Limits...
Calprotectin Increases the Activity of the SaeRS Two Component System and Murine Mortality during Staphylococcus aureus Infections.

Cho H, Jeong DW, Liu Q, Yeo WS, Vogl T, Skaar EP, Chazin WJ, Bae T - PLoS Pathog. (2015)

Bottom Line: The activity of the SaeRS TCS is repressed by certain divalent ions found in blood or neutrophil granules; however, the Zn bound-form of calprotectin relieves this repression.During staphylococcal encounter with murine neutrophils or staphylococcal infection of the murine peritoneal cavity, calprotectin increases the activity of the SaeRS TCS as well as the production of proinflammatory cytokines such as IL-1β and TNF-α, resulting in higher murine mortality.These results suggest that, under certain conditions, calprotectin can be exploited by S. aureus to increase bacterial virulence and host mortality.

View Article: PubMed Central - PubMed

Affiliation: Indiana University School of Medicine-Northwest, Gary, Indiana, United States of America.

ABSTRACT
Calprotectin, the most abundant cytoplasmic protein in neutrophils, suppresses the growth of Staphylococcus aureus by sequestering the nutrient metal ions Zn and Mn. Here we show that calprotectin can also enhance the activity of the SaeRS two component system (TCS), a signaling system essential for production of over 20 virulence factors in S. aureus. The activity of the SaeRS TCS is repressed by certain divalent ions found in blood or neutrophil granules; however, the Zn bound-form of calprotectin relieves this repression. During staphylococcal encounter with murine neutrophils or staphylococcal infection of the murine peritoneal cavity, calprotectin increases the activity of the SaeRS TCS as well as the production of proinflammatory cytokines such as IL-1β and TNF-α, resulting in higher murine mortality. These results suggest that, under certain conditions, calprotectin can be exploited by S. aureus to increase bacterial virulence and host mortality.

No MeSH data available.


Related in: MedlinePlus

The SaeRS TCS can be repressed by Cu, Fe, and Zn.(A) The effect of culture medium on the expression of SaeQ. S. aureus cells were grown to 0.5 OD600, and SaeQ protein was detected by Western blot analysis. Newman, S. aureus strain Newman; USA300, S. aureus strain USA300; + EDTA, addition of 1 mM EDTA. The quantification result of the Western blot is shown to the right. (B) The effect of iron on the P1 promoter activity (top) and SaeQ expression (bottom). P1 promoter activity was measured by LacZ assay for P1-lacZ fusion construct, while SaeQ was measured by Western blot analysis. -, no metal addition. (C) The effect of metal ions present in human blood on the P1 promoter activity (top) and SaeQ expression (bottom). S. aureus cells were grown in RPMI supplemented with 2 mM CaCl2, 20 μM CuSO4, 20 μM FeSO4, 500 μM MgSO4, 0.1 μM MnSO4, 0.04 μM NiSO4, or 20 μM ZnSO4 at 37°C for 16 h. Then the P1 promoter activity and SaeQ expression were measured by LacZ assay. Statistical comparison was made against the no metal (-) condition. (D) The effect of metal ions present in human neutrophil granules on the P1 promoter activity and SaeQ expression. Cells were grown in RPMI supplemented with 400 μM CaCl2, 130 μM FeSO4, 130 μM MnSO4, or 400 μM ZnSO4. All other conditions are the same as in (C). (E) The effect of metal chelation on the recovery of the P1 promoter activity (top) and SaeQ expression (bottom). S. aureus cells were grown for 16 h in RPMI supplemented with all metal ions (Mix) used in (D). The presented data represent three independent experiments. Error bars indicate standard error of the mean. Statistical significance was measured by unpaired, two-tailed t-test. *, p < 0.05; **, p < 0.01; ***, p < 0.001
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4492782&req=5

