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1.
Chinese Journal of Natural Medicines (English Ed.) ; (6): 423-435, 2023.
Article in English | WPRIM | ID: wpr-982713

ABSTRACT

Acute lung injury (ALI) is a prevalent and severe clinical condition characterized by inflammatory damage to the lung endothelial and epithelial barriers, resulting in high incidence and mortality rates. Currently, there is a lack of safe and effective drugs for the treatment of ALI. In a previous clinical study, we observed that Jinyinqingre oral liquid (JYQR), a Traditional Chinese Medicine formulation prepared by the Taihe Hospital, Affiliated Hospital of Hubei University of Medicine, exhibited notable efficacy in treating inflammation-related hepatitis and cholecystitis in clinical settings. However, the potential role of JYQR in ALI/acute respiratory distress syndrome (ARDS) and its anti-inflammatory mechanism remains unexplored. Thus, the present study aimed to investigate the therapeutic effects and underlying molecular mechanisms of JYQR in ALI using a mouse model of lipopolysaccharide (LPS)-induced ALI and an in vitro RAW264.7 cell model. JYQR yielded substantial improvements in LPS-induced histological alterations in lung tissues. Additionally, JYQR administration led to a noteworthy reduction in total protein levels within the BALF, a decrease in MPAP, and attenuation of pleural thickness. These findings collectively highlight the remarkable efficacy of JYQR in mitigating the deleterious effects of LPS-induced ALI. Mechanistic investigations revealed that JYQR pretreatment significantly inhibited NF-κB activation and downregulated the expressions of the downstream proteins, namely NLRP3 and GSDMD, as well as proinflammatory cytokine levels in mice and RAW2647 cells. Consequently, JYQR alleviated LPS-induced ALI by inhibiting the NF-κB/NLRP3/GSDMD pathway. JYQR exerts a protective effect against LPS-induced ALI in mice, and its mechanism of action involves the downregulation of the NF-κB/NLRP3/GSDMD inflammatory pathway.


Subject(s)
Humans , NF-kappa B/metabolism , Lipopolysaccharides/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Acute Lung Injury/metabolism , Lung , Phosphate-Binding Proteins/therapeutic use , Pore Forming Cytotoxic Proteins/therapeutic use
2.
J. venom. anim. toxins incl. trop. dis ; 27: e20200127, 2021. graf, tab
Article in English | LILACS, VETINDEX | ID: biblio-1154767

ABSTRACT

Insects can be found in numerous diverse environments, being exposed to pathogenic organisms like fungi and bacteria. Once these pathogens cross insect physical barriers, the innate immune system operates through cellular and humoral responses. Antimicrobial peptides are small molecules produced by immune signaling cascades that develop an important and generalist role in insect defenses against a variety of microorganisms. In the present work, a cecropin B-like peptide (AgCecropB) sequence was identified in the velvetbean caterpillar Anticarsia gemmatalis and cloned in a bacterial plasmid vector for further heterologous expression and antimicrobial tests. Methods AgCecropB sequence (without the signal peptide) was cloned in the plasmid vector pET-M30-MBP and expressed in the Escherichia coli BL21(DE3) expression host. Expression was induced with IPTG and a recombinant peptide was purified using two affinity chromatography steps with Histrap column. The purified peptide was submitted to high-resolution mass spectrometry (HRMS) and structural analyses. Antimicrobial tests were performed using gram-positive (Bacillus thuringiensis) and gram-negative (Burkholderia kururiensis and E. coli) bacteria. Results AgCecropB was expressed in E. coli BL21 (DE3) at 28°C with IPTG 0.5 mM. The recombinant peptide was purified and enriched after purification steps. HRMS confirmed AgCrecropB molecular mass (4.6 kDa) and circular dichroism assay showed α-helix structure in the presence of SDS. AgCrecropB inhibited almost 50% of gram-positive B. thuringiensis bacteria growth. Conclusions The first cecropin B-like peptide was described in A. gemmatalis and a recombinant peptide was expressed using a bacterial platform. Data confirmed tertiary structure as predicted for the cecropin peptide family. AgCecropB was capable to inhibit B. thuringiensis growth in vitro.(AU)


Subject(s)
Animals , Peptides , Soybeans/microbiology , Pore Forming Cytotoxic Proteins/classification , Cecropins/administration & dosage , Immune System
3.
Mem. Inst. Oswaldo Cruz ; 116: e200587, 2021. tab, graf
Article in English | LILACS | ID: biblio-1287343

