Dynamic changes of Bacterial Microbiomes in Oropharynx during Infection and Recovery of COVID-19 Omicron Variant.

Oropharyngeal microbiomes play a significant role in the susceptibility and severity of COVID-19, yet the role of these microbiomes play for the development of COVID-19 Omicron variant have not been reported. A total of 791 pharyngeal swab samples were prospectively included in this study, including 297 confirmed cases of Omicron variant (CCO), 222 confirmed case of Omicron who recovered (CCOR), 73 confirmed cases of original strain (CCOS) and 199 healthy controls (HC). All samples completed MiSeq sequencing. The results showed that compared with HC, conditional pathogens increased in CCO, while acid-producing bacteria decreased. Based on six optimal oropharyngeal operational taxonomy units (OTUs), we constructed a marker microbial classifier to distinguish between patients with Omicron variant and healthy people, and achieved high diagnostic efficiency in both the discovery queue and the verification queue. At same time, we introduced a group of cross-age infection verification cohort and Omicron variant subtype XBB.1.5 branch, which can be accurately distinguished by this diagnostic model. We also analyzed the characteristics of oropharyngeal microbiomes in two subgroups of Omicron disease group-severity of infection and vaccination times, and found that the change of oropharyngeal microbiomes may affect the severity of the disease and the efficacy of the vaccine. In addition, we found that some genera with significant differences gradually increased or decreased with the recovery of Omicron variant infection. The results of Spearman analysis showed that 27 oropharyngeal OTUs were closely related to 6 clinical indexes in CCO and HC. Finally, we found that the Omicron variant had different characterization of oropharyngeal microbiomes from the original strain. Our research characterizes oropharyngeal microbiomes of Omicron variant cases and rehabilitation cases, successfully constructed and verified the non-invasive diagnostic model of Omicron variant, described the correlation between microbial OTUs and clinical indexes. It was found that the infection of Omicron variant and the infection of original strain have different characteristics of oropharyngeal microbiomes.

Alterations in the human oral microbiota in systemic lupus erythematosus.

BACKGROUND: Alterations in oral microbiota in patients with systemic lupus erythematosus (SLE) is less evaluated. The aim of this study was to compare the characteristics of the oral microbiome in SLE patients and healthy controls, and construct an SLE classifier based on the oral microbiota. METHODS: We sequenced tongue-coating samples of individuals in treatment-naïve SLE (n = 182) and matched healthy controls (n = 280). We characterized the oral microbiome and constructed a microbial classifier in the derivation cohort and validated the results in the validation cohorts. Furthermore, the oral microbiome of posttreatment SLE (n = 73) was characterized. RESULTS: The oral microbial diversity of SLE was increased, and the microbial community was different between SLE and healthy controls. The genera Prevotella and Veillonella were enriched, while Streptococcus and Porphyromonas were reduced in SLE. In addition, an increase was noted in 27 predicted microbial functions, while a decrease was noted in 34 other functions. Thirty-nine operational taxonomy units (OTUs) were identified to be related with seven clinical indicators. Two OTUs were identified to construct a classifier, which yielded area under the curve values of 0.9166 (95% CI 0.8848-0.9483, p < 0.0001), 0.8422 (95% CI 0.7687-0.9157, p < 0.0001), and 0.8406 (95% CI 0.7677-0.9135, p < 0.0001) in the derivation, validation, and cross-regional validation groups, respectively. Moreover, as disease activity increased, Abiotrophia and Lactobacillales increased, while Phyllobacterium and unclassified Micrococcusaceae decreased. Finally, nine OTUs were selected to construct a classifier distinguishing posttreatment SLE patients from healthy controls, which achieved a diagnostic efficacy of 0.9942 (95% CI 0.9884-1, p < 0.0001). CONCLUSIONS: Our study comprehensively characterizes the oral microbiome of SLE and shows the potential of the oral microbiota as a non-invasive diagnostic biomarker in SLE.

Low-intensity transcranial ultrasound stimulation modulates neural activities in mice under propofol anaesthesia.

