Klebsiella aerogenes exacerbates colon tumorigenesis in the AOM/DSS-induced C57BL/6J mouse.

Klebsiella aerogenes (K. aerogenes, KA) is a gram-negative opportunistic pathogen from the Klebsiella species and the Enterobacteriaceae family. However, the impact of K. aerogenes on colorectal cancer (CRC) remains uncertain. A colitis-associated tumorigenesis animal model was established by administering azoxymethane (AOM) and dextran sulfate sodium (DSS) to C57BL/6J mice. The concentration of K. aerogenes gavage in mice was 109 cfu. The study measured the following parameters: tumor formation (number and size), intestinal permeability (MUC2, ZO-1, and Occludin), colonic inflammation (TNF-α, IL-1ß, IL-6, and IL-10), proliferation and the fluctuation of the intestinal flora. Under the AOM/DSS-treated setting, K. aerogenes colonization worsened colitis by exacerbating intestinal inflammatory reaction and destroying the mucosal barrier. The intervention markedly augmented the quantity and dimensions of neoplasm in the AOM/DSS mice, stimulated cellular growth, and impeded cellular programmed cell death. In addition, K. aerogenes exacerbated the imbalance of the intestinal microbiota by elevating the abundance of Pseudomonas, Erysipelatoclostridium, Turicibacter, Rikenella, and Muribaculum and leading to a reduction in the abundance of Odoribacter, Alloprevotella, Roseburia, and Lachnospiraceae_NK4A136_group. The presence of K. aerogenes in AOM/DSS-treated mice promoted tumorigenesis, worsened intestinal inflammation, disrupted the intestinal barrier, and caused disturbance to the gut microbiota.

Identification of plasma SAA2 as a candidate biomarker for the detection and surveillance of non-small cell lung cancer.

This study aimed to measure the expression of SAA2 in plasma and to assess its diagnostic efficacy as a biomarker for non-small cell lung cancer (NSCLC). The gene expression of SAA2 in NSCLC was analyzed based on a database. Then, SAA2 expression was detected by immunohistochemistry in lung tissue and by enzyme-linked immunosorbent assay in 90 patients with NSCLC and 61 normal controls. Finally, the diagnostic performance was assessed in terms of accuracy, sensitivity, and specificity. At the gene and protein levels, the SAA2 expression was significantly higher in the NSCLC group than in the control group (p<0.01). It was higher in lung squamous carcinoma than in lung adenocarcinoma and in males than in females, and this trend was also observed in the lung squamous carcinoma group. Of note, the expression of SAA2 increased with increasing disease stage. Receiver operating characteristic (ROC) curve analysis revealed that the sensitivity of SAA2 was 83.61%, the specificity was 91.11%, and the area under the curve (AUC) was 0.9252. Its accuracy was 68.89%, which was higher than that of other conventional diagnostic biomarkers, and the combined application can effectively improve the diagnostic efficiency. Based on the results, SAA2 expression was positively correlated with the disease stage of NSCLC. Notably, SAA2 is more concerning in male patients with lung squamous carcinoma, and it can help in the screening and diagnosis of NSCLC. SAA2 may represent a novel diagnostic biomarker in NSCLC.

Function and mechanism of exosomes derived from different cells as communication mediators in colorectal cancer metastasis.

Colorectal cancer (CRC) ranks as the second leading cause of cancer-related mortality, with metastasis being the primary determinant of poor prognosis in patients. Investigating the molecular mechanisms underlying CRC metastasis is currently a prominent and challenging area of research. Exosomes, as crucial intercellular communication mediators, facilitate the transfer of metabolic and genetic information from cells of origin to recipient cells. Their roles in mediating information exchange between CRC cells and immune cells, fibroblasts, and other cell types are pivotal in reshaping the tumor microenvironment, regulating key biological processes such as invasion, migration, and formation of pre-metastatic niche. This article comprehensively examines the communication function and mechanism of exosomes derived from different cells in cancer metastasis, while also presenting an outlook on current research advancements and future application prospects. The aim is to offer a distinctive perspective that contributes to accurate diagnosis and rational treatment strategies for CRC.

