able to exert antiviral features, at least in animal models. The aim of this study was to compare the transcriptome of peripheral blood mononuclear cells (PBMCs) from patients with AOSD and COVID-19 and to evaluate the role of PD1 on those diseases, especially in modulating macrophages polarization. Methods: This study enrolled patients with AOSD, COVID-19, and healthy donors HDs, undergoing clinical assessment and blood sample collection. Next-generation deep sequencing was performed to identify differences in PBMCs transcripts profiles. Plasma levels of PD1 were assessed by commercial ELISA kits. Monocyte-derived macrophages were polarized into M1 and M2 phenotypes. We analyzed the effect of PD1 on macrophages differentiation. At 10 days, macrophages were analyzed for surface expression of subtypes markers by flow cytometry. Cytokines production was measured in supernatants by Bio-Plex Assays. Results: In the transcriptomes from AOSD patients and COVID-19 patients, genes involved in inflammation, lipid catabolism, and monocytes activation were specifically dysregulated in AOSD and COVID-19 patients when compared to HDs. Patients affected by COVID-19, hospitalized in intensive care unit (ICU), showed higher levels of PD1 when compared to not-ICU hospitalized patients and HDs (ICU COVID-19 vs not-ICU COVID-19, p= 0.02; HDs vs ICU COVID-19, p= 0.0006). PD1 levels were increased in AOSD patients with SS ≥1 compared to patients with SS=0 (p=0.028) and HDs (p=0.048). In vitro treatment with PD1 of monocytes-derived macrophages from AOSD and COVID-19 patients induced a significant increase of M2 polarization vs control (p<0.05). Furthermore, a significant release of IL-10 and MIP-1ß from M2 macrophages was observed when compared to controls (p<0.05). Discussion: PD1 is able to induce pro-resolutory programs in both AOSD and COVID-19 increasing M2 polarization and inducing their activity. In particular, PD1-treated M2 macrophages from AOSD and COVID-19 patients increased the production of IL-10 and enhanced homeostatic restoration through MIP-1ß production.

IL-10 Promotes CXCL13 Expression in Macrophages Following Foot-and-Mouth Disease Virus Infection.

Foot-and-mouth disease (FMD) is one of the most contagious livestock diseases in the world, posing a constant global threat to the animal trade and national economies. The chemokine C-X-C motif chemokine ligand 13 (CXCL13), a biomarker for predicting disease progression in some diseases, was recently found to be increased in sera from mice infected with FMD virus (FMDV) and to be associated with the progression and severity of the disease. However, it has not yet been determined which cells are involved in producing CXCL13 and the signaling pathways controlling CXCL13 expression in these cells. In this study, the expression of CXCL13 was found in macrophages and T cells from mice infected with FMDV, and CXCL13 was produced in bone-marrow-derived macrophages (BMDMs) by activating the nuclear factor-kappaB (NF-κB) and JAK/STAT pathways following FMDV infection. Interestingly, CXCL13 concentration was decreased in sera from interleukin-10 knock out (IL-10-/-) mice or mice blocked IL-10/IL-10R signaling in vivo after FMDV infection. Furthermore, CXCL13 was also decreased in IL-10-/- BMDMs and BMDMs treated with anti-IL-10R antibody following FMDV infection in vitro. Lastly, it was demonstrated that IL-10 regulated CXCL13 expression via JAK/STAT rather than the NF-κB pathway. In conclusion, the study demonstrated for the first time that macrophages and T cells were the cellular sources of CXCL13 in mice infected with FMDV; CXCL13 was produced in BMDMs via NF-κB and JAK/STAT pathways; and IL-10 promoted CXCL13 expression in BMDMs via the JAK/STAT pathway.

Cytokine Profiling in Different SARS-CoV-2 Genetic Variants.

This study is a successor of our previous work concerning changes in the chemokine profile in infection that are associated with different SARS-CoV-2 genetic variants. The goal of our study was to take into account both the virus and the host immune system by assessing concentrations of cytokines in patients infected with different SARS-CoV-2 variants (ancestral Wuhan strain, Alpha, Delta and Omicron). Our study was performed on 340 biological samples taken from COVID-19 patients and healthy donors in the timespan between May 2020 and April 2022. We performed genotyping of the virus in nasopharyngeal swabs, which was followed by assessment of cytokines' concentration in blood plasma. We noted that out of nearly 30 cytokines, only four showed stable elevation independently of the variant (IL-6, IL-10, IL-18 and IL-27), and we believe them to be 'constant' markers for COVID-19 infection. Cytokines that were studied as potential biomarkers lose their diagnostic value as the virus evolves, and the specter of potential targets for predictive models is narrowing. So far, only four cytokines (IL-6, IL-10, IL-18, and IL-27) showed a consistent rise in concentrations independently of the genetic variant of the virus. Although we believe our findings to be of scientific interest, we still consider them inconclusive; further investigation and comparison of immune responses to different variants of SARS-CoV-2 is required.