BACKGROUND: Previous studies have reported that transcranial focused ultrasound stimulation can significantly decrease the time to emergence from intraperitoneal ketamine-xylazine anaesthesia in rats. However, how transcranial focused ultrasound stimulation modulates neural activity in anaesthetized rats is unclear. METHODS: In this study, to answer this question, we used low-intensity transcranial ultrasound stimulation (TUS) to stimulate the brain tissue of propofol-anaesthetized mice, recorded local field potentials (LFPs) in the mouse motor cortex and electromyography (EMG) signals from the mouse neck, and analysed the emergence and recovery time, mean absolute power, relative power and entropy of local field potentials. RESULTS: We found that the time to emergence from anaesthesia in the TUS group (20.3 ± 1.7 min) was significantly less than that in the Sham group (32 ± 2.6 min). We also found that compared with the Sham group, 20 min after low-intensity TUS during recovery from anaesthesia, (1) the absolute power of local field potentials in mice was significantly reduced in the [1-4 Hz] and [13-30 Hz] frequency bands and significantly increased in the [55-100 Hz], [100-140 Hz] and [140-200 Hz] frequency bands; (2) the relative power of local field potentials in mice was enhanced at [30-45 Hz], [100-140 Hz] and [140-200 Hz] frequency bands; (3) the entropy of local field potentials ([1-200 Hz]) was increased. CONCLUSION: These results demonstrate that low-intensity TUS can effectively modulate neural activities in both awake and anaesthetized mice and has a positive effect on recovery from propofol anaesthesia in mice.

Alterations in the human oral and gut microbiomes and lipidomics in COVID-19.

OBJECTIVE: To characterise the oral microbiome, gut microbiome and serum lipid profiles in patients with active COVID-19 and recovered patients; evaluate the potential of the microbiome as a non-invasive biomarker for COVID-19; and explore correlations between the microbiome and lipid profile. DESIGN: We collected and sequenced 392 tongue-coating samples, 172 faecal samples and 155 serum samples from Central China and East China. We characterised microbiome and lipid molecules, constructed microbial classifiers in discovery cohort and verified their diagnostic potential in 74 confirmed patients (CPs) from East China and 37 suspected patients (SPs) with IgG positivity. RESULTS: Oral and faecal microbial diversity was significantly decreased in CPs versus healthy controls (HCs). Compared with HCs, butyric acid-producing bacteria were decreased and lipopolysaccharide-producing bacteria were increased in CPs in oral cavity. The classifiers based on 8 optimal oral microbial markers (7 faecal microbial markers) achieved good diagnostic efficiency in different cohorts. Importantly, diagnostic efficacy reached 87.24% in the cross-regional cohort. Moreover, the classifiers successfully diagnosed SPs with IgG antibody positivity as CPs, and diagnostic efficacy reached 92.11% (98.01% of faecal microbiome). Compared with CPs, 47 lipid molecules, including sphingomyelin (SM)(d40:4), SM(d38:5) and monoglyceride(33:5), were depleted, and 122 lipid molecules, including phosphatidylcholine(36:4p), phosphatidylethanolamine (PE)(16:0p/20:5) and diglyceride(20:1/18:2), were enriched in confirmed patients recovery. CONCLUSION: This study is the first to characterise the oral microbiome in COVID-19, and oral microbiomes and lipid alterations in recovered patients, to explore their correlations and to report the successful establishment and validation of a diagnostic model for COVID-19.

CircRNA circ-0038718 promotes hepatocellular carcinoma progression through sponging miR-139-3p.

Hepatocellular Carcinoma (HCC) is the main histological subtype of liver malignancy with poor prognosis. A growing body of evidence showed that Circular RNAs (circRNAs) are related to HCC tumorigenesis and progression. In this study, we investigated the function and regulation of circ-0038718 in HCC. We found that circ-0038718 was frequently elevated in HCC specimens and cell lines. High expression levels of circ-0038718 were correlated with unfavorable prognosis in HCC patients. Furthermore, we demonstrated that knockdown of circ-0038718 attenuated HCC cell proliferation and metastatic abilities, while overexpression of circ-0038718 resulted the converse effect. Silencing circ-0038717 inhibited HCC xenograft tumor development in vivo. Mechanistically, circ-0038718 acted as the sponge of tumor-suppressive miR-139-3p to regulate HCC progression. Rescue experiments suggested the oncogenic activity of circ-0038718 was partially exerted via modulating miR-139-3p expression. Inhibition of miR-139-3p abrogated the regulatory effect of circ-0038718 in HCC cells. In summary, our results unveiled that circ-0038718 could serve as an crucial regulator of HCC progression and provide a potential therapeutic target for HCC treatment.