CpG oligodeoxynucleotides enhance chemosensitivity of 5-fluorouracil in HepG2 human hepatoma cells via downregulation of the antiapoptotic factors survivin and livin.

BACKGROUND: Recent studies indicated that a synthetic oligonucleotide containing un-methylated CpG oligodeoxynucleotides (CpG-ODN) has a potential function for cancer therapy. In this study, we evaluated the chemosensitizing effects of CpG-ODN in 5-fluorouracil (5-FU)-treated HepG2 human hepatoma cells. METHODS: Cell viability assay were utilized to evaluate the direct cytotoxicity of CpG-ODN in the presence or absence of 5-FU in HepG2 cells, and apoptosis as well as cell-cycle was examined by flow cytometry analysis. The mRNA expression of Bcl-2, Livin and Survivin within HepG2 cells treated with CpG-ODN and/or 5-FU were analyzed by Real Time PCR assay in vitro. RESULTS: CpG-ODN in combination with 5-FU could decrease cell viability, increase apoptosis and further induce HepG2 cells cycle arrest at S phase when compared with CpG-ODN or 5-FU. CpG-ODN or 5-FU could down-regulate the mRNA expression of Bcl-2 within HepG2 cells. The mRNA expression of Livin and Survivin decreased in cells treated with CpG-ODN alone but increased in cells treated with 5-FU alone. However, CpG-ODN in combination with 5-FU could down-regulate the mRNA expression of Livin and Survivin within HepG2 cells. CONCLUSIONS: Our finding demonstrated that CpG-ODN enhanced the chemosentivity of 5-FU in HepG2 human hepatoma cells at least in part by down-regulating the expression of Livin and Survivin, leading to apoptosis and further inducing cell cycle arrest at S phase. Therefore, CpG-ODN may be a potential candidate as chemosensitizer for human hepatocellular carcinoma.

Sea Cucumber Derived Triterpenoid Glycoside Frondoside A: A Potential Anti-Bladder Cancer Drug.

Bladder cancer is a highly recurrent disease and a common cause of cancer-related deaths worldwide. Despite recent developments in diagnosis and therapy, the clinical outcome of bladder cancer remains poor; therefore, novel anti-bladder cancer drugs are urgently needed. Natural bioactive substances extracted from marine organisms such as sea cucumbers, scallops, and sea urchins are believed to have anti-cancer activity with high effectiveness and less toxicity. Frondoside A is a triterpenoid glycoside isolated from sea cucumber, Cucumaria frondosa. It has been demonstrated that Frondoside A exhibits anti-proliferative, anti-invasive, anti-angiogenic, anti-cancer, and potent immunomodulatory effects. In addition, CpG oligodeoxynucleotide (CpG-ODN) has also been shown to have potent anti-cancer effects in various tumors models, such as liver cancer, breast cancer, and bladder cancer. However, very few studies have investigated the effectiveness of Frondoside A against bladder cancer alone or in combination with CpG-ODN. In this study, we first investigated the individual effects of both Frondoside A and CpG-ODN and subsequently studied their combined effects on human bladder cancer cell viability, migration, apoptosis, and cell cycle in vitro, and on tumor growth in nude mice using human bladder cancer cell line UM-UC-3. To interrogate possible synergistic effects, combinations of different concentrations of the two drugs were used. Our data showed that Frondoside A decreased the viability of bladder cancer cells UM-UC-3 in a concentration-dependent manner, and its inhibitory effect on cell viability (2.5 µM) was superior to EPI (10 µM). We also showed that Frondoside A inhibited UM-UC-3 cell migration, affected the distribution of cell cycle and induced cell apoptosis in concentration-dependent manners, which effectively increased the sub-G1 (apoptotic) cell fraction. In addition, we also demonstrated that immunomodulator CpG-ODN could synergistically potentiate the inhibitory effects of Frondoside A on the proliferation and migration of human bladder cancer cell line UM-UC-3. In in vivo experiments, Frondoside A (800 µg/kg/day i.p. for 14 days) alone and in combination with CpG-ODN (1 mg/kg/dose i.p.) significantly decreased the growth of UM-UC-3 tumor xenografts, without any significant toxic side-effects; however, the chemotherapeutic agent EPI caused weight loss in nude mice. Taken together, these findings indicated that Frondoside A in combination with CpG-ODN is a promising therapeutic strategy for bladder cancer.

