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Qin Wang

Publications and source records attributed to Qin Wang.

At least 37 records · Page 2Linked to original sources
PubMed2006

Neutrophil cytoskeletal rearrangements during capillary sequestration in bacterial pneumonia in rats.

RATIONALE: Neutrophils accumulate in pulmonary capillaries during acute inflammation. Initial events in injury recognition and sequestration do not occur through selectin-mediated rolling. Cytoskeletal rearrangements, as assessed by submembrane F-actin rims, result in poorly deformable neutrophils that may not pass through capillaries. OBJECTIVE: To test the hypothesis that neutrophils sequestering during pneumonia contain F-actin rims and to determine the roles of CD11/CD18, L-selectin expression, and neutrophil-platelet adhesion in neutrophil sequestration. METHODS: Neutrophils were compared in blood obtained simultaneously from venous and arterial sites before and 4 h after instillation of Streptococcus pneumoniae or Escherichia coli in rats. MEASUREMENTS AND MAIN RESULTS: At 4 h of pneumonia, the number of neutrophils was greater in the venous blood entering the lungs than in the arterial blood leaving the lungs, indicating that neutrophil sequestration was occurring. More neutrophils entering the lungs contained F-actin rims than did neutrophils exiting, and the venous-arterial difference in F-actin-rimmed neutrophil counts completely accounted for sequestration. In E. coli pneumonia, in which neutrophil adhesion is mediated by CD11/CD18, CD18 blockade 15 min before blood samples were obtained did not prevent this sequestration of F-actin-rimmed neutrophils. Neutrophils expressing high or low levels of L-selectin or of neutrophils that bound platelets while circulating did not preferentially sequester. CONCLUSIONS: Neutrophils with cytoskeletal rearrangements preferentially sequester within the lungs during pneumonia, and this sequestration is not due to CD11/CD18-mediated adhesion, L-selectin expression, or platelet adhesion to neutrophils, suggesting that cytoskeletal rearrangements result in sequestration of neutrophils.

Actins↗
PubMed2006

Technical feasibility and histopathologic studies of poly (N-isopropylacrylamide) as a non-adhesive embolic agent in swine rete mirabile.

BACKGROUND: Non-adhesive liquid embolic agents are increasingly gaining importance in the embolization of cerebral arteriovenous malformations (AVMs). We investigated the use of poly (N-isopropylacrylamide) (PNIPAM) as a non-adhesive embolic agent in swine rete mirabile. METHODS: The PNIPAM hydrogel was mixed with iohexol and embolization was performed in swine rete mirabile in 30 animals. The microcatheter was examined after embolization. Follow-up angiography was performed for embolic efficacy after embolization. Embolized retia were examined histopathologically, and the alterations of inside rete and surrounding tissue were observed. RESULTS: The copolymer hydrogel was used for rete embolization in 30 swine, 28 swine survived the procedure, 2 swine died, 1 swine died of cerebrum infarction and the other died of embolic agent reflux into the occipital artery. The inside wall of the microcatheter was smooth, without copolymer adhering to it. Follow-up angiography was performed in 22 swine, there was no rete recanalization in 20 swine and partial rete recanalization in 2 swine because of the trunk embolization of ascending pharyngeal arteries. Histopathologically, the copolymer was found diffused into vessels of 100 - 150 microm in diameter. In acute group, neutrophils scattered surrounding the copolymer and endothelial integrity was observed, without endothelial denuding and necrosis. In subacute and chronic groups, the copolymer was found inside retia, a few mononuclear cells and eosinocytes scattered inside and surrounding it. The muscular layer was loosened with most muscular nuclei degraded. CONCLUSION: Experimental rete embolization with PNIPAM, made radiopaque with iohexol, is technically feasible in swine. Because of its properties, PNIPAM has great potential as a therapeutic non-adhesive embolic agent.

Acrylic Resins↗
PubMed2006

Medicago truncatula mutants demonstrate the role of plant calcium oxalate crystals as an effective defense against chewing insects.

