Immune Paralysis Research Articles

Extracorporeal immune cell therapy of sepsis: ex vivo results

BackgroundImmune cell dysfunction plays a central role in sepsis-associated immune paralysis. The transfusion of healthy donor immune cells, i.e., granulocyte concentrates (GC) potentially induces tissue damage via local effects of neutrophils. Initial clinical trials using standard donor GC in a strictly extracorporeal bioreactor system for treatment of septic shock patients already provided evidence for beneficial effects with fewer side effects, by separating patient and donor immune cells using plasma filters. In this ex vivo study, we demonstrate the functional characteristics of a simplified extracorporeal therapy system using purified granulocyte preparations.MethodsPurified GC were used in an immune cell perfusion model prefilled with human donor plasma simulating a 6-h treatment. The extracorporeal circuit consisted of a blood circuit and a plasma circuit with 3 plasma filters (PF). PF1 is separating the plasma from the patient’s blood. Plasma is then perfused through PF2 containing donor immune cells and used in a dead-end mode. The filtrated plasma is finally retransfused to the blood circuit. PF3 is included in the plasma backflow as a redundant safety measure. The donor immune cells are retained in the extracorporeal system and discarded after treatment. Phagocytosis activity, oxidative burst and cell viability as well as cytokine release and metabolic parameters of purified GCs were assessed.ResultsCells were viable throughout the study period and exhibited well-preserved functionality and efficient metabolic activity. Course of lactate dehydrogenase and free hemoglobin concentration yielded no indication of cell impairment. The capability of the cells to secret various cytokines was preserved. Of particular interest is equivalence in performance of the cells on day 1 and day 3, demonstrating the sustained shelf life and performance of the immune cells in the purified GCs.ConclusionResults demonstrate the suitability of a simplified extracorporeal system. Furthermore, granulocytes remain viable and highly active during a 6-h treatment even after storage for 3 days supporting the treatment of septic patients with this system in advanced clinical trials.

Effects of Ventilator-Associated Pneumonia Among Saudian’s Critically Ill Patients, Systemic Review

Introduction: Mechanically ventilated patients are vulnerable to infectious diseases, such as ventilator-associated pneumonia (VAP), due to the breach of normal defence mechanisms and relative immune paralysis during ventilation. This study aimed to determine the risk factors for developing VAP among ventilated patients, as well as the incidence and effects of VAP in Saudi Arabia. Methods: A systematic review design was used. The included studies were published after 2015 in the English language and relevant to the topic of concern. Results: Eleven articles were selected for inclusion in the study. The incidence of VAP in Saudi Arabia was low during the study period. Risk factors for developing VAP included a lack of adequate nurse training, a failure to closely supervise ventilated patients, chest and rib injuries, reintubation, the supine position, and old age. VAP led to increased rates of sepsis, multi-drug-resistant infections, mortality, and longer ICU and hospital stays, as well as developing complications Conclusion: The use of the VAP prevention and treatment bundle and other strategies reduced the risk of ventilated patients developing VAP.

Advances in Immune Monitoring Approaches for Sepsis-Induced Immunosuppression.

Sepsis represents a life-threatening organ dysfunction due to an aberrant host response. Of note is that majority of patients have experienced a severe immune depression during and after sepsis, which is significantly correlated with the occurrence of nosocomial infection and higher risk of in-hospital death. Nevertheless, the clinical sign of sepsis-induced immune paralysis remains highly indetectable and ambiguous. Given that, specific yet robust biomarkers for monitoring the immune functional status of septic patients are of prominent significance in clinical practice. In turn, the stratification of a subgroup of septic patients with an immunosuppressive state will greatly contribute to the implementation of personalized adjuvant immunotherapy. In this review, we comprehensively summarize the mechanism of sepsis-associated immunosuppression at the cellular level and highlight the recent advances in immune monitoring approaches targeting the functional status of both innate and adaptive immune responses.

Challenging molecular dogmas in human sepsis using mathematical reasoning.

