Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 49
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Eur J Microbiol Immunol (Bp) ; 8(3): 63-69, 2018 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-30345085

RESUMO

The fever-inducing effect of lipopolysaccharides (LPS) is well known, and human blood is extremely responsive to this pyrogen. Recently, the safety of LPS-containing food supplements and probiotic drugs as immune-stimulants has been questioned, although these products are orally taken and do not reach the bloodstream undigested. The concerns are understandable, as endotoxaemia is a pathological condition, but the oral uptake of probiotic products containing LPS or Gram-negative bacteria does not pose a health risk, based on the available scientific evidence, as is reviewed here. The available methods developed to detect LPS and other pyrogens are mostly used for quality control of parentally applied therapeuticals. Their outcome varies considerably when applied to food supplements, as demonstrated in a simple comparative experiment. Products containing different Escherichia coli strains can result in vastly different results on their LPS content, depending on the method of testing. This is an inherent complication to pyrogen testing, which hampers the communication that the LPS content of food supplements is not a safety concern.

2.
Eur J Microbiol Immunol (Bp) ; 8(2): 41-46, 2018 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-29997910

RESUMO

Probiotics are considered to have a beneficial impact on humans, but in some cases, administration of live microorganisms might be risky. In the present study, immunomodulatory effects of different Escherichia coli strains and their super-natants were examined under different inflammatory conditions with living and heat-inactivated strains. HT-29 cells were incubated with E. coli strains (S2-G1, S2-G3, S2-G4 and S2-G8) and their supernatants with or without stimulation with tumor necrosis factor alpha (TNF-α) or interleukin (IL)-1ß. Quantification of IL-8 secretion and gene expression was performed by enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (PCR). IL-8 secretion by TNF-α- and IL-1ß-stimulated cells was attenuated by all four live strains. In contrast, heat inactivation resulted in an elevated IL-8 expression and secretion in unstimulated cells and did not maintain the anti-inflammatory effect of live bacteria in cytokine-stimulated cells. The supernatant of the live S2-G3 led to an elevated IL-8 secretion in unstimulated and IL-1ß-stimulated cells but not in TNF-α-stimulated cells. Live bacteria of all strains might induce an immunosuppressive effect after stimulation of HT-29 cells, whereas heat inactivation and the supernatant seem to induce an elevated immune response. These findings might have an impact depending on the indication and purpose of administration.

3.
Oncoimmunology ; 7(2): e1382791, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29308303

RESUMO

Cancer is one of the leading causes of death in the industrialized world and represents a tremendous social and economic burden. As conventional therapies fail to provide a sustainable cure for most cancer patients, the emerging unique immune therapeutic approach of bacteria-mediated tumor therapy (BMTT) is marching towards a feasible solution. Although promising results have been obtained with BMTT using various preclinical tumor models, for advancement a major concern is immunity against the bacterial vector itself. Pre-exposure to the therapeutic agent under field conditions is a reasonable expectation and may limit the therapeutic efficacy of BMTT. In the present study, we investigated the therapeutic potential of Salmonella and E. coli vector strains in naïve and immunized tumor bearing mice. Pre-exposure to the therapeutic agent caused a significant aberrant phenotype of the microenvironment of colonized tumors and limited the in vivo efficacy of established BMTT vector strains Salmonella SL7207 and E. coli Symbioflor-2. Using targeted genetic engineering, we generated the optimized auxotrophic Salmonella vector strain SF200 (ΔlpxR9 ΔpagL7 ΔpagP8 ΔaroA ΔydiV ΔfliF) harboring modifications in Lipid A and flagella synthesis. This combination of mutations resulted in an increased immune-stimulatory capacity and as such the strain was able to overcome the efficacy-limiting effects of pre-exposure. Thus, we conclude that any limitations of BMTT concerning anti-bacterial immunity may be countered by strategies that optimize the immune-stimulatory capacity of the attenuated vector strains.

