BACKGROUND: Immunosuppression is closely related to the pathogenesis of sepsis, but the underlying mechanisms have not yet been fully elucidated. In this study, we aimed to examine the role of the Sterile Alpha Motif, Src Homology 3 domain and nuclear localization signal 1 (SAMSN1) in sepsis and elucidate its potential molecular mechanism in sepsis induced immunosuppression. METHODS: RNA sequencing databases were used to validate SAMSN1 expression in sepsis. The impact of SAMSN1 on sepsis was verified using gene knockout mice. Flow cytometry was employed to delineate how SAMSN1 affects immunity in sepsis, focusing on immune cell types and T cell functions. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated gene editing in RAW264.7 macrophages enabled interrogation of SAMSN1 's regulatory effects on essential macrophage functions, including cell proliferation and phagocytic capacity. The mechanism of SAMSN1 in the interaction between macrophages and T cells was investigated using the RAW264.7 cell line and primary cell lines. RESULTS: SAMSN1 expression was significantly increased in patients with sepsis and was positively correlated with sepsis mortality. Genetic deletion of Samsn1 in murine sepsis model improved T cell survival, elevated T cell cytolytic activity, and activated T cell signaling transduction. Concurrently, Samsn1 knockout augmented macrophage proliferation capacity and phagocytic efficiency. In macrophage, SAMSN1 binds to Kelch-like epichlorohydrin-associated protein 1 (KEAP1), causing nuclear factor erythroid 2-related factor 2 (NRF2) to dissociate from the KEAP1-NRF2 complex and translocate into the nucleus. This promotes the transcription of the coinhibitory molecules CD48/CD86/carcinoembryonic antigen related cell adhesion molecule 1 (CEACAM1), which bind to their corresponding receptors natural killer cell receptor 2B4/CD152/T cell immunoglobulin and mucin domain-containing protein 3 (TIM3) on the surface of T cells, inducing T-cell exhaustion. CONCLUSIONS SAMSN1 deletion augmented adaptive T cell immunity and macrophage phagocytic-proliferative dual function. Furthermore, it mediates the KEAP1-NRF2 axis, which affects the expression of coinhibitory molecules on macrophages, leading to T-cell exhaustion. This novel immunosuppression mechanism potentially provides a candidate molecular target for sepsis immunotherapy.
Animals ; NF-E2-Related Factor 2/metabolism* ; Mice ; Macrophages/immunology* ; Sepsis/metabolism* ; Kelch-Like ECH-Associated Protein 1/genetics* ; T-Lymphocytes/immunology* ; Humans ; Signal Transduction/physiology* ; RAW 264.7 Cells ; Mice, Knockout ; Mice, Inbred C57BL ; Male ; Flow Cytometry ; T-Cell Exhaustion

OBJECTIVES: To evaluate the effect of colostrum oral immune therapy (COIT) on clinical outcomes in very low birth weight (VLBW) infants. METHODS: A computer-based search was conducted in databases including China National Knowledge Infrastructure, Wanfang Data, Weipu Database, Chinese Biomedical Literature Service System, PubMed, Embase, Web of Science, the Cochrane Library, and CINAHL for randomized controlled trials regarding the application of COIT in VLBW infants published from the establishment of the database to February 2024. Meta analysis was performed using RevMan 5.3 software. RESULTS: A total of 14 randomized controlled trials were included, involving 1 386 VLBW infants, with 690 in the COIT group and 696 in the control group. The results showed that COIT significantly reduced the incidence of clinical late-onset sepsis (LOS) (RR=0.75, 95%CI: 0.64-0.88, P<0.001), the incidence of blood culture-proven LOS (RR=0.72, 95%CI: 0.57-0.92, P=0.008), mortality rate (RR=0.70, 95%CI: 0.52-0.95, P=0.020), the incidence of necrotizing enterocolitis (RR=0.65, 95%CI: 0.46-0.92, P=0.020), and the incidence of feeding intolerance (RR=0.49, 95%CI: 0.29-0.80, P=0.004). It also shortened the time to achieve full enteral nutrition (MD=-2.13, 95%CI: -4.03 to -0.23, P=0.030). CONCLUSIONS COIT can reduce the incidence rates of LOS, necrotizing enterocolitis, and feeding intolerance, as well as the mortality rate, while also shortening the time to achieve full enteral nutrition in VLBW infants.
Humans ; Infant, Very Low Birth Weight ; Colostrum/immunology* ; Infant, Newborn ; Sepsis/prevention & control* ; Randomized Controlled Trials as Topic ; Administration, Oral