SummarySepsis is defined as a dysregulated host-response to infection, across all ages and pathogens. What defines a dysregulated state remains intensively researched but incompletely understood. Here, we dissect the meaning of this definition and its importance for the diagnosis and management of sepsis. We deliberate on pathophysiological features and dogmas that range from cytokine storms and immune paralysis to dormancy and altered homeostasis setpoints. Mathematical reasoning, used to test for plausibility, reveals three interlinked cardinal rules governing host-response trajectories in sepsis. Rule one highlights that the amplitude of the immune response while important is not sufficient and is strictly dependent on rule two, specifying bioenergetic capacity and are together dynamically driven by rule three, delineating stability and alterations in setpoints. We consider these rules and associated pathophysiological parameters for guiding data-science and artificial intelligence mining of multi-omics and big-data for improving the precision of diagnostic and therapeutic approaches to sepsis.FundingPG funded by the European Regional Development Fund and Welsh Government (Ser Cymru programme – Project Sepsis).

Клинический случай: «острая-на-хроническую» печеночная недостаточность (ACLF)

Acute-on-chronic liver failure (AcLF) is an acute liver disorder manifested as jaundice (serum bilirubin levels ≥5 mg/dL) and coagulopathy (Inr ≥1.5 or prothrombin activity < 40%), complicated by ascites and/or encephalopathy within 4 weeks, that is found in patients with the previously diagnosed or undiagnosed chronic liver disease. AcLF is a serious medical issue worldwide. The AcLF pathogenesis is based on the pronounced systemic inflammatory response to pathogenic antigens and biological structures produced during the liver cell death, with subsequent immune paralysis and multiple organ failure. Acute-on-chronic liver failure (AcLF) may develop at any stage, from compensated to decompensated cir- rhosis; the disorder may involve both hepatic and extrahepatic precipitating events. drug treatment of AcLF includes early detection and treat-ment of the precipitating factor and maintenance therapy. It has been proven that treatment of the trigger at an early stage reduces mortality,however, the management of AcLF is focused mostly on the maintenance therapy. AcLF belongs to the syndromes seldom diagnosed in clinical practice, that is why the AcLF case study is of special interest. The paper reports a confirmed case of AcLF.

Chloride intercellular channel 3 suppression‐mediated macrophage polarization: a potential indicator of poor prognosis of hepatitis B virus‐related acute‐on‐chronic liver failure

Patients with hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) are characterized by immune paralysis and susceptibility to infections. Macrophages are important mediators of immune responses can be subclassified into two main phenotypes: classically activated and alternatively activated. However, few studies have investigated changes to macrophage polarization in HBV-related liver diseases. Therefore, we investigated the functional status of monocyte-derived macrophages (MDMs) from patients with mild chronic hepatitis B (n = 226), HBV-related compensated cirrhosis (n = 36), HBV-related decompensated cirrhosis (n = 40), HBV-ACLF (n = 62) and healthy controls (n = 10), as well as Kupffer cells (KCs) from patients with HBV-ACLF (n = 3). We found that during the progression of HBV-related liver diseases, the percentage of CD163+ CD206+ macrophages increased, while the percentage of CD80+ human leukocyte antigen-DR+ macrophages decreased significantly. MDMs and KCs mainly exhibited high CD163+ CD206+ expression in patients with HBV-ACLF, which predicted poor clinical outcome and higher liver transplantation rate. Transcriptome sequencing analysis revealed that chloride intracellular channel-3 (CLIC3) was reduced in patients with HBV-ACLF, indicating a poor prognosis. To further study the effect of CLIC3 on macrophage polarization, human monocytic THP-1 cell-derived macrophages were used. We found that classical and alternative macrophage activation occurred through nuclear factor kappa B (NF-κB) and phosphoinositide 3-kinase/protein kinase B pathways, respectively. CLIC3 suppression inhibited NF-κB activation and promoted the alternative activation. In conclusion, macrophage polarization gradually changed from classically activated to alternatively activated as HBV-related liver diseases progressed. Both CLIC3 suppression and increased alternatively activated macrophage percentage were potential indicators of the poor prognosis of patients with HBV-ACLF.

