To determine whether lentinan could upregulate the expression of human-beta-defensin-2(HBD-2) in pulmonary epithelial cells (SPC-A-1), we stimulated pulmonary epithelial cells with lentinan and detected the expression of HBD-2mRNA by RT-PCR test. The results demonstrated that the expression of HBD-2mRNA in SPC-A-1 could be induced by lentinan in a concentration and time-dependent manner.
Adjuvants, Immunologic ; pharmacology ; Epithelial Cells ; metabolism ; Humans ; Lentinan ; pharmacology ; Lung ; cytology ; metabolism ; RNA, Messenger ; genetics ; metabolism ; beta-Defensins ; genetics ; metabolism

BACKGROUNDAntimicrobial peptides, including cathelicidin LL-37, human beta defensin (HBD)-2, and HBD-3, are important elements of the innate immune response and involved in modulation of the adaptive immunity, and they also play an important role in cutaneous defense against Mycobacterium tuberculosis.

METHODSThe fresh skin tissues and paraffin-embedded biopsy samples from three cutaneous tuberculosis, two tuberculids, and ten healthy individuals were collected. The expressions of LL-37, HBD-2, and HBD-3 mRNA in the lesions of three cutaneous tuberculosis and two tuberculids were detected by quantitative real-time polymerase chain reaction; the protein expressions were detected by immunohistochemistry and Western blotting methods.

RESULTSThe expressions of LL-37 mRNA and protein in the lesions of cutaneous tuberculosis and tuberculids were similar to that of normal skin. The expression of HBD-2 mRNA had an increasing trend in the lesions of cutaneous tuberculosis and tuberculids compared with that of normal skin; however, the expression of HBD-2 protein in the lesions of cutaneous tuberculosis had a decreasing trend compared with that of normal skin, and the expression of HBD-2 protein in the lesions of tuberculids was similar to that of normal skin. The expressions of HBD-3 mRNA and protein in lesions of cutaneous tuberculosis and tuberculids were similar to that of normal skin.

CONCLUSIONSOur study indicated that the expression of HBD-2 and HBD-3 mRNA and protein in lesions of cutaneous tuberculosis may be not consistent with that of tuberculids. However, an inherent limitation of the present study was that the sample size was small, and the roles and regulation mechanisms of LL-37, HBD-2, and HBD-3 in cutaneous tuberculosis and tuberculids need to be further investigated.

Adult ; Aged ; Antimicrobial Cationic Peptides ; genetics ; Female ; Humans ; Male ; Middle Aged ; RNA, Messenger ; analysis ; Tuberculosis, Cutaneous ; metabolism ; beta-Defensins ; genetics

OBJECTIVE: To investigate the association between the polymorphisms of 5'-UTR -52G/A (rs1799946), -44C/G (rs1800972), -20G/A (rs11362) in DEFB1 gene with chronic periodontitis in Henan Han population. METHODS: Peripheral blood genomic DNA of 436 patients with chronic periodontitis and 440 healthy controls were extracted and subjected to PCR-Sanger sequencing to determine the genotypes of DEFB1 5'-UTR -52G/A (rs1799946), -44C/G (rs1800972) and -20G/A (rs11362). The distribution of genotypes, allele frequencies and risk factors were analyzed by chi-square test and Logistic regression. RESULTS: There was no significant difference between healthy controls and chronic periodontitis in the genotype of -52G/A PCR- (rs1799946) and -20G/A (rs11362) (P> 0.05). While a significant difference was found between healthy controls and chronic periodontitis in -44C/G (rs1800972), the CC and CG genotype rate in the two groups were 64.5%, 82.1% and 28.2%, 14.4% respectively. One-way logistic analysis showed that the CG, GG genotype and allele G might be a protective factor. CONCLUSION The DEFB1 -44C/G (rs1800972) is associated with chronic periodontitis in Henan Han population, and the -44CG, GG genotype and G allele may be the protective factors of chronic periodontitis in Henan Han population.
Alleles ; Case-Control Studies ; Chronic Periodontitis ; genetics ; Gene Frequency ; Genetic Predisposition to Disease ; Genotype ; Humans ; Polymorphism, Genetic ; beta-Defensins ; genetics

OBJECTIVETo study the expression of human beta-defensin-3 (hBD-3) induced by lipopolysaccharide (LPS) in human bronchial epithelial (HBE) cells, and explore the role of hBD-3 in respiratory infection.

METHODSHBE cells were stimulated with different concentrations of LPS (0.01, 0.1, 1 and 10 microg/mL). hBD-3 mRNA expression was detected by RT-PCR 2 hrs later. hBD-3 protein expression was detected by Western blot 4 hrs later.

RESULTShBD-3 mRNA and protein was weakly expressed in normal HBE cells. LPS stimulation resulted in a significant increase of hBD-3 mRNA and protein expression (p<0.01). hBD-3 mRNA and protein expression increased with increasing LPS concentrations. There were significant differences in the hBD-3 mRNA and protein expression in cells stimulated by different concentrations of LPS (p<0.05).

CONCLUSIONSLPS can induce hBD-3 expression in a dose-dependent manner. hBD-3 might play a role in initial defensive reaction against bacterial invasion.

