Receptor-Mediated Sorting of Typhoid Toxin during Its Export from Salmonella Typhi-Infected Cells

Publication date: 9 November 2016
Source:Cell Host & Microbe, Volume 20, Issue 5
Author(s): Shu-Jung Chang, Jeongmin Song, Jorge E. Galán
Typhoid toxin is an essential virulence factor of Salmonella Typhi, the cause of typhoid fever. Typhoid toxin is secreted into the lumen of Salmonella-containing vacuole (SCV), after which it is packaged into vesicle carrier intermediates and released extracellularly through incompletely understood mechanisms. Following export, the toxin targets cells by interacting with human-specific Neu5Ac-terminated glycan receptors. We show that typhoid toxin is sorted from the SCV into vesicle carrier intermediates via interactions of its B subunit, PltB, with specific lumenal sialylated glycan packaging receptors. Cells deficient in N-glycosylation or the synthesis of specific gangliosides or displaying Neu5Gc-terminated, as opposed to Neu5Ac-terminated, glycans do not support typhoid toxin export. Additionally, typhoid toxin packaging requires the specific SCV environment, as toxin produced by an S. Typhi mutant with impaired trafficking is not properly sorted into vesicles. These results reveal how the exotoxin of an intracellular pathogen engages host pathways for packaging and release.

Graphical abstract

Teaser

Typhoid toxin is produced by intracellular S. Typhi and subsequently packaged into transport carriers, which take it to the extracellular space. Chang et al. show that typhoid toxin sorting into the transport intermediates requires a host glycan receptor and engagement by the toxin B subunit, PltB.


http://rss.sciencedirect.com/action/redirectFile?&zone=main&currentActivity=feed&usageType=outward&url=http%3A%2F%2Fwww.sciencedirect.com%2Fscience%3F_ob%3DGatewayURL%26_origin%3DIRSSSEARCH%26_method%3DcitationSearch%26_piikey%3DS1931312816304310%26_version%3D1%26md5%3De8eb59b1f8916b303fb48a15601a4479