4.
Oncotarget ; 8(30): 49988-50001, 2017 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-28637010

RESUMO

Cancer is a devastating disease and a large socio-economic burden. Novel therapeutic solutions are on the rise, although a cure remains elusive. Application of microorganisms represents an ancient therapeutic strategy, lately revoked and refined via simultaneous attenuation and amelioration of pathogenic properties. Salmonella Typhimurium has prevailed in preclinical development. Yet, using virulent strains for systemic treatment might cause severe side effects. In the present study, we highlight a modified strain based on Salmonella Typhimurium UK-1 expressing hexa-acylated Lipid A. We corroborate improved anti-tumor properties of this strain and investigate to which extent an intra-tumoral (i.t.) route of infection could help improve safety and retain advantages of systemic intravenous (i.v.) application. Our results show that i.t. infection exhibits therapeutic efficacy against CT26 and F1.A11 tumors similar to a systemic route of inoculation. Moreover, i.t. application allows extensive dose titration without compromising tumor colonization. Adverse colonization of healthy organs was generally reduced via i.t. infection and accompanied by less body weight loss of the murine host. Despite local application, adjuvanticity remained, and a CT26-specific CD8+ T cell response was effectively stimulated. Most interestingly, also secondary tumors could be targeted with this strategy, thereby extending the unique tumor targeting ability of Salmonella. The i.t. route of inoculation may reap the benefits of systemic infection and aid in safety assurance while directing potency of an oncolytic vector to where it is most needed, namely the primary tumor.


Assuntos
Terapia Biológica/métodos , Neoplasias/terapia , Infecções por Salmonella/microbiologia , Salmonella typhimurium/fisiologia , Imunidade Adaptativa , Administração Intravenosa , Animais , Terapia Biológica/efeitos adversos , Modelos Animais de Doenças , Humanos , Imunidade Inata , Imunomodulação , Injeções Intralesionais , Camundongos , Neoplasias/imunologia , Neoplasias/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Gut Pathog ; 9: 30, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28559930

RESUMO

BACKGROUND: Shiga toxin (Stx) producing Escherichia coli (E. coli) (STEC) is the most frequent cause of diarrhoea-positive haemolytic uraemic syndrome (D + HUS) in humans. In 2011, a huge outbreak with an STEC O104:H4 strain in Germany highlighted the limited possibilities for causative treatment of this syndrome. The responsible STEC strain was found to combine Stx production with adherence mechanisms normally found in enteroaggregative E. coli (EAEC). Pathotypes of E. coli evolve and can exhibit different adhesion mechanisms. It has been shown previously that neonatal gnotobiotic piglets are susceptible for infection with STEC, such as STEC O157:H7 as well as for EAEC, which are considered to be the phylogenetic origin of E. coli O104:H4. This study was designed to characterise the host response to infection with the STEC O104:H4 outbreak strain in comparison to an STEC O157:H7 isolate by evaluating clinical parameters (scoring) and markers of organ dysfunction (biochemistry), as well as immunological (flow cytometry, assessment of cytokines/chemokines and acute phase proteins) and histological alterations (light- and electron microscopy) in a gnotobiotic piglet model of haemolytic uraemic syndrome. RESULTS: We observed severe clinical symptoms, such as diarrhoea, dehydration and neurological disorders as well as attaching-and-effacing lesions (A/E) in the colon in STEC O157:H7 infected piglets. In contrast, STEC O104:H4 challenged animals exhibited only mild clinical symptoms including diarrhoea and dehydration and HUS-specific/severe histopathological, haematological and biochemical alterations were only inconsistently presented by individual piglets. A specific adherence phenotype of STEC O104:H4 could not be observed. Flow cytometric analyses of lymphocytes derived from infected animals revealed an increase of natural killer cells (NK cells) during the course of infection revealing a potential role of this subset in the anti-bacterial activity in STEC disease. CONCLUSIONS: Unexpectedly, E. coli O104:H4 infection caused only mild symptoms and minor changes in histology and blood parameters in piglets. Outcome of the infection trial does not reflect E. coli O104:H4 associated human disease as observed during the outbreak in 2011. The potential role of cells of the innate immune system for STEC related disease pathogenesis should be further elucidated.

6.
Genome Announc ; 4(5)2016 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-27688319

RESUMO

The probiotic Symbioflor 1 is a historical concoction of 10 isolates of Enterococcus faecalis Pulsed-field gel electrophoresis revealed two groups: one comprising eight identical clones (DSM16430, DSM16432, DSM16433, DSM16435 to DSM16439) and a further two isolates (DSM16431, DSM16434) with marginally different profiles. Here, we report a comparative analysis of the draft genome sequences of representative isolates.

