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1.
Protein J ; 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38662183

RESUMO

Bacteriophage endolysins are potential alternatives to conventional antibiotics for treating multidrug-resistant gram-negative bacterial infections. However, their structure-function relationships are poorly understood, hindering their optimization and application. In this study, we focused on the individual functionality of the C-terminal muramidase domain of Gp127, a modular endolysin from E. coli O157:H7 bacteriophage PhaxI. This domain is responsible for the enzymatic activity, whereas the N-terminal domain binds to the bacterial cell wall. Through protein modeling, docking experiments, and molecular dynamics simulations, we investigated the activity, stability, and interactions of the isolated C-terminal domain with its ligand. We also assessed its expression, solubility, toxicity, and lytic activity using the experimental data. Our results revealed that the C-terminal domain exhibits high activity and toxicity when tested individually, and its expression is regulated in different hosts to prevent self-destruction. Furthermore, we validated the muralytic activity of the purified refolded protein by zymography and standardized assays. These findings challenge the need for the N-terminal binding domain to arrange the active site and adjust the gap between crucial residues for peptidoglycan cleavage. Our study shed light on the three-dimensional structure and functionality of muramidase endolysins, thereby enriching the existing knowledge pool and laying a foundation for accurate in silico modeling and the informed design of next-generation enzybiotic treatments.

2.
Vet Res Commun ; 47(3): 1493-1503, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37097546

RESUMO

Salmonella enteritidis is one of the most important foodborne pathogens that cause numerous outbreaks worldwide. Some strains of Salmonella have become progressively resistant to antibiotics, so they could represent a critical threat to public health and have led to the use of alternative therapeutic approaches like phage therapy. In this study, a lytic phage, vB_SenS_TUMS_E4 (E4), was isolated from poultry effluent and characterized to evaluate its potential and efficacy for bio-controlling S. enteritidis in foods. Transmission electron microscopy revealed that E4 has a siphovirus morphotype, with an isometric head and non-contractile tail. Determining the host range showed that this phage can effectively infect different motile as well as non-motile Salmonella enterica serovars. The biological characteristics of E4 showed that it has a short latent period of about 15 min and a large burst size of 287 PFU/cell, and is also significantly stable in a broad range of pHs and temperatures. The E4 whole genome contains 43,018 bp and encodes 60 coding sequences (CDSs) but no tRNA genes. Bioinformatics analysis revealed that the genome of E4 lacks any genes related to lysogeny behavior, antibiotic resistance, toxins, or virulence factors. The efficacy of phage E4 as a bio-control agent was assessed in various foodstuffs inoculated with S. enteritidis at 4°C and 25°C, and the resulting data indicated that it could eradicate S. enteritidis after a very short time of 15 min. The findings of the present study showed that E4 is a hopeful candidate as a bio-control agent against S. enteritidis and has the potential to be used in various foodstuffs.


Assuntos
Bacteriófagos , Fagos de Salmonella , Animais , Bacteriófagos/genética , Genoma Viral , Especificidade de Hospedeiro , Fagos de Salmonella/genética , Salmonella enteritidis/genética
3.
Virus Genes ; 59(1): 132-141, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36357763

RESUMO

Pseudomonas aeruginosa is an opportunistic human pathogen that can lead to nosocomial infections which are in turn life threatening. The increase in antibiotic resistance, at an alarming rate, has resulted in a pressing need for alternative therapeutic approaches such as phage therapy, which hold promise according to several studies. This study featured the isolation and characterization of vB_PaeS_TUMS_P81, a new lytic Pseudomonas phage. The whole-genome sequencing indicated that it has a genome of 73,167 bp containing 93 predicted coding sequences. Genes involved in virulence or lysogeny pathway were nowhere to be found in the genome, so it is potentially safe when it comes to therapeutic applications. Genomic and phylogenetic analysis indicated that vB_PaeS_TUMS_P81 is a member of the genus Litunavirus, belonging to Schitoviridae family. The present study lays the groundwork for further research on treatment of P. aeruginosa infections.


