NLRP3 activation in macrophages promotes acute intestinal injury in neonatal necrotizing enterocolitis.

BACKGROUND: Macrophages are involved in various immune inflammatory disease conditions. This study aimed to investigate the role and mechanism of macrophages in regulating acute intestinal injury in neonatal necrotizing enterocolitis (NEC). METHODS: CD68, nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain-containing 3 (NLRP3), cysteine aspartate-specific protease-1 (caspase-1), and interleukin-1ß (IL-1ß) in paraffin sections of intestinal tissues from NEC and control patients were detected with immunohistochemistry, immunofluorescence, and western blot. Hypertonic pet milk, hypoxia and cold stimulation were used to establish a mouse (wild type and Nlrp3-/-) model of NEC. The mouse macrophage (RAW 264.7) and rat intestinal epithelial cell-6 lines were also cultured followed by various treatments. Macrophages, intestinal epithelial cell injuries, and IL-1ß release were determined. RESULTS: Compared to the gut "healthy" patients, the intestinal lamina propria of NEC patients had high macrophage infiltration and high NLRP3, caspase-1, and IL-1ß levels. Furthermore, in vivo, the survival rate of Nlrp3-/- NEC mice was dramatically improved, the proportion of intestinal macrophages was reduced, and intestinal injury was decreased compared to those of wild-type NEC mice. NLRP3, caspase-1, and IL-1ß derived from macrophages or supernatant from cocultures of macrophages and intestinal epithelial cells also caused intestinal epithelial cell injuries. CONCLUSIONS: Macrophage activation may be essential for NEC development. NLRP3/caspase-1/IL-1ß cellular signals derived from macrophages may be the underlying mechanism of NEC development, and all these may be therapeutic targets for developing treatments for NEC.

Non-spike and spike-specific memory T cell responses after the third dose of inactivated COVID-19 vaccine.

Background: During the COVID-19 epidemic, vaccination has become the most safe and effective way to prevent severe illness and death. Inactivated vaccines are the most widely used type of COVID-19 vaccines in the world. In contrast to spike-based mRNA/protein COVID-19 vaccines, inactivated vaccines generate antibodies and T cell responses against both spike and non-spike antigens. However, the knowledge of inactivated vaccines in inducing non-spike-specific T cell response is very limited. Methods: In this study, eighteen healthcare volunteers received a homogenous booster (third) dose of the CoronaVac vaccine at least 6 months after the second dose. CD4+ and CD8+ T cell responses against a peptide pool from wild-type (WT) non-spike proteins and spike peptide pools from WT, Delta, and Omicron SARS-CoV-2 were examined before and 1-2 weeks after the booster dose. Results: The booster dose elevated cytokine response in CD4+ and CD8+ T cells as well as expression of cytotoxic marker CD107a in CD8+ T cells in response to non-spike and spike antigens. The frequencies of cytokine-secreting non-spike-specific CD4+ and CD8+ T cells correlated well with those of spike-specific from WT, Delta, and Omicron. Activation-induced markers (AIM) assay also revealed that booster vaccination elicited non-spike-specific CD4+ and CD8+ T cell responses. In addition, booster vaccination produced similar spike-specific AIM+CD4+ and AIM+CD8+ T cell responses to WT, Delta, and Omicron, indicting strong cross-reactivity of functional cellular response between WT and variants. Furthermore, booster vaccination induced effector memory phenotypes of spike-specific and non-spike-specific CD4+ and CD8+ T cells. Conclusions: These data suggest that the booster dose of inactive vaccines broadens both non-spike-specific and spike-specific T cell responses against SARS-CoV-2.

Risk factors and outcomes of intraoperative hypothermia in neonatal and infant patients undergoing general anesthesia and surgery.

Objective: The incidence of intraoperative hypothermia remains high in pediatric patients during anesthesia and surgery even though core body temperature monitoring and warming systems have been greatly improved in recent years. We analyzed the risk factors and outcomes of intraoperative hypothermia in neonates and infants undergoing general anesthesia and surgery. Methods: The data on the incidence of intraoperative hypothermia, other clinical characteristics, and outcomes from electronic records of 1,091 patients (501 neonates and 590 infants between 28 days and 1 year old), who received general anesthesia and surgery, were harvested and analyzed. Intraoperative hypothermia was defined as a core temperature below 36°C during surgery. Results: The incidence of intraoperative hypothermia in neonates was 82.83%, which was extremely higher than in infants (38.31%, p < 0.001)-the same as the lowest body temperature (35.05 ± 0.69°C vs. 35.40 ± 0.68°C, p < 0.001) and the hypothermia duration (86.6 ± 44.5 min vs. 75.0 ± 52.4 min, p < 0.001). Intraoperative hypothermia was associated with prolonged PACU, ICU, hospital stay, postoperative bleeding, and transfusion in either age group. Intraoperative hypothermia in infants was also related to prolonged postoperative extubation time and surgical site infection. After univariate and multivariate analyses, the age (OR = 0.902, p < 0.001), weight (OR = 0.480, p = 0.013), prematurity (OR = 2.793, p = 0.036), surgery time of more than 60 min (OR = 3.743, p < 0.001), prewarming (OR = 0.081, p < 0.001), received >20 mL/kg fluid (OR = 2.938, p = 0.004), and emergency surgery (OR = 2.142, p = 0.019) were associated with hypothermia in neonates. Similar to neonates, age (OR = 0.991, p < 0.001), weight (OR = 0.783, p = 0.019), surgery time >60 min (OR = 2.140, p = 0.017), pre-warming (OR = 0.017, p < 0.001), and receive >20 mL/kg fluid (OR = 3.074, p = 0.001) were relevant factors to intraoperative hypothermia in infants along with the ASA grade (OR = 4.135, p < 0.001). Conclusion: The incidence of intraoperative hypothermia was still high, especially in neonates, with a few detrimental complications. Neonates and infants each have their different risk factors associated with intraoperative hypothermia, but younger age, lower weight, longer surgery time, received more fluid, and no prewarming management were the common risk factors.

Co-expression and interaction network analysis reveals dysregulated neutrophil and T-cell activation as the core mechanism associated with septic shock.

Septic shock as a subset of sepsis, has a much higher mortality, while the mechanism is still elusive. This study was aimed at identifying core mechanisms associated with septic shock and its high mortality by investigating transcriptome data. We screened 72 septic-shock-associated genes (SSAGs) with differential expression between septic shock and sepsis in the discovery dataset. Further gene set enrichment analysis identified upregulated neutrophil activation and impaired T-cell activation in septic shock. Co-expression analysis revealed nine co-expressed gene modules. In addition, we determined twenty-one prognostic SSAGs using cox regression analysis in an independent dataset. Moreover, protein-protein interaction (PPI) network revealed two clusters. Among these neutrophil activation was enriched in the most positively-related modules and the cluster2 PPI network, while T-cell activation was enriched in both the most negatively-related module and one of the most positively-related modules as well as the cluster1 PPI network. ELANE, LCN2 and IFI44 were identified as hub genes with CytoHubba methods and semantic similarity analysis. Notably, ELANE was the only prognostic gene and was further validated in an external dataset. Blood neutrophil count was demonstrated to increase in septic shock and be a risky factor of prognosis based on clinical data. In conclusions, septic shock is associated with upregulated neutrophil activation and dysregulated T-cell activation. Three hub genes might have potentials as sensitive markers for the further translational research and ELANE could be a robust prognostic biomarker and effective therapeutic target.