Integrated models of blood protein and metabolite enhance the diagnostic accuracy for Non-Small Cell Lung Cancer.

BACKGROUND: For early screening and diagnosis of non-small cell lung cancer (NSCLC), a robust model based on plasma proteomics and metabolomics is required for accurate and accessible non-invasive detection. Here we aim to combine TMT-LC-MS/MS and machine-learning algorithms to establish models with high specificity and sensitivity, and summarize a generalized model building scheme. METHODS: TMT-LC-MS/MS was used to discover the differentially expressed proteins (DEPs) in the plasma of NSCLC patients. Plasma proteomics-guided metabolites were selected for clinical evaluation in 110 NSCLC patients who were going to receive therapies, 108 benign pulmonary diseases (BPD) patients, and 100 healthy controls (HC). The data were randomly split into training set and test set in a ratio of 80:20. Three supervised learning algorithms were applied to the training set for models fitting. The best performance models were evaluated with the test data set. RESULTS: Differential plasma proteomics and metabolic pathways analyses revealed that the majority of DEPs in NSCLC were enriched in the pathways of complement and coagulation cascades, cholesterol and bile acids metabolism. Moreover, 10 DEPs, 14 amino acids, 15 bile acids, as well as 6 classic tumor biomarkers in blood were quantified using clinically validated assays. Finally, we obtained a high-performance screening model using logistic regression algorithm with AUC of 0.96, sensitivity of 92%, and specificity of 89%, and a diagnostic model with AUC of 0.871, sensitivity of 86%, and specificity of 78%. In the test set, the screening model achieved accuracy of 90%, sensitivity of 91%, and specificity of 90%, and the diagnostic model achieved accuracy of 82%, sensitivity of 77%, and specificity of 86%. CONCLUSIONS: Integrated analysis of DEPs, amino acid, and bile acid features based on plasma proteomics-guided metabolite profiling, together with classical tumor biomarkers, provided a much more accurate detection model for screening and differential diagnosis of NSCLC. In addition, this new mathematical modeling based on plasma proteomics-guided metabolite profiling will be used for evaluation of therapeutic efficacy and long-term recurrence prediction of NSCLC.

Improvement of lipid profile and reduction of body weight by shan he jian fei granules in high fat diet-induced obese rats.

BACKGROUND: The goal was to study lipid profiles (TG, TC, LDL, HDL), effects on serum leptin, and fat tissue adiponectin, and resistin as well as body weight effects of Shan He Jian Fei Granules (SHJFG) in rats on a high fat diet. METHODS: Rats were randomly divided into five groups: normal control group fed with normal fat diet, rats on high fat diet receiving low dosage, middle dosage, high dosage of Shan He Jian Fei Granules (SHJFG) as well as a high fat diet group receiving placebo. Rats were treated for 8 weeks. Body weight and naso-anal length of each rat were recorded and Lee's index was calculated. Serum TG, TC, LDL, HDL and leptin concentrations were analyzed. The gene expressions of adiponectin and resistin in adipose tissues were tested by RT-PCR. RESULTS: Compared to the high-fat diet group, body weights, Lee's indexes, weight of fat tissues and serum TG, TC, LDL and leptin of SHJFG groups significantly decreased (p < 0.05), whereas mRNA expressions of adiponectin and resistin of SHJFG groups significantly increased (p < 0.05). CONCLUSIONS: SHJFG could significantly lower body weight and serum TG, TC, and LDL of obese rats. The effects of SHJFG in lowering leptin synthesis and raising mRNA expression of adiponectin and resistin in fat tissues may act as part of the mechanisms in lowering body weight of obese rats. Further studies are needed to demonstrate whether SHJFG may also reduce overall cardiovascular morbidity and mortality like other lipid lowering drugs.

Cancer Cell Inhibiting Sea Cucumber (Holothuria leucospilota) Protein as a Novel Anti-Cancer Drug.