OBJECTIVE: To explore the clinical application value of metagenomic next-generation sequencing (mNGS) in pathogen detection of bloodstream infection secondary to hematologic diseases in children. METHODS: 42 children with bloodstream infections secondary to hematologic diseases admitted to the Children's Hematology and Tumor Center of the Affiliated Hospital of Guangdong Medical University from November 2021 to May 2023 were included in the study, and their clinical data, results of peripheral blood mNGS and traditional blood culture, pathogen distribution characteristics, and diagnostic efficacy of mNGS were retrospectively analyzed. RESULTS: Among the 42 children included, there were 2 cases (4.8%) of aplastic anemia (AA), 27 cases (64.3%) of acute lymphoblastic leukemia (ALL), 7 cases (16.7%) of acute myeloid leukemia (AML), 1 case (2.4%) of chronic myeloid leukemia (CML), 2 cases (4.8%) of hemophagocytic lymphohistiocytosis (HLH), 2 cases (4.8%) of non-Hodgkin lymphoma (NHL), and 1 case (2.4%) of Wiskott-Aldrich syndrome (WAS). In mNGS testing, pathogens were detected in 31 peripheral blood samples, with a positive rate of 73.8% (31/42), significantly higher than the pathogen positive rate of 16.7% (7/42) detected by traditional blood culture, and the difference was statistically significant (P < 0.05). Among the pathogen-positive cases detected by mNGS, 23 cases (74.2%) were positive for bacteria, 12 cases (38.7%) were positive for viruses, and 9 cases (29.0%) were positive for fungi. 32.2% (10/31) of the pathogen-positive samples detected by mNGS were mixed pathogens, which could not be effectively detected by traditional blood culture. CONCLUSION Peripheral blood mNGS has advantages in the detection of pathogens of bloodstream infection secondary to hematologic diseases, with a higher detection rate of pathogen positivity than traditional blood cultures. It can detect viruses, rare pathogens and mixed pathogens, and has good clinical application value.
Child ; Child, Preschool ; Female ; Humans ; Male ; Hematologic Diseases/immunology* ; High-Throughput Nucleotide Sequencing ; Metagenomics ; Retrospective Studies ; Sepsis/microbiology*

Interleukin-18 (IL-18) and IL-37b have recently become a research hotspot because of their biological antagonistic role in inflammatory response. Sepsis is an abnormal inflammatory response-mediated life-threatening organ dysfunction induced by infection. Septic shock is the most severe form of sepsis, and has attracted great attention in clinical research due to its high mortality. Basophils are one of the classical effector cells in the inflammatory response, which are involved in many aspects of the pathological process of sepsis. IL-18 is an important pro-inflammatory cytokine and plays a key role in the inflammatory response, while IL-37b is known for its anti-inflammatory function. Both IL-18 and IL-37b can regulate the function of basophils and the inflammatory response in sepsis reversely through interleukin-18 receptor α (IL-18Rα). Therefore, it is of great clinical significance to investigate the role and mechanism of IL-18, IL-37b and basophils in the pathogenesis of sepsis. Herein, the relevant literatures on the roles and potential mechanisms of IL-18, IL-37b and basophils in the pathogenesis of sepsis are summarized, aiming to provide theoretical basis and novel ideas for the future research on the potential roles of IL-18, IL-37b and basophils in sepsis.
Humans ; Sepsis/immunology* ; Basophils/immunology* ; Interleukin-18/metabolism* ; Interleukin-1/metabolism* ; Animals

