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RNase 7 contributes to the cutaneous defense against Enterococcus faecium.

Köten B, Simanski M, Gläser R, Podschun R, Schröder JM, Harder J - PLoS ONE (2009)

Bottom Line: RNase 7 was still active against E. faecium at low pH (5.5) or high NaCl (150 mM) concentration and the bactericidal activity of RNase 7 against E. faecium required no ribonuclease activity as shown by recombinant RNase 7 lacking enzymatic activity.Treatment of the skin extract with an RNase 7 specific antibody, which neutralizes the antimicrobial activity of RNase 7, diminished its E. faecium killing activity.Our data indicate that RNase 7 contributes to the E. faecium-killing activity of skin extracts and suggest an important role for RNase 7 in the protection of human skin against E. faecium colonization.

View Article: PubMed Central - PubMed

Affiliation: Department of Dermatology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.

ABSTRACT

Background: Human skin is able to mount a fast response against invading microorganisms by the release of antimicrobial proteins such as the ribonuclease RNase 7. Because RNase 7 exhibits high activity against Enterococcus faecium the aim of this study was to further explore the role of RNase 7 in the cutaneous innate defense system against E. faecium.

Methodology/principal findings: Absolute quantification using real-time PCR and ELISA revealed that primary keratinocytes expressed high levels of RNase 7. Immunohistochemistry showed RNase 7 expression in all epidermal layers of the skin with an intensification in the upper more differentiated layers. Furthermore, RNase 7 was secreted by keratinocytes in vitro and in vivo in a site-dependent way. RNase 7 was still active against E. faecium at low pH (5.5) or high NaCl (150 mM) concentration and the bactericidal activity of RNase 7 against E. faecium required no ribonuclease activity as shown by recombinant RNase 7 lacking enzymatic activity. To further explore the role of RNase 7 in cutaneous defense against E. faecium, we investigated whether RNase 7 contributes to the E. faecium killing activity of skin extracts derived from stratum corneum. Treatment of the skin extract with an RNase 7 specific antibody, which neutralizes the antimicrobial activity of RNase 7, diminished its E. faecium killing activity.

Conclusions/significance: Our data indicate that RNase 7 contributes to the E. faecium-killing activity of skin extracts and suggest an important role for RNase 7 in the protection of human skin against E. faecium colonization.

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Related in: MedlinePlus

Antimicrobial activity of RNase 7 against E. faecium at various pH and high salt conditions.The antimicrobial activity of RNase 7 (1.6 µg⋅ml−1) was tested in a microdilution assay against E. faecium (ATCC 6057) at various pH conditions or in the presence of 150 mM NaCl. Results are from triplicate determinations and presented as the mean±S.D.
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pone-0006424-g005: Antimicrobial activity of RNase 7 against E. faecium at various pH and high salt conditions.The antimicrobial activity of RNase 7 (1.6 µg⋅ml−1) was tested in a microdilution assay against E. faecium (ATCC 6057) at various pH conditions or in the presence of 150 mM NaCl. Results are from triplicate determinations and presented as the mean±S.D.

Mentions: To verify the antimicrobial activity of RNase 7 against E. faecium, we investigated natural RNase 7 for microbicidal activity in an antimicrobial microdilution assay against E. faecium (ATCC 6057). This strain was effectively killed by RNase 7 (lethal dose of 90% (LD90) = 0.4–0.8 µg⋅ml−1; not shown). To further support the idea of an antimicrobial function for RNase 7 in cutaneous defense, we performed antimicrobial assays in buffers with variable pH (5.5, 6.5 and 7.4). RNase 7 was active under all pH conditions (Fig. 5). In addition, E. faecium was also effectively killed by RNase 7 at 150 mM NaCl (Fig. 5).


RNase 7 contributes to the cutaneous defense against Enterococcus faecium.

Köten B, Simanski M, Gläser R, Podschun R, Schröder JM, Harder J - PLoS ONE (2009)

Antimicrobial activity of RNase 7 against E. faecium at various pH and high salt conditions.The antimicrobial activity of RNase 7 (1.6 µg⋅ml−1) was tested in a microdilution assay against E. faecium (ATCC 6057) at various pH conditions or in the presence of 150 mM NaCl. Results are from triplicate determinations and presented as the mean±S.D.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2712763&req=5

pone-0006424-g005: Antimicrobial activity of RNase 7 against E. faecium at various pH and high salt conditions.The antimicrobial activity of RNase 7 (1.6 µg⋅ml−1) was tested in a microdilution assay against E. faecium (ATCC 6057) at various pH conditions or in the presence of 150 mM NaCl. Results are from triplicate determinations and presented as the mean±S.D.
Mentions: To verify the antimicrobial activity of RNase 7 against E. faecium, we investigated natural RNase 7 for microbicidal activity in an antimicrobial microdilution assay against E. faecium (ATCC 6057). This strain was effectively killed by RNase 7 (lethal dose of 90% (LD90) = 0.4–0.8 µg⋅ml−1; not shown). To further support the idea of an antimicrobial function for RNase 7 in cutaneous defense, we performed antimicrobial assays in buffers with variable pH (5.5, 6.5 and 7.4). RNase 7 was active under all pH conditions (Fig. 5). In addition, E. faecium was also effectively killed by RNase 7 at 150 mM NaCl (Fig. 5).

Bottom Line: RNase 7 was still active against E. faecium at low pH (5.5) or high NaCl (150 mM) concentration and the bactericidal activity of RNase 7 against E. faecium required no ribonuclease activity as shown by recombinant RNase 7 lacking enzymatic activity.Treatment of the skin extract with an RNase 7 specific antibody, which neutralizes the antimicrobial activity of RNase 7, diminished its E. faecium killing activity.Our data indicate that RNase 7 contributes to the E. faecium-killing activity of skin extracts and suggest an important role for RNase 7 in the protection of human skin against E. faecium colonization.

View Article: PubMed Central - PubMed

Affiliation: Department of Dermatology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.

ABSTRACT

Background: Human skin is able to mount a fast response against invading microorganisms by the release of antimicrobial proteins such as the ribonuclease RNase 7. Because RNase 7 exhibits high activity against Enterococcus faecium the aim of this study was to further explore the role of RNase 7 in the cutaneous innate defense system against E. faecium.

Methodology/principal findings: Absolute quantification using real-time PCR and ELISA revealed that primary keratinocytes expressed high levels of RNase 7. Immunohistochemistry showed RNase 7 expression in all epidermal layers of the skin with an intensification in the upper more differentiated layers. Furthermore, RNase 7 was secreted by keratinocytes in vitro and in vivo in a site-dependent way. RNase 7 was still active against E. faecium at low pH (5.5) or high NaCl (150 mM) concentration and the bactericidal activity of RNase 7 against E. faecium required no ribonuclease activity as shown by recombinant RNase 7 lacking enzymatic activity. To further explore the role of RNase 7 in cutaneous defense against E. faecium, we investigated whether RNase 7 contributes to the E. faecium killing activity of skin extracts derived from stratum corneum. Treatment of the skin extract with an RNase 7 specific antibody, which neutralizes the antimicrobial activity of RNase 7, diminished its E. faecium killing activity.

Conclusions/significance: Our data indicate that RNase 7 contributes to the E. faecium-killing activity of skin extracts and suggest an important role for RNase 7 in the protection of human skin against E. faecium colonization.

Show MeSH
Related in: MedlinePlus