ABSTRACT

BACKGROUND The inappropriate use of antibiotics has led to the accelerated growth of resistance to antibiotics. The search for new therapeutic strategies (i.e., antimicrobial peptides-AMPs) has thus become a pressing need. OBJECTIVE Characterising and evaluating Sarconesiopsis magellanica larval fat body-derived AMPs. METHODS Fat body extracts were analysed by reversed-phase high-performance liquid chromatography (RP-HPLC); mass spectrometry was used for characterising the primary structure of the AMPs so found. ProtParam (Expasy) was used for analysing the AMPs' physico-chemical properties. Synthetic AMPs' antibacterial activity was evaluated. FINDINGS Four new AMPs were obtained and called sarconesin III, IV, V and VI. Sarconesin III had an α-helix structure and sarconesins IV, V and VI had linear formations. Oligomer prediction highlighted peptide-peptide interactions, suggesting that sarconesins III, V and VI could form self-aggregations when in contact with the microbial membrane. AMPs synthesised from their native molecules' sequences had potent activity against Gram-positive bacteria and, to a lesser extent, against Gram-negative and drug-resistant bacteria. Sarconesin VI was the most efficient AMP. None of the four synthetic AMPs had a cytotoxic effect. MAIN CONCLUSIONS S. magellanica larval fat body-derived antimicrobial peptides are an important source of AMPs and could be used in different antimicrobial therapies and overcoming bacterial resistance.


Subject(s)
Animals , Diptera , Fat Body , Microbial Sensitivity Tests , Pore Forming Cytotoxic Proteins , Calliphoridae , Larva , Anti-Bacterial Agents/pharmacology
4.
Chinese Journal of Biotechnology ; (12): 2915-2923, 2021.
Article in Chinese | WPRIM | ID: wpr-887853

ABSTRACT

Antimicrobial peptides are the most promising alternatives to antibiotics. However, the strategy of producing antimicrobial peptides by recombinant technology is complicated and expensive, which is not conducive to the large-scale production. Oxysterlin 1 is a novel type of cecropin antimicrobial peptide mainly targeting on Gram-negative bacteria and is of low cytotoxicity. In this study, a simple and cost-effective method was developed to produce Oxysterlin 1 in Escherichia coli. The Oxysterlin 1 gene was cloned into a plasmid containing elastin-like polypeptide (ELP) and protein splicing elements (intein) to construct the recombinant expression plasmid (pET-ELP-I-Oxysterlin 1). The recombinant protein was mainly expressed in soluble form in E. coli, and then the target peptide can be purified with a simple salting out method followed by pH changing. The final yield of Oxysterlin 1 was about 1.2 mg/L, and the subsequent antimicrobial experiment showed the expected antimicrobial activity. This study holds promise for large-scale production of antimicrobial peptides and the in-depth study of its antimicrobial mechanism.


Subject(s)
Elastin , Escherichia coli/genetics , Inteins , Peptides/pharmacology , Pore Forming Cytotoxic Proteins , Recombinant Fusion Proteins/genetics
5.
Chinese Journal of Biotechnology ; (12): 2890-2902, 2021.
Article in Chinese | WPRIM | ID: wpr-887851