Calcium oxalate is the most abundant insoluble mineral found in plants and its crystals have been reported in more than 200 plant families. In the barrel medic Medicago truncatula Gaertn., these crystals accumulate predominantly in a sheath surrounding secondary veins of leaves. Mutants of M. truncatula with decreased levels of calcium oxalate crystals were used to assess the defensive role of this mineral against insects. Caterpillar larvae of the beet armyworm Spodoptera exigua Hübner show a clear feeding preference for tissue from calcium oxalate-defective (cod) mutant lines cod5 and cod6 in choice test comparisons with wild-type M. truncatula. Compared to their performance on mutant lines, larvae feeding on wild-type plants with abundant calcium oxalate crystals suffer significantly reduced growth and increased mortality. Induction of wound-responsive genes appears to be normal in cod5 and cod6, indicating that these lines are not deficient in induced insect defenses. Electron micrographs of insect mouthparts indicate that the prismatic crystals in M. truncatula leaves act as physical abrasives during feeding. Food utilization measurements show that, after consumption, calcium oxalate also interferes with the conversion of plant material into insect biomass during digestion. In contrast to their detrimental effects on a chewing insect, calcium oxalate crystals do not negatively affect the performance of the pea aphid Acyrthosiphon pisum Harris, a sap-feeding insect with piercing-sucking mouthparts. The results confirm a long-held hypothesis for the defensive function of these crystals and point to the potential value of genes controlling crystal formation and localization in crop plants.

Animals↗
PubMed2006

Zein dynamic adsorption to carboxylic and alkyl coated surfaces.

The adsorption of a commercial zein sample on carboxylic (COOH) and alkyl (CH(3)) surfaces was monitored by high time resolution surface plasmon resonance. Zein showed higher affinity and higher mass adsorption on carboxylic than alkyl surfaces. A zein layer specific for each surface was obtained after flushing off loosely bound zein with 75% 2-propanol solutions. Zein deposits were examined under atomic force microscopy. Differences in layer thickness between carboxylic and alkyl surfaces were explained in terms of zein adsorption footprint.

2-Propanol↗
PubMed2006

Ezrin/radixin/moesin proteins are phosphorylated by TNF-alpha and modulate permeability increases in human pulmonary microvascular endothelial cells.

Endothelial cells (ECs) respond to TNF-alpha by altering their F-actin cytoskeleton and junctional permeability through mechanisms that include protein kinase C (PKC) and p38 MAPK. Ezrin, radixin, and moesin (ERM) regulate many cell processes that often require a conformational change of these proteins as a result of phosphorylation on a conserved threonine residue near the C terminus. This study tested the hypothesis that ERM proteins are phosphorylated on this critical threonine residue through TNF-alpha-induced activation of PKC and p38 and modulate permeability increases in pulmonary microvascular ECs. TNF-alpha induced ERM phosphorylation on the threonine residue that required activation of p38, PKC isoforms, and phosphatidylinositol-4-phosphate 5-kinase Ialpha, a major enzyme generating phosphatidylinositol 4,5-bisphosphate, and phosphorylated ERM were prominently localized at the EC periphery. TNF-alpha-induced ERM phosphorylation was accompanied by cytoskeletal changes, paracellular gap formation, and increased permeability to fluxes of dextran and albumin. These changes required activation of p38 and PKC and were completely prevented by inhibition of ERM protein expression using small interfering RNA. Thus, ERM proteins are phosphorylated through p38 and PKC-dependent mechanisms and modulate TNF-alpha-induced increases in endothelial permeability. Phosphorylation of ERM likely plays important roles in EC responses to TNF-alpha by modulating the F-actin cytoskeleton, adhesion molecules, and signaling events.

Binding Sites↗
PubMed2006

Tyrosine phosphatase SHP-2 regulates IL-1 signaling in fibroblasts through focal adhesions.