Cancer remains the primary cause of death worldwide. To develop less toxic anti-cancer drugs to relieve the suffering and improve the survival of cancer patients is the major focus in the anti-cancer field. To this end, marine creatures are being extensively studied for their anti-cancer effects, since extracts from at least 10% of the marine organisms have been shown to possess anti-tumor activities. As a classic Chinese traditional medicine, sea cucumbers and compounds extracted from the sea cucumbers, such as polysaccharides and saponins, have recently been shown to exhibit anti-cancer, anti-inflammatory, and anti-oxidant effects. Holothuria leucospilota (H. leucospilota) is a tropical edible sea cucumber species that has been successfully cultivated and farmed in large scales, providing a readily available source of raw materials to support the development of novel marine anti-cancer drugs. However, very few studies have so far been performed on the biological activities of H. leucospilota. In this study, we first investigated the anti-cancer effect of H. leucospilota protein on three cancer cell lines (i.e., HepG2, A549, Panc02) and three normal cell lines (NIH-3T3, HaCaT, 16HBE). Our data showed that H. leucospilota protein decreased the cell viabilities of HepG2, A549, HaCaT, 16HBE in a concentration-dependent manner, while Panc02 and NIH-3T3 in a time- and concentration-dependent manner. We also found that the inhibitory effect of H. leucospilota protein (≥10 µg/mL) on cell viability is near or even superior to EPI, a clinical chemotherapeutic agent. In addition, our data also demonstrated that H. leucospilota protein significantly affected the cell cycle and induced apoptosis in the three cancer cell lines investigated; in comparison, it showed no effects on the normal cell lines (i.e., NIH-3T3, HaCaT and 16HBE). Finally, our results also showed that H. leucospilota protein exhibited the excellent performance in inhibiting cell immigrations. In conclusion, H. leucospilota protein targeted the cancer cell cycles and induced cancer cell apoptosis; its superiority to inhibit cancer cell migration compared with EPI, shows the potential as a promising anti-cancer drug.

The Apoptosis Mechanism of Epirubicin Combined with BCG on Human Bladder Cancer Cells.

AIMS: The purpose of our study was to explore the combination effect of epirubicin and Bacillus Calmette Guerin (BCG) and its mechanism. BACKGROUND: Bladder cancer is a threat to human health worldwide. Commonly used chemotherapy drugs and biotherapy have significant therapeutic effects on bladder cancer, but the mechanism and combined effects are still unclear. OBJECTIVE: To evaluate the anti-cancer effect of epirubicin combined with BCG on human bladder cancer cells, our studies were carried out. METHODS: The viability of human bladder cancer cells with epirubicin and/or BCG treatments was examined by Cell Counting Kit-8 (CCK-8) assay. Apoptosis and cell cycle phase were determined by flow cytometry analysis. Pre-apoptosis factors of caspase-3, p53, B-cell lymphoma 2 associated X protein (Bax) and anti-apoptosis factor of B-cell lymphoma 2 (Bcl-2) were detected by western blot. RESULTS: The viability of human bladder cancer with epirubicin or BCG treatment was decreased and the viability with epirubicin combined with BCG treatment was decreased more, which were determined by CCK-8 assay. Both epirubicin and BCG increased the apoptosis rate of human bladder cancer and arrested more cells into G0/G1 phase, which were tested by flow cytometry. The expression of caspase-3, p53 and Bax was increased and the expression of Bcl-2 was decreased with epirubicin treatment on human bladder cells, which were analyzed by western blot. The expression of caspase-3 and p53 was increased with BCG treatment, which was examined by western blot. CONCLUSION: Epirubicin induced apoptosis in human bladder cancer cells by up-regulating the expression of proapoptotic factors (caspase-3, p53 and Bax) and down-regulating the expression of anti-apoptotic factor (Bcl-2). BCG promoted apoptosis of human bladder cancer cells by up-regulating the expression of caspase-3 and p53. BCG plays a potential role at the time of the combination of epirubicin and BCG on bladder cancer cells in early stage. Both epirubicin and BCG affected cell cycle distribution via arresting more bladder cancer cells at G0/G1 phase, which ultimately led bladder cancer proliferation in vitro and promoted apoptosis.

CpG Oligodeoxynucleotides Induces Apoptosis of Human Bladder Cancer Cells via Caspase-3-Bax/Bcl-2-p53 Axis.