ABSTRACT

The evolution, structure and antigenic epitopes prediction of Rana dybowskii antimicrobial peptide dybowskin-1ST were carried out using bioinformatics software available online. Its antibacterial mechanism and structural properties were analyzed, and its activity was verified by applying wound healing assay in mice and bacteriostatic assay in vitro. This provides the theoretical basis for the improvement of parental peptide and the development of novel derivative peptides. The software MEGA_X were used to conduct homology alignment and to construct a phylogenetic tree. The online software ProtParam, ProtScale, PeptideCutter, signal, TMHMM Server were respectively used to predict the physicochemical parameters, hydrophilia/hydrophobicity, shear sites, signal peptides, and transmembrane domains of dybowskin-1ST. The online software SOPMA, Jpred4, DNAstar Protean were used to predict the secondary structure of dybowskin-1ST, and SWISS-MODEL, I-TASSER were used to predict the tertiary structure. ABCpred and SYFPEITHI were respectively used to predict its B-and T-cell epitopes. The effect of dybowskin-1ST on the wound healing was observed on experimental mice. Kirby-Bauer method and dilution method were used to determine the bacteriostatic activity of dybowskin-1ST. The dybowskin-1ST consists of 59 amino acid residues, of which leucine accounts for 16.9%, with a molecular formula of C₃₁₈H₅₁₀N₈₀O₉₃S₂. Its theoretical isoelectric point is 5.10 and the charge is -2. The dybowskin-1ST and dybowskin-1CDYa are closely related phylogenetically. The secondary structure of dybowskin-1ST predicted by the three methods were similar, which consisted of α-helix (44.07%), extended strand (16.95%), β-turns (3.39%), and random coil (35.39%). The prediction of tertiary structure showed that dybowskin-1ST was mainly composed of α-helix, and it was regarded as a hydrophilic protein with signal peptide sequence. Subcellular localization analysis showed that the probability of secreting the mitochondrial targeted peptides was 0.944. Dybowskin-1ST is an extracellular protein with no transmembrane structure region, but contains seven phosphorylation sites, three T-cell epitopes and eight B-cell epitopes. The dybowskin-1ST promoted wound healing and effectively inhibited the growth of Escherichia coli and Staphylococcus aureus. However, it had limited antibacterial activity against fungi and drug-resistant bacteria. Although the structure of dybowskin-1ST is rich in α-helix, the verification experiments showed that its antibacterial ability needs to be enhanced. The reason may be that it is a negatively charged and hydrophilic protein, and amino acid modification with the aim of increasing the number of positive charges and changing the hydrophobicity may be used to obtain derived peptides with enhanced activity.


Subject(s)
Animals , Mice , Amino Acid Sequence , Phylogeny , Pore Forming Cytotoxic Proteins , Protein Structure, Secondary , Ranidae
6.
Chinese Journal of Biotechnology ; (12): 2534-2542, 2021.
Article in Chinese | WPRIM | ID: wpr-887819

ABSTRACT

Based on the cathelicidin family antimicrobial peptide Hc-CATH derived from sea snake, the Hc-16 and Hc-15 of 16 and 15 amino acid residues, were designed. By using CCK8, minimal inhibitory concentration, ELISA and bio-layer interferometry assays, their cytotoxicity, antibacterial activity, anti-inflammatory activity, and LPS neutralization activity was examined. Compared with Hc-15, Hc-16 had lower cytotoxicity and better broad-spectrum antibacterial activity against pathogens including clinically resistant bacteria, with the minimum inhibitory concentration of only 4.69 μg/mL. Hc-16 inhibited the expression of inflammatory cytokines of TNF-α and IL-6 induced by LPS, so as to significantly reduce the inflammatory response induced by infection. In addition, structure-activity relationship studies have shown that the phenylalanine at the C- and N-terminals of Hc-16 played a crucial role in its antibacterial and anti-inflammatory activity. Altogether, the designed Hc-16 has an excellent prospect to be developed into a novel antibiotic.


Subject(s)
Animals , Anti-Bacterial Agents/pharmacology , Anti-Infective Agents , Elapidae , Microbial Sensitivity Tests , Pore Forming Cytotoxic Proteins
7.
West China Journal of Stomatology ; (6): 188-194, 2021.
Article in Chinese | WPRIM | ID: wpr-878429

ABSTRACT

OBJECTIVES@#To evaluate the effects of antimicrobial peptide GH12 designed @*METHODS@#The cariogenic three-species biofilm consis-ted of the cariogenic @*RESULTS@#The biomass and density of the cariogenic three-species biofilm treated with GH12 decreased compared with those of the control. The number of @*CONCLUSIONS@#GH12 can reduce the number of


Subject(s)
Humans , Biofilms , Dental Caries , In Situ Hybridization, Fluorescence , Pore Forming Cytotoxic Proteins , Streptococcus mutans
8.
Chinese Journal of Biotechnology ; (12): 3142-3150, 2021.
Article in Chinese | WPRIM | ID: wpr-921412

ABSTRACT

The hinge structure, also known as hinge region or bend, is a special structure found in some antimicrobial peptides. Most studies on antimicrobial peptides focused on the standard secondary structure of α-helix and β-sheet, while the hinge structure and its functions were rarely studied. The hinge structure confers the antimicrobial peptides an improved structural flexibility, which may promote their disruptive effect on bacterial membrane or their binding efficiency to the intracellular targets, thus resulting in a higher antibacterial activity. Meanwhile, the hinge structure may reduce the structural rigidity, which may eliminate the cytotoxicity of antimicrobial peptides to eukaryotic cells. This article reviews the structural characteristics of the hinge structure, its effects on the biological activity of antimicrobial peptides and application in the molecular design, with the aim to provide a reference for the design and development of new antimicrobial peptides.