Peripheral HLA-G/ILT-2 immune checkpoint axis in acute and convalescent COVID-19 patients.

The immunosuppressive non-classical human leukocyte antigen-G (HLA-G) can elicits pro-viral activities by down-modulating immune responses. We analysed soluble forms of HLA-G, IL-6 and IL-10 as well as on immune effector cell expression of HLA-G and its cognate ILT-2 receptor in peripheral blood obtained from hospitalised and convalescent COVID-19 patients. Compared with convalescents (N = 202), circulating soluble HLA-G levels (total and vesicular-bound molecules) were significantly increased in hospitalised patients (N = 93) irrespective of the disease severity. During COVID-19, IL-6 and IL-10 levels were also elevated. Regarding the immune checkpoint expression of HLA-G/ILT-2 on peripheral immune effector cells, the frequencies of membrane-bound HLA-G on CD3+ and CD14+ cells were almost identical in patients during and post COVID-19, while the frequency of ILT-2 receptor on CD3+ and CD14+ cells was increased during acute infection. A multi-parametric correlation analysis of soluble HLA-G forms with IL-6, IL-10, activation markers CD25 and CD154, HLA-G, and ILT-2 expression on immune cells revealed a strong positive correlation of soluble HLA-G forms with membrane-bound HLA-G molecules on CD3+/CD14+ cells only in convalescents. During COVID-19, only vesicular-bound HLA-G were positively correlated with the activation marker CD25 on T cells. Thus, our data suggest that the elevated levels of soluble HLA-G in COVID-19 are due to increased expression in organ tissues other than circulating immune effector cells. The concomitant increased expression of soluble HLA-G and ILT-2 receptor frequencies supports the concept that the immune checkpoint HLA-G/ILT-2 plays a role in the immune-pathogenesis of COVID-19.

Differential regulatory T cell signature after recovery from mild COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is characterized by a range of symptoms in which host immune response have been associated with disease progression. However, the putative role of regulatory T cells (Tregs) in determining COVID-19 outcomes has not been thoroughly investigated. Here, we compared peripheral Tregs between volunteers not previously infected with SARS-CoV-2 (healthy control [HC]) and volunteers who recovered from mild (Mild Recovered) and severe (Severe Recovered) COVID-19. Peripheral blood mononuclear cells (PBMC) were stimulated with SARS-CoV-2 synthetic peptides (Pool Spike CoV-2 and Pool CoV-2) or staphylococcal enterotoxin B (SEB). Results of a multicolor flow cytometric assay showed higher Treg frequency and expression of IL-10, IL-17, perforin, granzyme B, PD-1, and CD39/CD73 co-expression in Treg among the PBMC from the Mild Recovered group than in the Severe Recovered or HC groups for certain SARS-CoV-2 related stimulus. Moreover, Mild Recovered unstimulated samples presented a higher Tregs frequency and expression of IL-10 and granzyme B than did that of HC. Compared with Pool CoV-2 stimuli, Pool Spike CoV-2 reduced IL-10 expression and improved PD-1 expression in Tregs from volunteers in the Mild Recovered group. Interestingly, Pool Spike CoV-2 elicited a decrease in Treg IL-17+ frequency in the Severe Recovered group. In HC, the expression of latency-associated peptide (LAP) and cytotoxic granule co-expression by Tregs was higher in Pool CoV-2 stimulated samples. While Pool Spike CoV-2 stimulation reduced the frequency of IL-10+ and CTLA-4+ Tregs in PBMC from volunteers in the Mild Recovered group who had not experienced certain symptoms, higher levels of perforin and perforin+granzyme B+ co-expression by Tregs were found in the Mild Recovered group in volunteers who had experienced dyspnea. Finally, we found differential expression of CD39 and CD73 among volunteers in the Mild Recovered group between those who had and had not experienced musculoskeletal pain. Collectively, our study suggests that changes in the immunosuppressive repertoire of Tregs can influence the development of a distinct COVID-19 clinical profile, revealing that a possible modulation of Tregs exists among volunteers of the Mild Recovered group between those who did and did not develop certain symptoms, leading to mild disease.

Oxidant- induced preconditioning: A pharmacologic approach for triggering renal 'self defense'.