462 Dysfunctional leukocyte mitochondrial metabolism is associated with immune paralysis in critically ill septic patients

OBJECTIVES/GOALS: The host immune response during sepsis is now recognized to have anti-inflammatory pathophysiology. We aim to determine whether mitochondrial dysfunction of leukocytes predicts which critically ill septic patients develop immune paralysis and to identify differences in cellular metabolites between patients with and without immune paralysis. METHODS/STUDY POPULATION: Critically ill septic and control adult patients were recruited from one of 6 ICUs in a single-center tertiary care academic hospital. After enrollment, peripheral blood mononuclear cells (PBMCs) were isolated from a tube of whole blood on day 0-1 after ICU admission. Flow cytometry to quantify monocyte HLA-DR was performed to determine whether patients were immune paralyzed or not. Mitochondrial functional assays of PBMCs were performed with inhibitors of the electron transport chain to assess for differences in oxidative phosphorylation and glycolysis utilization. Metabolic profiling of cell pellets was performed to evaluate for specific metabolites and pathways associated with immune paralyzed patients. RESULTS/ANTICIPATED RESULTS: A total of 101 patients were recruited, including 62 control and 39 septic patients. 81 patients had immune paralysis status available for analysis. 52% of all recruited subjects were immune paralyzed. Of these, 58% were controls and 75% were septic. Immune paralyzed septic and control patients showed features of reduced utilization of oxidative phosphorylation (ox phos) including reduced basal respiration, ATP production and maximal respiration compared with non-immune paralyzed septic and control patients. Immune paralyzed septic patients showed diminished glycolysis utilization compared with septic non-immune paralyzed patients. Finally, cellular kynurenine and quinolinate levels were low in both immune paralyzed control and septic patients compared with non-immune paralyzed patients. DISCUSSION/SIGNIFICANCE: The PBMCs of immune paralyzed septic patients show evidence of mitochondrial dysfunction, with reduced ox phos and glycolysis utilization. Low levels of kynurenine and quinolinate, metabolite precursors to NAD+, in immune paralyzed patients may signal key deficiencies and targetable therapeutic avenues for reversal of an immune paralyzed state.

Candida auris Bloodstream Infection Induces Upregulation of the PD-1/PD-L1 Immune Checkpoint Pathway in an Immunocompetent Mouse Model.

ABSTRACTCandida auris is a globally spreading yeast pathogen causing bloodstream infections with high mortality in critically ill patients. The inherent antifungal drug resistance of most C. auris isolates and threat of multidrug-resistant strains create a need for adjunct immunotherapeutic strategies. While C. albicans candidemia was shown to induce immune paralysis and activation of inhibitory immune checkpoints, in vivo data on host responses to C. auris bloodstream infection are lacking as is an immunocompetent murine infection model to study the immunopathology and immunotherapy of C. auris sepsis. Therefore, herein, we developed an immunocompetent C. auris sepsis model by intravenously infecting C57BL/6 mice with 1.5 × 108 to 8 × 108 yeast cells of aggregate-forming (AR-0384) and nonaggregative (AR-0381) C. auris reference isolates. Both isolates caused reproducible, inoculum-dependent increasing morbidity, mortality, and fungal burden in kidney tissue. Notably, morbidity and mortality outcomes were partially decoupled from fungal burden, suggesting a role of additional modulators of disease severity such as host immune responses. Flow cytometric analyses of splenic immune cells revealed significant upregulation of the programmed cell death protein 1 (PD-1) on T cells and its ligand PD-L1 on macrophages from mice infected with C. auris AR-0384 compared to uninfected mice. PD-L1 expression on macrophages from AR-0384-infected mice strongly correlated with fungal tissue burden (Spearman’s rank correlation coefficient [ρ] = 0.95). Altogether, our findings suggest that C. auris sepsis promotes a suppressive immune phenotype through PD-1/PD-L1 induction, supporting further exploration of PD-1/PD-L1 blockade as an immunotherapeutic strategy to mitigate C. auris candidiasis.IMPORTANCE Health authorities consider Candida auris to be one of the most serious emerging nosocomial pathogens due to its transmissibility, resistance to disinfection procedures, and frequent antifungal drug resistance. The frequency of multidrug-resistant C. auris isolates necessitates the development of novel therapeutic platforms, including immunotherapy. However, in vivo data on host interactions with C. auris are scarce, compounded by the lack of reliable immunocompetent mammalian models of C. auris candidemia. Herein, we describe a C. auris sepsis model in immunocompetent C57BL/6 mice and demonstrate reproducible and inoculum-dependent acute infection with both aggregate-forming and nonaggregative reference isolates from different clades. Furthermore, we show that C. auris sepsis induces upregulation of the PD-1/PD-L1 immune checkpoint pathway in infected mice, raising the potential of a therapeutic benefit of immune checkpoint blockade. Our immunocompetent model of C. auris sepsis could provide a facile preclinical platform to thoroughly investigate immune checkpoint blockade and combination therapy with antifungals.

