Role of YopP in suppression of tumor necrosis factor alpha release by macrophages during Yersinia infection

Boland, A. and Cornelis, G. R.. (1998) Role of YopP in suppression of tumor necrosis factor alpha release by macrophages during Yersinia infection. Infection and immunity, Vol. 66, H. 5. pp. 1878-1884.

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Official URL: http://edoc.unibas.ch/dok/A5259190

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The Yersinia plasmid-encoded Yop virulon enables extracellular adhering bacteria to deliver toxic effector proteins inside their target cells. It includes a type III secretion system (Ysc), at least two translocator proteins (YopB, YopD), and a set of intracellular Yop effectors (YopE, YopH, YopO, YopM, and YopP). Infection of macrophages with a wild-type strain leads to low levels of tumor necrosis factor alpha (TNF-alpha) release compared to infection with plasmid-cured strains, suggesting that the virulence plasmid encodes a factor impairing the normal TNF-alpha response of infected macrophages. This effect is correlated with the inhibition of the macrophage mitogen-activated protein kinase (MAPK) activities. To identify the Yop protein responsible for the suppression of TNF-alpha release, we infected J774A.1 and PU5-1.8 macrophages with a battery of knockout Yersinia enterocolitica mutants and we quantified the TNF-alpha released. Mutants affected in secretion (yscN), in translocation (yopB and yopD), or in synthesis of all the known Yop effectors (yopH, yopO, yopP, yopE, and yopM polymutants) were unable to block the TNF-alpha response of the macrophages. In contrast, single yopE, yopH, yopO, and yopM mutants behaved like the wild-type strain. A yopP mutant elicited elevated TNF-alpha release, and complementation of the yopP mutant or the yop effector polymutant strain with yopP alone led to a drop in TNF-alpha release. In addition, YopP was also responsible for the inhibition of the extracellular signal-regulated kinase2 (ERK2) and p38 MAPK activities. These results show that YopP is the Yop effector responsible for the Yersinia-induced suppression of TNF-alpha release by infected macrophages.
Faculties and Departments:05 Faculty of Science > Departement Biozentrum > Former Organization Units Biozentrum > Molecular Microbiology (Cornelis)
UniBasel Contributors:Cornelis, Guy R.
Item Type:Article, refereed
Article Subtype:Research Article
Publisher:American Society for Microbiology
Note:Publication type according to Uni Basel Research Database: Journal article
Last Modified:22 Mar 2012 14:20
Deposited On:22 Mar 2012 13:22

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