Interleukin-1beta (IL-1beta) mediates destruction of matrix collagens in diverse inflammatory diseases including arthritis, periodontitis, and pulmonary fibrosis by activating fibroblasts, cells that interact with matrix proteins through integrin-based adhesions. In vitro, IL-1beta signaling is modulated by focal adhesions, supramolecular protein complexes that are enriched with tyrosine kinases and phosphatases. We assessed the importance of tyrosine phosphatases in regulating cell-matrix interactions and IL-1beta signaling. In human gingival fibroblasts plated on fibronectin, IL-1beta enhanced the maturation of focal adhesions as defined by morphology and enrichment with paxillin and alpha-actinin. IL-1beta also induced activation of ERK and recruitment of phospho-ERK to focal complexes/adhesions. Treatment with the potent tyrosine phosphatase inhibitor pervanadate, in the absence of IL-1beta, recapitulated many of these responses indicating the importance of tyrosine phosphatases. Immunoblotting of collagen bead-associated complexes revealed that the tyrosine phosphatase, SHP-2, was also enriched in focal complexes/adhesions. Depletion of SHP-2 by siRNA or by homologous recombination markedly altered IL-1beta-induced ERK activation and maturation of focal adhesions. IL-1beta-induced tyrosine phosphorylation of SHP-2 on residue Y542 promoted focal adhesion maturation. Association of Gab1 with SHP-2 in focal adhesions correlated temporally with activation of ERK and was abrogated in cells expressing mutant (Y542F) SHP-2. We conclude that IL-1beta mediated maturation of focal adhesions is dependent on tyrosine phosphorylation of SHP-2 at Y542, leading to recruitment of Gab1, a process that may influence the downstream activation of ERK.

Actinin↗
PubMed2006

Is the anatomical protrusion on the posterior hypopharyngeal wall associated with cadavers of only the elderly?

Cricopharyngeal bars are commonly seen on a barium swallow radiologic examination and represent the failure of the cricopharyngeus to relax. Traditionally, the bars have been considered as functional or physiologic protrusions. Recently, anatomical cricopharyngeal protrusion has been found in about 30% of cadavers of the elderly, suggesting that such a structural change may become a physical barrier that affects the normal deglutition in a living person. This suggests that such a radiographic finding should be carefully considered when interpreting radiologic and manometrical examinations and managing dysphagia of the elderly. However, the finding of the anatomical cricopharyngeal protrusion was based on the observation of cadavers of the elderly (mean age = 77 years). The aim of this study was to further investigate whether such an anatomical cricopharyngeal protrusion exists in cadavers of other ages. Using the dissection method, we examined 63 human cadavers that were divided into three age groups: young adult (6 females and 10 males, age = 16-24 years old), adult (8 females and 23 males, age = 25-64 years old), and early elderly (5 females and 11 males, age = 65-69 years old). We found that 57 of the 63 cadavers had a smooth mucosal surface on the posterior hypopharyngeal and upper esophageal wall. A slightly thickened posterior muscular wall was observed at the cricoid level in six cadavers (five from the adult group and one from the early elderly group), but its boundary was not clearly identified. Taking the previous reports together, our results suggest that an anatomical cricopharyngeal protrusion is closely associated with the aging process.

Adolescent↗
PubMed2006

Effect of von Willebrand factor on the pharmacokinetics of recombinant human platelet glycoprotein Ibalpha-immunoglobulin G1 chimeric proteins.