Subject(s)
Anti-Bacterial Agents/pharmacology , Anti-Infective Agents/pharmacology , Antimicrobial Cationic Peptides/pharmacology , Pore Forming Cytotoxic Proteins , Protein Structure, Secondary
9.
Chinese Medical Journal ; (24): 2966-2975, 2020.
Article in English | WPRIM | ID: wpr-877923

ABSTRACT

Antimicrobial peptides (AMPs) are small molecules produced by a myriad of cells and play important roles not only in protecting against infections and sustaining skin barrier homeostasis but also in contributing to immune dysregulation under pathological conditions. Recently, increasing evidence has indicated that AMPs, including cathelicidin (LL-37), human β-defensins, S100 proteins, lipocalin 2, and RNase 7, are highly expressed in psoriatic skin lesions. These peptides broadly regulate immunity by interacting with various immune cells and linking innate and adaptive immune responses during the progression of psoriasis. In this review, we summarize the recent findings regarding AMPs in the pathogenesis of psoriasis with a main focus on their immunomodulatory abilities.


Subject(s)
Humans , Adaptive Immunity , Immunity, Innate , Pore Forming Cytotoxic Proteins , Psoriasis , Skin Diseases , beta-Defensins
10.
Infectio ; 17(3): 146-152, jul.-set. 2013. ilus
Article in Spanish | LILACS, COLNAL | ID: lil-702960

ABSTRACT

La vitamina D (VitD), además de su papel en el metabolismo mineral, tiene funciones inmunomoduladoras y podría participar activamente en la fisiopatogénesis de la infección por el VIH-1; sin embargo, la evidencia científica en este campo es limitada y controvertida. La VitD tiene propiedades antiinflamatorias que podrían disminuir la hiperactivación inmunológica, reduciendo el daño asociado a este fenómeno; además, promueve la expresión de péptidos con actividad anti-VIH-1, sustentando su papel protector. En contraste, la VitD activa el promotor del VIH-1 y podría potenciar la replicación del virus; adicionalmente, algunas variantes alélicas en el gen del receptor de la VitD, que aumentan su función, se han asociado con susceptibilidad al VIH-1. Esta revisión presenta evidencia científica sobre el efecto de la vía de la VitD en la patogénesis de la infección por el VIH-1, dada las implicaciones de este tópico en la identificación de nuevos blancos terapéuticos en esta infección.


Beyond its role in mineral metabolism, vitamin D (VitD) has immunomodulatory functions and can actively participate in the physiopathogenesis of HIV-1 infection; however, scientific evidence in this field is limited and controversial. VitD has anti-inflammatory properties that can reduce immune hyperactivation, decreasing the damage associated with this phenomenon. It also promotes the expression of antimicrobial peptides with anti-HIV-1 activity, supporting its protective role. In contrast, VitD activates the HIV-1 promoter and can increase viral replication. Furthermore, a number of allelic variants in the vitamin D receptor gene, which increase its function, have been associated with susceptibility to HIV-1 infection. Given the implications of this topic for the identification of new therapeutic targets in HIV infection, this review presents scientific evidence on the effect of the VitD pathway in HIV-1 pathogenesis.


Subject(s)
Humans , Vitamin D , Pathogenesis, Homeopathic , HIV-1 , Pore Forming Cytotoxic Proteins , Immune System Diseases
11.
Journal of Experimental Hematology ; (6): 431-434, 2011.
Article in Chinese | WPRIM | ID: wpr-244908