OBJECTIVE: To explore the clinical features of the sepsis in immunocompromised hosts and establish an early warning equation. METHODS: A retrospective study was conducted on sepsis patients admitted to the intensive care unit (ICU) of Binzhou Medical University Hospital from October 2011 to October 2022. General information, infection site, etiology results and drug susceptibility, clinical symptoms, inflammatory indicators, acute physiology and chronic health status evaluation II (APACHE II), sequential organ failure assessment (SOFA), incidence of immune paralysis, and outcome during hospitalization were collected. Based on whether they met the diagnostic criteria for immunocompromised hosts, patients were divided into immunocompromised group and immune normal group. The clinical information of the two groups were compared. Multivariate Logistic regression was used to analyze the risk factors of patients with immunocompromised sepsis and the regression equation model was initially established. Omnibus test and Hosmer-Lemeshow test were used to evaluate the model. RESULTS: A total of 169 patients with sepsis were included, including 61 in the immunocompromised group and 108 in the normal immune group. The top 3 infection sites in the immunocompromised group were bloodstream infection, pulmonary infection and abdominal infection. The top 3 infection sites in the normal immune group were pulmonary infection, bloodstream infection and abdominal infection. The infection rate of Gram-negative bacteria in the immunocompromised group was significantly lower than that in the normal group [49.2% (30/61) vs. 64.8% (70/108), P < 0.05]. The infection rate of Gram-positive bacteria [27.9% (17/61) vs. 13.9% (15/108)] and multidrug-resistant bacteria [54.1% (33/61) vs. 29.6% (32/108)] were significantly higher than those in normal immune group (both P < 0.05). In terms of clinical symptoms, the proportion of fever in the immunocompromised group was significantly lower than that in the immune normal group [49.2% (30/61) vs. 66.7% (72/108), P < 0.05]. Neutrophil count (NEU) and neutrophil percentage (NEU%) in the immunocompromised group were significantly lower than those in the normal immune group. Lymphocyte percentage (LYM%), neutrophil/lymphocyte ratio (NLR), C-reactive protein (CRP), procalcitonin (PCT), APACHE II score, combined shock rate, incidence of immune paralysis, and mortality during hospitalization in the immunocompromised group were significantly higher than those in the normal immune group. Logistic regression analysis showed that NLR, CRP and PCT were risk factors for patients with immunocompromised sepsis (all P < 0.05). The above indicators were used as covariables to construct a Logistic regression equation, that was, Logit (P) = 0.025X₁+0.010X₂+0.013X₃-2.945, where X₁, X₂ and X₃ represent NLR, CRP and PCT respectively. Omnibus test and Hosmer-Lemeshow test show that the model fits well and has certain early warning value. CONCLUSIONS Patients with immunocompromised sepsis have more intense inflammatory response, with Gram-negative bacteria being the predominant pathogen, and a higher incidence of Gram-positive bacterial infections and multi-drug resistant infections. The severity of the disease, in-hospital mortality, the incidence of shock and the incidence of immune paralysis after sepsis were significantly higher. NLR, CRP and PCT were independent risk factors for sepsis in immunocompromised hosts. The regression equation constructed based on this may have early warning significance for patients with immunocompromised sepsis.
Humans ; Sepsis/immunology* ; Immunocompromised Host ; Retrospective Studies ; Risk Factors ; Intensive Care Units ; Logistic Models ; Male ; APACHE ; Female ; Middle Aged ; Aged

Sepsis is a life-threatening organ dysfunction caused by the body's dysregulated response to infection. Reversible myocardial dysfunction caused by sepsis is known as septic cardiomyopathy. A thorough understanding of the pathogenesis of septic cardiomyopathy is crucial for early intervention to prevent its progression and improve the success rate of sepsis treatment. At present, the research on the pathogenesis of septic cardiomyopathy mainly focuses on two aspects: the systemic neuroimmune mechanism and the local changes of cardiomyocytes. The former mainly includes the autonomic nervous dysfunction mainly caused by sympathetic overactivation and the inflammatory storm induced by immune response disorder. The latter covers the dysregulation of calcium homeostasis, mitochondrial dysfunction and energy metabolism disorder of cardiomyocytes. Immune dysfunction is one of the key factors that cause the poor prognosis of patients with septic cardiomyopathy. Macrophages are sentinel cells of the body's innate immunity. Cardiac macrophages have been confirmed to be one of the most heterogeneous immune cells in the heart. According to their origin and differentiation, they can be divided into bone marrow-derived tissue infiltrating macrophages and cardiac resident macrophages, which have roles of polarization, phagocytosis, regulation of inflammatory response, and participate in innate and adaptive immunity. In the occurrence and development of septic cardiomyopathy, cardiac macrophages recruited from the blood participate in balancing the inflammation and repair of myocardial tissue through the conversion of pro-inflammatory phenotype and anti-inflammatory phenotype. Cardiac resident macrophages mediate immune phagocytosis to maintain the local homeostasis of cardiomyocytes, and the glycometabolic reprogramming of macrophages regulates the release of inflammatory factors, while macrophage metabolic reprogramming regulates the release of inflammatory factors. A deeper understanding of the biological behavior of macrophages, and regulating the polarization, metabolism and phagocytosis of cardiac macrophages, could serve as new target for the prevention and treatment of septic cardiomyopathy. Therefore, this article reviews the key pathogenesis of septic cardiomyopathy and the role of macrophages of different origins and differentiation, revealing the possibility of developing new strategies for the prevention and treatment of septic cardiomyopathy.
Humans ; Cardiomyopathies/pathology* ; Macrophages/immunology* ; Sepsis/complications* ; Myocytes, Cardiac