Keep a Little Fire Burning-The Delicate Balance of Targeting Sphingosine-1-Phosphate in Cancer Immunity.

The sphingolipid sphingosine-1-phosphate (S1P) promotes tumor development through a variety of mechanisms including promoting proliferation, survival, and migration of cancer cells. Moreover, S1P emerged as an important regulator of tumor microenvironmental cell function by modulating, among other mechanisms, tumor angiogenesis. Therefore, S1P was proposed as a target for anti-tumor therapy. The clinical success of current cancer immunotherapy suggests that future anti-tumor therapy needs to consider its impact on the tumor-associated immune system. Hereby, S1P may have divergent effects. On the one hand, S1P gradients control leukocyte trafficking throughout the body, which is clinically exploited to suppress auto-immune reactions. On the other hand, S1P promotes pro-tumor activation of a diverse range of immune cells. In this review, we summarize the current literature describing the role of S1P in tumor-associated immunity, and we discuss strategies for how to target S1P for anti-tumor therapy without causing immune paralysis.

Advances in quantitative assessment of immune function in critically ill patients

With the development of ELISA, flow cytometry, quantitative PCR and various omics techniques, the means of immune function evaluation are gradually improved. The existing definitions of immune function, such as excessive immunity, immunosuppression, immune paralysis and immune tolerance, remain in descriptive concepts and lacks quantitative diagnostic criteria. Clinical manifestations combined with biological indicators will be the most effective quantitative method in the future. A variety of research concentrating on immunotherapeutic drugs is still in progress, and the success of individualized immunotherapy will depend on accurate immune function evaluation.

Cirrhosis-associated immune dysfunction.

The term cirrhosis-associated immune dysfunction (CAID) comprises the distinctive spectrum of immune alterations associated with the course of end-stage liver disease. Systemic inflammation and immune deficiency are the key components of CAID. Their severity is highly dynamic and progressive, paralleling cirrhosis stage. CAID involves two different immune phenotypes: the low-grade systemic inflammatory phenotype and the high-grade systemic inflammatory phenotype. The low-grade systemic inflammatory phenotype can be found in patients with compensated disease or clinical decompensation with no organ failure. In this phenotype, there is an exaggerated immune activation but the effector response is not markedly compromised. The high-grade systemic inflammatory phenotype is present in patients with acute-on-chronic liver failure, a clinical situation characterized by decompensation, organ failure and high short-term mortality. Along with high-grade inflammation, this CAID phenotype includes intense immune paralysis that critically increases the risk of infections and worsens prognosis. The intensity of CAID has important consequences on cirrhosis progression and correlates with the severity of liver insufficiency, bacterial translocation and organ failure. Therapies targeting the modulation of the dysfunctional immune response are currently being evaluated in preclinical and clinical studies.

377: Airway macrophages in early CF lung disease show signs of immune paralysis

377: Airway macrophages in early CF lung disease show signs of immune paralysis

Alveolar Macrophages: Adaptation to Their Anatomic Niche during and after Inflammation.

