TY - JOUR

T1 - The Typhoid Toxin Promotes Host Survival and the Establishment of a Persistent Asymptomatic Infection

AU - Del Bel Belluz, Lisa

AU - Guidi, Riccardo

AU - Pateras, Ioannis S.

AU - Levi, Laura

AU - Mihaljevic, Boris

AU - Rouf, Syed Fazle

AU - Wrande, Marie

AU - Candela, Marco

AU - Turroni, Silvia

AU - Nastasi, Claudia

AU - Consolandi, Clarissa

AU - Peano, Clelia

AU - Tebaldi, Toma

AU - Viero, Gabriella

AU - Gorgoulis, Vassilis G.

AU - Krejsgaard, Thorbjørn

AU - Rhen, Mikael

AU - Frisan, Teresa

PY - 2016/4/7

Y1 - 2016/4/7

N2 - Bacterial genotoxins, produced by several Gram-negative bacteria, induce DNA damage in the target cells. While the responses induced in the host cells have been extensively studied in vitro, the role of these effectors during the course of infection remains poorly characterized. To address this issue, we assessed the effects of the Salmonella enterica genotoxin, known as typhoid toxin, in in vivo models of murine infection. Immunocompetent mice were infected with isogenic S. enterica, serovar Typhimurium (S. Typhimurium) strains, encoding either a functional or an inactive typhoid toxin. The presence of the genotoxic subunit was detected 10 days post-infection in the liver of infected mice. Unexpectedly, its expression promoted the survival of the host, and was associated with a significant reduction of severe enteritis in the early phases of infection. Immunohistochemical and transcriptomic analysis confirmed the toxin-mediated suppression of the intestinal inflammatory response. The presence of a functional typhoid toxin further induced an increased frequency of asymptomatic carriers. Our data indicate that the typhoid toxin DNA damaging activity increases host survival and favours long-term colonization, highlighting a complex cross-talk between infection, DNA damage response and host immune response. These findings may contribute to understand why such effectors have been evolutionary conserved and horizontally transferred among Gram-negative bacteria.

AB - Bacterial genotoxins, produced by several Gram-negative bacteria, induce DNA damage in the target cells. While the responses induced in the host cells have been extensively studied in vitro, the role of these effectors during the course of infection remains poorly characterized. To address this issue, we assessed the effects of the Salmonella enterica genotoxin, known as typhoid toxin, in in vivo models of murine infection. Immunocompetent mice were infected with isogenic S. enterica, serovar Typhimurium (S. Typhimurium) strains, encoding either a functional or an inactive typhoid toxin. The presence of the genotoxic subunit was detected 10 days post-infection in the liver of infected mice. Unexpectedly, its expression promoted the survival of the host, and was associated with a significant reduction of severe enteritis in the early phases of infection. Immunohistochemical and transcriptomic analysis confirmed the toxin-mediated suppression of the intestinal inflammatory response. The presence of a functional typhoid toxin further induced an increased frequency of asymptomatic carriers. Our data indicate that the typhoid toxin DNA damaging activity increases host survival and favours long-term colonization, highlighting a complex cross-talk between infection, DNA damage response and host immune response. These findings may contribute to understand why such effectors have been evolutionary conserved and horizontally transferred among Gram-negative bacteria.

U2 - 10.1371/journal.ppat.1005528

DO - 10.1371/journal.ppat.1005528

M3 - Journal article

C2 - 27055274

AN - SCOPUS:84964883733

VL - 12

JO - P L o S Pathogens

JF - P L o S Pathogens

SN - 1553-7366

IS - 4

M1 - e1005528

ER -