OBJECTIVE: To evaluate the anti-cancer effect of unmethylated cytosine-phosphorothioate-guanine (CpG)-containing oligodeoxynucleotides (ODNs) on human bladder cancer UM-UC-3 cells, our study was carried out. METHODS: The viability of cells (UM-UC-3, T24 and SV-HUC-1) with CpG ODN treatments was examined by cell counting kit-8 (CCK-8) assay. Apoptosis and cell cycle phase were determined by flow cytometry analysis. Pre-apoptosis factors of caspase-3, p53, B-cell lymphoma 2 associated X protein (Bax) and anti-apoptosis factor of B-cell lymphoma 2 (Bcl-2) were detected by western blot. RESULTS: Experimental results showed that the viability of human bladder cancer cells (UM-UC-3 and T24) with CpG ODN treatment was decreased and the viability of human normal urothelial cells (SV-HUC-1) with CpG ODN treatment was increased with time-dependance manner. Moreover, CpG ODN increased the apoptosis rate of UM-UC-3 cells and arrested more cells in G0G1 phase. Furthermore, the expression of caspase-3, p53 and Bax were increased and the expression of Bcl-2 was decreased with CpG ODN treatment on UM-UC-3 cells. CONCLUSION: CpG ODN promoted the proliferation of normal urinary transitional epithelial cells (SV-HUC-1) and inhibited the cell viability of human bladder cancer cells (UM-UC-3 and T24) in vitro. CpG ODN induced the apoptosis of human bladder cancer (UM-UC-3) cells in a cascade progress via enhancing the expression of caspase-3, p53 and Bax, and inhibiting the expression of Bcl-2 with significant time-dependancy. CpG ODN inhibited cell cycle distribution of human bladder cancer (UM-UC-3) cells with more cells were arrested in G0G1 phase. This study suggested that the CpG ODN is the potential candidate on human bladder cancer.

CpG Oligodeoxynucleotide Promotes Apoptosis of Human Bladder Cancer T24 Cells Via Inhibition of the Antiapoptotic Factors.

OBJECTIVE: Unmethylated cytosine-phosphorothioate-guanine oligodeoxynucleotide, a synthetic oligodeoxynucleotide, has been used as an adjuvant in clinic and in the antitumor activity. However, the antitumor mechanism of cytosine-phosphorothioate-guanine oligodeoxynucleotide against human bladder cancer is unknown. The purpose of this study is to evaluate the cytotoxicity and molecular mechanism of anticancer effect of cytosine-phosphorothioate-guanine oligodeoxynucleotide on T24 cells (a human bladder cancer cell line). METHODS: The cytotoxic activity of cytosine-phosphorothioate-guanine oligodeoxynucleotide was examined by cell viability assay in the presence and absence of 5-fluorouracil, respectively. Apoptosis and cell-cycle phase distribution were detected by flow cytometry analysis. To investigate the molecular mechanisms of cytosine-phosphorothioate-guanine oligodeoxynucleotide cytotoxicity, the expression of antiapoptotic factors (B-cell lymphoma-2 and Survivin, ß-actin as control) in RNA, and protein level was assayed by quantitative real-time polymerase chain reaction and automated capillary Western blot. RESULTS: The inhibition ratio of T24 cells treated with both cytosine-phosphorothioate-guanine oligodeoxynucleotide and 5-fluorouracil was higher than those treated with either cytosine-phosphorothioate-guanine oligodeoxynucleotide or 5-fluorouracil alone. In the combination group (cytosine-phosphorothioate-guanine oligodeoxynucleotide and 5-fluorouracil), the apoptosis rate was significantly increased, and more cells were arrested at "S" and "G2/M" phases compared to those in cytosine-phosphorothioate-guanine oligodeoxynucleotide or 5-fluorouracil alone. Furthermore, the expression of antiapoptotic factors was decreased by cytosine-phosphorothioate-guanine oligodeoxynucleotide alone or combined with 5-fluorouracil. CONCLUSION: Cytosine-phosphorothioate-guanine oligodeoxynucleotide promoted apoptosis and enhanced the chemosensitivity of 5-fluorouracil in T24 cells. Cytosine-phosphorothioate-guanine oligodeoxynucleotide downregulated the expression of antiapoptotic factors and inhibited cell-cycle phase by arresting more cells at "S" and "G2/M" phases. This study indicated the potential ability of cytosine-phosphorothioate-guanine oligodeoxynucleotide as a candidate drug for human bladder cancer.