Assuntos
Bacteriófagos , Fagos de Pseudomonas , Humanos , Bacteriófagos/genética , Pseudomonas aeruginosa/genética , Filogenia , Genômica , Fagos de Pseudomonas/genética , Genoma Viral/genética
4.
Arch Virol ; 168(1): 8, 2022 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-36565337

RESUMO

Pseudomonas aeruginosa is an opportunistic human pathogen that can cause life-threatening nosocomial infections. The alarming increase in antibiotic resistance has led to an urgent need for alternative therapeutic approaches, such as phage therapy, which has shown promising results in many studies. In this study, P121, a new lytic Pseudomonas phage, was isolated and characterized. Whole-genome sequencing showed that it has a genome of 73,001 bp that contains 91 predicted coding sequences. No genes involved in virulence or lysogeny were found in the genome, thus making it potentially safe for therapeutic applications. Genomic and phylogenetic analysis indicated that P121 is a member of the genus Litunavirus, family Schitoviridae. The present study provides some basic information for further research on treatment of P. aeruginosa infections.


Assuntos
Bacteriófagos , Fagos de Pseudomonas , Humanos , Bacteriófagos/genética , Pseudomonas aeruginosa , Filogenia , Genoma Viral , Genômica/métodos , Fagos de Pseudomonas/genética
5.
Probiotics Antimicrob Proteins ; 13(6): 1539-1545, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33843030

RESUMO

Regulation of immune responses is among the beneficial effects of probiotic bacteria on human health. In this study, we aim to investigate the effect of normal and heat-shocked Lactobacillus plantarum PTCC 1058 cell lysate on cytokine expression by human PBMCs. The mid-exponential phase L. plantarum (108 CFU/mL) were used to prepare cell lysate. Isolated PBMCs were stimulated with 100 µg/mL of each normal and heat-shocked L. plantarum cell lysate for 72 h. Non-stimulated PBMCs were also evaluated as negative control. The mRNA expression of IL-6, IL-10, IFN-É£, TNF-α, and TGF-ß genes was determined by quantitative RT-PCR amplification of total RNA extracted from PBMCs. Both types of cell lysate were able to increase pro-inflammatory cytokines and decrease anti-inflammatory cytokines. However, this effect was significantly stronger in heat-shocked cell lysate-treated PBMCs. Moreover, comparison of IFN-É£/IL-10, IFN-É£/TGF-ß, IL-6/IL-10, IL-6/TGF-ß, and TNF-α/IL-10 ratios in both conditions demonstrated that in the heat-shocked group, all of the above ratios were significantly higher than normal lysate treatment (p˂0.001), suggesting that heat-shocked probiotics are a potent inducer of the immune system in comparison to intact probiotics. Regarding these results, it may be possible to develop a new postbiotic product for the stimulation of immune responses of cancer patients or individuals who suffer from an immune defect.


Assuntos
Citocinas/metabolismo , Lactobacillus plantarum , Leucócitos Mononucleares/imunologia , Células Cultivadas , Temperatura Alta , Humanos , Interleucina-10 , Interleucina-6 , Fator de Crescimento Transformador beta , Fator de Necrose Tumoral alfa
6.
Res Pharm Sci ; 15(4): 381-389, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33312216

RESUMO

BACKGROUND AND PURPOSE: Granulocyte colony-stimulating factor (G-CSF) is routinely used in combination with chemotherapy to battle neutropenia. However, studies suggest that this chemokine may increase the risk of metastasis and malignancy in many cancers. To counteract the adverse effects of G-CSF in cancer, antibodies have been used to block its action. However, antibodies are large and complex molecules which makes their production expensive. Thus in this study, we aim to construct different structure variants of the G-CSF receptor containing different domains and select the best variant that prevents the adverse actions of this chemokine. These novel structures are smaller than antibodies and easier to produce. EXPERIMENTAL APPROACH: Different domains of the G-CSF receptor were designed and cloned into the pET28a expression vector. These recombinant receptor subunits were then expressed in Escherichia coli and purified using standard affinity chromatography techniques. Interaction of recombinant receptor subunits with G-CSF was assessed using enzyme-linked immunosorbent assay and NFS60 cells. FINDINGS / RESULTS: Two recombinant receptor subunits containing D1 + D2 + D3 domains and D2 domain showed the strongest inhibitory activity to G-CSF. CONCLUSION AND IMPLICATIONS: These novel recombinant receptor variants could be candidates for further studies in the development of novel therapeutics.