PURPOSE: Recombinant human platelet glycoprotein Ibalpha-immunoglobulin G1 chimeric proteins (GPIbalpha-Ig) have varying levels of anti-thrombotic activities based on their ability to compete for platelet mediated adhesion to von Willebrand Factor (vWF). Valine substituted GPIbalpha-Ig chimeras, at certain position, increase the binding affinity to vWF over its "wild-type" GPIbalpha-Ig analog. The purpose of this study was to determine the pharmacokinetics of two valine substituted GPIbalpha-Ig chimeras, GPIbalpha-Ig/1V (valine substitution at 239 position) and GPIbalpha-Ig/2V (double valine substitution at 233 and 239 position), in mice, rats and dogs. METHODS: Head-to-head comparisons of pharmacokinetics of GPIbalpha-Ig/1V and GPIbalpha-Ig/2V were investigated in rats and dogs after intravenous administration. Since vWF precipitates in the serum but not in plasma preparation, the concentration-time profiles of GPIbalpha-Ig/2V in rats were examined from the same blood samples for determination of matrix effect. The disposition of GPIbalpha-Ig/2V was also compared in vWF-deficient versus wild-type mice. RESULTS: For GPIbalpha-Ig/2V, the serum clearances were 2.62+/-0.27 ml/hr/kg in rats and 1.97+/-0.24 ml/hr/kg in dogs. The serum clearances of less potent GPIbalpha-Ig/1V were 1.08+/-0.08 and 0.97+/-0.19 ml/hr/kg in rats and dogs, respectively. In addition, the serum clearance of GPlbalpha-Ig/2V of 1.53 ml/hr/kg in vWF-deficient mice was lower than that in wild-type mice of 2.79 ml/hr/kg. CONCLUSION: The difference in disposition for valine substituted forms of GPIbalpha-Ig in laboratory animals are likely affected by their enhanced binding affinity for circulating vWF.

Amino Acid Substitution↗
PubMed2006

Perioperative myocardial ischemic injury in high-risk vascular surgery patients: incidence and clinical significance in a prospective clinical trial.

OBJECTIVE: The purpose of this study was to assess prospectively the incidence, health care resource utilization, and economic burden associated with perioperative myocardial ischemic injury (PMII) in high-risk patients undergoing noncardiac vascular surgery. METHODS: Two hundred thirty-six patients consented to participate in a pharmacoeconomic substudy as part of a randomized, multicenter clinical trial. Patients were assessed for myocardial ischemic injury by using clinical, biochemical, and electrocardiographic criteria. PMII was defined as fatal or nonfatal myocardial infarction, new or worsened congestive heart failure, or new arrhythmias. Resource utilization parameters were compared for patients with and without PMII. Patients underwent the following index procedures: open abdominal aortic aneurysm repair (n = 44), bypass for aortoiliac disease (n = 29), bypass for femoropopliteal disease (n = 62), bypass for femorotibial disease (n = 71), extra-anatomic bypass (n = 23), and miscellaneous (n = 7). Patients undergoing carotid endarterectomy or only endovascular interventions were excluded. The incremental cost of PMII was estimated by applying the average costs (adjusted to 2004 US dollars) of the hospital ward (dollar 700.00/d) or intensive care unit (dollar 2500.00/d) to the length of stay differences for patients with and without PMII. RESULTS: The overall mortality was 3.4% (8/236), and 7 of 8 deaths were related to PMII. PMII occurred in 42 (17.8%) of 236 patients: 22 myocardial infarctions, 11 congestive heart failures, and 12 new arrhythmias (3 patients had 2 PMII events). There was no evidence of differences in the incidence of PMII among the various index procedures. PMII was associated with a dramatic increase in resource utilization. The mean length of stay was 16.8 and 10.0 days for patients with and without PMII, respectively (P < .001). Intensive care unit care was required by 35 (83.3%) of 42 patients with and 121 (62.4%) of 194 patients without PMII (P < .009). The mean intensive care unit length of stay was 6.6 and 3.7 days for patients with and without PMII, respectively (P < .009). Ten (23.8%) of 42 patients with and 20 (10.3%) of 194 patients without PMII returned to the emergency department for care after discharge (P < .02). CONCLUSIONS: In modern vascular surgery practice, PMII remains common despite the availability of beta-blockers and other preventative strategies. PMII is associated with dramatic increases in resource utilization and cost. The increase in resource utilization associated with PMII resulted in an estimated incremental cost per patient of dollar 9980.00. If 250,000 high-risk open vascular operations are performed annually in the United States, the economic burden of PMII in these procedures alone approximates dollar 444 million. Strategies to decrease PMII incidence and severity should be evaluated in large-scale prospective trials.