Expression of recombination-activating genes and T cell receptor gene recombination in the human T cell leukemia cell line.

BACKGROUND: Recent studies have suggested that mature T cells can change their specificity through reexpression of recombination-activating genes (RAG) and RAG-mediated V(D)J recombination. This process is named receptor revision and has been observed in mature peripheral T cells from transgenic mice and human donors. However, whether thebreceptor revision in mature T cells is a random or orientated process remains poorly understood. Here we used the Jurkathuman T cell line, which represents a mature stage of T cell development, as a model to investigate the regulation of Tcell receptor (TCR) gene recombination. METHODS: TCR Dbeta-Jbeta signal joint T cell receptor excision DNA circles (sjTRECs) were determined by nested and seminested PCR. Double-strand DNA breaks at recombination signal sequences (RSSs) in the TCRVbeta chain locus were detected by ligation-mediated-PCR. Further analysis of the complementarity-determining region 3 (CDR3) size of the TCRVbeta chain was examined by the TCR GeneScan technique. RESULTS: RAG1, RAG2, and three crucial components of the nonhomologous DNA end-joining (NHEJ) pathway were readily detected in Jurkat. Characteristics of junctional diversity of Dbeta2-Jbeta2 signal joints and ds RSS breaks associated with the Dbeta2 5' and Dbeta 2 3' sites were detected in DNA from Jurkat cells. CDR3 size and the gene sequences of the TCRVbeta chain did not change during cell proliferation. CONCLUSIONS: RAG1 and RAG2 and ongoing TCR gene recombination are coexpressed in Jurkat cells, but the ongoing recombination process may not play a role in modification of the TCR repertoire.However, the results suggest that Jurkat could be used as a model for studying the regulation of RAGs and V(D)J recombination and as a "special" model of the coexistence of TCR gene rearrangements and "negative" receptor revision.

Improved preparation of class I HLA tetramers and their use in detecting CMV-specific CTL.

Different methods were used to prepare HLA tetramers and the yields of each method were compared. Our results indicate that preliminary refolding of the heavy chain (Hc) and light chain (beta 2m) yields more monomer than the typical conventional method with urea-solubilized Hc and beta 2m. We then used the corresponding tetramers to detect cytomegalovirus (CMV)-specific cytotoxic T lymphocytes (CTL). Increasing data suggest that the adoptive transfer of CMV-specific CTL constitutes an effective strategy against CMV infections. We designed a method that efficiently induces CMV-specific CTL to a higher frequency in vitro than is currently achieved. This method increased the percentage of CMV-specific CTL from below 1% to 20% of PBL, accounting for more than 40% of CD8+ T cells. Successful HLA tetramer preparation provides the basis for the subsequent detection of CMV-specific CTL in clinical applications.

Analysis of the CDR3 length of TCR alphabeta T cells in the peripheral blood of patients with chronic hepatitis B.

To clarify the characteristics of TCR alphabeta T cells in the peripheral blood of patients with chronic hepatitis B (CHB), we investigated the patterns of Complementarity Determining Region3 (CDR3) length distribution for all 24 TCR BV gene families and 32 TCR AV gene family in the peripheral blood lymphocytes of two patients with CHB and two healthy controls by immunoscope spectratyping technique. We found that the profiles of CDR3 length distribution for all TCR AV and TCR BV family showed Gaussian distribution (the polyclonal TCR alphabeta T cells) in healthy controls, however, the restricted usage of TCR BV and TCR AV family (the oligoclonal TCR alphabeta T cells) has been monitored in two CHB patients, furthermore, the oligoclonal TCR alphabeta T cells showed the different CDR3 sequences and length, it might be correlated to the different epitope of hepatitis B virus (HBV) or the different HLA type of the patients. Detailed analysis of the CDR3 length of TCR alphabeta T cells might be interesting to light on the further study of the individualized immunotherapy of CHB and the further research of the new T lymphocyte epitope vaccine of HBV.