Nanoparticle Conjugation of Ginsenoside Rg3 Inhibits Hepatocellular Carcinoma Development and Metastasis.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. The prognosis of HCC remains very poor; thus, an effective treatment remains urgent. Herein, a type of nanomedicine is developed by conjugating Fe@Fe3 O4 nanoparticles with ginsenoside Rg3 (NpRg3), which achieves an excellent coupling effect. In the dimethylnitrosamine-induced HCC model, NpRg3 application significantly prolongs the survival of HCC mice. Further research indicates that NpRg3 application significantly inhibits HCC development and eliminates HCC metastasis to the lung. Notably, NpRg3 application delays HCC-induced ileocecal morphology and gut microbial alterations more than 12 weeks during HCC progression. NpRg3 administration elevates the abundance of Bacteroidetes and Verrucomicrobia, but decreases Firmicutes. Twenty-nine predicted microbial gene functions are enriched, while seven gene functions are reduced after NpRg3 administration. Moreover, the metabolomics profile presents a significant progression during HCC development, but NpRg3 administration corrects tumor-dominant metabolomics. NpRg3 administration decreases 3-indolepropionic acid and urea, but elevates free fatty acids. Importantly, NpRg3 application remodels the unbalanced correlation networks between gut microbiota and metabolism during HCC therapy. In conclusion, nanoparticle conjugation of ginsenoside Rg3 inhibits HCC development and metastasis via the remodeling of unbalanced gut microbiota and metabolism in vivo, providing an antitumor therapy strategy.

UBQLN4 promotes progression of HCC via activating wnt-ß-catenin pathway and is regulated by miR-370.

BACKGROUND: Ubiquilin-4 (UBQLN4) is a member of the ubiquitin-proteasome system that is usually upregulated in many tumor cells. Its overexpression has been associated with poor disease outcomes in various cancer diseases. However, the underlying mechanism of UBQLN4 in the development of hepatocellular carcinoma (HCC) has not been elucidated. METHODS: Immunochemistry, real-time PCR, and western blotting were used to evaluate the expression levels of UBQLN4 in cancer tissues. Univariate, Cox-regression, and Kaplan-Meier analyses were performed to determine the association between UBQLN4 expression and HCC prognosis. Cell Counting Kit-8 (CCK-8), transwell, EDU and colony formation assays were conducted to evaluate the role of UBQLN4 in HCC cell progression. The gene set enrichment analysis and luciferase reporter experiments were conducted to find the mechanism of UBQLN4 in HCC. RESULTS: Ubiquilin-4 (UBQLN4) was overexpressed in HCC tissues. Besides, overexpression of UBQLN4 was associated with poor overall survival and disease-free survival rate of HCC patients. The loss-of-function analysis revealed that suppression of UBQLN4 inhibited the proliferation and invasion of HCC cells in vivo and in vitro. The KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis showed that UBQLN4 could regulate activation of the wnt-ß-catenin pathway in HCC cells. Furthermore, our results showed that UBQLN4 was downregulated by miR-370, which acted as a tumor suppressor gene in HCC progression. CONCLUSION: The results of the present study suggest that the miR-370/UBQLN4 axis may play a critical role in the progression of HCC. These findings may inform future strategies for the development of therapeutic agents against HCC.

Human microbiome is a diagnostic biomarker in hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality worldwide. Increasing evidence indicates a close relationship between HCC and the human microbiota. Herein, we reviewed the important potential of the human microbiota as a diagnostic biomarker of HCC. DATA SOURCES: Several innovative studies have investigated the characteristics of the gut and oral microbiomes in patients with HCC and proposed that the human microbiome has the potential to be a diagnostic biomarker of HCC. Literature from February 1999 to February 2019 was searched in the PubMed database using the keywords "microbiota" or "microbiome" or "microbe" and "liver cancer" or "hepatocellular carcinoma", and the results of clinical and experimental studies were analyzed. RESULTS: Specific changes occur in the human microbiome of patients with HCC. Moreover, the gut microbiome and oral microbiome can be used as non-invasive diagnostic biomarkers for HCC. Furthermore, they also have certain diagnostic potential for precancerous diseases of HCC. The diagnostic potential of the blood microbiota and ascites microbiota in HCC will be gradually discovered in the future. CONCLUSIONS: The human microbiome is valuable to the diagnosis of HCC and provides a novel strategy for targeted therapy of HCC. The human microbiome may be widely used in the diagnosis, treatment and prognosis for multiple system diseases or cancers in the future.