ABSTRACT

This study was aimed to explore whether the perforin gene 1 (PRF1) mutation is the basis of genetic susceptibility to pathogenesis of acquired severe aplastic anemia (SAA). DNA exon2 and exon3 of PRF1 gene in peripheral blood mononuclear cells in 31 SAA patients and 15 normal controls were amplified by PCR; the sequencing was performed by using ABI pRISM 373OXL sequencer; the mutation loci were sought through checking sequences with GenBank-reported sequences; after the mutation sequences were found, those were cloned into M13 phage vector, then the corresponding sequences of gained 2 chromosomes were sequenced respectively to determine the distribution of different mutations on chromosomes. The results showed that (1) one homozygous mutation (822 C > T, synonymous mutation) and one heterozygous mutation (907 G > A, methionine 303 valine) were found in PRF1 coding region of 2 SAA patients. These mutations were not detected in normal controls. (2) 1 SNP (rs885822) in the coding region was detected in SAA patients and controls, and the heterozygosity rate between the 2 groups was different (p < 0.05). It is concluded that perforin gene mutation may be one risk factor in the aberrant proliferation and activation of cytotoxic T cells in pathogenesis of a part of patients with aplastic anemia.


Subject(s)
Adolescent , Adult , Aged , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Young Adult , Anemia, Aplastic , Genetics , Base Sequence , Case-Control Studies , Genetic Predisposition to Disease , Heterozygote , Mutation , Perforin , Pore Forming Cytotoxic Proteins , Genetics
12.
Chinese Journal of Contemporary Pediatrics ; (12): 223-226, 2011.
Article in Chinese | WPRIM | ID: wpr-308828

ABSTRACT

<p><b>OBJECTIVE</b>To study the expression of perforin and granzyme B (GzmB) in the lungs of asthmatic rats and the effect of recombinant human growth hormone (rhGH) on the expression.</p><p><b>METHODS</b>Thirty Sprague-Dawley male rats were randomly divided into a normal control group and asthma groups with and without rhGH treatment. An asthma model was prepared by repeated sensitization with ovalbumin and aluminium hydroxide. The morphological changes of the airway were observed by hematoxylin and eosin staining. Terminal deoxyribonucleotide transferase-mediated Dutp-bintin (TUNLE) was used to detect the apoptosis of epithelial cells in the airway. RT-PCR was used to detect the mRNA transcripts of perforin and GzmB in the lung tissues.</p><p><b>RESULTS</b>A significantly increased apoptosis rate of airway epithelial cells was noted in the untreated asthma group. The apoptosis rate was significantly ruduced in the rhGH-treated asthma group (P<0.05). Compared with the control group, perforin and GzmB expression in the lungs in the untreated asthma group increased significantly. The rhGH-treated asthma group demonstrated significantly decreased perforin (0.48 ± 0.08 vs 0.63 ± 0.08; P<0.05) and GzmB (0.44 ± 0.13 vs 0.71 ± 0.15; P<0.05) expression in the lungs compared with the untreated asthma group. Both PFP (r=0.800, P<0.05) and GzmB (r=0.806, P<0.01) were positively correlated with the apoptosis rate of airway epithelial cells.</p><p><b>CONCLUSIONS</b>Perforin and GzmB may play important roles in the pathogenesis of asthma. rhGH treatment can inhibit apoptosis of airway epithelial cells and airway remodeling, possibly through a reduction in perforin and GzmB expression.</p>


Subject(s)
Animals , Male , Rats , Apoptosis , Asthma , Metabolism , Bronchi , Pathology , Granzymes , Genetics , Human Growth Hormone , Pharmacology , Pore Forming Cytotoxic Proteins , Genetics , RNA, Messenger , Rats, Sprague-Dawley
13.
Biomedical and Environmental Sciences ; (12): 333-340, 2010.
Article in English | WPRIM | ID: wpr-306920