Acute kidney injury (AKI) is a common event, occurring in ~5% and ~35% of hospitalized and ICU patients, respectively. The development of AKI portends an increased risk of morbidity, mortality, prolonged hospitalization, and subsequent development of chronic kidney disease (CKD). Given these facts, a multitude of experimental studies have addressed potential methods for inducing AKI prevention in high-risk patients. However, successful clinical translation of promising experimental data has remained elusive. Over the past decade, our laboratory has focused on developing a method for safely triggering AKI protection by inducing "kidney preconditioning" in mice by the intravenous administration of a combination of Fe sucrose (FeS) + tin protoporphyrin (SnPP). These agents induce mild, but short lived, 'oxidant stress' which synergistically activate a number of kidney 'self-defense' pathways (e.g., Nrf2, ferritin, IL-10). Within 18-24 h of Fe/SnPP administration, marked protection against diverse forms of experimental toxic and ischemic AKI results. FeS/SnPP-mediated reductions in kidney injury can also indirectly decrease injury in other organs by mitigating the so called "organ cross talk" phenomenon. Given these promising experimental data, three phase 1b clinical trials were undertaken in healthy subjects and patients with stage 3 or 4 CKD. These studies demonstrated that FeS/SnPP were well tolerated and that they up-regulated the cytoprotective Nrf2, ferritin, and IL-10 pathways. Two subsequent phase 2 trials, conducted in patients undergoing 'on-pump' cardiovascular surgery or in patients hospitalized with COVID 19, confirmed FeS/SnPP safety. Furthermore, interim data analyses revealed statistically significant improvements in several clinical parameters. The goals of this review are to: (i) briefly discuss the historical background of renal "preconditioning"; (ii) present the experimental data that support the concept of FeS/SnPP- induced organ protection; and (iii) discuss the initial results of clinical trials that suggest the potential clinical utility of an 'oxidant preconditioning' strategy.

In Vitro Characterization of a Tissue Renin-Angiotensin System in Human Nucleus Pulposus Cells.

Low back pain is a clinically highly relevant musculoskeletal burden and is associated with inflammatory as well as degenerative processes of the intervertebral disc. However, the pathophysiology and cellular pathways contributing to this devastating condition are still poorly understood. Based on previous evidence, we hypothesize that tissue renin-angiotensin system (tRAS) components, including the SARS-CoV-2 entry receptor angiotensin-converting enzyme 2 (ACE2), are present in human nucleus pulposus (NP) cells and associated with inflammatory and degenerative processes. Experiments were performed with NP cells from four human donors. The existence of angiotensin II, angiotensin II type 1 receptor (AGTR1), AGTR2, MAS-receptor (MasR), and ACE2 in human NP cells was validated with immunofluorescent staining and gene expression analysis. Hereafter, the cell viability was assessed after adding agonists and antagonists of the target receptors as well as angiotensin II in different concentrations for up to 48 h of exposure. A TNF-α-induced inflammatory in vitro model was employed to assess the impact of angiotensin II addition and the stimulation or inhibition of the tRAS receptors on inflammation, tissue remodeling, expression of tRAS markers, and the release of nitric oxide (NO) into the medium. Furthermore, protein levels of IL-6, IL-8, IL-10, and intracellular as well as secreted angiotensin II were assessed after exposing the cells to the substances, and inducible nitric oxide synthase (iNOS) levels were evaluated by utilizing Western blot. The existence of tRAS receptors and angiotensin II were validated in human NP cells. The addition of angiotensin II only showed a mild impact on gene expression markers. However, there was a significant increase in NO secreted by the cells. The gene expression ratios of pro-inflammatory/anti-inflammatory cytokines IL-6/IL-10, IL-8/IL-10, and TNF-α/IL-10 were positively correlated with the AGTR1/AGTR2 and AGTR1/MAS1 ratios, respectively. The stimulation of the AGTR2 MAS-receptor and the inhibition of the AGTR1 receptor revealed beneficial effects on the gene expression of inflammatory and tissue remodeling markers. This finding was also present at the protein level. The current data showed that tRAS components are expressed in human NP cells and are associated with inflammatory and degenerative processes. Further characterization of the associated pathways is warranted. The findings indicate that tRAS modulation might be a novel therapeutic approach to intervertebral disc disease.

Diversified Effects of COVID-19 as a Consequence of the Differential Metabolism of Phospholipids and Lipid Peroxidation Evaluated in the Plasma of Survivors and Deceased Patients upon Admission to the Hospital.