Gut microbiome analysis as a tool towards targeted non-invasive biomarkers for early hepatocellular carcinoma.

OBJECTIVE: To characterise gut microbiome in patients with hepatocellular carcinoma (HCC) and evaluate the potential of microbiome as non-invasive biomarkers for HCC. DESIGN: We collected 486 faecal samples from East China, Central China and Northwest China prospectively and finally 419 samples completed Miseq sequencing. We characterised gut microbiome, identified microbial markers and constructed HCC classifier in 75 early HCC, 40 cirrhosis and 75 healthy controls. We validated the results in 56 controls, 30 early HCC and 45 advanced HCC. We further verified diagnosis potential in 18 HCC from Xinjiang and 80 HCC from Zhengzhou. RESULTS: Faecal microbial diversity was increased from cirrhosis to early HCC with cirrhosis. Phylum Actinobacteria was increased in early HCC versus cirrhosis. Correspondingly, 13 genera including Gemmiger and Parabacteroides were enriched in early HCC versus cirrhosis. Butyrate-producing genera were decreased, while genera producing-lipopolysaccharide were increased in early HCC versus controls. The optimal 30 microbial markers were identified through a fivefold cross-validation on a random forest model and achieved an area under the curve of 80.64% between 75 early HCC and 105 non-HCC samples. Notably, gut microbial markers validated strong diagnosis potential for early HCC and even advanced HCC. Importantly, microbial markers successfully achieved a cross-region validation of HCC from Northwest China and Central China. CONCLUSIONS: This study is the first to characterise gut microbiome in patients with HCC and to report the successful diagnosis model establishment and cross-region validation of microbial markers for HCC. Gut microbiota-targeted biomarkers represent potential non-invasive tools for early diagnosis of HCC.

Thrombin cleavage of osteopontin controls activation of hepatic stellate cells and is essential for liver fibrogenesis.

Liver biopsy is the current reliable way of evaluating liver fibrosis. However, no specific sera biomarker could be applied in clinical diagnosis. As the pivotal role of osteopontin (OPN) reported in numerous liver diseases, thrombin-cleaved OPN (Thr-OPN) exposes an integrin-binding motif that promoted biological functions. Herein, we investigated the potential of Thr-OPN in liver fibrosis. Using patient samples, mouse models and hepatic stellate cells (HSCs), we analyzed the involvement of Thr-OPN in liver fibrosis. The result showed that, first, Thr-OPN level was significantly higher in patients with liver cirrhosis than that in patients with chronic hepatitis B and healthy controls. Thr-OPN level was positively correlated with liver fibrosis degree in clinical samples. Then in mouse models, it showed a similar correlation between hepatic Thr-OPN levels and liver fibrosis degree. Thr-OPN peptides exacerbated liver fibrosis in OPN-deficient mice, whereas the neutralization of Thr-OPN alleviated liver fibrosis in wild-type mice. Furthermore, when compared with full-length OPN (FL-OPN), Thr-OPN exhibited a greater ability to promote HSC activation, proliferation, and migration via mitogen-activated protein (MAP) kinase and nuclear factor (NF)-κB pathways. In conclusion, Thr-OPN, not FL-OPN, was critically involved in the exacerbation of liver fibrosis by α9 and α4 integrins via MAP kinase and NF-κB signaling pathway, thus representing a novel diagnostic biomarker and treatment target for liver cirrhosis.

Long non-coding RNA PVT1 promotes tumor progression by regulating the miR-143/HK2 axis in gallbladder cancer.