7.
Appl Microbiol Biotechnol ; 100(24): 10479-10493, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27430741

RESUMO

Wild-type human interleukin-10 (hIL-10) is a non-covalent homodimer with a short half-life, thus limiting its therapeutic applications in vivo. To avoid loss of function due to dimer dissociation, we designed a synthetic hIL-10 analog by bridging both monomers via a 15 amino acid-long peptide spacer in a C-terminal to N-terminal fashion. For secretory expression in Escherichia coli, a 1156 bp fragment was generated from template vector pAZ1 by fusion PCR encoding a T7 promoter region and the signal sequence of the E. coli outer membrane protein F fused in frame to two tandem E. coli codon-optimized mature hIL-10 genes connected via a 45 nucleotide linker sequence. The construct was cloned into pUC19 for high-level expression in E. coli BL21 (DE3). The mean concentrations of hIL-10 fusion protein in the periplasm and supernatant of E. coli at 37 °C growth temperature were 130 ± 40 and 2 ± 1 ng/ml, respectively. The molecular mass of the recombinant protein was assessed via matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) analysis, indicating correct processing of the signaling sequence in E. coli. In vitro biological activity was shown by phosphorylation of signal transducer and activator of transcription protein 3 and suppression of tumor necrosis factor α secretion in lipopolysaccharide-stimulated macrophages.


Assuntos
Escherichia coli/metabolismo , Expressão Gênica , Interleucina-10/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Clonagem Molecular , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Interleucina-10/química , Interleucina-10/genética , Peso Molecular , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
8.
Pediatr Allergy Immunol ; 27(7): 702-708, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27294404

RESUMO

BACKGROUND: Accessible markers to predict the development of atopic diseases are highly desirable but yet matter of debate. OBJECTIVE: We investigated the role of blood eosinophils at 4 weeks and 7 months of life and their association with developing atopic dermatitis (AD) in a birth cohort of children with atopic heredity. METHODS: Infant blood samples for eosinophil counts were taken from 559 infants at 4 weeks and from 467 infants at 7 month of life with at least one atopic parent. Elevation of blood eosinophils was defined as ≥ 5% of total leukocytes and the asscociation for the occurrence of AD was assessed by entering 2 × 2 tables and the odds ratios were estimated followed by hypothesis testing against the alternate working hypothesis: odds ratio < > 1. Survival analysis was carried out estimating the Kaplan-Meier product limit estimator from the life-time table of AD score and time to AD manifestation stratified by the eosinophil binary score. RESULTS: Elevated blood eosinophils observed at 4 weeks were significantly associated with the occurrence of AD in the whole cohort at the age of 7 months (p = 0.007), 1 year (p = 0.004), 2 years (p = 0.007) and 3 years (p = 0.006) of life. AD occurred app. 12 weeks earlier in infants with elevated blood eosinophils at 4 weeks of life. Blood eosinophil counts ≥5% at 7 months of life failed to show significance for AD; for eosinophils at 4.5% a significant association at 7 months (p = 0.005), and 1 year of life (p = 0.039), 2 years (p = 0.033) and 3 years (p = 0.034) was observed. CONCLUSION: Elevated blood eosinophils at age 4 weeks have a predictive value for the onset of atopic dermatitis in infancy and early childhood in children with high risk for atopy. Early eosinophil counts may therefore be helpful for counseling parents to provide infant skincare but furthermore identify individuals for interventional trials aiming at allergy prevention.


Assuntos
Dermatite Atópica/diagnóstico , Eosinófilos/imunologia , Contagem de Células , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Imunoglobulina E/sangue , Lactente , Recém-Nascido , Masculino , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Risco
9.
Sci Rep ; 6: 26752, 2016 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-27229737

RESUMO

The gut microbiota not only influences host metabolism but can also affect brain function and behaviour through the microbiota-gut-brain axis. To explore the potential role of the intestinal microbiota in anorexia nervosa (AN), we comprehensively investigated the faecal microbiota and short-chain fatty acids in these patients before (n = 55) and after weight gain (n = 44) in comparison to normal-weight participants (NW, n = 55) along with dietary intake and gastrointestinal complaints. We show profound microbial perturbations in AN patients as compared to NW participants, with higher levels of mucin-degraders and members of Clostridium clusters I, XI and XVIII and reduced levels of the butyrate-producing Roseburia spp. Branched-chain fatty acid concentrations, being markers for protein fermentation, were elevated. Distinct perturbations in microbial community compositions were observed for individual restrictive and binge/purging AN-subtypes. Upon weight gain, microbial richness increased, however perturbations in intestinal microbiota and short chain fatty acid profiles in addition to several gastrointestinal symptoms did not recover. These insights provide new leads to modulate the intestinal microbiota in order to improve the outcomes of the standard therapy.


