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PUBLIC RELEASE DATE:
14-Mar-2011

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Contact: NIAID Office of Communications
niaidnews@niaid.nih.gov
301-402-1663
NIH/National Institute of Allergy and Infectious Diseases
@NIAIDNews

Study helps explain how pathogenic E. coli bacterium causes illness

Scientists at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, have shown how the O157:H7 strain of Escherichia coli causes infection and thrives by manipulating the host immune response. The bacterium secretes a protein called NleH1 that directs the host immune enzyme IKK-beta to alter specific immune responses. This process not only helps the bacterium evade elimination by the immune system, it also works to prolong the survival of the infected host, enabling the bacterium to persist and ultimately spread to unaffected individuals. This finely balanced mechanism, observed in both laboratory and animal models, could be relevant to other pathogens involved in foodborne diseases.

While most E. coli strains help check the growth of harmful bacteria in the guts of animals and humans, a few E. coli strains, such as O157:H7, can cause severe diarrhea, abdominal cramps and, in rare cases, death. Human cases of E. coli O157:H7 have been linked to consumption of raw, undercooked, or spoiled meat.

NIAID researchers plan to use the new information to further study how the host immune system mounts a response to E. coli O157:H7 when infection begins and how the bacterium selectively blocks these defenses. Several foodborne pathogens, including Shigella and Salmonella, use a similar secretion system to disrupt host immune responses and infect gut cells.

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ARTICLE: F Wan, et al. IKK-beta phosphorylation regulates RPS3 nuclear translocation and NF-kappa B function during infection with Escherichia coli strain O157:H7. Nature Immunology. DOI 10.1038/ni.2007

Michael Lenardo, M.D., Chief of the Molecular Development Section of the NIAID Laboratory of Immunology, is available to comment on this article.

To schedule interviews, please contact the NIAID Ofice of Communications at 301-402-1663 or niaidnews@niaid.nih.gov.

NIAID conducts and supports research--at NIH, throughout the United States, and worldwide--to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID Web site at http://www.niaid.nih.gov.

The National Institutes of Health (NIH)--The Nation's Medical Research Agency--includes 27 Institutes and Centers and is a component of the U. S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.



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