7.
Comput Biol Chem ; 84: 107168, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31791808

RESUMO

The cyclotides are the largest known family of cyclic proteins, which are found in several plant families including Violaceae. They are circular bioactive peptides consisting of 28-37 amino acids, which possess a cyclic cystine knot (CCK) motif and could be useful in biotechnology and drug design as scaffolds for peptide-based drugs. This study describes our finding of a potentially novel gene transcript from the petals of the Iranian Viola tricolor (V. tricolor) flowers. This study is based on the cDNA screening method employed for isolation of cyclotide precursor genes and in silico analysis. Our study resulted in the finding of a novel cyclotide-like precursor from V. tricolor, which is documented in the NCBI by GenBank accession number: KP065812. The in silico analysis revealed that there are lots of similar sequences in many other plant families and they all exhibit some different features from previously discovered cyclotide precursors. The differences occur particularly in the main cyclotide domain that exists without the usual CCK structure. All of these hypothetical precursors have a conserved ER-signal sequence, a Cysteine (C)-rich sequence forming two zinc finger motifs and a cyclotide-like region containing several conserved elements including two highly conserved C residues. In conclusion, using the cDNA screening method we found a potentially new cyclotide-like precursor gene and in silico studies revealed its significant characteristics that may open up a new research line on the distribution and evolution of cyclotides.


Assuntos
Ciclotídeos/análise , Proteínas de Plantas/análise , Precursores de Proteínas/análise , Viola/química , Sequência de Aminoácidos , Ciclotídeos/química , Ciclotídeos/genética , Flores/química , Genes de Plantas , Irã (Geográfico) , Folhas de Planta/química , Proteínas de Plantas/química , Proteínas de Plantas/genética , Precursores de Proteínas/química , Precursores de Proteínas/genética , Alinhamento de Sequência , Análise de Sequência de DNA
8.
Immunol Invest ; 49(8): 875-896, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31856615

RESUMO

Despite the existence of vaccination, antibiotic therapy, and antibody therapies, infectious diseases still remain as one of the biggest challenges to human health all over the world. Among the different methods for treatment and prevention of infectious diseases, antibodies are well known but poorly developed. There is a new subclass of antibodies calledheavy-chain antibodies that belong to the IgG isotype. However, they are low in molecular weight and lost the first constant domain (CH1). Their single-domain antigen-binding fragments, identified as nanobodies, have unique characteristics, which make them superior in comparison with the conventional antibodies. Low molecular weight and small size, high stability and solubility, ease of expression, good tissue penetration, and low-cost production make nanobodies an appropriate alternative to use against infectious disease. In this research, we review the properties of nanobodies and their potential applications in controlling human infections and inflammations.


Assuntos
Doenças Transmissíveis/diagnóstico , Doenças Transmissíveis/terapia , Controle de Infecções , Anticorpos de Domínio Único/farmacologia , Anticorpos de Domínio Único/uso terapêutico , Gerenciamento Clínico , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Humanos , Controle de Infecções/métodos , Anticorpos de Domínio Único/imunologia , Resultado do Tratamento
9.
Microb Pathog ; 135: 103661, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31400445

