Biomedical subjects

Jing Zhang

Publications and source records attributed to Jing Zhang.

At least 127 records · Page 7Linked to original sources

PubMed2006

Herpes simplex virus 1 infection induces the expression of proinflammatory cytokines, interferons and TLR7 in human corneal epithelial cells.

Herpetic epithelial and stromal keratitis is a sight-threatening ocular infection. To study the role of the epithelium in the innate response to herpes simplex virus 1 (HSV-1) infection of the cornea, we used a telomerase-immortalized human corneal epithelial cell (HCEC) line, HUCL, and primary HCECs as a model and infected the cells with HSV-1 (KOS strain). HSV-1 infection of HCECs resulted in a two-phase activation of nuclear factor-kappaB (NF-kappaB), JNK and p38, with the first peak at 1-4 hr and a second peak at 8 hr. Concomitant with the first peak of activation, transcriptional expression of interleukin (IL)-6, IL-8, tumour necrosis factor (TNF)-alpha and interferon (IFN)-beta was rapidly induced in HSV-1-infected cells. HSV-1 infection also induced the production of IL-6, IL-8, and TNF-alpha in both HUCL cells and primary HCECs. Coincident with the second phase of NF-kappaB activation in HSV-1-infected HCECs, the expression of Toll-like receptor 7 (TLR7) was induced, whereas the level of TLR3 was greatly down-regulated. Thus, in response to HSV-1 infection, HCECs produce proinflammatory cytokines, leading to infiltration, and IFNs to enhance the antiviral activity in the cornea, probably through sequential activation of TLRs.

Cells, Cultured↗

PubMed2006

Effect and mechanism of melatonin's action on the proliferation of human umbilical vein endothelial cells.

Melatonin is the major secretory product of the pineal gland and is considered an important natural oncostatic agent. The anticancer activity of melatonin is due to its immunomodulatory, anti-proliferative and antioxidative effects. At present there are no direct data available as to melatonin's possible influence on angiogenesis, which is a major biological mechanism responsible for tumor growth and dissemination. The current study investigated the influence of melatonin on angiogenesis. Human umbilical vein endothelial cells (HUVECs) were cultured, identified, and purified. Cell growth and viability, DNA fragmentation and cell cycle analyses were determined. To elucidate the mechanism of action of melatonin, Western blot analyses for P53, Bax and Bcl-2 expression were carried out. The results demonstrate the anti-proliferative and apoptosis-inducing effects of melatonin; these changes were associated with cell cycle arrest, upregulation of P53 and Bax and downregulation of Bcl-2. Taken together, our data showed that melatonin in high concentrations markedly reduces HUVECs proliferation, induces cellular apoptosis, and modulates cell cycle length. P53 and Bax/Bcl-2 expression changes may be involved in these actions of melatonin.

Cell Proliferation↗

PubMed2006

Cardioprotective effects of ghrelin and des-octanoyl ghrelin on myocardial injury induced by isoproterenol in rats.