Assuntos
Anorexia Nervosa/metabolismo , Anorexia Nervosa/microbiologia , Ácidos Graxos Voláteis/metabolismo , Fezes/microbiologia , Gastroenteropatias/complicações , Microbioma Gastrointestinal , Adolescente , Adulto , Anorexia Nervosa/complicações , Dieta , Ingestão de Alimentos , Feminino , Humanos , Ganho de Peso , Adulto Jovem
10.
Oncotarget ; 7(16): 22605-22, 2016 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-26981777

RESUMO

To date, virulent bacteria remain the basis of most bacteria mediated cancer therapies. For clinical application attenuation is required. However, this might result in a drastically lowered therapeutic capacity. Herein we argue that the E. coli probiotic Symbioflor-2, with a history of safe application may constitute a viable tumor therapeutic candidate. We demonstrate that Symbioflor-2 displays a highly specific tumor targeting ability as determined in murine CT26 and RenCa tumor models. The excellent specificity was ascribed to reduced levels of adverse colonization. A high safety standard was demonstrated in WT and Rag1-/- mice. Thus, Symbioflor-2 may represent an ideal tumor targeting delivery system for therapeutic molecules. Moreover, Symbioflor-2 was capable of inducing CT26 tumor clearance as result of an adjuvant effect on tumor specific CD8+ T cells analogous to the Salmonella variant SL7207. However, lower therapeutic efficacy against RenCa tumors suggested a generally reduced therapeutic potency for probiotics. Interestingly, concurrent depletion of Gr-1+ or Ly6G+ cells installed therapeutic efficacy equal to SL7207, thus highlighting the role of innate effector cells in restraining the anti-tumor effects of Symbioflor-2. Collectively, our findings argue for a strategy of safe strain application and a more sustainable use of bacteria as a delivery system for therapeutic molecules.


Assuntos
Antineoplásicos/administração & dosagem , Portadores de Fármacos/farmacologia , Escherichia coli , Neoplasias , Probióticos/farmacologia , Animais , Sistemas de Liberação de Medicamentos/métodos , Camundongos , Camundongos Endogâmicos BALB C
11.
Bioorg Med Chem Lett ; 25(14): 2809-12, 2015 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-25987372
12.
Eur J Microbiol Immunol (Bp) ; 5(1): 81-93, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25883796

RESUMO

The probiotic product Symbioflor2 (DSM 17252) is a bacterial concentrate of six different Escherichia coli genotypes, whose complete genome sequences are compared here, between each other as well as to other E. coli genomes. The genome sequences of Symbioflor2 E. coli components contained a number of virulence-associated genes. Their presence seems to be in conflict with a recorded history of safe use, and with the observed low frequency of adverse effects over a period of more than 6 years. The genome sequences were used to identify unique sequences for each component, for which strain-specific hybridization probes were designed. A colonization study was conducted whereby five volunteers were exposed to an exceptionally high single dose. The results showed that the probiotic E. coli could be detected for 3 months or longer in their stools, and this was in particular the case for those components containing higher numbers of virulence-associated genes. Adverse effects from this long-term colonization were absent. Thus, the presence of the identified virulence genes does not result in a pathogenic phenotype in the genetic background of these probiotic E. coli.

13.
Genome Announc ; 3(2)2015 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-25745009

RESUMO

The complete genome of probiotic Escherichia coli strain G3/10 is presented here. In addition, the probiotic E. coli strains G1/2, G4/9, G5, G6/7, and G8 are presented in draft form. These six strains together comprise the probiotic product Symbioflor 2 (DSM 17252).

14.
Gut Microbes ; 5(2): 239-44, 2014 Mar-Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24637604

RESUMO

There is convincing evidence from both human and animal studies suggesting that the infant intestinal microbiota plays an important role in regulating immune responses associated with the development of allergic diseases. To date there are, however, still no definite bacterial taxa or particular subsets of the microbiota that have been consistently associated with allergic diseases, which is mainly attributable to the methodological dissimilarities between studies. As such there is a need to apply different methodological concepts to enhance a deeper and more refined understanding of the relationship between the gut microbiota and allergies. Within our recent studies we reported that colonization by clostridia in early infancy increased the risk of atopic dermatitis. Using subsequent mediation analysis, we demonstrated that birth mode and having older siblings strongly impacted the infant microbiota which in turn affected the risk of atopic dermatitis. The results of these mediation analyses contributed stronger evidence for a causal link of birth mode and birth order on allergy risk through modulation of the microbiota composition.