ABSTRACT

<p><b>OBJECTIVE</b>LcrV is an important component for the development of a subunit vaccine against plague. To reduce immunosuppressive activity of LcrV, a recombinant LcrV variant lacking amino acids 271 to 326 (rV270) was prepared by different methods in this study.</p><p><b>METHODS</b>A new strategy that produced non-tagged or authentic rV270 protein was designed by insertion of rV270-thrombin-hexahistidine fusion gene into the vector pET24a, or by insertion of hexahistidine-enterokinase-rV270 or hexahistitine-factor Xa-rV270 fusion gene into the vector pET32a. After Co(2+) affinity chromatography, a purification strategy was developed by cleavage of His tag on column, following Sephacryl S-200HR column filtration chromatography.</p><p><b>RESULTS</b>Removal of His tag by thrombin, enterokinase and factor Xa displayed a yield of 99.5%, 32.4% and 15.3%, respectively. Following Sephacryl S-200HR column filtration chromatography, above 97% purity of rV270 protein was obtained. Purified rV270 that was adsorbed to 25% (v/v) Al(OH)₃ adjuvant in phosphate-buffered saline (PBS) induced very high titers of antibody to rV270 in BALB/c mice and protected them (100% survival) against subcutaneous challenge with 10⁶ CFU of Y. pestis virulent strain 141.</p><p><b>CONCLUSION</b>The completely authentic rV270 protein can be prepared by using enterokinase or factor Xa, but they exhibited extremely low cleavage activity to the corresponding recognition site. Thrombin cleavage is an efficient strategy to prepare non-tagged rV270 protein and can be easily operated in a large scale due to its relatively low cost and high cleavage efficacy. The recombinant rV270 can be used as a key component to develop a subunit vaccine of plague.</p>


Subject(s)
Animals , Female , Mice , Amino Acid Sequence , Antibodies, Bacterial , Blood , Antigens, Bacterial , Genetics , Allergy and Immunology , Blotting, Western , Cloning, Molecular , Electrophoresis, Polyacrylamide Gel , Escherichia coli , Genetics , Genetic Vectors , Mice, Inbred BALB C , Molecular Sequence Data , Plague , Allergy and Immunology , Plague Vaccine , Genetics , Allergy and Immunology , Plasmids , Pore Forming Cytotoxic Proteins , Genetics , Allergy and Immunology , Protein Engineering , Methods , Recombinant Fusion Proteins , Genetics , Allergy and Immunology , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Survival Analysis , Vaccines, Subunit , Genetics , Allergy and Immunology , Yersinia pestis , Allergy and Immunology
14.
Journal of Experimental Hematology ; (6): 1316-1320, 2010.
Article in Chinese | WPRIM | ID: wpr-332369

ABSTRACT

The study was aimed to investigate the etiology and the clinical characteristics of patients with hemophagocytic syndrome. The clinical data of 38 patients with hemophagocytic syndrome were retrospectively analyzed, and prf1 and stx11 were detected for the mutational analysis. The results showed that 38 cases were diagnosed as hemophagocytic syndrome, including 1 case of familial hemophagocytic lymphohistiocytosis (FHL), 14 cases associated with infectious disease (36.84%), 10 cases with malignancies (26.32%), 7 cases with rheumatic disease (18.42%), other 6 cases of unknown etiology (15.79%). 9 out of 38 cases died with mortality of 23.68%, including 4 cases associated with infectious disease, 2 cases with malignancies, 1 case with rheumatic disease, and 2 cases of unknown etiology. One case was found to have prf1 mutation, and was diagnosed as FHL at last. It is concluded that the causes of HPS are diverse, different etiology results in different outcome. It is important to find etiology when HPS is diagnosed, and prf1 and stx11 genetic analysis plays a important role in the diagnosis of FHL.


Subject(s)
Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Young Adult , DNA Mutational Analysis , Exons , Lymphohistiocytosis, Hemophagocytic , Genetics , Perforin , Pore Forming Cytotoxic Proteins , Genetics , Qa-SNARE Proteins , Genetics , Retrospective Studies
15.
Chinese Medical Journal ; (24): 2851-2855, 2009.
Article in English | WPRIM | ID: wpr-266028

ABSTRACT

<p><b>BACKGROUND</b>Recent studies have reported germline mutations in the perforin gene (PRF1) in some types of hemophagocytic lymphohistiocytosis (HLH). However, the prevalence of PRF1 mutations in HLH in Chinese pediatric patients has not been extensively studied. The aim of this study was to investigate the prevalence of mutations and sequence variations in the PRF1 gene in Chinese pediatric patients with HLH.</p><p><b>METHODS</b>Polymerase chain reaction (PCR) was performed with five pairs of primers for the coding exons and the flanking intron sequences of PRF1. Sequencing of PCR products was subsequently applied in 30 pediatric patients with HLH and in 50 controls.</p><p><b>RESULTS</b>Three heterozygous mutations in a coding region were found, which resulted in amino acid changes (C102F, S108N and T450M) in three patients. These mutations were not detected in control subjects. One patient had compound heterozygous mutations (S108N and T450M) in PRF1 as the background defect, and documented familial HLH type 2 (FHL2). One synonymous sequence variant (Q540Q) was observed in one patient but not in the controls. Two SNPs (A274A, H300H) in the coding region were detected in HLH patients and controls, but without differences in the heterozygosity rate between the two groups (P > 0.05 for all comparisons).</p><p><b>CONCLUSIONS</b>We have identified three patients with three heterozygous missense mutations in PRF1; two of those three mutations (C102F and S108N) have so far been found only from Chinese patients. These findings are useful in evaluating the prevalence of PRF1 mutations in Chinese pediatric patients with HLH, and to correlate their genotype with phenotype. Some patients without familial history probably have primary HLH, which should be suspected even beyond the usual age range.</p>