As a result of SARS-CoV-2 infection, inflammation develops, which promotes oxidative stress, leading to modification of phospholipid metabolism. Therefore, the aim of this study is to compare the effects of COVID-19 on the levels of phospholipid and free polyunsaturated fatty acids (PUFAs) and their metabolites produced in response to reactions with reactive oxygen species (ROS) and enzymes (cyclooxygenases-(COXs) and lipoxygenase-(LOX)) in the plasma of patients who either recovered or passed away within a week of hospitalization. In the plasma of COVID-19 patients, especially of the survivors, the actions of ROS and phospholipase A2 (PLA2) cause a decrease in phospholipid fatty acids level and an increase in free fatty acids (especially arachidonic acid) despite increased COXs and LOX activity. This is accompanied by an increased level in lipid peroxidation products (malondialdehyde and 8-isoprostaglandin F2α) and lipid mediators generated by enzymes. There is also an increase in eicosanoids, both pro-inflammatory as follows: thromboxane B2 and prostaglandin E2, and anti-inflammatory as follows: 15-deoxy-Δ-12,14-prostaglandin J2 and 12-hydroxyeicosatetraenoic acid, as well as endocannabinoids (anandamide-(AEA) and 2-arachidonylglycerol-(2-AG)) observed in the plasma of patients who recovered. Moreover, the expression of tumor necrosis factor α and interleukins (IL-6 and IL-10) is increased in patients who recovered. However, in the group of patients who died, elevated levels of N-oleoylethanolamine and N-palmitoylethanolamine are found. Since lipid mediators may have different functions depending on the onset of pathophysiological processes, a stronger pro-inflammatory response in patients who have recovered may be the result of the defensive response to SARS-CoV-2 in survivors associated with specific changes in the phospholipid metabolism, which could also be considered a prognostic factor.

Immune modulation as a consequence of SARS-CoV-2 infection.

Erroneous immune responses in COVID-19 could have detrimental effects, which makes investigation of immune network underlying COVID-19 pathogenesis a requisite. This study aimed to investigate COVID-19 related alterations within the frame of innate and adaptive immunity. Thirty-four patients clinically diagnosed with mild, moderate and severe COVID-19 disease were enrolled in this study. Decreased ILC1 and increased ILC2 subsets were detected in mild and moderate patients compared to healthy controls. NK cell subsets and cytotoxic capacity of NK cells were decreased in severe patients. Moreover, CD3+ T cells were reduced in severe patients and a negative correlation was found between CD3+ T cells and D-dimer levels. Likewise, moderate and severe patients showed diminished CD3+CD8+ T cells. Unlike T and NK cells, plasmablast and plasma cells were elevated in patients and IgG and IgA levels were particularly increased in severe patients. Severe patients also showed elevated serum levels of pro-inflammatory cytokines such as TNF-α, IL-6 and IL-8, reduced intracellular IFN-γ and increased intracellular IL-10 levels. Our findings emphasize that SARS-CoV-2 infection significantly alters immune responses and innate and acquired immunity are differentially modulated in line with the clinical severity of the disease. Elevation of IL-10 levels in NK cells and reduction of CD3+ and CD8+ T cells in severe patients might be considered as a protective response against the harmful effect of cytokine storm seen in COVID-19.

Effects of niacin on intestinal epithelial Barrier, intestinal Immunity, and microbial community in weaned piglets challenged by PDCoV.