AIM: To determine the cardioprotective action of ghrelin and des-octanoyl ghrelin in rats with isoproterenol-induced myocardial injury. METHODS: Rats were subcutaneously injected with isoproterenol (ISO; 20, 10, and 5 mg/kg) on d 1, 2 and 3, respectively, and then 3 mg/kg for the next 7 d with or without ghrelin or des-octanoyl-ghrelin (100 microg/kg, twice daily). Plasma ghrelin and growth hormone levels were assayed using radioimmunoassay methods. Growth hormone secretagogue receptor (GHSR) and ghrelin mRNA were determined using RT-PCR. The maximal binding capacity and the affinity for [3H]ghrelin were determined by receptor binding assays. RESULTS: Compared with controls, ISO-treated rats showed severe myocardial injury, cardiomegaly, infarction-like necrosis and massive fibrosis with increases in irradiated-ghrelin (ir-ghrelin) content in plasma by 67% and myocardia by 66% and in the mRNA level in the myocardia by 93% (P<0.01). ISO-treated rats had 95% (P<0.01) higher GHSR mRNA levels in the myocardia. The maximal binding capacity of [3H]ghrelin for myocardial sarcolemma was higher in ISO-treated rats than in controls. Ghrelin administration improved cardiac function and ameliorated cardiomegaly and attenuated myocardial lipid peroxidation injury and relieved cardiac fibrosis as compared with ISO treatment alone. Administration of des-octanoyl ghrelin effectively antagonized ISO-induced myocardial injury and improved all parameters measured. However, the therapeutic effect of des-octanoyl ghrelin was significantly weaker than that of ghrelin. The plasma growth hormone level increased markedly, by 1.5-fold (P<0.01), with ghrelin administration as compared with that in controls, but was unaltered in des-octanoyl ghrelin group. CONCLUSION: Myocardial ghrelin and GHSR were up-regulated during ISO-induced myocardial injury. The protective effect of ghrelin against ISO-induced cardiac function injury and fibrosis was more potent than that of des-octanoyl ghrelin, which suggests that ghrelin could be an endogenous cardioprotective factor in ischemic heart disease, and that its effects include growth hormone-dependent and -independent pathways.

Animals↗

PubMed2006

Study of the antifungal ability of Bacillus subtilis strain PY-1 in vitro and identification of its antifungal substance (iturin A).

A Bacillus strain, denoted as PY-1, was isolated from the vascular bundle of cotton. Biochemical, physiological and 16S rDNA sequence analysis proved that it should belong to Bacillus subtilis. The PY-1 strain showed strong ability against many common plant fungal pathogens in vitro. The antibiotics produced by this strain were stable in neutral and basic conditions, and not sensitive to high temperature. From the culture broth of PY-1 strain, five antifungal compounds were isolated by acidic precipitation, methanol extraction, gel filtration and reverse-phase HPLC. Advanced identification was performed by mass spectrometry and nuclear magnetic resonance spectroscopy. These five antifungal compounds were proved to be the isomers of iturin A: A2, A3, A4, A6 and A7. In fast atom bombardment mass spectrometry/mass spectrometry collision-induced dissociation spectra, fragmentation ions from two prior linear acylium ions were observed, and the prior ion, Tyr-Asn-Gln-Pro-Asn-Ser-betaAA-Asn-CO+, was first reported.

Antifungal Agents↗

PubMed2006

New potential antimalarial agents: therapeutic-index evaluation of pyrroloquinazolinediamine and its prodrugs in a rat model of severe malaria.

Tetra-acetamide pyrroloquinazolinediamine (PQD-A4) and bis-ethylcarbamyl pyrroloquinazolinediamine (PQD-BE) are new derivatives of pyrroloquinazolinediamine (PQD) and are being investigated as potential chemotherapeutic agents for the treatment of malaria. Comparative studies to assess the therapeutic indices of PQD-A4, PQD-BE, and PQD were conducted in Plasmodium berghei-infected rats following daily intragastric dosing for three consecutive days. Artesunate (AS), a standard drug for treatment of severe malaria, was used as a comparator. The minimum doses required to clear malaria parasitemia were 156 micromol/kg of body weight for AS and 2.4 micromol/kg for PQD, PQD-4A, and PQD-BE. The maximum tolerated dose (MTD) of AS was 625 micromol/kg, and its therapeutic index was calculated to be 4. The MTDs of PQD-A4, PQD-BE, and PQD were found to be 190, 77, and 24 micromol/kg, respectively, yielding therapeutic indices of 80, 32, and 10, respectively. Although PQD-A4 and PQD-BE are only half as potent as PQD based on their curative effects, the two new derivatives, PQD-4A and PQD-BE, are 8.0-fold and 3.2-fold safer, respectively, than their parent compound when they are dosed for three consecutive days. Oral PQD-A4 and PQD-BE are 44 to 70 times more potent on an mg basis than intravenous AS. As assessed from the therapeutic index over 3 days, PQD-A4, PQD-BE, and PQD administered orally are 20.0, 8.0, and 2.5 times safer than AS given intravenously. The results indicate that PQD-4A is a promising candidate for antimalarial treatment.