Assuntos
Trato Gastrointestinal/microbiologia , Hipótese da Higiene , Hipersensibilidade/epidemiologia , Hipersensibilidade/imunologia , Microbiota/fisiologia , Irmãos , Animais , Dermatite Atópica/imunologia , Feminino , Humanos , Recém-Nascido , Masculino
15.
BMC Biotechnol ; 13: 82, 2013 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-24093616

RESUMO

BACKGROUND: Interleukin-10 homologues encoded by Herpes viruses such as Epstein-Barr virus (EBV) and human cytomegalovirus (HCMV) hold interesting structural and biological characteristics compared to human interleukin-10 (hIL-10) that render these proteins promising candidates for therapeutic application in inflammatory bowel disease (IBD). Intestinal delivery of cytokines using bacterial carriers as chassis represents a novel approach for treatment of IBD patients. For proof of concept, a Sec-dependent transporter construct was designed for secretory expression of recombinant viral IL-10 proteins in the periplasm of Escherichia coli laboratory strain BL21 (DE3), which might serve as part of a prospective lysis based delivery and containment system. RESULTS: The signal peptide of E. coli outer membrane protein F fused to the mature form of the viral IL-10 proteins enabled successful transport into the periplasm, a compartment which seems crucial for proper assembly of the dimeric configuration of the cytokines. Cytokine concentrations in different bacterial compartments were determined by ELISA and achieved yields of 67.8 ng/ml ± 24.9 ng/ml for HCMV IL-10 and 1.5 µg/ml ± 841.4 ng/ml for EBV IL-10 in the periplasm. Immunoblot analysis was used to confirm the correct size of the E. coli-derived recombinant cytokines. Phosphorylation of signal transducer and activator of transcription 3 (STAT3) as part of the signal transduction cascade after IL-10 receptor interaction, as well as suppression of tumor necrosis factor α (TNF-α) release of lipopolysaccharide-stimulated mouse macrophages were used as read-out assays for proving in vitro biological activity of the E. coli derived, recombinant viral IL-10 counterparts. CONCLUSIONS: In this study, proof of principle is provided that E. coli cells are a suitable chassis for secretory expression of viral IL-10 cytokines encoded by codon-optimized synthetic genes fused to the E. coli ompF signal sequence. In vitro biological activity evidenced by activation of transcription factor STAT3 and suppression of TNF-α in mammalian cell lines was shown to be strictly dependent on export of viral IL-10 proteins into the periplasmic compartment. E. coli might serve as carrier system for in situ delivery of therapeutic molecules in the gut, thus representing a further step in the development of novel approaches for treatment of IBD.


Assuntos
Citomegalovirus/genética , Herpesvirus Humano 4/genética , Interleucina-10/metabolismo , Proteínas Virais/metabolismo , Animais , Linhagem Celular , Escherichia coli/genética , Escherichia coli/metabolismo , Vetores Genéticos/genética , Humanos , Doenças Inflamatórias Intestinais/terapia , Interleucina-10/genética , Camundongos , Periplasma/metabolismo , Fosforilação , Porinas/genética , Porinas/metabolismo , Sinais Direcionadores de Proteínas/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Fator de Transcrição STAT3/metabolismo , Análise de Sequência de DNA , Transdução de Sinais , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Proteínas Virais/genética
16.
J Allergy Clin Immunol ; 132(3): 601-607.e8, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23900058