BACKGROUND: The long non-coding RNA PVT1 (lncRNA PVT1) has been reported to act as an oncogenic regulator of several cancers. However, its expression and function in gallbladder cancer (GBC) remain largely unknown. METHODS: In situ hybridization (ISH) and quantitative real-time PCR (qPCR) were performed to detect the expression of PVT1 and miR-143 in GBC tissues and cell lines. Immunohistochemistry (IHC) assays were performed to assess the expression of the hexokinase 2 (HK2) protein. The relationships among PVT1, miR-143 and HK2 were evaluated using dual-luciferase reporter, RNA immunoprecipitation (RIP) and biotin pull-down assays. The biological functions of PVT1, miR-143 and HK2 in GBC cells were explored with cell counting kit 8 (CCK-8), 5-ethynyl-20-deoxyuridine (EdU), colony formation, transwell, wound healing and glucose metabolism assays in vitro. For in vivo experiments, a xenograft model was used to investigate the effects of PVT1 and HK2 on GBC. RESULTS: PVT1 was upregulated in GBC tissues and cells and was positively associated with malignancies and worse overall survival. PVT1 knockdown inhibited cell proliferation, migration, and invasion in vitro and restrained tumor growth in vivo. Further studies demonstrated that PVT1 positively regulated HK2 expression via its competing endogenous RNA (ceRNA) activity on miR-143. Additionally, HK2 expression and function were positively correlated with PVT1. Furthermore, we observed that the PVT1/miR-143/HK2 axis promoted cell proliferation and metastasis by regulating aerobic glucose metabolism in GBC cells. CONCLUSIONS: The results of our study reveal a potential ceRNA regulatory pathway in which PVT1 modulates HK2 expression by competitively binding to endogenous miR-143 in GBC cells, which may provide new insights into novel molecular therapeutic targets for GBC.

Low microRNA-139 expression associates with poor prognosis in patients with tumors: A meta-analysis.

BACKGROUND: microRNA-139 (miR-139) is dysregulated in various types of tumors and plays a key role in carcinogenesis. miR-139 may be used as a diagnostic and prognostic biomarker of cancers. However, the data from the literature are not consistent. The present study aimed to verify the prognostic and diagnostic values of miR-139 in solid tumors. DATA SOURCES: PubMed, Web of Science and Embase databases were searched and publications from January 2011 to August 2017 were included. We used Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) database to further validate this meta-analysis. RESULTS: Eight individual studies from seven articles were included. Pooled analyses showed that low miR-139 expression was related to worse overall survival (OS) [hazard ratio (HR) = 2.27; 95% confidence intervals (CI): 1.74-2.95; P < 0.001] in solid tumors, including hepatocellular carcinoma (HCC) and glioblastoma multiforme (GBM), consisting with the results of TCGA. However, our results of CRC showed that low miR-139 expression was associated with poor OS which was contradictory with the results in TCGA database and need larger samples to validate the phenomenon; whereas for CRC patients, high miR-139 expression predicted poor RFS, which was in good accordance with TCGA results. The results of 27 microarrays from GEO database showed that miR-139 expression levels were lower in tumor tissues compared to adjacent non-tumor tissues or healthy tissues. Decreased miR-139 expression was also significantly correlated with poor differentiation grade (OR = 3.57; 95% CI: 1.44-8.85; P = 0.006). However, the combined data indicated that no associations between miR-139 expression and the following parameters such as age (pooled OR = 1.50; 95% CI: 0.69-3.24; P = 0.304), gender (pooled OR = 0.92; 95% CI: 0.56-1.51; P = 0.738), tumor size (pooled OR = 1.51; 95% CI: 0.69-3.31; P = 0.298), late tumor-node-metastasis stage (pooled OR = 1.63; 95% CI: 0.99-2.68; P = 0.057) and lymph-node-metastasis (pooled OR = 0.66; 95% CI: 0.34-1.28; P = 0.222). CONCLUSIONS: Low miR-139 expression was related to poor prognosis in HCC and GBM, which could be regarded as a potential prognostic biomarker. However, its precise functional role in CRC still need to be further investigated through larger samples and multicenter studies.

Coreopsis Tinctoria Modulates Lipid Metabolism by Decreasing Low-Density Lipoprotein and Improving Gut Microbiota.

BACKGROUND/AIMS: The prevalence of hyperlipidemia is increasing rapidly. The role of Coreopsis tinctoria (CT) in amending lipid metabolism in hyperlipidemia patients has not been reported. This study aims to evaluate the role of CT in altering lipid metabolism in hyperlipidemia patients and to explore the possible mechanisms mediated by gut microbiota in hyperlipidemia mice models. METHODS: A retrospective analysis in 40 hyperlipidemia patients was conducted, in which 20 patients took fenofibrate and another 20 patients normatively drank water with CT. Hyperlipidemia mice models were also established. Blood biochemical tests were performed using an automatic biochemical analyzer. Liver histopathology was observed by hematoxylin and eosin staining. Ileocecal samples were collected from mice, and bacterial DNA was extracted and sequenced by MiSeq sequencing. Bacterial composition and differences were analyzed. RESULTS: In hyperlipidemia patients, CT was associated with decreased triglyceride and low-density lipoprotein (LDL) levels without liver injury. The experimental hyperlipidemia model also verified a similar result. Gut microbial richness and diversity were significantly decreased in hyperlipidemic mice, but increased after CT treatment. Bacterial communities were significantly differentiated between normal controls and hyperlipidemic mice. CT administration improved gut microbiota composition to an approximately normal status. Meanwhile, CT administration attenuated bacterial alterations at the class, order, family, and genus levels in hyperlipidemic mice. Importantly, the genera Barnesiella, Lactobacillus, and Helicobacter achieved high discriminatory power in hyperlipidemic mice relative to normal controls. CONCLUSIONS: CT can modulate blood lipid metabolism with improvement of liver function by decreasing LDL and improving gut microbiota compositions. These findings may provide novel therapeutic strategies for patients with hyperlipidemia.