The objective was to evaluate effects of niacin on the intestinal epithelial barrier, intestinal immunity, and microbial community in weaned piglets challenged by Porcine Deltacoronavirus (PDCoV). In this study, fifteen weaned piglets were randomly assigned to 1 of 3 groups, (1) control group, normal diet; (2) PDCoV group, infected with 1 × 107 TCID50 of the PDCoV CHN-HN-17 strain by oral administration; (3) NA + PDCoV group, infected with 1 × 107 TCID50 of the PDCoV CHN-HN-17 strain by oral administration following administration of 40 mg of niacin for three days. The results showed that PDCoV infection induced diarrhea and other clinical symptoms with intestinal villi shedding and atrophy in weaned piglets. Niacin alleviated the symptoms of diarrhea and intestinal damage of PDCoV-infected weaned piglets. Additionally, PDCoV increased (P < 0.05) the mRNA expression of tight junction proteins [zonula occludens-1 (ZO-1) and Claudin] and antimicrobial peptides [porcine ß defensin 1 (pBD1), pBD2, proline-arginine rich 39-amino acid peptide (PR39) and protegrin 1-5 (PG1-5) in the jejunum and ileum of weaned piglets, while niacin increased (P < 0.05) the expression of PG1-5 compared with PDCoV. PDCoV increased (P < 0.05) the contents of serum interleukin-1ß (IL-1ß), IL-8 and intestinal IL-8, and up-regulated the mRNA expression of tumor necrosis factor-α (TNF-α), IL-1ß, IL-6, IL-10, IL-12, and IL-18 in ileum of weaned piglets compared with control. However, niacin decreased (P < 0.05) the contents of serum IL-1ß, IL-6 and intestinal IL-10 and IL-8, and also reduced (P < 0.05) the mRNA expression of ileal TNF-α, IL-10 and IL-12 in the PDCoV-infected piglets. Compared with control, PDCoV up-regulated (P < 0.05) the mRNA expression of key genes related to innate immune and antiviral molecules [toll-like receptor 4 (TLR4), NOD1, NOD2, DDX58, CCL2, STAT2, Mx1, IFN-γ, and protein kinase R (PKR) in the ileum of weaned piglets. Niacin decreased (P < 0.05) the mRNA expression of NOD1, NOD2, STAT2, IFN-γ, and PKR in PDCoV-infected weaned piglets. Moreover, the mRNA expression of IL-6 decreased (P < 0.05) and 2'-5'-oligoadenylate synthetase (OAS), IFN-α, and PKR increased (P < 0.05) in PDCoV-infected IPEC-J2 cells treated with niacin in vitro. Furthermore, niacin decreased (P < 0.05) the elevation of protein expression including inducible NOS (iNOS), nuclear factor-κB (NF-κB p65), inhibitor kappa B (IKKß), histone deacetylase [Sirtuin 1 (SIRT1) and histone deacetylase 7 (HDAC7) and phosphorylation of histone H3 at serine s10 (pH3s10) in the ileum of PDCoV-infected piglets, and increased (P < 0.05) the expression of G protein-coupled receptor (GPR109A). PDCoV disrupted the composition and structure of microflora in the colon of weaned piglets, and reduced the relative abundance of the beneficial bacteria Spirobacterium, but niacin could improve the intestinal microbial flora of the PDCoV-infected piglets associated with increasing the relative abundance of Lactobacillus. Overall, niacin could alleviate diarrhea, intestinal barrier damages, intestinal immune response and colonic microflora disfunction in PDCoV-infected weaned piglets.

Vincamine, an active constituent of Vinca rosea ameliorates experimentally induced acute lung injury in Swiss albino mice through modulation of Nrf-2/NF-κB signaling cascade.

Acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) is one of the leading pulmonary inflammatory disorders causing significant morbidity and mortality. Vincamine is a novel phytochemical with promising anti-inflammatory properties. In the current work, the protective effect of vincamine was studied in vitro (Raw 264.7 macrophages) and in vivo against lipopolysaccharide (LPS) induced ALI in Swiss albino mice. Vincamine significantly reduced nitrite and TNF-α release from the LPS stimulated macrophages and increased the levels of IL-10, indicating potent anti-inflammatory effects. It was observed that vincamine at the dose of 40 mg/kg, significantly reduced LPS induced inflammatory cell count in blood and in bronchoalveolar lavage (BAL) fluid. Further, vincamine exerted potent suppression of inflammation by reducing the expression of proinflammatory cytokines, while significantly increased (p < 0.001) the expression of anti-inflammatory cytokine (IL-10 and IL-22). Interestingly, histological changes were reversed in vincamine treated groups in a dose-dependent manner. Immunohistochemical analysis revealed significantly enhanced expression of NF-κB, TNF-α and COX-2 while reduced expression of Nrf-2 in disease control group, which were significantly (p < 0.001) ameliorated by vincamine. We, to the best of our knowledge, report for the first time that vincamine possesses protective potential against LPS induced inflammation and oxidative stress, possibly by inhibiting the NF-κB cascade, while positively regulating the Nrf-2 pathway. These findings are of potential relevance for COVID-19 management concerning the fact that lung injury and ARDS are its critical features.

Decidual immune response following COVID-19 during pregnancy varies by timing of maternal SARS-CoV-2 infection.