At the early stages of life development, alveoli are colonized by embryonic macrophages, which become resident alveolar macrophages (ResAM) and self-sustain by local division. Genetic and epigenetic signatures and, to some extent, the functions of ResAM are dictated by the lung microenvironment, which uses cytokines, ligand-receptor interactions, and stroma cells to orchestrate lung homeostasis. In resting conditions, the lung microenvironment induces in ResAM a tolerogenic programming that prevents unnecessary and potentially harmful inflammation responses to the foreign bodies, which continuously challenge the airways. Throughout life, any episode of acute inflammation, pneumonia being likely the most frequent cause, depletes the pool of ResAM, leaving space for the recruitment of inflammatory monocytes that locally develop in monocyte-derived alveolar macrophages (InfAM). During lung infection, the local microenvironment induces a temporary inflammatory signature to the recruited InfAM to handle the tissue injury and eliminate the pathogens. After a few days, the recruited InfAM, which locally self-sustain and develop as new ResAM, gain profibrotic functions required for tissue healing. After the complete resolution of the infectious episode, the functional programming of both embryonic and monocyte-derived ResAM remains altered for months and possibly for the entire life. Adult lungs thus contain a wide diversity of ResAM since every infection brings new waves of InfAM which fill the room left open by the inflammatory process. The memory of these innate cells called trained immunity constitutes an immunologic scar left by inflammation, notably pneumonia. This memory of ResAM has advantages and drawbacks. In some cases, lung-trained immunity offers better defense capacities against autoimmune disorders and the long-term risk of infection. At the opposite, it can perpetuate a harmful process and lead to a pathological state, as is the case among critically ill patients who have immune paralysis and are highly susceptible to hospital-acquired pneumonia and acute respiratory distress syndrome. The progress in understanding the kinetics of response of alveolar macrophages (AM) to lung inflammation is paving the way to new treatments of pneumonia and lung inflammatory process.

Early Prognosis Effect of Cellular Immune Paralysis on Brain Complications of Extracorporeal Membrane Oxygenation Children with Severe Sepsis

Objective: The aim of the study was to explore the relationship between criticality, brain complications, and immune mechanisms in extracorporeal membrane oxygenation (ECMO) children with pneumonia and severe sepsis. Methods: Patients with simple pneumonia (group I), ECMO patients with pneumonia and severe sepsis accompanied by brain complications (group II), and those without brain complication (group III) admitted to our pediatric intensive care unit were selected to be investigated. The relationship among the peripheral blood subgroups of immune cells, immune factors, adaptive immune responses, endothelial factors, and criticality and brain complications was then studied. Results: Severe paralysis of normal immunity, excess abnormal immunity, and endothelial injury were consistent with the increase in the absolute value of base excess, lactic acid (Lac) content, and average hospitalization days and brain complications involved in group II (vs. group I). The ratio of CD63+ macrophage and CD63+ neutrophil subpopulation increased (p < 0.05); the expression levels of elastase+ neutrophil denatured subgroup (p < 0.05), the ratio of CCR2highCX3CR1low/CCR2lowCX3CR1high of macrophages and neutrophils (p < 0.0001), high-mobility group box 1 (HMGB1), YTHDF1, interleukin-17 protein and mRNA, and RAGE gene decreased to some extent (p < 0.05); the expression levels of Th1 cells chemokine CXCL9 protein and mRNA and sTIE2 protein increased to some extent (p < 0.05); the adaptive immune response of CD8+ CTL stimulated by lipopolysaccharide (LPS) was slightly enhanced (p < 0.05) in group III(vs. group II), which was consistent with the improvement of criticality, average hospitalization days, and the absence of brain complications in group III (vs. group II). Conclusion: ECMO support with brain complication was related to the upregulation of HMGB1 and YTHDF1 protein; the decreased number of CD63+ macrophages and neutrophils; the increased denatured neutrophil subgroup, especially the upregulated ratio of CCR2highCX3CR1low/CCR2lowCX3CR1high of macrophages and neutrophils; the imbalance of Th17/Th1, LPS-specific CD8+ CTL adaptive immune response paralysis; and the reduced endothelial sTIE2 protein expression level which caused clinical deterioration and prolonged average hospitalization days.

Rationale for Polyclonal Intravenous Immunoglobulin Adjunctive Therapy in COVID-19 Patients: Report of a Structured Multidisciplinary Consensus.

Introduction: Adjunctive therapy with polyclonal intravenous immunoglobins (IVIg) is currently used for preventing or managing infections and sepsis, especially in immunocompromised patients. The pathobiology of COVID-19 and the mechanisms of action of Ig led to the consideration of this adjunctive therapy, including in patients with respiratory failure due to the SARS-CoV-2 infection. This manuscript reports the rationale, the available data and the results of a structured consensus on intravenous Ig therapy in patients with severe COVID-19. Methods: A panel of multidisciplinary experts defined the clinical phenotypes of COVID-19 patients with severe respiratory failure and, after literature review, voted for the agreement on the rationale and the potential role of IVIg therapy for each phenotype. Due to the scarce evidence available, a modified RAND/UCLA appropriateness method was used. Results: Three different phenotypes of COVID-19 patients with severe respiratory failure were identified: patients with an abrupt and dysregulated hyperinflammatory response (early phase), patients with suspected immune paralysis (late phase) and patients with sepsis due to a hospital-acquired superinfection (sepsis by bacterial superinfection). The rationale for intravenous Ig therapy in the early phase was considered uncertain whereas the panelists considered its use in the late phase and patients with sepsis/septic shock by bacterial superinfection appropriate. Conclusion: As with other immunotherapies, IVIg adjunctive therapy may have a potential role in the management of COVID-19 patients. The ongoing trials will clarify the appropriate target population and the true effectiveness.