Subject(s)
Adolescent , Child , Child, Preschool , Female , Humans , Infant , Male , Amino Acid Sequence , Epstein-Barr Virus Infections , Genetics , Lymphohistiocytosis, Hemophagocytic , Genetics , Molecular Sequence Data , Mutation , Perforin , Polymerase Chain Reaction , Pore Forming Cytotoxic Proteins , Genetics
16.
Indian J Biochem Biophys ; 2007 Aug; 44(4): 204-8
Article in English | IMSEAR | ID: sea-27993

ABSTRACT

Aerolysin is a toxin (protein in nature) secreted by the strains of Aeromonas spp. and plays an important role in the virulence of Aeromonas strains. It has also found several applications such as for detection of glycosylphosphatidylinositol (GPI)-anchored proteins etc. A. hydrophila is a ubiquitous Gram-negative bacterium which causes frequent harm to the aquaculture. To obtain a significant amount of recombinant aerolysin in the active form, in this study, we expressed the aerolysin in E. coli under the control of T7 RNase promoter. The coding region (AerA-W) of the aerA gene of A. hydrophila XS91-4-1, excluding partial coding region of the signal peptide was cloned into the vector pET32a and then transformed into E. coli b121. After optimizing the expression conditions, the recombinant protein AerA-W was expressed in a soluble form and purified using His.Bind resin affinity chromatography. Recombinant aerolysin showed hemolytic activity in the agar diffusive hemolysis test. Western blot analysis demonstrated good antigenicity of the recombinant protein.


Subject(s)
Aeromonas hydrophila/metabolism , Bacterial Toxins/immunology , Chromatography, Affinity , Cloning, Molecular/methods , Escherichia coli/genetics , Pore Forming Cytotoxic Proteins/immunology , Protein Sorting Signals/genetics , Recombinant Proteins/isolation & purification
17.
Chinese Journal of Biotechnology ; (12): 846-851, 2007.
Article in Chinese | WPRIM | ID: wpr-327936

ABSTRACT

Pseudomonas aeruginosa is an important opportunistic human pathogen. It encodes many virulence factors and one of them is type III secretion system (TTSS). Effectors proteins can be delivered into host cells directly by this system, causing necrosis or apoptosis. popN gene is the first gene in the popN operon of TTSS gene cluster. To investigate its function, popN gene deletion mutant was generated in this study, and we found this mutant can secrete effectors proteins constitutively under non-inducting condition in DMEM medium containing serum. The results indicated that PopN is a negative regulator of the TTSS expression. However, no secreted effector proteins were detectable when the popN- mutant was grown in LB medium under non-inducting condition. To investigate the possible reasons, effects of growth status and protease (s) inhibitors on the TTSS were investigated. We present evidences that indicate protease mediated degradation of secreted effector proteins played a key role in the phenotypic inconsistency of popN- mutant.


Subject(s)
ADP Ribose Transferases , Metabolism , Bodily Secretions , Bacterial Proteins , Genetics , Metabolism , Bodily Secretions , Bacterial Toxins , Metabolism , Gene Expression Regulation, Bacterial , Mutation , Peptide Hydrolases , Genetics , Metabolism , Pore Forming Cytotoxic Proteins , Genetics , Bodily Secretions , Protease Inhibitors , Pharmacology , Pseudomonas aeruginosa , Genetics , Metabolism , Virulence
18.
Article in English | IMSEAR | ID: sea-24354

