Listeriolysin O (LLO), a member of the cholesterol-dependent cytolysin (CDC) family, is a major virulence factor of Listeria monocytogenes and contributes to bacterial escape from intracellular killing of macrophages. LLO is activated under weakly acidic conditions; however, the molecular mechanism of this pH-dependent expression of cytolytic activity of LLO is poorly understood. In this study, CDCs including LLO, ivanolysin O (ILO), seeligeriolysin O (LSO), pneumolysin (PLY), streptolysin O (SLO) and perfringolysin O (PFO) were prepared as recombinant proteins and examined for their functional changes after treatment under various pH conditions.
View Article and Find Full Text PDFObjective: To examine whether intervention by infectious diseases physicians (IDPs) in the treatment decisions that emphasize adequate antifungal treatment and early removal of central venous catheter for patients with Candida bloodstream infection (BSI) improves prognosis.
Design: Retrospective cohort study of patients with Candida BSI, comparing the prognosis of patients before and after the start of the intervention.
Setting: A 1,240-bed, tertiary care university hospital.
Two pathogenic species in the genus Listeria, Listeria monocytogenes and Listeria ivanovii, are characterized by the production of hemolysins belonging to cholesterol-dependent cytolysins, listeriolysin O (LLO) and ivanolysin O (ILO), respectively. LLO, produced by L. monocytogenes, is able to induce gamma interferon (IFN-gamma) production and contributes to the generation of Th1-dependent protective immunity.
View Article and Find Full Text PDFSeeligeriolysin O (LSO), one of the cholesterol-dependent cytolysins produced by Listeria seeligeri, shows 80% homology to listeriolysin O (LLO) produced by Listeria monocytogenes at the amino acid sequence level. In addition to cytolytic activity, LLO has been shown to exhibit cytokine-inducing activity. In order to determine whether LSO is also capable of exhibiting these two different activities, we constructed a recombinant full-length LSO (rLSO530) and a noncytolytic truncated derivative with a C-terminal deletion (rLSO483) and compared these molecules with recombinant LLO.
View Article and Find Full Text PDFMycobacterium abscessus accounts for 80% of rapidly growing mycobacterial pulmonary infections and can be lethal. Treatment is difficult because of the paucity of effective drugs. We describe a patient with pulmonary M.
View Article and Find Full Text PDFListeriolysin O (LLO), a cholesterol-binding cytolysin of Listeria monocytogenes, exhibits cytokine-inducing and cytolytic activities. Because the cytolytic activity was abolished by cholesterol treatment but the cytokine-inducing activity was not, these activities appeared to be linked to different domains of the LLO molecule. In this study, we constructed recombinant full-length LLO (rLLO529) and various truncated derivatives and examined their cytolytic, cholesterol-binding, and gamma interferon (IFN-gamma)-inducing activities.
View Article and Find Full Text PDFThe mechanism of gamma interferon (IFN-gamma) production induced by listeriolysin O (LLO), a cytolytic virulence factor of Listeria monocytogenes, was analyzed with special reference to the involvement of macrophage-derived cytokines in spleen cells of mice. LLO purified from the culture supernatant of L. monocytogenes was capable of inducing a high level of IFN-gamma when its cytolytic activity was blocked by cholesterol treatment.
View Article and Find Full Text PDFPneumolysin (PLY), an important virulence factor of Streptococcus pneumoniae, is known to exert various effects on the host immune cells, including cytokine induction, in addition to its known cytolytic activity as a member of the thiol-activated cytolysins. It is of interest to determine whether cytolytic activity is involved in triggering the cytokine production. In this study, we constructed full-length recombinant PLY and noncytolytic truncated PLYs with C-terminal deletions to examine the response of spleen cells to these PLY preparations.
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