While COVID-19 infection during pregnancy is common, fetal transmission is rare, suggesting that intrauterine mechanisms form an effective blockade against SARS-CoV-2. Key among these is the decidual immune environment of the placenta. We hypothesize that decidual leukocytes are altered by maternal SARS-CoV-2 infection in pregnancy and that this decidual immune response is shaped by the timing of infection during gestation. To address this hypothesis, we collected decidua basalis tissues at delivery from women with symptomatic COVID-19 during second (2nd Tri COVID, n = 8) or third trimester (3rd Tri COVID, n = 8) and SARS-CoV-2-negative controls (Control, n = 8). Decidual natural killer (NK) cells, macrophages and T cells were evaluated using quantitative microscopy, and pro- and anti-inflammatory cytokine mRNA expression was evaluated using quantitative reverse transcriptase PCR (qRT-PCR). When compared with the Control group, decidual tissues from 3rd Tri COVID exhibited significantly increased macrophages, NK cells and T cells, whereas 2nd Tri COVID only had significantly increased T cells. In evaluating decidual cytokine expression, we noted that IL-6, IL-8, IL-10 and TNF-α were significantly correlated with macrophage cell abundance. However, in 2nd Tri COVID tissues, there was significant downregulation of IL-6, IL-8, IL-10, and TNF-α. Taken together, these results suggest innate and adaptive immune responses are present at the maternal-fetal interface in maternal SARS-CoV-2 infections late in pregnancy, and that infections earlier in pregnancy show evidence of a resolving immune response. Further studies are warranted to characterize the full scope of intrauterine immune responses in pregnancies affected by maternal COVID-19.

Effectiveness of Curcumin on Outcomes of Hospitalized COVID-19 Patients: A Systematic Review of Clinical Trials.

Despite the ongoing vaccination efforts, there is still an urgent need for safe and effective treatments to help curb the debilitating effects of COVID-19 disease. This systematic review aimed to investigate the efficacy of supplemental curcumin treatment on clinical outcomes and inflammation-related biomarker profiles in COVID-19 patients. We searched PubMed, Scopus, Web of Science, EMBASE, ProQuest, and Ovid databases up to 30 June 2021 to find studies that assessed the effects of curcumin-related compounds in mild to severe COVID-19 patients. Six studies were identified which showed that curcumin supplementation led to a significant decrease in common symptoms, duration of hospitalization and deaths. In addition, all of these studies showed that the intervention led to amelioration of cytokine storm effects thought to be a driving force in severe COVID-19 cases. This was seen as a significant (p < 0.05) decrease in proinflammatory cytokines such as IL1ß and IL6, with a concomitant significant (p < 0.05) increase in anti-inflammatory cytokines, including IL-10, IL-35 and TGF-α. Taken together, these findings suggested that curcumin exerts its beneficial effects through at least partial restoration of pro-inflammatory/anti-inflammatory balance. In conclusion, curcumin supplementation may offer an efficacious and safe option for improving COVID-19 disease outcomes. We highlight the point that future clinical studies of COVID-19 disease should employ larger cohorts of patients in different clinical settings with standardized preparations of curcumin-related compounds.

More Evidence of the Link of Interleukin-6 and Interleukin-10 with Critical COVID-19: A Report in Mexican Patients.

BACKGROUND: According to the World Health Organization, Mexico presents one of the highest mortality rates due to coronavirus disease 2019 (COVID-19). The "cytokine storm" phenomenon has been proposed as a pathological hallmark of severe COVID-19. OBJECTIVE: To determine the association of serum cytokine levels with COVID-19 severity. METHODS: We studied the cytokines IL-2, IL-4, IL-6, IL-10, TNF-α, and the IFN-γ serum levels through flow cytometry in 56 COVID-19 patients (24 critical and 32 non-critical) from Northwest Mexico. RESULTS: We observed a significant increase in the IL-6 and the IL-10 levels in the sera of critical patients. These cytokines were also associated with mechanical ventilation necessity and death, IL-6 showing AUC values above 0.7 for both variables; and correlated with Na+, creatinine, and platelet levels. On the other hand, no association was found between IL-2, IL-4, TNF-α, and IFN-γ with tested variables. CONCLUSION: Our results corroborate previous observations regarding IL-6 and IL-10 involvement in the severity of COVID-19.

Clinical and inflammatory features based machine learning model for fatal risk prediction of hospitalized COVID-19 patients: results from a retrospective cohort study.

OBJECTIVES: To appraise effective predictors for COVID-19 mortality in a retrospective cohort study. METHODS: A total of 1270 COVID-19 patients, including 984 admitted in Sino French New City Branch (training and internal validation sets randomly split at 7:3 ratio) and 286 admitted in Optical Valley Branch (external validation set) of Wuhan Tongji hospital, were included in this study. Forty-eight clinical and laboratory features were screened with LASSO method. Further multi-tree extreme gradient boosting (XGBoost) machine learning-based model was used to rank importance of features selected from LASSO and subsequently constructed death risk prediction model with simple-tree XGBoost model. Performances of models were evaluated by AUC, prediction accuracy, precision, and F1 scores. RESULTS: Six features, including disease severity, age, levels of high-sensitivity C-reactive protein (hs-CRP), lactate dehydrogenase (LDH), ferritin, and interleukin-10 (IL-10), were selected as predictors for COVID-19 mortality. Simple-tree XGBoost model conducted by these features can predict death risk accurately with >90% precision and >85% sensitivity, as well as F1 scores >0.90 in training and validation sets. CONCLUSION: We proposed the disease severity, age, serum levels of hs-CRP, LDH, ferritin, and IL-10 as significant predictors for death risk of COVID-19, which may help to identify the high-risk COVID-19 cases. KEY MESSAGES A machine learning method is used to build death risk model for COVID-19 patients. Disease severity, age, hs-CRP, LDH, ferritin, and IL-10 are death risk factors. These findings may help to identify the high-risk COVID-19 cases.