ppat.1005026.g001: The SaeRS TCS can be repressed by Cu, Fe, and Zn.(A) The effect of culture medium on the expression of SaeQ. S. aureus cells were grown to 0.5 OD600, and SaeQ protein was detected by Western blot analysis. Newman, S. aureus strain Newman; USA300, S. aureus strain USA300; + EDTA, addition of 1 mM EDTA. The quantification result of the Western blot is shown to the right. (B) The effect of iron on the P1 promoter activity (top) and SaeQ expression (bottom). P1 promoter activity was measured by LacZ assay for P1-lacZ fusion construct, while SaeQ was measured by Western blot analysis. -, no metal addition. (C) The effect of metal ions present in human blood on the P1 promoter activity (top) and SaeQ expression (bottom). S. aureus cells were grown in RPMI supplemented with 2 mM CaCl2, 20 μM CuSO4, 20 μM FeSO4, 500 μM MgSO4, 0.1 μM MnSO4, 0.04 μM NiSO4, or 20 μM ZnSO4 at 37°C for 16 h. Then the P1 promoter activity and SaeQ expression were measured by LacZ assay. Statistical comparison was made against the no metal (-) condition. (D) The effect of metal ions present in human neutrophil granules on the P1 promoter activity and SaeQ expression. Cells were grown in RPMI supplemented with 400 μM CaCl2, 130 μM FeSO4, 130 μM MnSO4, or 400 μM ZnSO4. All other conditions are the same as in (C). (E) The effect of metal chelation on the recovery of the P1 promoter activity (top) and SaeQ expression (bottom). S. aureus cells were grown for 16 h in RPMI supplemented with all metal ions (Mix) used in (D). The presented data represent three independent experiments. Error bars indicate standard error of the mean. Statistical significance was measured by unpaired, two-tailed t-test. *, p < 0.05; **, p < 0.01; ***, p < 0.001

Mentions: The activity of the P1 promoter of the sae operon and the expression of SaeQ are indicators for the activity of the SaeRS TCS [4,5]. When the expression of SaeQ was analyzed in three different growth conditions, the strain USA300 showed a much higher expression of SaeQ in RPMI (Roswell Park Memorial Institute medium) than in either TSB (tryptic soy broth) or human serum (Fig 1A). The distinct SaeQ expression pattern was not observed with the strain Newman, which carries SaeS L18P, a mutant SaeS with constitutive kinase activity [4,30] (Fig 1A), suggesting that SaeS is responsible for the distinct expression of SaeQ in USA300.


Calprotectin Increases the Activity of the SaeRS Two Component System and Murine Mortality during Staphylococcus aureus Infections.

Cho H, Jeong DW, Liu Q, Yeo WS, Vogl T, Skaar EP, Chazin WJ, Bae T - PLoS Pathog. (2015)

The SaeRS TCS can be repressed by Cu, Fe, and Zn.(A) The effect of culture medium on the expression of SaeQ. S. aureus cells were grown to 0.5 OD600, and SaeQ protein was detected by Western blot analysis. Newman, S. aureus strain Newman; USA300, S. aureus strain USA300; + EDTA, addition of 1 mM EDTA. The quantification result of the Western blot is shown to the right. (B) The effect of iron on the P1 promoter activity (top) and SaeQ expression (bottom). P1 promoter activity was measured by LacZ assay for P1-lacZ fusion construct, while SaeQ was measured by Western blot analysis. -, no metal addition. (C) The effect of metal ions present in human blood on the P1 promoter activity (top) and SaeQ expression (bottom). S. aureus cells were grown in RPMI supplemented with 2 mM CaCl2, 20 μM CuSO4, 20 μM FeSO4, 500 μM MgSO4, 0.1 μM MnSO4, 0.04 μM NiSO4, or 20 μM ZnSO4 at 37°C for 16 h. Then the P1 promoter activity and SaeQ expression were measured by LacZ assay. Statistical comparison was made against the no metal (-) condition. (D) The effect of metal ions present in human neutrophil granules on the P1 promoter activity and SaeQ expression. Cells were grown in RPMI supplemented with 400 μM CaCl2, 130 μM FeSO4, 130 μM MnSO4, or 400 μM ZnSO4. All other conditions are the same as in (C). (E) The effect of metal chelation on the recovery of the P1 promoter activity (top) and SaeQ expression (bottom). S. aureus cells were grown for 16 h in RPMI supplemented with all metal ions (Mix) used in (D). The presented data represent three independent experiments. Error bars indicate standard error of the mean. Statistical significance was measured by unpaired, two-tailed t-test. *, p < 0.05; **, p < 0.01; ***, p < 0.001
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492782&req=5