Animals↗

PubMed2006

AsialoGM1-mediated IL-8 release by human corneal epithelial cells requires coexpression of TLR5.

PURPOSE: In this study, it was determined that human corneal epithelial cells (HCECs) express asialoganglioside ganliotetraosylceramide (asialoGM1) and toll-like receptor (TLR)-5, and their interaction induces interleukin (IL)-8 release through Ca(2+) transient activation and mitogen-activated protein kinase (MAPK) stimulation. METHODS: Expression of asialoGM1 and TLR5 was detected in SV40 HCECs by Western blot and flow cytometry analyses and their association by coimmunoprecipitation. Single-cell fluorescence imaging was used to measure intracellular free Ca(2+) transients in fura-2-loaded cells. The enzyme-linked immunosorbent assay (ELISA) was used to quantify IL-8 production in both cultured and primary HCECs. RESULTS: The HCECs expressed both asialoGM1 and TLR5 receptors. Ligation of asialoGM1 resulted in protein-protein interaction with TLR5, followed by transient increases in Ca(2+) influx through L-type voltage-dependent Ca(2+) channels. This led to P2Y receptor stimulation along with membrane depolarization, resulting from increases in ATP release into the medium. Intracellular Ca(2+) transients led to time-dependent extracellular signal-regulated kinase (ERK) MAPK pathway stimulation, followed by a 9.5-fold increase in IL-8 release. Similarly, in primary HCECs, asialoGM1 receptor stimulation resulted in an 8.1-fold increase. With a TLR5 neutralizing antibody, no asialoGM1-induced increases in IL-8 release occurred, and this response was not suppressed in the presence of a TLR2 neutralizing antibody. CONCLUSIONS: IL-8 release by HCECs is mediated through ligand-induced asialoGM1 protein-protein interactions with TLR5. This response is dependent on ATP efflux into the medium, followed by P2Y receptor stimulation. Such activation, in turn, results in increases in Ca(2+) influx through L-type voltage-dependent Ca(2+) channels, as well as stimulation of the ERK pathway.

Adenosine Triphosphate↗

PubMed2006

von Hippel-Lindau gene mutation in non-syndromic familial pheochromocytomas.

Approximately 50% of patients with non-syndromic familial pheochromocytomas had germline von Hippel-Lindau (VHL) gene mutations, but no reports on the subject were available in China. A total of five unrelated Chinese families with non-syndromic familial pheochromocytomas were screened for VHL gene mutation by polymerase chain reaction (PCR) and subsequent direct sequencing. Missense germline mutations of VHL gene were detected in four of the five families. Arg161Gln (695G-A) mutation was found in two families, and the other two families had Leu163Phe (700C-T) and Arg167Trp (712C-T) mutation, respectively. In conclusion, VHL gene may have frequent mutation in Chinese patients with non-syndromic familial pheochromocytomas.

Adrenal Gland Neoplasms↗

PubMed2006

Central mechanisms of gastric electrical stimulation involving neurons in the paraventricular nucleus of the hypothalamus in rats.