Bronchi ; drug effects ; metabolism ; Dose-Response Relationship, Drug ; Humans ; Lipopolysaccharides ; toxicity ; RNA, Messenger ; analysis ; beta-Defensins ; analysis ; genetics

In order to study PBD-2 and PoIFNgamma, the chimeric gene PBD-2-PoIFNgamma was synthesized by overlap extension PCR, and amplified PoIFNgamma on the basis of this sequence, then cloned into yeast expression vector pPICZalphaA separately to get the recombinant plasmid pPICZalphaA-PBD-2-PoINFgamma and pPICZalphaA-PoINFgamma. The recombinant plasmid was digested by Sac I and introduced into Pichia pastoris X33 cells by electroporation. Positive clones were screened and cultivated in BMMY medium containing 0.5% methanol for 72 h. SDS-PAGE and Western blotting analysis showed that the screened recombinant could secrete PBD-2-PoINFgamma and PoINFgamma separately. The activity of fusion protein was not detected by cytopathic effect inhibition assay and agar diffusion assay, but detected obvious antiviral activity of PoINFgamma. The helix and random coil contents was showed vary greatly between PoIFNgamma and PBD-2-PoLNFgamma by circular dichroism analysis. It was speculated that the fusion protein was not correctly folded and may affect the activity of PBD-2-PoINFgamma.
Animals ; Genetic Vectors ; genetics ; Interferon-gamma ; biosynthesis ; genetics ; Pichia ; genetics ; metabolism ; Recombinant Fusion Proteins ; biosynthesis ; chemistry ; genetics ; Swine ; beta-Defensins ; biosynthesis ; genetics

OBJECTIVETo research the effects of recombinant human beta-defensin-3 (hBD-3) on expression of interleukin-17A (IL-17A) and interleukin-22 (IL-22) in BEAS-2B cell.

METHODSThe BEAS-2B cells were stimulated with different concentrations of hBD-3 for 6 hours and 24 hours, respectively. Toll-like receptor 2 (TLR2), IL-17A and IL-22 mRNA expression levels were determined by real-time PCR, and the expression levels of IL-17A and IL-22 protein were examined by enzyme linked immune-sorbent assay.

RESULTSTLR2 mRNA in BEAS-2B cells were significantly increased in a concentration-and time-dependent manner after stimulating by hBD-3 for 24 hours compared to 6 hours. The IL-17A has significantly increased in mRNA and protein levels stimulated 24 hours in a concentration of 100 ng/ml, however, IL-17A mRNA expression has increased while protein didn't change stimulated 6 hours in a concentration of 50 ng/ml. The IL-22 mRNA and protein expression reached peak levels after stimulating in a concentration of 50 ng/ml of hBD-3 while IL-22 expression declined in mRNA and protein levels as the concentration of hBD-3 increased.

CONCLUSIONSRecombinant hBD-3 can up-regulated the expression of TLR2, IL-17A and IL-22, lower concentration of hBD-3 mainly increased the expression of IL-22 while higher concentration of hBD-3 mainly increased the expression of IL-17A. These results show that different concentrations of hBD-3 maybe activate different transcription factors which was mediated by TLR2, initiating host immune response.

Cell Line ; Humans ; Interleukin-17 ; genetics ; metabolism ; Interleukins ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Toll-Like Receptor 2 ; genetics ; metabolism ; beta-Defensins ; genetics ; metabolism

OBJECTIVE: To study the changes in the expression of rat beta-defensin-2 (RBD-2) gene in the lung tissue with P. aeruginosa (PA) pneumonia following tracheal mechanical ventilation (MV), and to evaluate the pathogenesis of ventilator-associated pneumonia (VAP). METHODS: A total of 58 normal healthy Sprague-Dawley rats, weighing between 280 and 320 g, were randomly divided into the control group and the conventional MV group (CMV). A tracheal catheter was inserted via mouth in every rat under urethane anesthesia. PA (1 MIC, 0.2 ml) was instilled into the tracheal in the control group. Rats of CMV group received MV (V(T)=12 ml/kg) through tracheal tube for 24 hours, and then were challenged intra-tracheally with PA (1 MIC, 0.2 ml). Fluid loss was replenished through intravenous infusion. The arterial catheter was used for hemodynamics, parameters were monitored, and arterial blood gases were determined. Samples of lung were harvested at 0 hours, 15 hours, 3 hours, 6 hours, 12 hours, 1 day, 3 days and 5 days, respectively, after bacterial challenge. The mRNA of RBD-2 was detected by reverse transcription-polymerase chain reaction (RT-PCR), and the protein levels were analyzed by Western blotting. RESULTS: Expression of RBD-2 mRNA and protein was lower in CMV group compared with the control 3 hours before instillation of bacteria. RBD-2 mRNA increased 3 hours after bacteria instillation, reaching the peak at 12-24 hours. No significant difference in RBD-2 expression between the control group and the CMV group within 3 hours, but it was significantly higher at 3 hours, 6 hours, 12 hours, 1 day, 3 days and 5 days in the control group than in the CMV group. The number of inflammatory cells infiltrating the bronchial submucous layer was significantly higher in the control group than in the CMV group (P<0.05). There was milder interstitial pulmonary edema and less red blood cells in the alveoli in the control group than in the CMV group. The mortality rate of the CMV group was 60%, which was significantly higher than that of the control group (20%, P<0.05). The positive rates of blood culture and bronchoalveolar lavage fluid (BALF) bacterial culture were also higher in the CMV group (P<0.05). The survival rate in CMV group (40%) was lower than that of the control group (P<0.05). CONCLUSION: The lowering of BD-2 gene and protein expression in the CMV group 3 hours after bacteria challenge might be one of the contributory factors in causing VAP.
Disease Models, Animal ; Lung/metabolism ; Lung/pathology ; Pneumonia, Ventilator-Associated/*metabolism ; Pneumonia, Ventilator-Associated/pathology ; RNA, Messenger/metabolism ; Random Allocation ; Rats, Sprague-Dawley ; beta-Defensins/genetics ; beta-Defensins/*metabolism