Immune characterization of a Colombian family cluster with SARS-CoV-2 infection. / Caracterización inmunológica de un grupo familiar colombiano con infección por SARS-CoV-2

INTRODUCTION: Immunological markers have been described during COVID-19 and persist after recovery. These immune markers are associated with clinical features among SARSCoV-2 infected individuals. Nevertheless, studies reporting a comprehensive analysis of the immune changes occurring during SARS-CoV-2 infection are still limited. OBJECTIVE: To evaluate the production of proinflammatory cytokines, the antibody response, and the phenotype and function of NK cells and T cells in a Colombian family cluster with SARS-CoV-2 infection. MATERIALS AND METHODS: Proinflammatory cytokines were evaluated by RT-PCR and ELISA. The frequency, phenotype, and function of NK cells (cocultures with K562 cells) and T-cells (stimulated with spike/RdRp peptides) were assessed by flow cytometry. Anti-SARS-CoV-2 antibodies were determined using indirect immunofluorescence and plaque reduction neutralization assay. RESULTS: During COVID-19, we observed a high proinflammatory-cytokine production and a reduced CD56bright-NK cell and cytotoxic response. Compared with healthy controls, infected individuals had a higher frequency of dysfunctional CD8+ T cells CD38+HLA-DR-. During the acute phase, CD8+ T cells stimulated with viral peptides exhibited a monofunctional response characterized by high IL-10 production. However, during recovery, we observed a bifunctional response characterized by the co-expression of CD107a and granzyme B or perforin. CONCLUSION: Although the proinflammatory response is a hallmark of SARS-CoV-2 infection, other phenotypic and functional alterations in NK cells and CD8+ T cells could be associated with the outcome of COVID-19. However, additional studies are required to understand these alterations and to guide future immunotherapy strategies.

Introducción. Se han descrito diferentes marcadores inmunológicos durante la COVID-19, los cuales persisten incluso después de la convalecencia y se asocian con los estadios clínicos de la infección. Sin embargo, aún son pocos los estudios orientados al análisis exhaustivo de las alteraciones del sistema inmunológico en el curso de la infección. Objetivo. Evaluar la producción de citocinas proinflamatorias, la reacción de anticuerpos, y el fenotipo y la función de las células NK y los linfocitos T en una familia colombiana con infección por SARS-CoV-2. Materiales y métodos. Se evaluaron las citocinas proinflamatorias mediante RT-PCR y ELISA; la frecuencia, el fenotipo y la función de las células NK (en cocultivos con células K562) y linfocitos T CD8+ (estimulados con péptidos spike/RdRp) mediante citometría de flujo, y los anticuerpos anti-SARS-CoV-2, mediante inmunofluorescencia indirecta y prueba de neutralización por reducción de placa. Resultados. Durante la COVID-19 hubo una producción elevada de citocinas proinflamatorias, con disminución de las células NK CD56bright y reacción citotóxica. Comparados con los controles sanos, los individuos infectados presentaron con gran frecuencia linfocitos T CD8+ disfuncionales CD38+HLA-DR-. Además, en los linfocitos T CD8+ estimulados con péptidos virales, predominó una reacción monofuncional con gran producción de IL-10 durante la fase aguda y una reacción bifuncional caracterizada por la coexpresión de CD107a y granzima B o perforina durante la convalecencia. Conclusión. Aunque la reacción inflamatoria caracteriza la infección por SARS-CoV-2, hay otras alteraciones fenotípicas y funcionales en células NK y linfocitos T CD8+ que podrían asociarse con la progresión de la infección. Se requieren estudios adicionales para entender estas alteraciones y guiar futuras estrategias de inmunoterapia.

Topoisomerase 2 inhibitor etoposide promotes interleukin-10 production in LPS-induced macrophages via upregulating transcription factor Maf and activating PI3K/Akt pathway.