The protein X4 of severe acute respiratory syndrome-associated coronavirus is expressed on both virus-infected cells and lung tissue of severe acute respiratory syndrome patients and inhibits growth of Balb/c 3T3 cell line.

BACKGROUND: The genome of the severe acute respiratory syndrome-associated coronavirus (SARS-CoV) includes sequences encoding the putative protein X4 (ORF8, ORF7a), consisting of 122 amino acids. The deduced sequence contains a probable cleaved signal peptide sequence and a C-terminal transmembrane helix, indicating that protein X4 is likely to be a type I membrane protein. This study was conducted to demonstrate whether the protein X4 was expressed and its essential function in the process of SARS-CoV infection. METHODS: The prokaryotic and eukaryotic protein X4-expressing plasmids were constructed. Recombinant soluble protein X4 was purified from E. coli using ion exchange chromatography, and the preparation was injected into chicken for rising specific polyclonal antibodies. The expression of protein X4 in SARS-CoV-infected Vero E6 cells and lung tissues from patients with SARS was performed using immunofluorescence assay and immunohistochemistry technique. The preliminary function of protein X4 was evaluated by treatment with and over-expression of protein X4 in cell lines. Western blot was employed to evaluate the expression of protein X4 in SARS-CoV particles. RESULTS: We expressed and purified soluble recombinant protein X4 from E.coli, and generated specific antibodies against protein X4. Western blot proved that the protein X4 was not assembled in the SARS-CoV particles. Indirect immunofluorescence assays revealed that the expression of protein X4 was detected at 8 hours after infection in SARS-CoV-infected Vero E6 cells. It was also detected in the lung tissues from patients with SARS. Treatment with and overexpression of protein X4 inhibited the growth of Balb/c 3T3 cells as determined by cell counting and MTT assays. CONCLUSION: The results provide the evidence of protein X4 expression following SARS-CoV infection, and may facilitate further investigation of the immunopathological mechanism of SARS.

[High cell density fed-batch culture of E.coli expressing rhVEGF121].

OBJECTIVE: To investigate the optimal high cell density fermentation conditions of recombinant E.coli BL21/pET- 24a/hVEGF(121) expressing recombinant human vascular endothelial growth factor (rhVEGF(121)). METHODS: The effects of the composition of the fermentation medium, induction time and fed-batch carbon sources on the expression level of rhVEGF(121) and cell output were analyzed. RESULTS AND CONCLUSION: When cultured in modified M9 medium and induced for 4 h in the presence of 0.5 mmol/L IPTG at 37 degrees celsius; with glycerol as the carbon sources by continuous fed-batch mode, the recombinant E.coli expressed rhVEGF(121) at the level up to 23% of the total proteins and the yield reached 68 g/L. The optimized fermentation condition for recombinant E.coli enables high expression level of rhVEGF(121).

Immunogenicity of SARS inactivated vaccine in BALB/c mice.

Severe acute respiratory syndrome (SARS) is a serious infectious threat to public health. To create a novel trial vaccine and evaluate its potency, we attempted to generate a SARS inactivated vaccine using SARS coronavirus (SARS-CoV) strain F69 treated with formaldehyde and mixed with Al(OH)3. Three doses of the vaccine were used to challenge three groups of BALB/c mice. We found that the mice exhibited specific IgM on day 4 and IgG on day 8. The peak titers of IgG were at day 47 in low-dose group (1:19,200) and high-dose group (1:38,400) whereas in middle-dose group (1:19,200), the peak was at day 40. On day 63, the IgG levels reached a plateau. Neutralization assay demonstrated that the antisera could protect Vero-E6 cells from SARS-CoV's infection. Analysis of the antibody specificity revealed that the mouse antisera contained a mixture of antibodies specifically against the structure proteins of SARS-CoV. Furthermore, the mouse antisera conferred higher amount of antibodies against protein N, polypeptide S4 and S2 than those of proteins M and 3CL. These findings suggest that the inactivated SARS-CoV could preserve its antigenicity and the inactivated vaccine can stimulate mice to produce high levels of antibodies with neutralization activity. Results also suggest that polypeptides originating from protein N or S might be a potential target for the generation of a recombinant SARS vaccine.

