Invasive phenotype and apoptosis induction of Plesiomonas shigelloides P-1 strain to Caco-2 cells

Abstract

Aims: The mechanism of the host cell invasion of Plesiomonas shigelloides and its capability to induce apoptosis were investigated. Methods and Results: We performed a time course experiment on the bacterial adherence and invasion of the P. shigelloides P-1 strain into Caco-2 cells using an invasion assay and flow cytometry. The adherence of P. shigelloides to the Caco-2 cells was almost completed within 10 min after the infection. Thereafter, P. shigelloides starts internalization within the Caco-2 cells, which was completed within 60 min after the infection. Based on the invasion assay using nocodazole, cytochalasin D, and genistein, it became clear that the mechanism of the internalization depended on the signal transduction followed by the rearrangement of the cytoskeletal protein. Based on the DNA laddering and TUNEL methods, the cytotoxicity of the Caco-2 cells by the invasion of P. shigelloides occurred through the induction of apoptosis. Conclusions: This work demonstrated that the mechanism of invasion of P. shigelloides into Caco-2 cells and the invasion of P. shigelloides induces apoptotic cell death. Significance and Impact of the Study: This work revealed the virulence factor, which may be important for understanding of the pathogenesis of P. shigelloides.

Primary structure and function of a cytotoxic outer-membrane protein (ComP) of Plesiomonas shigelloides

“…We have previously shown that invasion of P. shigelloides in a cell induces apoptotic cell death (Tsugawa et al , 2005). The pathogenicity of P. shigelloides might depend on the interactions of the bacteria with the host cells, i.e.…”

“…The OD of the wells at 550 nm was determined. We assessed DNA laddering of infected Caco-2 cells for 24 h, as previously described by Tsugawa et al (2005). The DNA was isolated using the Wizard Genomic DNA purification Kit (Promega, Madison, WI) according to the manufacturer's guidelines.…”

“…It is likely that an interaction between the bacteria and the host cells is important for pathogenicity. Plesiomonas shigelloides has been shown to enter Caco-2 cells (Theodoropoulos et al, 2001), and we demonstrated that P. shigelloides cells induce apoptosis of Caco-2 cells following infection (Tsugawa et al, 2005). We recently isolated a 40-kDa cytotoxic outer-membrane protein (ComP) from a culture supernatant of a clinically isolated strain of P. shigelloides, P-1, and observed a positive reaction with the protein in the suckling mouse assay (Okawa et al, 2004).…”

Structure of the Core Region from the Lipopolysaccharide of Plesiomonas shigelloides Strain 302‐73 (Serotype O1)

“…[3,4] P. shigelloides is capable of adhering to and entering into the human colon carcinoma Caco-2 cells, inducing apoptotic cell death. [5,6] Recently, the heat-shock protein GroEL from P. shigelloides was found to promote adhesion to Caco-2 cells, and in this way, most likely starts the invasion mechanism. [7] To date, various virulence factors have been described to determine the pathogenic mechanism of P. shigelloides, which included enterotoxins, [8][9][10] cholera-like toxin, [11] β-saccharides were characterized by chemical analysis, 2D NMR spectroscopy and MALDI-TOF mass spectrometry.…”

Purificação e caracterização de uma toxina enterotóxica, citotóxina e letal produzida por amostras de Plesiomonas shigelloides isoladas de água de rio.

“…Bactérias enteropatogênicas, tais como E. coli, Salmonella spp e Shigella spp também são capazes de produzir fatores de virulência que promovem colonização e produção de toxinas que são importantes nas etiologias das doenças diarréicas (Cavalieri et al, 1984;Weinrauch e Zychlinsk 1999). No entanto, os fatores virulência em P. shigelloides ainda não estão bem definidos e, em especial, sua participação na enteropatogenia causada por esta bactéria (Hostaka et al, 2002;Theodoropoulos et al, 2001;Tsugawa et al, 2005).…”