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.
This report describes the biological activity, characterization, and SAR leading to 9d (BMS-754807) a small molecule IGF-1R kinase inhibitor in clinical development.
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.
Symbioflor2
is a probiotic product composed of six
genotypes, which has a beneficial effect on irritable bowel syndrome. Our objective was to understand the individual impact of each of the six ...genotypes on the host, together with the combined impact of the six in the compound Symbioflor2
. Gnotobiotic mice were mono-associated with one of the six genotypes or associated with the compound product. Ileal and colonic gene expression profiling was carried out, and data were compared between the different groups of gnotobiotic mice, along with that obtained from conventional (CV) mice and mice colonized with the probiotic
Nissle 1917. We show that Symbioflor2
genotypes induce intestinal transcriptional responses involved in defense and immune mechanisms. Using mice associated with Symbioflor2
, we reveal that the product elicits a balanced response from the host without any predominance of a single genotype. The Nissle strain and the six bacterial genotypes have different effects on the intestinal gene expression, suggesting that the impacts of these probiotics are not redundant. Our data show the effect of the Symbioflor2
genotypes at the molecular level in the digestive tract, which further highlights their beneficial action on several aspects of intestinal physiology.
Purpose: We examined the tumor-targeting and therapeutic effects of 67 Cu-labeled single amino acid mutant forms of anti-L1 monoclonal antibody chCE7 in nude mice with orthotopically implanted
...SKOV3ip human ovarian carcinoma cells.
Experimental Design: For radioimmunotherapy, chCE7 antibodies with a mutation of histidine 310 to alanine (chCE7H310A) and a mutation of asparagine
297 to glutamine (chCE7agl) were generated to achieve more rapid blood clearance. Biodistributions of 67 Cu-4-(1,4,8,11-tetraazacyclotetradec-1-yl)-methyl benzoic acid tetrachloride (CPTA)–labeled mutant antibodies were measured
in nude mice bearing SKOV3ip human ovarian cancer metastases. The effects of single i.v. injections of 67 Cu-chCE7agl alone on tumor reduction and survival were investigated. In addition, a combination of low-dose 67 Cu-radioimmunotherapy with unlabeled anti-L1 antibody L1-11A on survival was investigated.
Results: 67 Cu-CPTA-chCE7agl showed high (up to 49% ID/g) and persistent (up to 168 h) uptake in SKOV3ip metastases, with low levels in
normal tissues. 67 Cu-CPTA-chCE7H310A revealed a shorter half-life in the blood and a lower tumor uptake and retention. A single low dose of
4 MBq of 67 Cu-chCE7agl reduced tumor growth but did not prolong survival significantly, whereas a single 10.5 MBq dose of 67 Cu-chCE7agl reduced tumor growth and prolonged survival significantly. The combination of unlabeled monoclonal antibody L1-11A
with a subtherapeutic dose of 67 Cu-radioimmunotherapy also prolonged survival significantly.
Conclusion: The results show improved pharmacokinetics and biodistributions as well as the therapeutic effect of the 67 Cu-labeled single amino acid mutant chCE7agl. Therapeutic data indicate, for the first time, the feasibility of combining
anti–L1-directed growth inhibition and 67 Cu-radioimmunotherapy, thereby increasing the efficiency of antibody treatment of metastatic ovarian carcinoma.
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.
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.
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
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.
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