RESUMO

Treponema (T.) denticola is one of the key etiological agents in the development of periodontitis. The major outer sheath protein (Msp) of T. denticola has been shown to mediate pathogenesis and to facilitate adhesion of T. denticola to mucosal surfaces. This study aimed to find short polypeptides in the amino acid sequence of Msp which may be immunogenic and might elicit protective antisera against T. denticola. The complete msp sequence was divided into six fragments and the corresponding genes were cloned and expressed. Antisera against the polypeptides were raised in rabbits and fragment 3 (F3), hereinafter called PerioVax3 was the most potent fragment of the Msp in terms of yielding high titer antiserum. An adhesion assay was done to examine the inhibitory effects of antisera on the attachment of T. denticola to human gingival fibroblasts (HGFs) and human fibronectin. Antiserum against PerioVax3 significantly inhibited attachment of T. denticola to the substratum. Also, antiserum against PerioVax3 inhibited detachment of HGFs upon T. denticola exposure. To begin examining the clinical relevance of this work, blood samples from 12 sever periodontitis patients were collected and the sera were used in western blotting against the recombinant polypeptides. Periodontitis patient antisera exclusively detected PerioVax3 in western blotting. The data suggest that PerioVax3 carries epitopes that may trigger humoral immunity against T. denticola, which may protect against its adhesion functions. The complexity of periodontitis suggests that PerioVax3 may be considered for testing as a component of an experimental multivalent periodontal vaccine in further preclinical and clinical studies.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Epitopos/imunologia , Periodontite/imunologia , Treponema denticola/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/farmacologia , Antígenos de Bactérias/sangue , Antígenos de Bactérias/genética , Aderência Bacteriana/efeitos dos fármacos , Aderência Bacteriana/imunologia , Proteínas da Membrana Bacteriana Externa/sangue , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas de Bactérias/genética , Linhagem Celular , Clonagem Molecular , Modelos Animais de Doenças , Fibroblastos , Fibronectinas , Humanos , Masculino , Periodontite/sangue , Coelhos , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Treponema denticola/genética , Vacinas , Fatores de Virulência/imunologia
10.
J Parasit Dis ; 41(4): 1132-1138, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29114153

RESUMO

Plasmodium vivax parasite causes the largest number of malaria infection in some malarious areas of the world including Iran. Considering transfer and genetic dynamics of the parasite population in a specific area can help us to predict the spread of the infection either emergence of new cases or drug resistance in the context of elimination program in the malarious areas. Study on the genetic diversity of common alleles in a given geographical area, for vaccine and immune level studies can be important. The purpose of this study was to know the status of P. vivax Duffy Binding Protein (PvDBP) polymorphism in patients infected with the parasite in malaria endemic southeastern Iran. The fragment of gene corresponding to PvDBP of thirty P. vivax malaria infected individuals was amplified. A 1176 bp band related to this fragment was purified and PCR-RFLP method was employed using enzymatic digestion with PstI and RsaI restriction enzymes. Ten percent of samples were sent for sequencing. PCR-RFLP showed that 99.7% of the samples were cut as the same together, either the PstI enzyme or the enzyme of RsaI. In each case, only 2 isolates were unlike others. Findings revealed that there is at least 96% identity among isolates in the nucleotide level. Amino acid pattern of PvDBP in Iranian isolates showed little discrepancies with those PvDBP genes that have been recorded in GenBank. Sequencing of PvDBP isolates of Iranian P. vivax infected patients showed low level of genetic polymorphism among them. Results of this study can prepare valuable information for malaria policy makers to intend them in their malaria control program.

11.
Biomed Pharmacother ; 93: 245-254, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28646705

RESUMO

It has been shown that Granulocyte colony-stimulating factor (G-CSF) has a higher expression in malignant tumors, and anti-G-CSF therapy considerably decreases tumor growth, tumor vascularization and metastasis. Thus, blocking the signaling pathway of G-CSF could be beneficial in cancer therapy. This study is aimed at designing and producing a monoclonal nanobody that could act as an antagonist of G-CSF receptor. Nanobodies are the antigen binding fragments of camelid single-chain antibodies, also known as VHH. These fragments have exceptional properties which makes them ideal for tumor imaging and therapeutic applications. We have used our previously built nanobody phage libraries to isolate specific nanobodies to the G-CSF receptor. After a series of cross-reactivity and affinity experiments, two unique nanobodies were selected for functional analysis. Proliferation assay, real-time PCR and immunofluorescence assays were used to characterize these nanobodies. Finally, VHH26 nanobody that was able to specifically bind G-CSF receptor (G-CSF-R) on the surface of NFS60 cells and efficiently block G-CSF-R downstream signaling pathway in a dose-dependent manner was selected. This nanobody could be further developed into a valuable tool in tumor therapy and it forms a basis for additional studies in preclinical animal models.