Acute lung injury (ALI) is a significant complication of sepsis, characterized by high morbidity, mortality, and poor prognosis. Neutrophils, as critical intrinsic immune cells in the lung, play a fundamental role in the development and progression of ALI. During ALI, neutrophils generate neutrophil extracellular traps (NETs), and excessive NETs can intensify inflammatory injury. Research indicates that Taohe Chengqi decoction (THCQD) can ameliorate sepsis-induced lung inflammation and modulate immune function. This study aimed to investigate the mechanisms by which THCQD improves ALI and its relationship with NETs in sepsis patients, seeking to provide novel perspectives and interventions for clinical treatment. The findings demonstrate that THCQD enhanced survival rates and reduced lung injury in the cecum ligation and puncture (CLP)-induced ALI mouse model. Furthermore, THCQD diminished neutrophil and macrophage infiltration, inflammatory responses, and the production of pro-inflammatory cytokines, including interleukin-1β (IL-1β), IL-6, and tumor necrosis factor α (TNF-α). Notably, subsequent experiments confirmed that THCQD inhibits NET formation both in vivo and in vitro. Moreover, THCQD significantly decreased the expression of peptidyl arginine deiminase 4 (PAD4) protein, and molecular docking predicted that certain active compounds in THCQD could bind tightly to PAD4. PAD4 overexpression partially reversed THCQD's inhibitory effects on PAD4. These findings strongly indicate that THCQD mitigates CLP-induced ALI by inhibiting PAD4-mediated NETs.
Extracellular Traps/immunology* ; Acute Lung Injury/immunology* ; Animals ; Sepsis/immunology* ; Drugs, Chinese Herbal/pharmacology* ; Mice ; Neutrophils/immunology* ; Male ; Protein-Arginine Deiminase Type 4/genetics* ; Mice, Inbred C57BL ; Humans ; Disease Models, Animal ; Cytokines/metabolism*

The COVID-19 pandemic is still raging across the world. Everyday thousands of infected people lost their lives. What is worse, there is no specific medicine and we do not know when the end of the pandemic will come. The nearest global pandemic is the 1918 influenza, which caused about 50 million deaths and partly terminate the World War Ⅰ. We believe that no matter the virus H1N1 for the 1918 influenza or 2019-nCoV for COVID-19, they are essentially the same and the final cause of death is sepsis. The definition and diagnostic/management criteria of sepsis have been modified several times but the mortality rate has not been improved until date. Over decades, researchers focus either on the immunosuppression or on the excessive inflammatory response following trauma or body exposure to harmful stimuli. But the immune response is very complex with various regulating factors involved in, such as neurotransmitter, endocrine hormone, etc. Sepsis is not a kind of disease, instead a misbalance of the body following infection, trauma or other harmful stimulation. Therefore we should re-think sepsis comprehensively with the concept of systemic biology, i.e. inflammationomics.
Betacoronavirus ; Coronavirus Infections ; complications ; epidemiology ; immunology ; Humans ; Immune Tolerance ; Inflammation ; complications ; Influenza A Virus, H1N1 Subtype ; Influenza, Human ; complications ; epidemiology ; immunology ; Pandemics ; Pneumonia, Viral ; complications ; epidemiology ; immunology ; Sepsis ; etiology

Cardiac dysfunction, a common consequence of sepsis, is the major contribution to morbidity and mortality in patients. Sodium tanshinone IIA sulfonate (STS) is a water-soluble derivative of Tanshinone IIA (TA), a main active component of Salvia miltiorrhiza Bunge, which has been widely used in China for the treatment of cardiovascular and cerebral system diseases. In the present study, the effect of STS on sepsis-induced cardiac dysfunction was investigated and its effect on survival rate of rats with sepsis was also evaluated. STS treatment could significantly decrease the serum levels of C-reactive protein (CRP), procalcitonin (PCT), cardiac troponin I (cTn-I), cardiac troponin T (cTn-T), and brain natriuretic peptide (BNP) in cecal ligation and puncture (CLP)-induced) septic rats and improve left ventricular function, particularly at 48 and 72 h after CLP. As the pathogenesis of septic myocardial dysfunction is attributable to dysregulated systemic inflammatory responses, several key cytokines, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-10 (IL-10) and high mobility group protein B1 (HMGB1), were detected to reveal the possible mechanism of attenuation of septic myocardial dysfunction after being treated by STS. Our study showed that STS, especially at a high dose (15 mg·kg), could efficiently suppress inflammatory responses in myocardium and reduce myocardial necrosis through markedly reducing production of myocardial TNF-α, IL-6 and HMGB1. STS significantly improved the 18-day survival rate of rats with sepsis from 0% to 30% (P < 0.05). Therefore, STS could suppress inflammatory responses and improve left ventricular function in rats with sepsis, suggesting that it may be developed for the treatment of sepsis.
Animals ; C-Reactive Protein ; genetics ; immunology ; Cecum ; surgery ; Drugs, Chinese Herbal ; administration & dosage ; chemistry ; Female ; Heart ; drug effects ; physiopathology ; Humans ; Interleukin-6 ; genetics ; immunology ; Ligation ; adverse effects ; Male ; Myocardium ; immunology ; Phenanthrenes ; administration & dosage ; chemistry ; Punctures ; adverse effects ; Rats ; Salvia miltiorrhiza ; chemistry ; Sepsis ; drug therapy ; etiology ; immunology ; physiopathology ; Troponin T ; genetics ; immunology ; Tumor Necrosis Factor-alpha ; genetics ; immunology

