To evaluate the role of the acidic pH of phagosomes on the invasive ability and fate of Listeria monocytogenes within host cells, entry and replication of this gram-positive bacterium in a human enterocyte-like cell line (Caco-2) were investigated by a combination of biochemical and ultrastructural approaches, The effects of inhibitors of vacuolar acidification - the lipophilic weak base ammonium chloride, the carboxylic ionophore monensin and the vacuolar proton ATPase inhibitor bafilomycin A(1) - on the bacterial invasion pathway were analysed, These agents, which raise the intracellular vesicle acidic pH of living cells by different mechanisms, affected L. monocytogenes replication in Caco-2 cells, Bacteria internalised by bafilomycin-treated cells were unable to escape from phagosomes, as demonstrated by electronmicroscopy. The results provide evidence that low pH is required for efficient intracellular growth of L. monocytogenes.
The effects of inhibitors of vacuolar acidification on the release of Listeria monocytogenes from phagosomes of Caco-2 cells / Conte, Maria Pia; G., Petrone; Longhi, Catia; Valenti, Piera; R., Morelli; F., Superti; Seganti, Lucilla. - In: JOURNAL OF MEDICAL MICROBIOLOGY. - ISSN 0022-2615. - 44:6(1996), pp. 418-424. [10.1099/00222615-44-6-418]
The effects of inhibitors of vacuolar acidification on the release of Listeria monocytogenes from phagosomes of Caco-2 cells
CONTE, Maria Pia;LONGHI, Catia;VALENTI, PIERA;SEGANTI, Lucilla
1996
Abstract
To evaluate the role of the acidic pH of phagosomes on the invasive ability and fate of Listeria monocytogenes within host cells, entry and replication of this gram-positive bacterium in a human enterocyte-like cell line (Caco-2) were investigated by a combination of biochemical and ultrastructural approaches, The effects of inhibitors of vacuolar acidification - the lipophilic weak base ammonium chloride, the carboxylic ionophore monensin and the vacuolar proton ATPase inhibitor bafilomycin A(1) - on the bacterial invasion pathway were analysed, These agents, which raise the intracellular vesicle acidic pH of living cells by different mechanisms, affected L. monocytogenes replication in Caco-2 cells, Bacteria internalised by bafilomycin-treated cells were unable to escape from phagosomes, as demonstrated by electronmicroscopy. The results provide evidence that low pH is required for efficient intracellular growth of L. monocytogenes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.