BACKGROUND: Gastric electrical stimulation (GES) has been shown to be effective in inducing satiety in patients with obesity, as well as in treating nausea and vomiting in patients with gastroparesis. It is conceivable that these effects are mediated via the central nervous system, although there is a lack of studies or evidences. The aims of this study were to investigate the effects of GES with different parameters on neurons in the paraventricular nucleus (PVN) of the hypothalamus and to study whether the neuronal response was related to stimulation parameters. METHODS: Extracellular potentials of single neurons in the PVN were recorded in anesthetized rats at baseline, during gastric distention (GD) and during GES with various sets of parameters. RESULTS: Of 115 PVN neurons tested by GD, 104 were GD-responsive neurons. Most of these GD-responsive neurons were responsive to GES of various parameters. 1) GES with parameters used in treating obesity, activated neurons both excited (GD-E) and inhibited (GD-I) by gastric distention; it excited 48.4% (16/33) of the GD-E neurons and 60.4% (29/48) of GD-I neurons. 2) GES with increased pulse width was of the highest efficacy in exciting the GD-responsive neurons, whereas a reduction in stimulation frequency resulted in a lower activation. 3) GES with parameters used in treating gastroparesis solicited neuronal responses opposite to those with parameters used for treating obesity. CONCLUSION: GES activates gastric-related neurons in the PVN, and the excitatory effect of GES seems related to stimulation strength. The GES used for treating gastroparesis and the GES used for treating obesity seem to solicit different neuronal responses in the PVN.

Animals↗

PubMed2006

Implantable gastric stimulation alters expression of oxytocin- and orexin-containing neurons in the hypothalamus of rats.

BACKGROUND: Implantable gastric stimulation (IGS) has been proposed as a therapeutic option for treating obese patients. We studied the underlying central mechanism behind the reduction of food intake and body weight by gastric electrical stimulation (GES), by studying the expression of anorexigenic and orexigenic-peptide containing neurons in the hypothalamus. METHODS: Oxytocin antiserum, orexin antiserum and c-Fos protein-antiserum were used for immunostaining technique. Brain sections were obtained from the control rats and those with 2 hours of GES with parameters typically used in the treatment of obesity in humans. RESULTS: A) 2-hr IGS increased the expression of oxytocin-immunoreactive (IR) neurons in the paraventricular nucleus (PVN, 23.7+/-1.8 vs 31.1+/-2.2, P<0.05) and the supraoptic nucleus (SON, 29.0+/-2.2 vs 39.7+/-2.5, P<0.01). However, the expression of orexinIR neurons in the lateral hypothalamic area (LHA) was decreased (27.8+/-2.6 vs 20.6+/-1.7, P<0.01). B) The expression of c-Fos positive neurons was increased in the PVN and SON with IGS. A coexistence of oxytocin-IR positive neurons and c-Fos-IR ones in the PVN and SON from the adjacent brain sections was observed, confirming the activation of OT-containing neurons in the PVN and SON following IGS. CONCLUSION: IGS increases the expression of hypothalamic neurons containing the anorexigenic neuropeptide, oxytocin, and decreases the expression of neurons containing the orexigenic neuropeptide, orexin. This central anorexigenic effect of GES may contribute to the reduced appetite and increased satiety in obese patients with IGS therapy.

Animals↗

PubMed2006

Ethanol production from dilute-Acid softwood hydrolysate by co-culture.

Dilute-acid softwood hydrolysate, with glucose and xylose as the dominant sugars, was fermented to ethanol by co-cultures. The strains used include Saccharomyces cerevisiae 2.535 (1#), Pachysolen tannophilis ATCC 2.1662 (2#), and recombinant Escherichia coli (3#) constructed in our laboratory carrying both pdc and adhB genes derived from Zymomonas mobilis. Before fermentation, the co-cultures were adapted for five batches. Observation under light microscope showed aggregation of adapted strains, which could possibly improve their ability to degrade inhibitors. In addition, we tried to detoxify the dilute-acid softwood hydrolysate with a combined method before fermentation. Our study showed that fermentation of detoxified hydrolysate by adapted co-culture (1# + 2#) generated an exceptionally high ethanol yield on total sugar of 0.49 g/g, corresponding to 96.1% of the maximal theoretical value after 48 h; fermentation of detoxified hydrolysate by adapted co-culture (1# + 3#) is faster (24 h) and could reach a high ethanol yield (0.45 g/g total sugar). These experiments suggest that both adaptation and detoxification significantly improve hydrolysate fermentation and ethanol production.