Aged↗
PubMed2006

Inhibitory effects of fluorobenzaldehydes on the activity of mushroom tyrosinase.

The effects of fluorobenzaldehydes (2-,3- and 4-fluorobenzaldehyde) on the activity of mushroom tyrosinase have been studied. The results show that fluorobenzaldehydes can strongly inhibit both monophenolase activity and diphenolase activity of the enzyme and the inhibition is reversible. The IC50 values were estimated as 1.62 mM, 1.06 mM and 0.16 mM for diphenolase activity and as 1.35 mM, 1.18 mM and 1.05 mM for monophenolase activity, respectively. The lag time of the monophenolase was obviously lengthened by these three fluorobenzaldehydes. When the concentration of inhibitors reached 2.0 mM, the lag time was lengthened from 33 s to 142 s, 168 s and 190 s, respectively. Kinetic analyses show that the inhibition mechanism of 2-fluorobenzaldehyde on the diphenolase was competitive inhibition of the diphenolase activity, and that of 3-fluorobenzaldehyde and 4-fluorobenzaldehyde were of a mixed-type. The inhibition constants for these three fluorobenzaldehydes on the diphenolase were determined and compared.

Agaricales↗
PubMed2006

A systematic review of Chinese medicinal herbs for acute bronchitis.

OBJECTIVES: To assess the effectiveness and safety of Chinese medicinal herbs for treating uncomplicated acute bronchitis. DATA SOURCES: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which includes the Cochrane Acute Respiratory Infections Group's specialized register; The Chinese Cochrane Centre's Controlled Trials Register; MEDLINE; EMBASE; and the Chinese Biomedical Database (CBM). METHODS: We only included randomized controlled trials. At least two authors extracted data and assessed trial quality. MAIN RESULTS: Four trials reported the time to improvement of cough, fever, and rales associated with bronchitis and showed that patients treated with Chinese herbs had a shorter duration of signs and symptoms. Two trials reported the proportion of patients with improved signs and symptoms at follow-up and showed that Chinese herbs were beneficial in terms of relief of signs and symptoms. Thirteen (13) trials analyzed the data on physician global assessment of improvement at follow-up. Nine (9) of 13 trials showed that Chinese herbs were superior to routine treatment and the other four trials showed a similar effect to routine treatment. In general, Chinese herbs appeared beneficial. Only one trial reported adverse effects during treatment. CONCLUSIONS: There are insufficient quality data to recommend the routine use of Chinese herbs for acute bronchitis. The benefit found in this systematic review could be due to publication bias and study-design limitations of the individual studies. In addition, the safety of Chinese herbs is unknown due to the lack of toxicological evidence on these Chinese herbs, though adverse events are rarely reported.

Journal Article↗
PubMed2006

Recombinant human B7-H4 expressed in Escherichia coli inhibits T lymphocyte proliferation and IL-2 secretion in vitro.

AIM: To explore the biofunctions of human B7-H4 generated from prokaryotic system. METHODS: The gene of human B7-H4 extracellular region (IgV-like and IgC-like domains) was obtained by PCR from human cDNA FLJ22418 and then inserted into the prokaryotic expression vector pGEX-5X-3 expressing glutathione s-transferase (GST) fusion protein. After being identified by restriction enzyme digestion and sequencing, the recombinant vector was transferred into host strain E coli BL21-RIL(DE3). A 47 kDa fusion protein (GST/hB7-H4) was induced by isopropyl-beta-D-thiogalactopyranoside (IPTG) and purified by standard methods reported in the prokaryotic system. The inhibitory effect of GST/hB7-H4 on proliferation of T cells was observed in vitro by CD3mAb activated T-cell culturing system and [(3)H]-thymidine incorporation assay. The concentrations of interleukin-2 and iterferon-g in the supernatants of T cells were determined by ELISA. RESULTS: We successfully constructed the method for high-level expression and purification of the hB7-H4 extracellular domain as GST fusion protein from E coli. The GST/hB7-H4 fusion protein produced in bacteria had obvious biological activity to inhibit T-lymphocyte proliferation and IL-2 secretion. CONCLUSION: The prokaryote expression system could be used to generate hB7-H4 protein with natural spatial conformations and biological functions, which provided an efficient and economical way for the preparation of this target protein.

