Innate Recognition of Intracellular Bacterial Growth Is Driven by the TIFA-Dependent Cytosolic Surveillance Pathway

Autor: Ryan G. Gaudet, Cynthia X. Guo, Raphael Molinaro, Haila Kottwitz, John R. Rohde, Anne-Sophie Dangeard, Cécile Arrieumerlou, Stephen E. Girardin, Scott D. Gray-Owen
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Cell Reports, Vol 19, Iss 7, Pp 1418-1430 (2017)
Druh dokumentu: article
ISSN: 2211-1247
DOI: 10.1016/j.celrep.2017.04.063
Popis: Intestinal epithelial cells (IECs) act as sentinels for incoming pathogens. Cytosol-invasive bacteria, such as Shigella flexneri, trigger a robust pro-inflammatory nuclear factor κB (NF-κB) response from IECs that is believed to depend entirely on the peptidoglycan sensor NOD1. We found that, during Shigella infection, the TRAF-interacting forkhead-associated protein A (TIFA)-dependent cytosolic surveillance pathway, which senses the bacterial metabolite heptose-1,7-bisphosphate (HBP), functions after NOD1 to detect bacteria replicating free in the host cytosol. Whereas NOD1 mediated a transient burst of NF-κB activation during bacterial entry, TIFA sensed HBP released during bacterial replication, assembling into large signaling complexes to drive a dynamic inflammatory response that reflected the rate of intracellular bacterial proliferation. Strikingly, IECs lacking TIFA were unable to discriminate between proliferating and stagnant intracellular bacteria, despite the NOD1/2 pathways being intact. Our results define TIFA as a rheostat for intracellular bacterial replication, escalating the immune response to invasive Gram-negative bacteria that exploit the host cytosol for growth.
Databáze: Directory of Open Access Journals