ppat.1005026.g001: The SaeRS TCS can be repressed by Cu, Fe, and Zn.(A) The effect of culture medium on the expression of SaeQ. S. aureus cells were grown to 0.5 OD600, and SaeQ protein was detected by Western blot analysis. Newman, S. aureus strain Newman; USA300, S. aureus strain USA300; + EDTA, addition of 1 mM EDTA. The quantification result of the Western blot is shown to the right. (B) The effect of iron on the P1 promoter activity (top) and SaeQ expression (bottom). P1 promoter activity was measured by LacZ assay for P1-lacZ fusion construct, while SaeQ was measured by Western blot analysis. -, no metal addition. (C) The effect of metal ions present in human blood on the P1 promoter activity (top) and SaeQ expression (bottom). S. aureus cells were grown in RPMI supplemented with 2 mM CaCl2, 20 μM CuSO4, 20 μM FeSO4, 500 μM MgSO4, 0.1 μM MnSO4, 0.04 μM NiSO4, or 20 μM ZnSO4 at 37°C for 16 h. Then the P1 promoter activity and SaeQ expression were measured by LacZ assay. Statistical comparison was made against the no metal (-) condition. (D) The effect of metal ions present in human neutrophil granules on the P1 promoter activity and SaeQ expression. Cells were grown in RPMI supplemented with 400 μM CaCl2, 130 μM FeSO4, 130 μM MnSO4, or 400 μM ZnSO4. All other conditions are the same as in (C). (E) The effect of metal chelation on the recovery of the P1 promoter activity (top) and SaeQ expression (bottom). S. aureus cells were grown for 16 h in RPMI supplemented with all metal ions (Mix) used in (D). The presented data represent three independent experiments. Error bars indicate standard error of the mean. Statistical significance was measured by unpaired, two-tailed t-test. *, p < 0.05; **, p < 0.01; ***, p < 0.001
Mentions: The activity of the P1 promoter of the sae operon and the expression of SaeQ are indicators for the activity of the SaeRS TCS [4,5]. When the expression of SaeQ was analyzed in three different growth conditions, the strain USA300 showed a much higher expression of SaeQ in RPMI (Roswell Park Memorial Institute medium) than in either TSB (tryptic soy broth) or human serum (Fig 1A). The distinct SaeQ expression pattern was not observed with the strain Newman, which carries SaeS L18P, a mutant SaeS with constitutive kinase activity [4,30] (Fig 1A), suggesting that SaeS is responsible for the distinct expression of SaeQ in USA300.

Bottom Line: The activity of the SaeRS TCS is repressed by certain divalent ions found in blood or neutrophil granules; however, the Zn bound-form of calprotectin relieves this repression.During staphylococcal encounter with murine neutrophils or staphylococcal infection of the murine peritoneal cavity, calprotectin increases the activity of the SaeRS TCS as well as the production of proinflammatory cytokines such as IL-1β and TNF-α, resulting in higher murine mortality.These results suggest that, under certain conditions, calprotectin can be exploited by S. aureus to increase bacterial virulence and host mortality.

View Article: PubMed Central - PubMed

Affiliation: Indiana University School of Medicine-Northwest, Gary, Indiana, United States of America.

ABSTRACT
Calprotectin, the most abundant cytoplasmic protein in neutrophils, suppresses the growth of Staphylococcus aureus by sequestering the nutrient metal ions Zn and Mn. Here we show that calprotectin can also enhance the activity of the SaeRS two component system (TCS), a signaling system essential for production of over 20 virulence factors in S. aureus. The activity of the SaeRS TCS is repressed by certain divalent ions found in blood or neutrophil granules; however, the Zn bound-form of calprotectin relieves this repression. During staphylococcal encounter with murine neutrophils or staphylococcal infection of the murine peritoneal cavity, calprotectin increases the activity of the SaeRS TCS as well as the production of proinflammatory cytokines such as IL-1β and TNF-α, resulting in higher murine mortality. These results suggest that, under certain conditions, calprotectin can be exploited by S. aureus to increase bacterial virulence and host mortality.

No MeSH data available.


Related in: MedlinePlus