ABSTRACT
BACKGROUND/AIMS: The current study aims to investigate the protective effects of Bifidobacterium infantis on the abnormal immune response to inflammatory bowel disease (IBD) in dextran sodium sulfate (DSS)-induced colitis. METHODS: Eight-week-old BALB/c mice were separated into five groups at random (control, DSS, DSS+B9 [B. infantis 1×10⁹ CFU], DSS+B8 [B. infantis 1×10⁸ CFU], and DSS+B7 [B. infantis 1×10⁷ CFU]). Colitis was induced by 5% DSS ad libitum for 7 days, at which time we assessed weight, the disease activity index (DAI) score, and the histological damage score. The nuclear transcription factor Foxp3 (a marker of Treg cells), cytokines interleukin-10 (IL-10) and transforming growth factor β1 (TGF-β1), and related proteins (programmed cell death ligand 1 [PD-L1] and programmed cell death 1 [PD-1]) were detected by an immunohistochemical method and Western blot. RESULTS: B. infantis increased weight, decreased DAI scores and histological damage scores, increased the protein expression of Foxp3 (p<0.05) and cytokines IL-10 and TGF-β1 in mouse colon tissue (p<0.05), and increased the expression of PD-L1 in the treatment groups relative to that in the DSS group (p<0.05). The effect of B. infantis on Foxp3 and PD-L1 was dose dependent in the treatment groups (p<0.05). PD-L1 was positively correlated with Foxp3, IL-10, and TGF-β1. CONCLUSIONS: In a mouse model of IBD, B. infantis can alleviate intestinal epithelial injury and maintain intestinal immune tolerance and thus may have potential therapeutic value for the treatment of immune damage in IBD.
Subject(s)
Animals , Mice , Bifidobacterium , Blotting, Western , Cell Death , Colitis , Colon , Cytokines , Dextrans , Immune Tolerance , Inflammatory Bowel Diseases , Interleukin-10 , Methods , Models, Theoretical , Sodium , T-Lymphocytes, Regulatory , Transcription Factors , Transforming Growth FactorsABSTRACT
Objective To examine the expression levels of procalcitonin (PCT),neutrophils apolipoprotein (human neutrophil lipocalin,HNL) and neutrophil CD64 (CD64) in the blood of patients with bacterial infection and investigate their utility in early diagnosis and treatment of bacterial infection.Methods A total of 210 patients with confirmed infection who were treated in hospital from February 2013 to May 2017 were enrolled.The patients were classified into bacterial infection group (105 cases) and viral infection group (105 cases).Additionally,a cohort of 80 healthy subjects were randomly selected from health checkup during the same period as the control group.PCT and HNL were determined on the UPT up-converting phosphor microbial immunity analyzer provided by Beijing Hotgen Biotech Company.BD FACS calibur flow cytometer was used to measure and calculate CD64 percentage.Results The levels of PCT,HNL,CD64 and WBC were compared between bacterial infection group,viral infection group and control group.The between-group difference was statistically significant (P＜0.05).The CD64 and WBC levels were significantly different between viral infection group and control group (P＜0.05),but the PCT and HNL levels were not different significantly between viral infection group and control group (P＞0.05).The area under the ROC curve of PCT,namely AUC PCT,was 0.855,and AUC (HNL) was 0.930,AUC (CD64) 0.928,and AUC (WBC) 0.729.The cutoff value of PCT,HNL and CD64 for diagnosis of bacterial infections was ＞0.79 ng/mL,＞87.43 ng/mL,and ＞9.01％,respectively.Conclusions Bacterial infection is associated with elevated levels of PCT,HNL and CD64,which can be used in early diagnosis of bacterial infections.HNL may provide the highest diagnostic value.
ABSTRACT
Objective To observe the mechanisms of autophagic eukaryotic cells in Acinetobacter microvilli removal and protein histological study on apoptosis induced by macrophages .Methods A model of Acinetobacter baumannii infection was established in 24 female OCR mice .The mice were randomly divided into control group (n= 12) and observation group (n= 12) .The control group was injected with normal saline ,and the observation group was injected with autophagy eukaryotic cells ,the histopathological changes of Acinetobacter and the induction of macrophage apoptosis were observed .Results There was no significant difference in the bacterial counts between the two groups of mice immediately after implantation (P>0 .05) ,the bacterial counts in the 24 and 48 h in the observation group was significantly lower than that in the control group (P<0 .05) .The lung tissue of mice in the ob-servation group injected after autophagy was normal ,the alveolar cavity was open ,no abnormal substances were found ,the alveolar wall was not obviously thickened ,and no inflammatory cell infiltration was found in the wall .The mice in the control group were in-jected with normal saline and lacked the ability to remove Acinetobacter ,resulting in a large number of inflammatory cell infiltra-tion ,vasodilatation ,and congestion in some mice .Conclusion Autophagic eukaryotic cells injected with Acinetobacter baumannii can increase the clearance rate ,induce apoptosis of macrophages and improve the quality of Acinetobacter baumannii .
ABSTRACT
Objective To observe the mechanisms of autophagic eukaryotic cells in Acinetobacter microvilli removal and protein histological study on apoptosis induced by macrophages .Methods A model of Acinetobacter baumannii infection was established in 24 female OCR mice .The mice were randomly divided into control group (n= 12) and observation group (n= 12) .The control group was injected with normal saline ,and the observation group was injected with autophagy eukaryotic cells ,the histopathological changes of Acinetobacter and the induction of macrophage apoptosis were observed .Results There was no significant difference in the bacterial counts between the two groups of mice immediately after implantation (P>0 .05) ,the bacterial counts in the 24 and 48 h in the observation group was significantly lower than that in the control group (P<0 .05) .The lung tissue of mice in the ob-servation group injected after autophagy was normal ,the alveolar cavity was open ,no abnormal substances were found ,the alveolar wall was not obviously thickened ,and no inflammatory cell infiltration was found in the wall .The mice in the control group were in-jected with normal saline and lacked the ability to remove Acinetobacter ,resulting in a large number of inflammatory cell infiltra-tion ,vasodilatation ,and congestion in some mice .Conclusion Autophagic eukaryotic cells injected with Acinetobacter baumannii can increase the clearance rate ,induce apoptosis of macrophages and improve the quality of Acinetobacter baumannii .