Assuntos
Fator Estimulador de Colônias de Granulócitos/antagonistas & inibidores , Receptores de Fator Estimulador de Colônias de Granulócitos/metabolismo , Anticorpos de Domínio Único/metabolismo , Animais , Linhagem Celular Tumoral , Humanos , Camundongos , Neovascularização Patológica/metabolismo , Transdução de Sinais , Anticorpos de Cadeia Única/metabolismo
12.
Int J Food Microbiol ; 243: 52-57, 2017 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-27978506

RESUMO

Phage therapy is an old method of combating bacterial pathogens that has recently been taken into consideration due to the alarming spread of antibiotic resistance. Escherichia coli O157:H7 is a foodborne pathogen that causes hemorrhagic colitis and life-threatening Hemolytic Uremic Syndrome (HUS). There are several studies on isolation of specific phages against E. coli O157:H7 and more than 60 specific phages have been published so far. Although in vitro experiments have been successful in elimination or reduction of E. coli O157:H7numbers, in vivo experiments have not been as promising. This may be due to escape of bacteria to locations where phages have difficulties to enter or due to the adverse conditions in the gastrointestinal tract that affect phage viability and proliferation. To get around the latter obstacle, an alternative phage delivery method such as polymer microencapsulation should be tried. While the present time results are not very encouraging the work should be continued as more efficient phage treatment regimens might be found in future.


Assuntos
Agentes de Controle Biológico/uso terapêutico , Infecções por Escherichia coli/prevenção & controle , Escherichia coli O157/virologia , Doenças Transmitidas por Alimentos/prevenção & controle , Síndrome Hemolítico-Urêmica/prevenção & controle , Terapia por Fagos/métodos , Bacteriófagos/crescimento & desenvolvimento , Infecções por Escherichia coli/microbiologia , Escherichia coli O157/patogenicidade , Doenças Transmitidas por Alimentos/microbiologia , Trato Gastrointestinal/microbiologia , Síndrome Hemolítico-Urêmica/microbiologia , Humanos
13.
Enzyme Microb Technol ; 93-94: 18-28, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27702479

RESUMO

Lipases as significant biocatalysts had been widely employed to catalyze various chemical reactions such as ester hydrolysis, ester synthesis, and transesterification. Improving the activity and thermostability of enzymes is desirable for industrial applications. The lipase of Serratia marcescens belonging to family I.3 lipase has a very important pharmaceutical application in production of chiral precursors. In the present study, to achieve improved lipase activity and thermostability, using computational predictions of protein, four mutant lipases of SML (MutG2P, MutG59P, Mut H279K and MutL613WA614P) were constructed by site-directed mutagenesis. The recombinant mutant proteins were over-expressed in E. coli and purified by affinity chromatography on the Ni-NTA system. Circular dichroism spectroscopy, differential scanning calorimetry and kinetic parameters (Km and kcat) were determined. Our results have shown that the secondary structure of all lipases was approximately similar to one another. The MutG2P and MutG59P were more stable than wild type by approximately 2.3 and 2.9 in T1/2, respectively. The catalytic efficiency (kcat/Km) of MutH279K was enhanced by 2-fold as compared with the wild type (p<0.05). These results indicate that using protein modeling program and creating mutation, can enhance lipase activity and/or thermostability of SML and it also could be used for improving other properties of enzyme to the desired requirements as well as further mutations.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Lipase/genética , Lipase/metabolismo , Serratia marcescens/enzimologia , Serratia marcescens/genética , Substituição de Aminoácidos , Proteínas de Bactérias/química , Biocatálise , Estabilidade Enzimática , Temperatura Alta , Concentração de Íons de Hidrogênio , Cinética , Lipase/química , Modelos Moleculares , Mutagênese Sítio-Dirigida , Engenharia de Proteínas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Especificidade por Substrato , Temperatura
14.
Arch Med Res ; 46(1): 31-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25604604