Acetic Acid↗

PubMed2006

Topotecan is a substrate for multidrug resistance associated protein 4.

Topotecan (TPT) is a semisynthetic water-soluble derivative of camptothecin (CPT) used as second-line therapy in patients with metastatic ovarian carcinoma, small cell lung cancer, and other malignancies. However, both dose-limiting toxicity and tumor resistance hinder the clinical use of TPT. The mechanisms for resistance to TPT are not fully defined, but increased efflux of the drug by multiple drug transporters including P-glycoprotein (PgP), multidrug resistance associated protein 1 (MRP1) and breast cancer resistance protein (BCRP) from tumor cells has been highly implicated. This study aimed to investigate whether overexpression of human MRP4 rendered resistance to TPT by examining the cytotoxicity profiles using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazonium bromide (MTT) assay and cellular accumulation of TPT in HepG2 cells stably overexpressing MRP4. Two kinds of cell lines, HepG2 with insertion of an empty vector plasmid (V/HepG2), HepG2 cells stably expressing MRP4 (MRP4/HepG2), were exposed to TPT for 4 or 48 hr in the absence or presence of various MRP4 inhibitors including DL-buthionine-(S,R)-sulphoximine (BSO), diclofenac, celecoxib, or MK-571. The intracellular accumulation of TPT and paclitaxel (a PgP substrate) by V/HepG2 and MRP4/HepG2 cells was determined by incubation of TPT with the cells and the amounts of the drug in cells were determined by validated HPLC methods. The study demonstrated that MRP4 conferred a 12.03- and 6.86-fold resistance to TPT in the 4- and 48-hr drug-exposure MTT assay, respectively. BSO, MK-571, celecoxib, or diclofenac sensitised MRP4/HepG2 cells to TPT cytotoxicity and partially reversed MRP4-mediated resistance to TPT. In addition, the accumulation of TPT was significantly reduced in MRP4/HepG2 cells compared to V/HepG2 cells, and one-binding site model was found the best fit for the MRP4-mediated efflux of TPT, with an estimated K(m) of 1.66 microM and V(max) of 0.341 ng/min/106 cells. Preincubation of MRP4/HepG2 cells with BSO (200 microM) for 24 hr, celecoxib (50 microM), or MK-571 (100 microM) for 2 hr significantly increased the accumulation of TPT over 10 min in MRP4/HepG2 cells by 28.0%, 37.3% and 32.5% (P < 0.05), respectively. By contrast, there was no significant difference in intracellular accumulation of paclitaxel in V/HepG2 and MRP4/HepG2 cells over 120 min. MRP4 also rendered resistance to adefovir dipivoxil (bis-POM-PMEA) and methotrexate, two reported MRP4 substrates. MRP4 did not exhibit any significant resistance to other model drugs including vinblastine, vincristine, etoposide, carboplatin, cyclosporine and paclitaxel in both long (48 hr) and short (4 hr) drug-exposure MTT assays. These findings indicate that MRP4 confers resistance to TPT and TPT is the substrate for MRP4. Further studies are needed to explore the role of MRP4 in resistance to, toxicity and pharmacokinetics of TPT in cancer patients.

Antineoplastic Agents↗

PubMed2006

Reversal of resistance to oxazaphosphorines.

