Search engine for discovering works of Art, research articles, and books related to Art and Culture
Javascript must be enabled to continue!
Sensitivities of Human Monocytes and Epithelial Cells to Pneumolysin Are Different
View through CrossRef
ABSTRACTTheStreptococcus pneumoniaepore-forming toxin, pneumolysin, is an important virulence factor in pneumococcal pneumonia. The effect of pneumolysin on human lung epithelial and monocyte cell viability was compared. Pneumolysin caused a dose-dependent loss of viability of human lung epithelial (A549 and L132) and monocyte (U937 and THP-1) cell lines. Analysis of the dose-response curves revealed similar log 50% inhibitory concentration (pIC50) values for A549, L132, and THP-1 of 0.12± 0.1, 0.02± 0.04, and 0.12± 0.13 hemolytic units (HU), respectively, but U937 cells showed a significantly greater pIC50of 0.42± 0.12 HU. Differentiation of A549 and L132 with phorbol ester or THP-1 with gamma interferon had no effect on their sensitivity to pneumolysin. However, a significant decrease in the potency of pneumolysin against U937 cells followed gamma interferon treatment. The Hill slopes of the inhibition curves were greater than unity, indicating that pneumolysin may act with positive cooperativity. Analysis of pneumolysin-treated THP-1 cells by electron microscopy revealed membrane lesions of between 100 and 200 nm in diameter.
American Society for Microbiology
Title: Sensitivities of Human Monocytes and Epithelial Cells to Pneumolysin Are Different
Description:
ABSTRACTTheStreptococcus pneumoniaepore-forming toxin, pneumolysin, is an important virulence factor in pneumococcal pneumonia.
The effect of pneumolysin on human lung epithelial and monocyte cell viability was compared.
Pneumolysin caused a dose-dependent loss of viability of human lung epithelial (A549 and L132) and monocyte (U937 and THP-1) cell lines.
Analysis of the dose-response curves revealed similar log 50% inhibitory concentration (pIC50) values for A549, L132, and THP-1 of 0.
12± 0.
1, 0.
02± 0.
04, and 0.
12± 0.
13 hemolytic units (HU), respectively, but U937 cells showed a significantly greater pIC50of 0.
42± 0.
12 HU.
Differentiation of A549 and L132 with phorbol ester or THP-1 with gamma interferon had no effect on their sensitivity to pneumolysin.
However, a significant decrease in the potency of pneumolysin against U937 cells followed gamma interferon treatment.
The Hill slopes of the inhibition curves were greater than unity, indicating that pneumolysin may act with positive cooperativity.
Analysis of pneumolysin-treated THP-1 cells by electron microscopy revealed membrane lesions of between 100 and 200 nm in diameter.
Related Results
Relative Roles of Pneumolysin and Hydrogen Peroxide fromStreptococcus pneumoniaein Inhibition of Ependymal Ciliary Beat Frequency
Relative Roles of Pneumolysin and Hydrogen Peroxide fromStreptococcus pneumoniaein Inhibition of Ependymal Ciliary Beat Frequency
ABSTRACTCiliated ependymal cells line the ventricular system of the brain and the cerebral aqueducts. This study characterizes the relative roles of pneumolysin and hydrogen peroxi...
Abstract 155: Contribution of Foamy Monocytes to Nascent Atherosclerosis
Abstract 155: Contribution of Foamy Monocytes to Nascent Atherosclerosis
Infiltration of monocytes into the arterial wall and subsequent differentiation into macrophages, which take up lipoproteins to become foam cells, is a key step in atherogenesis. W...
Investigations into the puerperium of Beagle-breed female dogs
Investigations into the puerperium of Beagle-breed female dogs
The present thesis focusses on the study of the puerperium of female dogs, with the general objective to increase available knowledge regarding the puerperium of that species and t...
Fractalkine/CX3CR1 Signaling Promotes Angiogenic Potentials in CX3CR1 Expressing Monocytes
Fractalkine/CX3CR1 Signaling Promotes Angiogenic Potentials in CX3CR1 Expressing Monocytes
Abstract
Introduction : Myelo-monocytic cells expressing CD11b are involved in angiogenesis, but their specific roles and underlying mechanisms are unclear. CX3CR1 i...
Interaction of pneumolysin-sufficient and -deficient isogenic variants of Streptococcus pneumoniae with human respiratory mucosa
Interaction of pneumolysin-sufficient and -deficient isogenic variants of Streptococcus pneumoniae with human respiratory mucosa
Streptococcus pneumoniae is the most common cause of community-acquired pneumonia, and pneumolysin, a hemolytic toxin, is thought to be an important virulence factor. We have studi...
Effect of Streptococcus pneumoniae on human respiratory epithelium in vitro
Effect of Streptococcus pneumoniae on human respiratory epithelium in vitro
A total of 11 of 15 Streptococcus pneumoniae culture filtrates and all five bacterial autolysates produced by cell death in the stationary phase caused slowed ciliary beating and d...
INHIBITION OF ENDOTHELIAL CELL PROLIFERATION BY NORMAL HUMAN MONOCYTES
INHIBITION OF ENDOTHELIAL CELL PROLIFERATION BY NORMAL HUMAN MONOCYTES
Human peripheral blood monocytes and macrophages possess factors which are capable of inhibiting or stimulating endothelial cell proliferation. We have further explored if such act...
Cell‐free‐synthesized interleukin‐6 (BSF‐2/IFN‐β2) exhibits hepatocyte‐stimulating activity
Cell‐free‐synthesized interleukin‐6 (BSF‐2/IFN‐β2) exhibits hepatocyte‐stimulating activity
Secretory products of cultured human blood monocytes contain a hepatocyte‐stimulating factor which is able to induce the acute‐phase proteins α2‐macroglobulin and fibrinogen in rat...