RESUMO

BACKGROUNDS AND AIMS: Oral administration of selenium nanoparticles has an immunomodulatory effect on individuals with cancer. In the present study we aimed to compare the cancer preventive effect via administration of different doses of selenium nanoparticles in mice with cancer. METHODS: Forty 6- to 8-week-old inbred female BALB/c mice were used and divided into four test and control groups; each group contained ten mice. Group 1 (administered PBS) was used as the control and the test groups 2, 3, and 4 were daily administered 50, 100, and 200 µg of selenium nanoparticles, respectively, for 60 days. After 60 days, tumor induction was carried out and 10 days later serum samples were collected to measure the cytokines. Tumor growth and life span of the mice were also monitored during the study. RESULTS: The results showed a significant increase in serum IFN-γ and the ratio of IFN-γ/IL-4 in all administered doses compared to control. In addition, in mice that received higher doses of selenium nanoparticles (200 µg/day), lower tumor volume and extended life span were observed compared to control. Administration of selenium nanoparticles in normal mice without tumor challenge caused a nonsignificant increase in cytokine production, indicating that selenium supplementation has no effect on the immune response in the absence of tumor challenge. CONCLUSIONS: The 200-µg dose of selenium nanoparticles can induce more efficient responses against breast tumors.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Interferon gama/sangue , Interleucina-4/sangue , Nanopartículas/uso terapêutico , Selênio/uso terapêutico , Animais , Neoplasias da Mama/mortalidade , Quimioprevenção , Feminino , Humanos , Imunomodulação/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Taxa de Sobrevida
15.
Iran J Biotechnol ; 13(2): 1-9, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28959284

RESUMO

BACKGROUND: Tumor associated antigens can be viably used to enhance host immune response. OBJECTIVES: The immunomodulatory effect of biogenic selenium nanoparticles (SeNPs) was compared between treated and untreated mice with crude antigens of 4T1 cells. MATERIALS AND METHODS: Female inbred BALB/c mice (60) were injected by cancinogenic 4T1 cells causing breast cancer. After 10 days, all tumor bearing mice were divided into 4 groups. Group 1 was daily provided oral PBS and injected by the same buffer after tumor induction and was considered as control. Group 2 received only 100 µg/day SeNPs as an oral supplement for 30 days. Group 3 was only injected with 4T1 cells crude antigens with nil supplementation of SeNPs. Group 4 animals were supplemented 100 µg/day SeNPs for 30 days and simultaneously injected with crude antigens of 4T1 cells. All antigens or PBS injections were introduced at 7, 14 and 28 days following tumor induction. Oral PBS and SeNPs supplementation initiated from the first day of tumor induction and continued up to 30 days. During tumor growth, animal weights and survival rates were monitored and at the end of the study the concentrations of different cytokines and DTH responses were measured. RESULTS: Data clearly showed that the levels of cellular immunomodulatory components (granzyme B, IL-12, IFN-γ, and IL-2) significantly increased (P < 0.05) in mice treated with both SeNPs and crude antigens of 4T1 cells in comparison to the other groups. In contrast, the levels of TGF-ß in these mice decreased. CONCLUSIONS: Although SeNPs showed a noticeable boosting effect for the immune response in mice bearing tumor exposed to crude antigens of 4T1 cells, further complementary studies seem to be inevitable.