The oxazaphosphorines including cyclophosphamide (CPA), ifosfamide (IFO) and trofosfamide are one important group of alkylating agents. However, resistance is the major hindrance for success of oxazaphosphorine chemotherapy. The mechanism of resistance to oxazaphosphorines is not fully identified, but recently some novel insights into these aspects have been generated by using sensitive analytical techniques and powerful pharmacogenetic techniques. Potential mechanisms for oxazaphosphorine resistance include decreased activation by cytochrome P450s (e.g. CYP3A4, CYP2C9 and CYP2B6), increased deactivation of the agents by deactivating enzymes such as aldehyde dehydrogenases (ALDHs), increased cellular thiol level, increased DNA repair capacity, and altered cellular apoptotic response to DNA repair, e.g. deficient apoptosis due to lack of cellular mechanisms to result in cell death following DNA damage. In addition, decreased cellular accumulation of cytotoxic species of oxazaphosphorines may also play a role in the resistance. This review highlights the pharmacology of oxazaphosphorine anticancer drugs and possible agents that reverse the resistance to these agents. Possible agents that can overcome oxazaphosphorine resistance include inducers of CYPs, modulators of GSTs and ALDHs, modulators of DNA repair process, antisense oligonucleotides against genes encoding various enzymes and signalling proteins, and novel gene delivery systems. Most of these agents have been investigated in preclinical studies and promising results have been observed. To date, several types of these agents are being evaluated in Phase III trials in cancer patients. Further studies are needed to identify the molecular targets associated with resistance to oxazaphosphorines.

Antineoplastic Agents↗

PubMed2006

RNA interference and potential applications.

RNA interference (RNAi) is the process of using specific sequences of double-stranded RNA (dsRNA) to knock down the expression level of sequence-homologous genes. Such ability of small interfering RNA (siRNA) in mammalian cells will undoubtedly revolutionize the study of functional genomics, the discovery of drug targets and even the treatment of human diseases. In this review we briefly describe the history of RNAi discovery, the RNAi mechanism and the general guideline for siRNA design as well as various methods for siRNA production and delivery. We also introduce the potential applications of siRNA, inducible siRNA and siRNA library in speeding up basic biomedical research and in acting as potential therapeutic agents for treatment of numerous human diseases.

Animals↗

PubMed2006

Detection of biomarkers with a multiplex quantitative proteomic platform in cerebrospinal fluid of patients with neurodegenerative disorders.

Biomarkers are needed to assist in the diagnosis and medical management of various neurodegenerative disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), and dementia with Lewy body (DLB). We have employed a multiplex quantitative proteomics method, iTRAQ (isobaric Tagging for Relative and Absolute protein Quantification), in conjunction with multidimensional chromatography, followed by tandem mass spectrometry (MS/MS), to simultaneously measure relative changes in the proteome of cerebrospinal fluid (CSF) obtained from patients with AD, PD, and DLB compared to healthy controls. The diagnosis of AD and DLB was confirmed by autopsy, whereas the diagnosis of PD was based on clinical criteria. The proteomic findings showed quantitative changes in AD, PD, and DLB as compared to controls; among more than 1,500 identified CSF proteins, 136, 72, and 101 of the proteins displayed quantitative changes unique to AD, PD, and DLB, respectively. Eight unique proteins were confirmed by Western blot analysis, and the sensitivity at 95% specificity was calculated for each marker alone and in combination. Several panels of unique makers were capable of distinguishing AD, PD and DLB patients from each other as well as from controls with high sensitivity at 95% specificity. Although these preliminary findings must be validated in a larger and different population of patients, they suggest that a roster of proteins may be generated and developed into specific biomarkers that could eventually assist in clinical diagnosis and monitoring disease progression of AD, PD and DLB.

Alzheimer Disease↗

PubMed2006

[The effect on the differentiation and maturation of dendritic cells by lupane acetate of cortex periplocae].

AIM: To investigate the effect of lupane acetate of cortex periplocae (CPLA) on the differentiation, maturation and immune activity of human peripheral blood mononuclear cell (PBMC)-derived dendritic cells (DCs) in vitro. METHODS: PBMC isolated from human peripheral blood was cultured with GM-CSF, IL-4 for 5 d and stimulated with TNF-alpha (as positive control) or CPLA to induce DCs. The morphological characteristics of DC were observed under inverted microscope and transmisson electron microscope. The expressions of CD1a, CD83, CD80 and CD86 were analyzed by flow cytometry. IL-12, IFN-gamma production in the culture supernatant of DCs was detected by ELISA. MTT method was used to determine the proliferation of T cells stimulated by DCs. RESULTS: After 10-days culture with cytokines and CPLA, PBMC developed into mature DCs with typical morphological characteristics and high expressions of CD1a, CD83, CD80 and CD86 on the cellular surface (P<0.05). CPLA enhanced IL-12 and IFN-gamma production by DCs (P<0.05). CPLA-treated DCs markedly stimulated proliferation of T cells (P<0.05). CONCLUSION: CPLA may induce the differentiation and maturation of DC, up-regulate cytokines production and increase the immune activity of DC.