RESUMO

BACKGROUND: Perturbations in the intestinal microbiota may disrupt mechanisms involved in the development of immunologic tolerance. The present study aimed to examine the establishment of the infant microbiota and its association to the development of atopic dermatitis (AD). METHODS: Within a randomized, placebo-controlled trial on the prevention of AD by oral supplementation of a bacterial lysate between week 5 and the end of month 7, feces was collected at the ages of 5 weeks (n = 571), 13 weeks (n = 332), and 31 weeks (n = 499) and subjected to quantitative PCRs to detect bifidobacteria, bacteroides, lactobacilli, Escherichia coli, Clostridium difficile, and Clostridium cluster I. RESULTS: Birth mode, breast-feeding but also birth order had a strong effect on the microbiota composition. With increasing number of older siblings the colonization rates at age 5 weeks of lactobacilli (P < .001) and bacteroides (P = .02) increased, whereas rates of clostridia decreased (P < .001). Colonization with clostridia, at the age of 5 and 13 weeks was also associated with an increased risk of developing AD in the subsequent 6 months of life (odds ratioadjusted = 2.35; 95% CI, 1.36-3.94 and 2.51; 1.30-4.86, respectively). Mediation analyses demonstrated that there was a statistically significant indirect effect via Clostridium cluster I colonization for both birth mode and birth order in association to AD. CONCLUSION: The results of this study are supportive for a role of the microbiota in the development of AD. Moreover, the "beneficial" influence of older siblings on the microbiota composition suggests that this microbiota may be one of the biological mechanisms underlying the sibling effect.


Assuntos
Bactérias/isolamento & purificação , Dermatite Atópica/microbiologia , Fezes/microbiologia , Intestinos/microbiologia , Bactérias/genética , Carga Bacteriana , Ordem de Nascimento , Aleitamento Materno , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Parto Obstétrico , Dermatite Atópica/diagnóstico , Dermatite Atópica/prevenção & controle , Feminino , Humanos , Lactente , Masculino , Prevenção Primária
17.
PLoS One ; 8(6): e66682, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23840518

RESUMO

Probiotic bacteria have a wide range of applications in veterinary and human therapeutics. Inactivated probiotics are complex samples and quality control (QC) should measure as many molecular features as possible. Capillary electrophoresis coupled to mass spectrometry (CE/MS) has been used as a multidimensional and high throughput method for the identification and validation of biomarkers of disease in complex biological samples such as biofluids. In this study we evaluate the suitability of CE/MS to measure the consistency of different lots of the probiotic formulation Pro-Symbioflor which is a bacterial lysate of heat-inactivated Escherichia coli and Enterococcus faecalis. Over 5000 peptides were detected by CE/MS in 5 different lots of the bacterial lysate and in a sample of culture medium. 71 to 75% of the total peptide content was identical in all lots. This percentage increased to 87-89% when allowing the absence of a peptide in one of the 5 samples. These results, based on over 2000 peptides, suggest high similarity of the 5 different lots. Sequence analysis identified peptides of both E. coli and E. faecalis and peptides originating from the culture medium, thus confirming the presence of the strains in the formulation. Ontology analysis suggested that the majority of the peptides identified for E. coli originated from the cell membrane or the fimbrium, while peptides identified for E. faecalis were enriched for peptides originating from the cytoplasm. The bacterial lysate peptides as a whole are recognised as highly conserved molecular patterns by the innate immune system as microbe associated molecular pattern (MAMP). Sequence analysis also identified the presence of soybean, yeast and casein protein fragments that are part of the formulation of the culture medium. In conclusion CE/MS seems an appropriate QC tool to analyze complex biological products such as inactivated probiotic formulations and allows determining the similarity between lots.


Assuntos
Bactérias/metabolismo , Probióticos , Proteômica , Eletroforese Capilar , Espectrometria de Massas , Controle de Qualidade
18.
PLoS One ; 8(4): e60350, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23565233

