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Morphologically Distinct Escherichia coli Bacteriophages Differ in Their Efficacy and Ability to Stimulate Cytokine Release In Vitro.

Khan Mirzaei M, Haileselassie Y, Navis M, Cooper C, Sverremark-Ekström E, Nilsson AS - Front Microbiol (2016)

Bottom Line: In order to address concerns over safety and the poorly understood pharmacokinetics of phages and their associated cocktails, immunological characterization is required.Despite co-incubation with different cell types, phages maintained a high killing efficiency, reducing extended-spectrum beta-lactamase-producing Escherichia coli numbers by 1-4 log10 compared to untreated controls.When provided with a suitable bacterial host, phages were also able to actively reproduce in the presence of human cells resulting in an approximately 2 log10 increase in phage titer compared to the initial inoculum.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University Stockholm, Sweden.

ABSTRACT
Due to a global increase in the range and number of infections caused by multi-resistant bacteria, phage therapy is currently experiencing a resurgence of interest. However, there are a number of well-known concerns over the use of phages to treat bacterial infections. In order to address concerns over safety and the poorly understood pharmacokinetics of phages and their associated cocktails, immunological characterization is required. In the current investigation, the immunogenicity of four distinct phages (taken from the main families that comprise the Caudovirales order) and their interaction with donor derived peripheral blood mononuclear cells and immortalized cell lines (HT-29 and Caco-2 intestinal epithelial cells) were investigated using standard immunological techniques. When exposed to high phage concentrations (10(9) PFU/well), cytokine driven inflammatory responses were induced from all cell types. Although phages appeared to inhibit the growth of intestinal epithelial cell lines, they also appear to be non-cytotoxic. Despite co-incubation with different cell types, phages maintained a high killing efficiency, reducing extended-spectrum beta-lactamase-producing Escherichia coli numbers by 1-4 log10 compared to untreated controls. When provided with a suitable bacterial host, phages were also able to actively reproduce in the presence of human cells resulting in an approximately 2 log10 increase in phage titer compared to the initial inoculum. Through an increased understanding of the complex pharmacokinetics of phages, it may be possible to address some of the safety concerns surrounding phage preparations prior to creating new therapeutic strategies.

No MeSH data available.


Related in: MedlinePlus

Cell cytotoxicity and inhibition of proliferation by exposure to phages. (A) Phage exposure to intestinal epithelial cells; HT-29 (n = 4)  and Caco-2 (n = 4) . Data are presented as the mean ± SD. ∗P < 0.05 by two tailed t-test compared to the medium control. (B) Phage exposure of PBMCs. Data are from two replicates from four donors.
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Figure 3: Cell cytotoxicity and inhibition of proliferation by exposure to phages. (A) Phage exposure to intestinal epithelial cells; HT-29 (n = 4) and Caco-2 (n = 4) . Data are presented as the mean ± SD. ∗P < 0.05 by two tailed t-test compared to the medium control. (B) Phage exposure of PBMCs. Data are from two replicates from four donors.

Mentions: In a long term assessment of the cytotoxic effects of individual phages on IECs and PBMCs, phages at a concentration of 109 PFU/well were not lethal to the HT-29 and Caco-2 cells after 96 h of incubation (P < 0.05 by two tailed t-test) and no significant differences between the cell lines were observed (Figure 3). Phage stimulated IECs produced a significantly (P < 0.05 by two tailed t-test) higher OD response compared to the negative control. Phages were unable to induce a significant cytotoxic effect on PBMCs.


Morphologically Distinct Escherichia coli Bacteriophages Differ in Their Efficacy and Ability to Stimulate Cytokine Release In Vitro.

Khan Mirzaei M, Haileselassie Y, Navis M, Cooper C, Sverremark-Ekström E, Nilsson AS - Front Microbiol (2016)

Cell cytotoxicity and inhibition of proliferation by exposure to phages. (A) Phage exposure to intestinal epithelial cells; HT-29 (n = 4)  and Caco-2 (n = 4) . Data are presented as the mean ± SD. ∗P < 0.05 by two tailed t-test compared to the medium control. (B) Phage exposure of PBMCs. Data are from two replicates from four donors.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4814447&req=5

Figure 3: Cell cytotoxicity and inhibition of proliferation by exposure to phages. (A) Phage exposure to intestinal epithelial cells; HT-29 (n = 4) and Caco-2 (n = 4) . Data are presented as the mean ± SD. ∗P < 0.05 by two tailed t-test compared to the medium control. (B) Phage exposure of PBMCs. Data are from two replicates from four donors.
Mentions: In a long term assessment of the cytotoxic effects of individual phages on IECs and PBMCs, phages at a concentration of 109 PFU/well were not lethal to the HT-29 and Caco-2 cells after 96 h of incubation (P < 0.05 by two tailed t-test) and no significant differences between the cell lines were observed (Figure 3). Phage stimulated IECs produced a significantly (P < 0.05 by two tailed t-test) higher OD response compared to the negative control. Phages were unable to induce a significant cytotoxic effect on PBMCs.

Bottom Line: In order to address concerns over safety and the poorly understood pharmacokinetics of phages and their associated cocktails, immunological characterization is required.Despite co-incubation with different cell types, phages maintained a high killing efficiency, reducing extended-spectrum beta-lactamase-producing Escherichia coli numbers by 1-4 log10 compared to untreated controls.When provided with a suitable bacterial host, phages were also able to actively reproduce in the presence of human cells resulting in an approximately 2 log10 increase in phage titer compared to the initial inoculum.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University Stockholm, Sweden.

ABSTRACT
Due to a global increase in the range and number of infections caused by multi-resistant bacteria, phage therapy is currently experiencing a resurgence of interest. However, there are a number of well-known concerns over the use of phages to treat bacterial infections. In order to address concerns over safety and the poorly understood pharmacokinetics of phages and their associated cocktails, immunological characterization is required. In the current investigation, the immunogenicity of four distinct phages (taken from the main families that comprise the Caudovirales order) and their interaction with donor derived peripheral blood mononuclear cells and immortalized cell lines (HT-29 and Caco-2 intestinal epithelial cells) were investigated using standard immunological techniques. When exposed to high phage concentrations (10(9) PFU/well), cytokine driven inflammatory responses were induced from all cell types. Although phages appeared to inhibit the growth of intestinal epithelial cell lines, they also appear to be non-cytotoxic. Despite co-incubation with different cell types, phages maintained a high killing efficiency, reducing extended-spectrum beta-lactamase-producing Escherichia coli numbers by 1-4 log10 compared to untreated controls. When provided with a suitable bacterial host, phages were also able to actively reproduce in the presence of human cells resulting in an approximately 2 log10 increase in phage titer compared to the initial inoculum. Through an increased understanding of the complex pharmacokinetics of phages, it may be possible to address some of the safety concerns surrounding phage preparations prior to creating new therapeutic strategies.

No MeSH data available.


Related in: MedlinePlus