Application of alpha1-antitrypsin in a rat model of veno-arterial extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a life-saving intervention for patients suffering from respiratory or cardiac failure. The ECMO-associated morbidity and mortality depends to a large extent on the underlying disease and is often related to systemic inflammation, consecutive immune paralysis and sepsis. Here we tested the hypothesis that human α1-antitrypsin (SERPINA1) due to its anti-protease and anti-inflammatory functions may attenuate ECMO-induced inflammation. We specifically aimed to test whether intravenous treatment with α1-antitrypsin reduces the release of cytokines in response to 2 h of experimental ECMO. Adult rats were intravenously infused with α1-antitrypsin immediately before starting veno-arterial ECMO. We measured selected pro- and anti-inflammatory cytokines and found, that systemic levels of tumor necrosis factor-α, interleukin-6 and interleukin-10 increase during experimental ECMO. As tachycardia and hypertension developed in response to α1-antitrypsin, a single additional bolus of fentanyl and midazolam was given. Treatment with α1-antitrypsin and higher sedative doses reduced all cytokine levels investigated. We suggest that α1-antitrypsin might have the potential to protect against both ECMO-induced systemic inflammation and immune paralysis. More studies are needed to corroborate our findings, to clarify the mechanisms by which α1-antitrypsin inhibits cytokine release in vivo and to explore the potential application of α1-antitrypsin in clinical ECMO.

Cellular and Exosomal Regulations of Sepsis-Induced Metabolic Alterations

Sepsis is a sustained systemic inflammatory condition involving multiple organ failures caused by dysregulated immune response to infections. Sepsis induces substantial changes in energy demands at the cellular level leading to metabolic reprogramming in immune cells and stromal cells. Although sepsis-associated organ dysfunction and mortality have been partly attributed to the initial acute hyperinflammation and immunosuppression precipitated by a dysfunction in innate and adaptive immune responses, the late mortality due to metabolic dysfunction and immune paralysis currently represent the major problem in clinics. It is becoming increasingly recognized that intertissue and/or intercellular metabolic crosstalk via endocrine factors modulates maintenance of homeostasis, and pathological events in sepsis and other inflammatory diseases. Exosomes have emerged as a novel means of intercellular communication in the regulation of cellular metabolism, owing to their capacity to transfer bioactive payloads such as proteins, lipids, and nucleic acids to their target cells. Recent evidence demonstrates transfer of intact metabolic intermediates from cancer-associated fibroblasts via exosomes to modify metabolic signaling in recipient cells and promote cancer progression. Here, we review the metabolic regulation of endothelial cells and immune cells in sepsis and highlight the role of exosomes as mediators of cellular metabolic signaling in sepsis.

Antiinflammatory phytochemicals against virus-induced hyperinflammatory responses: Scope, rationale, application, and limitations.

Uncontrolled inflammatory responses or cytokine storm associated with viral infections results in deleterious consequences such as vascular leakage, severe hemorrhage, shock, immune paralysis, multi-organ failure, and even death. With the emerging new viral infections and lack of effective prophylactic vaccines, evidence-based complementary strategies that limit viral infection-mediated hyperinflammatory responses could be a promising approach to limit host tissue injury. The present review emphasizes the potentials of antiinflammatory phytochemicals in limiting hyperinflammatory injury caused by viral infections. The predominant phytochemicals along with their mechanism in limiting hyperimmune and pro-inflammatory responses under viral infection have been reviewed comprehensively. How certain phytochemicals can be effective in limiting hyper-inflammatory response indirectly by favorably modulating gut microbiota and maintaining a functional intestinal barrier has also been presented. Finally, we have discussed improved systemic bioavailability of phytochemicals, efficient delivery strategies, and safety measures for effective antiinflammatory phytotherapies, in addition to emphasizing the requirement of tightly controlled clinical studies to establish the antiinflammatory efficacy of the phytochemicals. Collectively, the review provides a scooping overview on the potentials of bioactive phytochemicals to mitigate pro-inflammatory injury associated with viral infections.