ABSTRACT

BACKGROUND & OBJECTIVES: Perforin is one of the major effector molecules of cytotoxic cells associated with killing of cells harbouring intracellular bacterial infection. The precise role of perforin positive cells in tuberculosis still remains controversial. The present study was done to determine the number of circulating CD4(+) and CD8(+) perforin positive cells to assess the level of cytotoxic response against Mycobacterium tuberculosis in patients with pulmonary tuberculosis. METHODS: Intracellular perforin and surface CD4 and CD8 staining of peripheral blood lymphocytes was done using specific monoclonal antibodies and enumerated using flowcytometry. RESULTS: A significantly decreased total lymphocytes (P<0.01), CD4 (P<0.001) and CD8 (P<0.01) lymphocyte counts in PTB patients was observed compared to normal healthy individuals (NHS). Intracellular perforin staining showed significantly elevated percentages of total (P<0.05) and CD8 (P<0.01) perforin positive cells in PTB patients compared to NHS. However, the absolute counts of total, CD4 and CD8 cells positive for perforin were similar in patients and NHS. INTERPRETATION & CONCLUSION: Our results suggest that during active stage of pulmonary tuberculosis there was an increased percentage of CD8 cells positive for perforin, irrespective of their absolute counts. Further, CD8(+) perforin positive cells may have increased cytolytic activity against M. tuberculosis in active pulmonary tuberculosis.


Subject(s)
Adult , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Case-Control Studies , Humans , Immunity, Cellular , Membrane Glycoproteins/immunology , Mycobacterium tuberculosis/immunology , Perforin , Pore Forming Cytotoxic Proteins , Tuberculosis, Pulmonary/immunology
19.
Journal of Biomedical Engineering ; (6): 1075-1077, 2005.
Article in Chinese | WPRIM | ID: wpr-238274

ABSTRACT

Perforin and granzyme are important effector molecules in cytolytic cells. They can induce apoptosis of tumor cells and infection cells. The research of biologic missile is noticed with the progress in therapy targeting to the disease. It is supposed that perforin and granzyme play an important role in biological missiles because of their biologic function and structure. A review on several aspects of these effector molecules is presented.


Subject(s)
Animals , Humans , Granzymes , Killer Cells, Natural , Allergy and Immunology , Membrane Glycoproteins , Allergy and Immunology , Therapeutic Uses , Neoplasms , Allergy and Immunology , Therapeutics , Perforin , Pore Forming Cytotoxic Proteins , Serine Endopeptidases , Allergy and Immunology , Therapeutic Uses , T-Lymphocytes, Cytotoxic , Allergy and Immunology
20.
Chinese Journal of Pathology ; (12): 198-201, 2005.
Article in Chinese | WPRIM | ID: wpr-265150

ABSTRACT

<p><b>OBJECTIVE</b>To study the roles of granzyme B and perforin in diagnosing acute rejection after liver transplantation, and the relationship between their activity index (AI) and Banff's histological grading criteria.</p><p><b>METHODS</b>Liver biopsies were processed as for routine surgical specimens and labeled with granzyme B and perforin monoclonal antibodies. The number of positive cells/mm(2) was determined as activity index (AI) by IPP image analysis software. Histologic findings were used as the "gold standard" in diagnosing acute rejection.</p><p><b>RESULTS</b>Of 41 liver biopsy samples studied, acute rejection was noted in 21 cases, the remaining 20 cases showed no evidence of rejection. The AI of granzyme B and perforin in the acute rejection group was significantly higher than that in the non-acute rejection group (< 0.001). In the acute rejection group, the AI in moderate to severe acute rejection was higher than that in mild to indeterminate acute rejection (< 0.001). Compared with the "golden" histologic criteria, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of granzyme B in diagnosing acute rejection were 90.0%, 95.2%, 94.7%, 90.9% and 92.7% respectively. The values of these parameters for perforin were also above 80%.</p><p><b>CONCLUSIONS</b>Granzyme B and perforin are key markers of activated immune cells in acute rejection and highly expressed during acute liver rejection episodes. As ancillary investigations, these parameters demonstrated high sensitivity and specificity in diagnosing acute rejection in allograft post-transplant liver biopsies.</p>


Subject(s)
Humans , Biomarkers , Biopsy , Graft Rejection , Diagnosis , Metabolism , Granzymes , Metabolism , Liver , Metabolism , Pathology , Liver Transplantation , Allergy and Immunology , Membrane Glycoproteins , Metabolism , Perforin , Pore Forming Cytotoxic Proteins , Metabolism , Sensitivity and Specificity
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