[Preparation and identification of egg yolk antibodies against HLA-A* 0201 heavy chain].

OBJECTIVE: To prepare a high-titer specific and efficient egg yolk immunoglobulin (IgY). METHODS: The antigen of HLA-A* 0201 heavy chain was used to immunize the hens together with Freud's adjuvant and the eggs these hens laid were collected. IgY was purified from the egg yolk by water extraction, salt precipitation with ammonium sulfate and dialysis. The immunoactivity of the IgY was measured by enzyme-linked immunosorbent assay (ELISA) and its purity was determined by SDS-PAGE. RESULTS: The titer of IgY was 1 10(6) as shown by ELISA, with protein concentration of 9.77 mg/ml. The purity of the resultant IgY was more than 90% as suggested by SDS-PAGE analysis. CONCLUSIONS: The antigen of HLA-A* 0201 heavy chain along with complete Freund adjuvant is effective to elicit an immune response of hens for producing IgY antibodies in high yields.

Curcumin induces FasL-related apoptosis through p38 activation in human hepatocellular carcinoma Huh7 cells.

AIM: The aim of this study is to explore the underlying molecular mechanism of curcumin-induced apoptosis in human hepatocellular carcinoma (HCC) Huh7 cells. MAIN METHODS: Fas and FasL mRNA expression was analyzed by reverse transcription PCR. Western blot was applied to detect the protein expression of Bcl-2 family members, MAPK family members, c-Jun, c-Fos, ATF-2, caspase-3, PARP, TNF receptor family members and the respective ligands. Apoptotic cells were assayed with annexin V/PI double staining and flow cytometry. KEY FINDINGS: Curcumin treatment resulted in a fast and significant increase of Fas and Fas ligand (FasL) along with activation of caspase-3 and cleavage of PARP in Huh7 cells. Inhibition of caspase-3 activity by the specific inhibitor Z-DEVD-FMK rescued Huh7 cells from curcumin-induced apoptosis. Neutralization of FasL significantly protected the cells from curcumin-induced caspase-3 activation and apoptosis in a dose-dependent manner. Moreover, p38 was rapidly activated in response to curcumin, and inactivation of p38 by pharmacologic inhibitor SB203580 dramatically suppressed curcumin-induced FasL expression and apoptosis. SIGNIFICANCE: Our results demonstrated that curcumin induces apoptosis through p38-denpendent up-regulation of FasL in Huh7 cells.

Promotion of immunity of mice to Pasteurella multocida and hog cholera vaccine by pig interleukin-6 gene and CpG motifs.

A novel oligodeoxynuleotides containing 11 CpG motifs was synthesized and inserted into the VR1020 plasmid containing pig interleukin-6 (IL-6) gene (VPIL6) to construct recombinant plasmid, VPIL6C. The chitosan nanoparticles (CNP) were prepared by ionic cross linkage to entrap the VPIL6C (VPIL6C-CNP), VPIL6 (VPIL6-CNP) and CpG (CpG-CNP). 42-Day old female mice were divided into four groups and intramuscularly injected respectively with 6 pmol VPIL6C-CNP, VPIL6-CNP, CpG-CNP and VR1020-CNP along with the bivalent vaccines against the Pasteurellosis and hog cholera. The blood was weekly collected from mice after vaccination to detect the changes of immunoglobulins, specific antibodies, IL-2, IL-4, IL-6 and immune cells. 28 days after vaccination, the mice were orally challenged with virulent Pasteurella multocida. The results showed that in comparison with those of the control VR1020 group, the content of immunoglobulins, specific antibodies and interleukins significantly increased in the sera from the treated two groups (P<0.05). Meanwhile, the number of lymphocytes and monocytes also remarkably elevated in the treated groups (P<0.05). The immune responses of VPIL6C mice were notably stronger than those of VPIL6 and CpG group. The challenge results proved that the overall immunity was further promoted in the treated mice which resisted the challenge infection; while the control mice manifested evident symptoms and lesions, and died of infection. These suggested that VPIL6C-CNP could better promote the immunity and resistance of mice against Pasteurellosis than VPIL6-CNP and CpG-CNP, and facilitate the development of effective adjuvant to enhance the immunity of animal against infection.