Human Leukocyte Antigen-DR Isotype Expression in Monocytes and T Cells Interferon-Gamma Release Assay in Septic Patients and Correlation With Clinical Outcome

Background: Sepsis is a life-threatening dysregulated host response to infection responsible of multiple organs dysfunction (Sepsis-3 International Consensus Definition), during which clinical outcome is a balance between inflammation and immune suppression. Monocytes and lymphocytes may play an important role in immune paralysis, and their impaired functional activity can decrease overall immune system efficiency. We evaluated sepsis-induced changes in monocytes human leukocyte antigen-DR isotype (HLA-DR) expression and T cell capacity of interferon (IFN)-γ production in relation with patient’s clinical outcome. Methods: Analysis of HLA-DR expression on blood monocytes (mHLA-DR) was performed in 55 patients with high procalcitonin (hPCT, > 0.5 ng/mL,) and suspected/confirmed sepsis, and 20 controls. HLA-DR absolute quantification and IFN-γ release assay were monitored in 16 septic patients for 4 weeks following sepsis confirmation. Results: Cytofluorimetric analysis revealed a significant decrease of mHLA-DR percentage in septic patients with adverse outcome compared to patients with better clinical outcome (88.4% vs. 98.6% with P < 0.05), in combination with a significant decrease of absolute number of HLA-DR molecules per monocyte (P < 0.05, starting at 1 week of follow-up). Lymphocytes stimulation with phytohemagglutinin (PHA), Staphylococcus aureus ( S. aureus ) and Candida albicans ( C. albicans ) showed a severe declining of IFN-γ release related to fatal clinical outcome of patients. Conclusions: This immunologic anergy of innate and adaptative immunity showed an early immune paralysis during sepsis which appears correlated with the impairment of clinical outcome. J Clin Med Res. 2021;13(5):293-303 doi: https://doi.org/10.14740/jocmr4474

The protective role of YTHDF1-knock down macrophages on the immune paralysis of severe sepsis rats with ECMO

ObjectiveTo examine the role of YTHDF1 knock-down macrophages on the immunity of severe sepsis rats with ECMO. Methods15 SD rats were randomly allocated into 3 groups: mild sepsis (I), severe sepsis with ECMO (II), and YTHDF1 knock-down macrophages treatment groups (III). Blood biochemical indexes, different immune factors and brain changes were detected by RT-PCR, ELISA, ELISPOT and HE staining. Isolated macrophages subtypes and signal proteins were detected by flow cytometry, western blot and m6A RNA methylation test. ResultsThe levels of HMGB1, RAGE, YTHDF1 and IL-17 in peripheral blood were significantly higher (p < 0.01), while the level of CXCL9 and TNF-α, and LPS-specific CD8+CTL function were significantly decreased in group II compared with group I (p < 0.01). The ratio of CD63+ macrophages (p < 0.05) and CD64+ macrophages (p< 0.05) decreased and the level of elastase (p < 0.01) and CCR2highCX3CR1low/CCR2lowCX3CR1high (p < 0.01) of macrophages increased in group II. The above were consistent with the severity of biochemical indicators, the increasing endothelial injury factor (Ang2/Ang1), lower endothelial protective factor (sTie2), severer brain injury in group II. After YTHDF1 knock-down macrophages treatment, the above indexes' changes were opposite when Group III versus Group II through the down-regulation of m6A RNA methylation of JAK2/STAT3 (p < 0.01) and protein expression of PJAK2/PSTAT3 (p < 0.05) in isolated macrophages. ConclusionsYTHDF1 knock-down macrophages improved the immune paralysis of macrophages, Th1/Th17 and CTL and reduced the entry of macrophages into the brain to cause endothelial damage of severe sepsis rats with ECMO through the inhibition of HMGB1/RAGE and YTHDF1, m6A RNA methylation of JAK2/STAT3 and PJAK2/PSTAT3 proteins expression in macrophages.