Topoisomerase (TOP) inhibitors were commonly used as chemotherapeutic agents in the treatment of cancers. In our present study, we found that etoposide (ETO), a topoisomerase 2 (TOP2) inhibitor, upregulated the production of Interleukin 10 (IL-10) in lipopolysaccharide (LPS)-stimulated macrophages. Besides, other TOP2 inhibitors including doxorubicin hydrochloride (DOX) and teniposide (TEN) were also able to augment IL-10 production. Meanwhile, the expression levels of pro-inflammatory factors, for example IL-6 and TNF-α, were also decreased accordingly by the treatment of the TOP2 inhibitors. Of note, ETO facilitated IL-10 secretion, which might be regulated by transcription factor Maf via PI3K/AKT pathway, as pharmaceutic blockage of kinase PI3K or AKT attenuated ETO-induced Maf and IL-10 expression. Further, in LPS-induced mice sepsis model, the enhanced generation of IL-10 was observed in ETO-treated mice, whereas pro-inflammatory cytokines were decreased, which significantly reduced the mortality of mice from LPS-induced lethal cytokine storm. Taken together, these results indicated that ETO may exhibit an anti-inflammatory role by upregulating the alteration of transcription factor Maf and promoting subsequential IL-10 secretion via PI3K/Akt pathway in LPS-induced macrophages. Therefore, ETO may serve as a potential anti-inflammatory agent and employed to severe pro-inflammatory diseases including COVID-19.

The Gene Signature of Activated M-CSF-Primed Human Monocyte-Derived Macrophages Is IL-10-Dependent.

During inflammatory responses, monocytes are recruited into inflamed tissues, where they become monocyte-derived macrophages and acquire pro-inflammatory and tissue-damaging effects in response to the surrounding environment. In fact, monocyte-derived macrophage subsets are major pathogenic cells in inflammatory pathologies. Strikingly, the transcriptome of pathogenic monocyte-derived macrophage subsets resembles the gene profile of macrophage colony-stimulating factor (M-CSF)-primed monocyte-derived human macrophages (M-MØ). As M-MØ display a characteristic cytokine profile after activation (IL10high TNFlow IL23low IL6low), we sought to determine the transcriptional signature of M-MØ upon exposure to pathogenic stimuli. Activation of M-MØ led to the acquisition of a distinctive transcriptional profile characterized by the induction of a group of genes (Gene set 1) highly expressed by pathogenic monocyte-derived macrophages in COVID-19 and whose presence in tumor-associated macrophages (TAM) correlates with the expression of macrophage-specific markers (CD163, SPI1) and IL10. Indeed, Gene set 1 expression was primarily dependent on ERK/p38 and STAT3 activation, and transcriptional analysis and neutralization experiments revealed that IL-10 is not only required for the expression of a subset of genes within Gene set 1 but also significantly contributes to the idiosyncratic gene signature of activated M-MØ. Our results indicate that activation of M-CSF-dependent monocyte-derived macrophages induces a distinctive gene expression profile, which is partially dependent on IL-10, and identifies a gene set potentially helpful for macrophage-centered therapeutic strategies.

Suppressive Monocytes Impair MAIT Cells Response via IL-10 in Patients with Severe COVID-19.

Immune cell responses are strikingly altered in patients with severe coronavirus disease 2019 (COVID-19), but the immunoregulatory process in these individuals is not fully understood. In this study, 23 patients with mild and 22 patients with severe COVID-19 and 6 asymptomatic carriers of COVID-19 were enrolled, along with 44 healthy controls (HC). Peripheral immune cells in HC and patients with COVID-19 were comprehensively profiled using mass cytometry. We found that in patients with severe COVID-19, the number of HLA-DRlow/- monocytes was significantly increased, but that of mucosal-associated invariant T (MAIT) cells was greatly reduced. MAIT cells were highly activated but functionally impaired in response to Escherichia coli and IL-12/IL-18 stimulation in patients with severe COVID-19, especially those with microbial coinfection. Single-cell transcriptome analysis revealed that IFN-stimulated genes were significantly upregulated in peripheral MAIT cells and monocytes from patients with severe COVID-19. IFN-α pretreatment suppressed MAIT cells' response to E. coli by triggering high levels of IL-10 production by HLA-DRlow/--suppressive monocytes. Blocking IFN-α or IL-10 receptors rescued MAIT cell function in patients with severe COVID-19. Moreover, plasma from patients with severe COVID-19 inhibited HLA-DR expression by monocytes through IL-10. These data indicate a unique pattern of immune dysregulation in severe COVID-19, which is characterized by enrichment of suppressive HLA-DRlow/- monocytes associated with functional impairment of MAIT cells through the IFN/IL-10 pathway.