LDHA is a direct target of miR-30d-5p and contributes to aggressive progression of gallbladder carcinoma.

Gallbladder cancer (GBC) is the most general biliary tract malignancy, with poor prognosis due to rapid tumor progression and lack of specific symptoms. Lactate dehydrogenase-A (LDHA) can promote Warburg effect to produce lactate and Adenosine Triphosphate (ATP) in aerobic condition, which contributes to oncogenesis metastasis and drug resistance in various cancers. However, the expression and functional role of LDHA in GBC are largely unknown. We determined that LDHA was over-expressed in GBC tumor tissues compared with normal tissues, which was also an independent prognostic factor for the overall survival of GBC patients by tissue microarrays analysis. In addition, RNAi-mediated LDHA silencing could suppress the GBC cell proliferation, invasion, colony formation and glycolysis while promoting cell apoptosis in vitro. Similar results were observed in GBC cells treated with LDHA specific inhibitor FX11. Moreover, we confirmed that knockdown of LDHA could inhibit tumor growth in vivo. Additionally, we found that the 3'-untranslated region (3'-UTR) of LDHA mRNA was the direct target of microRNA-30d-5p (miR-30d-5p), which was low expressed in GBC tissues and associated with poor prognosis of GBC patients. Our findings disclose a novel role for miR-30d-5p/LDHA axis contribute to aggressive progression by reprogramming the metabolic process in GBC cells, and suggest a potential application of miR-30d-5p/LDHA axis in prognosis prediction and GBC treatment.

Cetuximab Enhanced the Cytotoxic Activity of Immune Cells during Treatment of Colorectal Cancer.

BACKGROUND/AIMS: Cetuximab is a chimeric IgG1 monoclonal antibody which targets the extracellular domain of epidermal growth factor receptor. This antibody is widely used for colorectal cancer (CRC) treatment but its influence on the immune system is incompletely understood. METHODS: The immune influence of cetuximab therapy in CRC patients was investigated by analyzing peripheral blood mononuclear cells using flow cytometry. We undertook in vitro cytotoxicity and cytokine-profile assays to ascertain the immunomodulatory effect of cetuximab treatment. RESULTS: The number of CD3+ T, CD8+ T, and natural killer (NK) cells was increased significantly and T-regulatory cells reduced gradually after cetuximab treatment. Percentage of CD4+ T, natural killer T (NKT)-like, invariant NKT, and dendritic cells was similar between baseline patients and cetuximab patients. Expression of CD137 on NK and CD8+ T cells was increased significantly after 4 weeks of cetuximab therapy. In vitro cetuximab treatment markedly increased expression of CD137 and CD107a on NK and CD8+ T cells. Cetuximab treatment promoted the cytotoxic activity of NK and CD8+ T cells against tumor cells. CONCLUSION: Cetuximab treatment promotes activation of the immune response but alleviates immunosuppression: this might be the underlying anti-CRC effect of cetuximab.

Analysis of the Repertoire Features of TCR Beta Chain CDR3 in Human by High-Throughput Sequencing.

