title: Hypermutator Salmonella Heidelberg induces an early cell death in epithelial cells.
abstract: We have previously described that a strain of Salmonella Heidelberg with a hypermutator phenotype, B182, adhered strongly to HeLa cells. In this work, we showed that this hypermutator Salmonella strain invaded HeLa epithelial cells and induced cytoskeleton alteration. Those changes lead to HeLa cell death which was characteristic of apoptosis. For the first time, we showed that this hypermutator strain induced apoptosis associated with the activation of caspases 2, 9 and 3. Complementation of B182 strain showed a decrease in cells death induction. In the presence of other Salmonella Heidelberg with a normomutator phenotype, such as WT and SL486, cell death and caspase 3 were undetectable. These results suggested that early apoptosis and caspase 3 activation were specific to B182. Besides, B182 induced LDH release and caspase 3 activation in CaCo-2 and HCT116 cells. Heat-treated B182 and diffusible products failed to induce this phenotype. Epithelial cells treatment with cytochalasin D caused the inhibition of B182 internalisation and caspase 3 activation. These results showed that this cell death required active S. Heidelberg B182 protein synthesis and bacterial internalisation. However sipB and sopB, usually involved in apoptosis induced by Salmonella were not overexpressed in B182, contrary to fimA and fliC. Comparative genome analysis showed numerous mutations as in rpoS which would be more investigated. The role of the hypermutator phenotype might be suspected to be implicated in these specific features. This result expands our knowledge about strong mutators frequently found in bacterial organisms isolated from clinical specimens.
authors: Equipe Microbiologie Risques Infectieux, EA 1254, SFR Biosit, Université Européenne de Bretagne, Université de Rennes 1, 2 Avenue du Professeur Léon Bernard, 35043 Rennes, France.
authors: Sandrine
authors: S
authors: Le Gall-David
authors: Equipe Microbiologie Risques Infectieux, EA 1254, SFR Biosit, Université Européenne de Bretagne, Université de Rennes 1, 2 Avenue du Professeur Léon Bernard, 35043 Rennes, France.
authors: Neila
authors: N
authors: Zenbaa
authors: ANSES-ANMV, 8 rue Claude Bourgelat, 35306, Fougères, France.
authors: Damien
authors: D
authors: Bouchard
authors: Plateforme microscopie électronique MRic Campus Santé, Rennes 1, France.
authors: Marie-Thérèse
authors: MT
authors: Lavault
authors: Equipe Microbiologie Risques Infectieux, EA 1254, SFR Biosit, Université Européenne de Bretagne, Université de Rennes 1, 2 Avenue du Professeur Léon Bernard, 35043 Rennes, France.
authors: Martine
authors: M
authors: Bonnaure-Mallet
authors: Equipe Microbiologie Risques Infectieux, EA 1254, SFR Biosit, Université Européenne de Bretagne, Université de Rennes 1, 2 Avenue du Professeur Léon Bernard, 35043 Rennes, France; CHU, 2 rue Henri Le Guilloux, 35033 Rennes cedex 9, France.
authors: Anne
authors: A
authors: Jolivet-Gougeon
authors: Equipe Microbiologie Risques Infectieux, EA 1254, SFR Biosit, Université Européenne de Bretagne, Université de Rennes 1, 2 Avenue du Professeur Léon Bernard, 35043 Rennes, France. Electronic address: Latifa.bousarghin@univ-rennes1.fr.
authors: Latifa
authors: L
authors: Bousarghin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D001483:Base Sequence; D018938:Caco-2 Cells; D053143:Caspase 2 / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism*; D053453:Caspase 9 / Q000378:metabolism; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D004789:Enzyme Activation; D004847:Epithelial Cells / Q000382:microbiology; D006367:HeLa Cells; D054884:Host-Pathogen Interactions; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D012475:Salmonella / Q000145:classification / Q000235:genetics / Q000502:physiology*; D012480:Salmonella Infections / Q000382:microbiology*; D016415:Sequence Alignment
chemical_list: C490360:CASP2 protein, human; C505407:CASP3 protein, human; C506433:CASP9 protein, human; D053143:Caspase 2; D053148:Caspase 3; D053453:Caspase 9; D003546:Cysteine Endopeptidases
keywords: Apoptosis; Caspase 2; Caspase 3; Cell death; Lactate dehydrogenase; Salmonella Heidelberg