B7-1 Antigen↗
PubMed2006

Purification and some properties of beta-N-acetyl-D-glucosaminidase from viscera of green crab (Scylla serrata).

Beta-N-acetyl-D-glucosaminidase was purified from viscera of green crab (Scylla serrata) by extraction with 0.01 M Tris-HCl buffer (pH 7.5) containing 0.2 M NaCl, ammonium sulfate fractionation, and then chromatography on Sephadex G-100 and DEAE-cellulose (DE-32). The purified enzyme showed a single band on polyacrylamide gel electrophoresis, and the specific activity was determined to be 7990 U/mg. The molecular weight of the whole enzyme was determined to be 132.0 kD, and the enzyme is composed of two identical subunits with molecular mass of 65.8 kD. The optimum pH and optimum temperature of the enzyme for the hydrolysis of p-nitrophenyl-N-acetyl-beta-D-glucosaminide (pNP-NAG) were found to be at pH 5.6 and at 50 degrees C, respectively. The study of its stability showed that the enzyme is stable in the pH range from 4.6 to 8.6 and at temperatures below 45 degrees C. The kinetic behavior of the enzyme in the hydrolysis of pNP-NAG followed Michaelis-Menten kinetics with Km of 0.424 +/- 0.012 mM and Vmax of 17.65 +/- 0.32 micromol/min at pH 5.8 and 37 degrees C, and the activation energy was determined to be 61.32 kJ/mol. The effects of some metal ions on the enzyme were surveyed, and the results show that Na+ and K+ have no effects on the enzyme activity; Mg2+ and Ca2+ slightly activate the enzyme, while Ba2+, Zn2+, Mn2+, Hg2+, Pb2+, Cu2+, and Al3+ inhibit the enzyme to different extents.

Acetylglucosamine↗
PubMed2006

Novel selective cytotoxicity of wild sarsaparilla rhizome extract.

Among six fractions, including total extract and fractions of hexane, ethyl acetate, butanol, water and boiling water extracted and separated from wild sarsaparilla rhizome, the hexane fraction (HRW) was the most effective in eliminating four different human cancer cell lines with cellular viability less than 6.8%. HRW exhibited the highest potency against human leukaemia cells with an IC50 (concentration that inhibited the growth rate of cells by 50%) of 3.3 +/- 0.3 microg mL(-1), which was 17.6-fold smaller than that against normal human umbilical vein endothelial cells (IC50, 58.0 +/- 1.5 microg mL(-1)). For its rich natural resources, simple extraction procedure and high yield (3.2%), HRW has the potential to be developed as a selective anti-cancer nutraceutical or pharmaceutical natural health product with low side effects and high economical return.

Antineoplastic Agents, Phytogenic↗
PubMed2006

[Expression of Merlin in cortex of temporal lobe and in hippocampal CA1 region of the Kindling Model of Epilepsy induced by corciaria lactone in rats].