BACKGROUND/AIMS: To ward off a wide variety of pathogens, the human adaptive immune system harbors a vast array of T-cell receptors, collectively referred to as the TCR repertoire. Assessment of the repertoire features of TCR is vital for us to deeper understand of immune behaviour and immune response. METHODS: In this study, we used a combination of multiplex-PCR, Illumina sequencing and IMGT (ImMunoGeneTics)/HighV-QUEST for a standardized analysis of the repertoire features of TCR beta chain in the blood of healthy individuals, including the repertoire features of public TCR complementarity-determining regions (CDR3) sequences, highly expanded clones, long TCR CDR3 sequences. RESULTS: We found that public CDR3 sequences and high-frequency sequences had the same characteristics, both of them had fewer nucleotide additions and shorter CDR3 length, which were closer to the germline sequence. Moreover, our studies provided evidence that public amino acid sequences are produced by multiple nucleotide sequences. Notably, there was skewed VDJ segment usage in long CDR3 sequences, the expression levels of 10 TRßV segments, 7 TRßJ segments and 2 TRßD segments were significantly different in the long CDR3 sequences compared to the short CDR3 sequences. Moreover, we identified that extensive N additions and increase of D gene usage contributing to TCR CDR3 length, and observed there was distinct usage frequency of amino acids in long CDR3 sequences compared to the short CDR3 sequences. CONCLUSIONS: Some repertoire features could be observed in the public sequences, highly abundance clones, and long TCR CDR3 sequences, which might be helpful for further study of immune behavior and immune response.

Decreased IL-17 during treatment of sputum smear-positive pulmonary tuberculosis due to increased regulatory T cells and IL-10.

BACKGROUND: Tuberculosis (TB) remains a major public health concern worldwide. Previous studies have demonstrated that IL-17 plays an important role in initial immune response and is involved in both immune-mediated protection and pathology following infection with Mycobacterium tuberculosis (MTB). However, the alterations and regulation of plasma IL-17 level during TB treatment remain unclear. Moreover, the cell type responsible for the production of IL-17 in TB patients requires further study. METHODS: A total of 20 acid-fast bacilli smear-positive (AFB-positive) pulmonary TB patients and 20 age- and gender-matched healthy volunteers were included in our study. Blood samples were collected in heparinized tubes at the time of diagnosis (AFB-positive group) and 3 weeks after the initiation of therapy, when the sputum smear conversion (AFB-negative group) occurred, followed by symptomatic improvement. IL-17 levels and IL-17-producing cells in PBMCs were detected. Lymphocyte populations in the peripheral blood between the AFB-positive and AFB-negative groups were compared by flow-cytometry. A549 cells, a cell line of alveolar epithelial cells, were applied to determine the extent of the pathological damage mediated by IL-17 following MTB infection. Recombinant human IL-10 was used to investigate the regulation of IL-17 expression after sputum smear conversion in AFB-positive pulmonary TB patients. RESULTS: Plasma IL-17 level were elevated in patients with sputum AFB-positive pulmonary TB, but substantially decreased after TB treatment and smear conversion. Our data indicate that NKT-like cells might be the main source of IL-17, in addition to conventional T cells in AFB-positive pulmonary TB patients. The secretion of IL-17 may be suppressed by regulatory T (Treg) cells and IL-10 during TB treatment. Moreover, the IL-17 levels were positively correlated to both the C-reactive protein and erythrocyte sedimentation rate. Therefore, IL-17 was capable of alveolar epithelial cell damage following MTB infection. CONCLUSION: The increase in the frequency of Treg cells and IL-10 levels was associated with a decrease in IL-17 in patients receiving TB treatment. Thus, IL-10 and Tregs may function to inhibit immune-mediated pathology in TB patients.

Regular Exercise Enhances the Immune Response Against Microbial Antigens Through Up-Regulation of Toll-like Receptor Signaling Pathways.

BACKGROUND/AIMS: Regular physical exercise can enhance resistance to many microbial infections. However, little is known about the mechanism underlying the changes in the immune system induced by regular exercise. METHODS: We recruited members of a university badminton club as the regular exercise (RE) group and healthy sedentary students as the sedentary control (SC) group. We investigated the distribution of peripheral blood mononuclear cell (PBMC) subsets and functions in the two groups. RESULTS: There were no significant differences in plasma cytokine levels between the RE and SC groups in the true resting state. However, enhanced levels of IFN-γ, TNF-α, IL-6, IFN-α and IL-12 were secreted by PBMCs in the RE group following microbial antigen stimulation, when compared to the SC group. In contrast, the levels of TNF-α and IL-6 secreted by PBMC in the RE group were suppressed compared with those in SC group following non-microbial antigen stimulation (concanavalin A or α-galactosylceramide). Furthermore, PBMC expression of TLR2, TLR7 and MyD88 was significantly increased in the RE group in response to microbial antigen stimulation. CONCLUSION: Regular exercise enhances immune cell activation in response to pathogenic stimulation leading to enhanced cytokine production mediated via the TLR signaling pathways.