Antigens, CD↗

PubMed2006

Integrative haptic and visual interaction for simulation of PMMA injection during vertebroplasty.

In vertebroplasty, physician relies on both sight and feel to properly place the bone needle through various tissue types and densities, and to help monitor the injection of PMMA or cement into the vertebra. Incorrect injecting and reflux of the PMMA into areas where it should not go can result in detrimental clinical complication. This paper focuses on the human-computer interaction for simulating PMMA injection in our virtual spine workstation. Fluoroscopic images are generated from the CT patient volume data and simulated volumetric flow using a time varying 4D volume rendering algorithm. The user's finger movement is captured by a data glove. Immersion CyberGrasp is used to provide the variable resistance felt during injection by constraining the user's thumb. Based on our preliminary experiments with our interfacing system comprising simulated fluoroscopic imaging and haptic interaction, we found that the former has a larger impact on the user's control during injection.

Computer Simulation↗

PubMed2006

Native anti-tumor responses elicited by immunization with a low dose of unmodified live tumor cells.

The present study demonstrates that immunization with a low dose of unmodified live myeloma tumor cells (FO) elicited tumor-specific immunity. BALB/c mice were vaccinated with 10(4) live dendritic cells (DC)-FO fusion cells or 10(3) live FO cells. 80% of vaccinated mice survived from the later challenge with 1 x 10(6) FO cells, whereas all control mice developed tumors. Additionally, vaccination with live FO cells gave no protection against the growth of Lewis lung carcinoma cells in C57BL/6 mice. Cellular immunity was found to be primarily responsible for anti-tumor responses. In an adoptive immune model, the development of myeloma was greatly reduced by transfusion of lymphocytes but not sera from mice immunized with FO. T cells from immunized mice also induced lysis of FO cells in the cytotoxic T lymphocyte (CTL) assay. After co-culture with FO, IFN-gamma released from immunized T helper cells increased >10-fold, while IL-4 remained unchanged in comparison with control T cells. These findings provided the first evidence that immunization with a low dose of unmodified live FO cells was safe to mice and capable of eliciting specific protective immunity against tumor growth.

Animals↗

PubMed2006

[Construction of the prokaryotic expression vector and expression of human CIDE-3 gene].

AIM: To construct a prokaryotic expression vector for human CIDE-3 gene, and to express the gene in E.coli BL21(DE3). METHODS: The total RNA was extracted from human hepatocellular carcinoma cell line HepG2. CIDE-3 gene fragment was amplified by RT-PCR and was cloned into the pET28a(+) vector. The recombinant vector was identified by restriction endonuclease digestion analysis and DNA sequencing, and then it was transformed into E.coli BL21(DE3) through IPTG induction to express the target protein bearing His tag. RESULTS: A 516 bp of CIDE-3 gene fragment was obtained. After E.coli BL21(DE3) was transformed with recombinant vector pET28a(+)-CIDE-3 and through IPTG induction, the recombinant protein with relative molecular masse about 23,000 was obtained. SDS-PAGE analysis showed that the expressed product was mainly inclusion bodies, accounting for 32% of the total bacterial proteins. CONCLUSION: Recombinant expression vector pET28a(+)-CIDE-3 is constructed successfully. The expressed CIDE-3 protein will be helpful to our further research.

Apoptosis Regulatory Proteins↗