16.
Biologicals ; 43(2): 130-5, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25481729

RESUMO

The Chinese hamster ovary (CHO) cell line is one of the predominant hosts used in the bioproduction of pharmaceutical proteins. There have been many concerns about the use of animal cell lines in biopharm industries, and one of the most important concerns has been residual host-cell DNA. Improper integration of residual DNA into the recipient genomes could activate oncogenes or deactivate tumor suppressor genes. Real-time polymerase chain reaction (PCR) is a routine assay method used in the quantification of DNA. In this study, genomic CHO DNA was purified and subjected to real-time PCR. The efficiency of the reaction was calculated, and the limit of detection (LOD) was determined. The calculated efficiency for the primers using the SYBR Green method was 94.3% (r(2) = 0.998). A melting curve analysis showed neither unspecific products nor primer dimers. The calculated efficiency for the TaqMan assay was 96.6% (r(2) = 1). The results showed that the LOD of the SYBR Green and TaqMan assays were 100 fg and 10 fg, respectively. Since the LOD of the TaqMan assay showed a better sensitivity than the SYBR Green, this method could be used directly on the final products for the quantification of residual DNA, without prior DNA extraction.


Assuntos
DNA/análise , Compostos Orgânicos/química , Reação em Cadeia da Polimerase em Tempo Real/métodos , Animais , Benzotiazóis , Células CHO , Cricetinae , Cricetulus , Diaminas , Quinolinas , Sensibilidade e Especificidade
17.
Turk J Haematol ; 31(2): 149-54, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25035672

RESUMO

OBJECTIVE: One of the major goals of cancer treatment is the monitoring of chemotherapeutic protocols. Quantitative and comparative cytokine expression profiling could be reliable to be used for biomarkers in deadly and fast-growing cancers such as acute myeloid leukemia (AML). The present study aims to assess and further validate cytokines with probable effects on proliferation and maturation of blood cells in AML. MATERIALS AND METHODS: Gene expression levels of IL-1ß, IL-10, IL-8, TNF-α, and IFN-γ were analyzed before and after chemotherapy and after granulocyte colony-stimulating factor (G-CSF) therapy in 46 AML patients by an in-house quantitative comparative RT-PCR method. RESULTS: Our findings indicated that although the gene expression level of TNF-α was almost constant in all 3 samples, IL-1ß, IL-8, and IL-10 expression levels showed a decrease after chemotherapy and an increase after G-CSF therapy. On the other hand, the expression level of IFN-γ had a different pattern with an increase after chemotherapy and a decrease after G-CSF therapy. CONCLUSION: Taken together, the results of this study are in support of the idea that the analyzed cytokines could be useful biomarkers for AML treatment monitoring. However, further molecular epidemiological investigations are suggested to elaborate more cancer monitoring biomarkers.

18.
Mol Biol Rep ; 41(9): 5943-52, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24972567

RESUMO

Plasmid DNA vaccination is a promising vaccine platform for prevention and treatment of infectious disease. Enhancement of the DNA vaccine potency by co-inoculation of immunoadjuvant has been shown to be an effective strategy. Modulation of dendritic cells and T-cells locomotion and trafficking to prime an immune response is mediated by distinct chemokines. The recent study was designed to elucidate the adjuvant activity of plasmid expressing CC-chemokine ligand 20 (pCCL20) in co-inoculation with hepatitis C virus (HCV) core DNA vaccine immunization. pCCL20 was constructed and evaluated for its functional expression. Sub-cutaneous inoculation of pCCL20 with HCV core DNA vaccine was performed via electroporation in BALB/c mice on day 0 and 14 and a HCV core protein booster was applied on day 28. On week after final immunization, both humoral and cell-mediated immune responses were assessed by indirect ELISA for core specific antibodies, lymphocyte proliferation, cytokine ELISA/ELISpot and cytotoxic Grenzyme B (GrzB) release assays. Mice were co-immunized with pCCL20 developed higher levels of core specific IFN-γ/IL-4 ratio and IL-2 release, IFN-γ producing cells, lymphocyte proliferation and cytotoxic Grenzyme B release in both draining lymph nodes and spleen cells of immunized mice. The core-specific serum total IgG and IgG2a/IgG1 ratio were significantly higher when the pCCL20 was co-inoculated. These results suggest the potential of CCL20 chemokine as vaccine adjuvant to enhance Th1 mediated cellular and humoral immune responses in HCV core DNA immunization.