RESUMO

Site-specific enzymatic reactions with microbial transglutaminase (mTGase) lead to a homogenous species of immunoconjugates with a defined ligand/antibody ratio. In the present study, we have investigated the influence of different numbers of 1,4,7,10-tetraazacyclododecane-N-N'-N''-N'''-tetraacetic acid (DOTA) chelats coupled to a decalysine backbone on the in vivo behavior of the chimeric monoclonal anti-L1CAM antibody chCE7agl. The enzymatic conjugation of (DOTA)1-decalysine, (DOTA)3-decalysine or (DOTA)5-decalysine to the antibody heavy chain (via Gln295/297) gave rise to immunoconjugates containing two, six or ten DOTA moieties respectively. Radiolabeling of the immunoconjugates with (177)Lu yielded specific activities of approximately 70 MBq/mg, 400 MBq/mg and 700 MBq/mg with increasing numbers of DOTA chelates. Biodistribution experiments in SKOV3ip human ovarian cancer cell xenografts demonstrated a high and specific accumulation of radioactivity at the tumor site for all antibody derivatives with a maximal tumor accumulation of 43.6±4.3% ID/g at 24 h for chCE7agl-[(DOTA)-decalysine]2, 30.6±12.0% ID/g at 24 h for chCE7agl-[(DOTA)3-decalysine]2 and 49.9±3.1% ID/g at 48 h for chCE7agl-[(DOTA)5-decalysine)]2. The rapid elimination from the blood of chCE7agl-[(DOTA)-decalysine]2 (1.0±0.1% ID/g at 24 h) is associated with a high liver accumulation (23.2±4.6% ID/g at 24 h). This behavior changed depending on the numbers of DOTA moieties coupled to the decalysine peptide with a slower blood clearance (5.1±1.0 (DOTA)3 versus 11.7±1.4% ID/g (DOTA)5, p<0.005 at 24 h) and lower radioactivity levels in the liver (21.4±3.4 (DOTA)3 versus 5.8±0.7 (DOTA)5, p<0.005 at 24 h). We conclude that the site-specific and stoichiometric uniform conjugation of the highly DOTA-substituted decalysine ((DOTA)5-decalysine) to an anti-tumor antibody leads to the formation of immunoconjugates with high specific activity and excellent in vivo behavior and is a valuable option for radioimmunotherapy and potentially antibody-drug conjugates (ADCs).


Assuntos
Compostos Heterocíclicos com 1 Anel/química , Polilisina/química , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/farmacocinética , Antineoplásicos/química , Antineoplásicos/farmacocinética , Linhagem Celular Tumoral , Quelantes/química , Quelantes/farmacocinética , Feminino , Compostos Heterocíclicos com 1 Anel/síntese química , Humanos , Imunoconjugados/química , Imunoconjugados/farmacocinética , Imunoglobulina G/química , Cadeias Pesadas de Imunoglobulinas/química , Camundongos , Neoplasias Ovarianas/tratamento farmacológico , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/farmacocinética , Distribuição Tecidual , Transglutaminases/metabolismo , Transplante Heterólogo
19.
Genome Announc ; 1(1)2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23405346

RESUMO

Here, we report the complete and annotated genome sequence of the probiotic Enterococcus faecalis Symbioflor 1 clone DSM 16431, included in a commercial probiotic product used for more than 50 years without any reports of infection. This sequence will provide new insights into the biology of this nonpathogenic and probiotic microorganism.

20.
J Allergy Clin Immunol ; 129(4): 1040-7, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22464674

RESUMO

BACKGROUND: Lower prevalence of atopy was found in children with continuous exposure to livestock and thus to microbial compounds. In animal models exposure to endotoxin (LPS) decreases allergic sensitization and airway inflammation. OBJECTIVE: We sought to evaluate the effect of orally applied bacterial lysate in infancy on the prevalence of atopic dermatitis (AD) after the treatment phase at 7 months of age. METHODS: This randomized, placebo-controlled trial included 606 newborns with at least single heredity for atopy. From week 5 until the end of month 7, infants were treated orally with bacterial lysate containing heat-killed gram-negative Escherichia coli Symbio and gram-positive Enterococcus faecalis Symbio or its placebo. Children were followed until 3 years of age. RESULTS: There was no difference in the primary outcome between the active and placebo groups in the total study group. AD prevalence was significantly reduced at the end of the intervention phase (31 weeks of age) in the subgroup of infants with single heredity for atopy (relative risk, 0.52; 95% CI, 0.3-0.9). Ten percent (15/154) of infants in the active group had AD compared with 19% (27/145, P = .030) in the placebo group. This was more pronounced in the group of infants with paternal heredity for atopy (11% vs 32%, P = .004; relative risk, 0.34; 95% CI, 0.2-0.7). CONCLUSION: Feeding of bacterial lysate might have prevented the development of AD, especially in children with paternal atopy, possibly indicating a preventive property only in subjects with a limited risk for atopy.


Assuntos
Bactérias/imunologia , Dermatite Atópica/prevenção & controle , Dessensibilização Imunológica , Administração Oral , Pré-Escolar , Dermatite Atópica/epidemiologia , Dermatite Atópica/imunologia , Feminino , Humanos , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Lactente , Masculino , Pais , Prevalência , Risco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA