Associations of Gut Microbiota and Fatty Metabolism With Immune Thrombocytopenia.

Objective: To determine whether gut microbiota, fatty metabolism and cytokines were associated with immune thrombocytopenia (ITP). Methods: In total, 29 preliminarily diagnosed ITP patients and 33 healthy volunteers were enrolled. Fecal bacterial were analyzed based on 16S rRNA sequencing. Plasma cytokines and motabolites were analyzed using flow cytometry and liquid chromatography-mass spectrometry (LC-MS), respectively. Results: Bacteroides, Phascolarctobacterium, and Lactobacillus were enriched at the genus level in ITP patients, while Ruminococcaceae UCG-002, Eubacterium coprostanoligeues, Megamonas, and Lachnospiraceae NC2004 were depleted. At the phylum level, the relative abundance of Proteobacteria and Chloroflexi increased in ITP patients, while Firmicutes, Actinobacteria, and the Firmicutes/Bacteroidetes ratio decreased. Plasma levels of 5-hydroxyeicosatetraenoic acid (5-HETE), 6-trans-12-epi-leukotriene B4 (6t,12e-LTB4), and resolvin D2 (RvD2) were upregulated, and stachydrine, dowicide A, dodecanoylcarnitine were downregulated in ITP patients. Furthermore, RvD2 is positively correlated with order Bacteroidetes VC2.1 Bac22, 5-HETE is positively correlated with genus Azospirillum, and 6t,12e-LTB4 is positively correlated with genus Cupriavidus. In addition, stachydrine is positively correlated with family Planococcaceae, dowicide A is positively correlated with class MVP-15, and dodecanoylcarnitine is positively correlated with order WCHB1-41. Plasma levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were upregulated in ITP patients. Conclusion: Our study revealed a relationship between microbiota and fatty metabolism in ITP. Gut microbiota may participate in the pathogenesis of ITP through affecting cytokine secretion, interfering with fatty metabolism.

Dynamic monitoring of circulating CD8+ T and NK cell function in patients with septic shock.

BACKGROUND: Septic shock is a great threat to human life. Our aim is to explore the immune status and dynamic changes of circulating cytotoxic cells in septic shock patients. METHODS: Forty-eight septic shock patients (9 non-survivors and 39 survivors) and 30 healthy controls (HCs) were enroled in our study. The function of cytotoxic cells was dynamically monitored by flow cytometry. RESULTS: The number of circulating CD8+ T and NK cells decreased significantly in septic shock patients, while the number of CD8+ T cells rose in survivors 5 days after admission. The frequency of HLA-DR+CD8+ T/ NK cells increased in both groups after admission but decreased in non-survivors on day 3. Moreover, the frequency of GrA+/GrB+/perforin+NK and GrB+CD8+ T cells decreased to varying degrees in both groups, and the frequency of GrB+/perforin+CD8+ T cells on the second day of non-survivors was significantly lower than that of survival patients. Besides, the frequency of CXCR3+CD8+ T/ NK cells was decreased in both groups and remained low in non-survivors, but remarkably increased in survivors after day 3. And the concentrations of cytokines IL-6, IL-10, TNF-α and IFN-γ were significantly increased in septic shock patients. CONCLUSIONS: Circulating CD8+ T and NK cells reduced but activation function was compensatory enhanced in septic shock patients. The frequency of GrB+/PFP+CD8+ T and CXCR3+CD8+ T/NK cells may predict the progression of septic shock patients 2-3 days after admission.

Low endotoxin E. coli strain-derived plasmids reduce rAAV vector-mediated immune responses both in vitro and in vivo.

The major challenge of recombinant adeno-associated virus (rAAV) vectors is host immunological barriers. Compared to the neutralizing antibody and the cytotoxic T lymphocyte response, the host immune responses induced by unsatisfactory rAAV manufacturing were largely ignored previously. rAAV vector production usually requires large amounts of plasmid DNAs. The DNA are commonly isolated from the DH5α bacterial strain, which contains lipopolysaccharide (LPS) contamination. LPS, also named endotoxin, in plasmid DNA is intractable, and residual endotoxin in the subsequent rAAV vectors may result in substantial host immune response. Recently, a ClearColi K12 bacterial strain is commercially available, with genetically modified LPS that does not trigger endotoxic response in mammalian cells. Here, we produced rAAV-DJ vectors by plasmids yielded from either DH5α or ClearColi K12 bacterial strains. Our data indicated that the ClearColi K12 strain had satisfactory protection for the rAAV inverted terminal repeat (ITR) sequence. As expected, the ClearColi K12-derived rAAV-DJ vectors had lower endotoxin levels. The physical and biological equivalency of the purified viral stocks were confirmed by electron micrographs, Coomassie blue staining, and transduction assays. Most importantly, the ClearColi K12-derived rAAV-DJ vectors triggered reduced nuclear factor-kappa B (NF-κB) signaling pathway both in cell cultures in vitro and in C57BL/6 mice retinas in vivo. We believe that the use of the ClearColi K12 bacterial strain could eliminate the LPS in the purified vector stock at the source. Our data indicate its promising use in future clinical development.

Highly activated TRAIL+ CD56bright NK cells are associated with the liver damage in HBV-LC patients.

BACKGROUND: Chronic hepatitis B-related liver cirrhosis(HBV-LC)is the most common cirrhosis in China, which is characterized as liver damage and high mortality. We aim to investigate the characteristics of TRAIL+NK cells in patients with HBV-LC and their relationship with liver damage in patients with HBV-LC. METHODS: Thirty cases each of chronic hepatitis B (CHB), HBV-related compensated liver cirrhosis (HBV-CLC) and HBV-related decompensated liver cirrhosis (HBV-DLC) patients were recruited in this study. Thirty age-and sex-matched healthy individuals were recruited as healthy controls (HCs). NK cell phenotypes were determined using flow cytometry. Serum chemokine concentrations were ascertained using the CBA Flex set. Cell apoptosis was analyzed using the Annexin V-PE/7-AAD apoptosis Kit. RESULTS: CD56bright NK cells increased, but CD56dim NK cells reduced in HBV-LC patients. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) was mainly expressed on CD56bright NK cells. As the degree of liver damage increased, the frequency and activation of total TRAIL+NK cells and TRAIL+NK cell subsets continued to increase, especially in the HBV-LC patients. Furthermore, the difference in frequency and activation of total TRAIL+NK cells between the HBV-CLC and HBV-DLC groups was mainly due to the highly activation and increase of TRAIL+CD56bright NK cells. With the increasing degree of liver damage, CXCR3-associated chemokines (including CXCL9, CXCL10 and CXCL11) were constantly increased, particularly in the HBV-DLC group. The expression of CXCR3 on CD56bright NK cells was almost 100 % in all enrolled cohorts. CXCR3-associated chemokines were negatively correlated with liver function and positively correlated with fibrosis degree. TRAIL+CD56bright NK cells were negatively correlated with liver function, and positively correlated with fibrosis degree and CXCR3-associated chemokines. The apoptosis of K562 cells and hepatocytes was suppressed partially by the TRAIL-neutralizing antibodies. CONCLUSIONS: The increase of CXCR3-related chemokines (including CXCL9, CXCL10 and CXCL11) might be related to the migration of TRAIL+ CD56bright NK cells to the liver. Highly activated TRAIL+ CD56bright NK cells were associated with the liver damage in HBV-LC patients. These findings may provide new perspectives and theoretical basis for future immunotherapy of HBV-LC patients.

Evodiamine inhibits high-fat diet-induced colitis-associated cancer in mice through regulating the gut microbiota.

OBJECTIVE: High-fat diet is one of the main risk factors that disrupt the balance of gut microbiota, which eventually will induce colorectal cancer (CRC). Evodiamine (EVO) is a wildly used multifunctional traditional Chinese medicine extract. In this study, we investigated the role of gut microbiota in high-fat diet-propelled CRC and the potential of EVO for CRC chemoprevention. METHODS: Gut microbiota, serum d-lactic acid and endotoxin from 38 patients with colon cancer and 18 healthy subjects were detected by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA). In addition, body mass index, phospho-signal transducer and activator of transcription 3 (p-STAT3) expression in cancer tissues and paracancerous tissues were detected by immunohistochemistry. A mouse intestinal inflammatory tumor model was established by azomethane/sodium dextran sulfate, followed by treatment with EVO and 5-aminosalicylic acid (ASA). Gut microbiota and inflammatory factors were detected by quantitative polymerase chain reaction, while serum d-lactic acid and endotoxin were detected by ELISA. Furthermore, cell proliferation, cell apoptosis, and interleukin (IL)-6/STAT3/P65 pathway were evaluated by 5-ethynyl-2'-deoxyuridine, terminal-deoxynucleotidyl transferase-mediated nick-end labeling, and Western blot assays. RESULTS: In patients with colon cancer, the numbers of Enterococcus faecalis and Escherichia coli were increased, while those of Bifidobacterium, Campylobacter and Lactobacillus were decreased. Serum endotoxin and d-lactic acid levels and p-STAT3 levels were significantly increased. In the mouse model, both EVO and ASA inhibited tumor formation, decreased the proliferation of tumor cells, and induced apoptosis of tumor cells. Compared with the control group, the numbers of E. faecalis and E. coli were decreased, while Bifidobacterium, Campylobacter and Lactobacillus numbers were increased. In the EVO group, serum endotoxin and d-lactic acid levels and inflammatory factors were significantly decreased. Further, the IL6/STAT3/P65 signaling pathway was inhibited in the EVO group. CONCLUSION: EVO may inhibit the occurrence of colon cancer by regulating gut microbiota and inhibiting intestinal inflammation. The potential mechanism involves inhibition of the IL6/STAT3/P65 signaling pathway, revealing its potential therapeutic significance in clinical applications.