Human beta defensin 4 is a small cationic peptide with a broad range of antimicrobial activity. It plays an important role in innate immunity of human body, especially in mucosal and epithelial defense. In this study, the full-length encoding gene of HBD4 was synthesized by overlap extension polymerase chain reaction and inserted into cloning vector pMD18-T. The gene encoding mature peptide of HBD4 was amplified by PCR and cloned into prokaryotic expression vector pGEX-4T-2. Then pGEX-4T-2/mHBD4 was transformed into E. coli DH5 alpha, which was induced by isopropy-beta-D-thiogalactoside (IPTG). The identification was made by means of endonuclease digestion, DNA sequencing, sodium dodecyl sulphate-polyacrylamine gel electrophoresis (SDS-PAGE). The results showed that the synthesized gene and cloned gene were identical to the HBD4 gene sequence registered in GenBank and were successfully cloned into cloning vector pMD18-T and prokaryotic expression vector pGEX-4T-2. After IPTG induction, the GST-HBD4 fusion protein was successfully expressed in E. coli.
Anti-Infective Agents ; Cloning, Molecular ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Humans ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; beta-Defensins ; biosynthesis ; genetics

The inductive conditions for the flask-shaking of E.coli BL21-pET-hBD3-Bra had been optimized, at the same time, the expressed protein had been purified and analyzed. The effect of three factors which were IPTG concentration, induction time and temperature on growth of strain and on the yield of hBD3-Bra was analyzed in detail. The result indicated that the concentration of IPTG had little effect on the growth and the expression of target protein between 0.2-1 mmol/L, Biomass would be improved as time passed, but the target protein didn't increase obviously as the same time, temperature was the most important factor, the expressed level of hBD3-Bra, as high as about 35% of total cell protein, could be gained when strain was induced by IPTG under 30 degrees C. Further analysis showed the best temperature for growth was 30 degrees C-32 degrees C and for expression protein was 30 degrees C.The purified hBD3-Bra has a weak antimicrobial activity, but is 200 times sweeter than that of sucrose. After digested by thrombin and purified by affinity column, the natural des-pGlul-Brazzein also has 600-time sweetness of sucrose, and the recombinant hBD3 has a high antimicrobial activity again E. coli and S. aureus.
Anti-Infective Agents ; Escherichia coli ; genetics ; metabolism ; Humans ; Plant Proteins ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; pharmacology ; Sweetening Agents ; Temperature ; beta-Defensins ; biosynthesis ; genetics

In recent years, Bacterial resistance is more and more serious for the irrational use of antibiotics produces resistant strains and other reasons. Human are trying to solve the problem from different ways, including the study of antimicrobial peptides. Defensin is one of the most important of antimicrobial peptides. A novel antimicrobial peptide, human beta-defensin 3, was isolated and demonstrated a salt-insensitive broad spectrum of potent antimicrobial activity against many potentially pathogenic microbes. The total RNA was extracted from human tonsil and the hbetaD-3 specific cDNA sequence was amplified with RT-PCR. After sequenced, the target DNA fragment was cloned into pQE-80L vector together with the DNA fragment encoding carrier protein DHFR. The recombinant vectors were transformed into E. coli M15 and the expression was induced based on the optimal values of the IPTG concentration incubation temperature and induction time determined in the previous section. The expressed proteins were analyzed by SDS-PAGE and Western-blotting. The mass of the recombinant protein was about 40% of total bacteria protein. Isolate and purify the target protein. The recombinant hbetaD-3 fusion proteins possess the antimicrobial activity to staphylococcus aureus, multiresistant staphylococcus aureus (only vancomycin-sensitive) and Candida albicans in the assay of drug susceptibility. Advanced study can be continued based on our experiments.
Cloning, Molecular ; Escherichia coli ; genetics ; Plasmids ; Recombinant Fusion Proteins ; biosynthesis ; isolation & purification ; pharmacology ; Staphylococcus aureus ; drug effects ; Tetrahydrofolate Dehydrogenase ; genetics ; beta-Defensins ; biosynthesis ; genetics ; pharmacology