Assuntos
Adjuvantes Imunológicos/genética , Quimiocina CCL20/genética , Hepacivirus/imunologia , Vacinas de DNA/imunologia , Vacinas contra Hepatite Viral/imunologia , Animais , Quimiocina CCL20/imunologia , Citocinas , DNA Viral/imunologia , Feminino , Hepacivirus/genética , Humanos , Imunização Secundária , Camundongos , Camundongos Endogâmicos BALB C , Plasmídeos/genética , Proteínas do Core Viral/imunologia , Vacinas contra Hepatite Viral/genética
19.
Hepat Mon ; 14(3): e14611, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24693317

RESUMO

BACKGROUND: Using molecular adjuvants offers an attractive strategy to augment DNA vaccine-mediated immune responses. Several studies have revealed that an efficient HCV vaccine model should be able to induce both humoral and cell mediated immune responses targeting the conserved regions of the virus to circumvent the immune escape mutants. The beta chemokine Macrophage Inflammatory Protein 3-beta (MIP-3beta) is a key modulator of dendritic cells (DCs) and T-cells interaction, functions during immune response induction and is secreted specifically by cells in the lymphoid tissues. OBJECTIVES: In the present study, we questioned whether co-administration of MIP-3beta gene could enhance the immune responses to HCV core in DNA vaccination. MATERIALS AND METHODS: Expression and biological activity of MIP-3beta expressing plasmid were evaluated by ELISA and transwell migration assays, respectively. HCV core DNA vaccine ± plasmid expressing MIP-3beta were electroporated subcutaneously to the front foot pads of BALB/c mice on days 0 and 14, and HCV core protein booster was applied to all core-DNA-vaccine received mice on the day 28. Both cell mediated immunity (proliferation, IFN-γ and IL-4 cytokine release, IFN-γ ELISpot and cytotoxic Granzyme B release assays) and humoral immune responses (total IgG and IgG2a/IgG1 subtyping) were evaluated ten days after final immunization. RESULTS: Mice covaccinated with MIP-3beta elicited an enhanced Th1 biased systemic immune response as evidenced by higher IFN-γ/IL-4 and anti-core IgG2a/IgG1 ratio, lymphoproliferation, strong cytolytic GrzB release and enhanced population of IFN-γ producing immunocytes. Likewise, the humoral immune response assumed as the total anti-core IgG level was augmented by MIP-3beta co-delivery. CONCLUSIONS: These results exhibited the immuno potentiator effects of MIP-3beta plasmid when coadministrated with the HCV core DNA vaccine. Complimentary studies integrating MIP-3beta as a genetic adjuvant in HCV-core-DNA vaccination models are warranted.

20.
Gastroenterol Res Pract ; 2014: 185035, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24527027

RESUMO

To find genes involved in tumorigenesis and the development of esophageal cancer, the suppression subtractive hybridization (SSH) method was used to identify genes that are overexpressed in esophageal cancer tissues compared to normal esophageal tissues. In our SSH library, the forkhead box O3 (FOXO3), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and myeloid differentiation primary response 88 (MYD88) genes were the most highly upregulated genes, and they were selected for further studies because of their potential role in the induction of autophagy. Upregulation of these genes was also observed in clinical samples using qRT-PCR. In addition, coexpression analysis of the autophagy-related genes Beclin1, ATG12, Gabarapl, PIK3C3, and LC3 demonstrated a significant correlation between the differentially overexpressed genes and autophagy. Autophagy is an important mechanism in tumorigenesis and the development of chemoresistance in cancer cells. The upregulation of FOXO3, GAPDH, and MYD88 variants in esophageal cancer suggests a role for autophagy and provides new insight into the biology of esophageal cancer. We propose that FOXO3, GAPDH, and MYD88 are novel targets for combating autophagy in esophageal cancer.

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