BACKGROUNDSepsis is a major cause of mortality in Intensive Care Units. Anesthetic dose isoflurane and 100% oxygen were proved to be beneficial in sepsis; however, their application in septic patients is limited because long-term hyperoxia may induce oxygen toxicity and anesthetic dose isoflurane has potential adverse consequences. This study was scheduled to find the optimal combination of isoflurane and oxygen in protecting experimental sepsis and its mechanisms.

METHODSThe effects of combined therapy with isoflurane and oxygen on lung injury and sepsis were determined in animal models of sepsis induced by cecal ligation and puncture (CLP) or intraperitoneal injection of lipopolysaccharide (LPS) or zymosan. Mouse RAW264.7 cells or human peripheral blood mononuclear cells (PBMCs) were treated by LPS to probe mechanisms. The nuclear factor kappa B (NF-κB) signaling molecules were examined by Western blot and cellular immunohistochemistry.

RESULTSThe 0.5 minimum alveolar concentration (MAC) isoflurane in 60% oxygen was the best combination of oxygen and isoflurane for reducing mortality in experimental sepsis induced by CLP, intraperitoneal injection of LPS, or zymosan. The 0.5 MAC isoflurane in 60% oxygen inhibited proinflammatory cytokines in peritoneal lavage fluids (tumor necrosis factor-alpha [TNF-β]: 149.3 vs. 229.7 pg/ml, interleukin [IL]-1β: 12.5 vs. 20.6 pg/ml, IL-6: 86.1 vs. 116.1 pg/ml, and high-mobility group protein 1 [HMGB1]: 323.7 vs. 449.3 ng/ml; all P< 0.05) and serum (TNF-β: 302.7 vs. 450.7 pg/ml, IL-1β: 51.7 vs. 96.7 pg/ml, IL-6: 390.4 vs. 722.5 pg/ml, and HMGB1: 592.2 vs. 985.4 ng/ml; all P< 0.05) in septic animals. In vitro experiments showed that the 0.5 MAC isoflurane in 60% oxygen reduced inflammatory responses in mouse RAW264.7 cells, after LPS stimulation (all P< 0.05). Suppressed activation of NF-κB pathway was also observed in mouse RAW264.7 macrophages and human PBMCs after LPS stimulation or plasma from septic patients. The 0.5 MAC isoflurane in 60% oxygen also prevented the increases of phospho-IKKβ/β, phospho-IκBβ, and phospho-p65 expressions in RAW264.7 macrophages after LPS stimulation (all P< 0.05).

CONCLUSIONCombined administration of a sedative dose of isoflurane with 60% oxygen improves survival of septic animals through reducing inflammatory responses.

Adult ; Anesthesia ; methods ; Animals ; Blotting, Western ; Bronchoalveolar Lavage Fluid ; Disease Models, Animal ; Female ; Humans ; Inflammation ; drug therapy ; Isoflurane ; therapeutic use ; Leukocytes, Mononuclear ; metabolism ; Lipopolysaccharide Receptors ; metabolism ; Lipopolysaccharides ; pharmacology ; Lung Injury ; drug therapy ; immunology ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; NF-kappa B ; metabolism ; Oxygen ; therapeutic use ; Peroxidase ; metabolism ; RAW 264.7 Cells ; Rats, Sprague-Dawley ; Sepsis ; drug therapy ; immunology ; Tumor Necrosis Factor-alpha ; metabolism