OBJECTIVE: To explore the relationship between merlin and hippocampal sclerosis of temporal epilepsy. METHODS: The kindling model of epilepsy induced by corciaria lactone (CL) in rats was used. The expression of merlin in neuron of cortex of temporal lobe and hippocampal CA1 region was observed using immunohistochemistry method. Comparison of the amount of neuron with expression of merlin in the two locations was made between the kindled group, non-kindled group and control group. RESULTS: The expression of merlin in neuron of cortex of temporal lobe and hippocampal CA1 region of the kindled group was higher than the expression of the other two groups (P < 0.05), and there was no significant difference between the expression in the non-kindled group and that in the control group (P > 0.05). The expression of merlin in glial cell of the same region of all groups was seldom seen. CONCLUSION: The super-expression of merlin in neuron of cortex of temporal lobe and hippocampal CA1 region of the kindled rats may be involved in the process of neuronal apoptosis and hippocampal sclerosis.

Animals↗
PubMed2006

[Construction of human breast carcinoma cell line transfected with OX40L and its costimulatory effect on T cells].

BACKGROUND & OBJECTIVE: Costimulator OX40 (CD134) belongs to TNFR family, and its ligand OX40L (CD134L) belongs to TNF family. OX40-OX40L signal plays an important role in immune regulation, which can increase the production of cytokines and enhance the survival of antigen-specific T cells. This research was to transfect OX40L into human breast cancer cell line MDA-MB-435 to construct OX40L-MDA-MB-435 cells, and to investigate the costimulatory effect of OX40-OX40L signal on biological activity of T cells in vitro. METHODS: cDNA fragment encoding OX40L was obtained from human mature dendritic cells by reverse transcription-polymerase chain reaction (RT-PCR), and inserted into eukaryotic expression vector pcDNA3.1. The recombinant plasmid pcDNA3.1-OX40L was transfected into MDA-MB-435 cells, and verified by indirect immunophenotyping and RT-PCR. The effect of OX40L-MDA-MB-435 cells to the biological activity of T cells was investigated by MTT, enzyme-linked immunosorbent assay (ELISA), and direct immunophenotyping. RESULTS: OX40L-MDA-MB-435 cells were successfully constructed. These cells efficiently promoted the proliferation of T cells, enhanced the secretion of interleukin-2 (IL-2) (973.4 ng/ml at the 7th day) and interferon-gamma (IFN-gamma) (3,689.167 pg/ml at the 3rd day), and down-regulated the expression of Fas on T cells [(68.3+/-5.6)%, P<0.05]. CONCLUSION: OX40L-MDA-MB-435 cells could activate T cells in vitro, promote T cell proliferation and cytokine secretion, and suppress T cell activation-induced cell death.

Breast Neoplasms↗
PubMed2006

[Construction and expression of human-mouse chimeric antibody against human CD40].

AIM: To construct and express a chimeric antibody against human CD40 molecule by genetic engineering antibody transformation. METHODS: Total RNA was extracted from the murine hybridoma cell 5C11 which secreted anti-CD40 monoclonal antibody (mAb). The genes encoding V(H) and V(L) of mAb 5C11 were amplified by RT-PCR. According to sequence analysis, the primer was designed to amplify signal peptide sequences relative to V(H) and V(L) genes. The V(H) and V(L) genes of mAb 5C11 and relative signal peptide sequences were spliced with C(H) and C(kappa) genes of human IgG1 to construct expression plasmid pIRES/h5C11 of human-mouse chimeric antibody gene and the plasmid was transfected into 293T cells under Lipofectamine mediation for transient expression. Expressed product was analyzed by flow cytometry. RESULTS: The result of NCBI gene data bank blast revealed that cloned gene sequence accorded with mice' V(H) and V(L) genes and feature of signal peptide sequence. The constructed plasmid pIRES/h5C11 was correct. The restriction endonuclease digestion analysis and PCR showed that the recombinant genes were subsequently cloned into vector pIRES. FACS analysis showed that human-mouse chimeric antibody against human CD40 maintained the binding activity and specificity to human CD40 molecule. CONCLUSION: The gene encoding variable region of human-mouse chimeric antibody against CD40 is cloned successfully and the human-mouse chimeric antibody against CD40 is expressed transiently in 293T cells.

Animals↗