BLACKSBURG, Va., March 28, 2013 -- A new study by researchers at the Center for Modeling Immunity to Enteric Pathogens (MIEP) at Virginia Bioinformatics Institute provides novel insight into how enteroaggregative Escherichia coli, also known as EAEC, interacts with its host. This new knowledge could be used by scientists to devise new therapeutic strategies against E.coli. The study was published in PLOS One.

Photo courtesy of Michael Kiernan, University Relations

EAEC infection is the most common cause of persistent diarrhea worldwide and is most frequently seen in malnourished children living in developing countries. Because these children are unable to mount an effective immune response to the bacteria, the infection often persists once it gains a foothold. A 2011 outbreak in northern Germany received international attention when it sickened more than 3,000 people, causing 53 deaths.

“In many parts of the world, the relationship between infection and malnutrition is a vicious cycle. For example, malnourished EAEC-infected individuals experience a chronic burden linked to growth retardation. Our study in mice suggests that promoting inflammation may help clear the bacterial infection soon after infection,” said Josep Bassaganya-Riera, a professor of immunology, director of the Nutritional Immunology and Molecular Medicine Laboratory and the principal investigator of MIEP.

The MIEP team created a mouse model of EAEC infection to investigate host–bacteria interactions. Previous studies have shown that activation of PPAR γ, a protein that aids in metabolic regulation, plays a crucial role in suppressing inflammation and regulating immune responses.  When investigators blocked the function of PPAR γ in EAEC-infected mice, they observed that the animals developed a faster and more effective defense against the disease.

“Pharmacological inhibition of PPAR γ reduced disease and bowel pathology following infection by inducing potent inflammatory responses.  Protective immune responses to EAEC are characterized by the predominance of effector T helper 17 cells that promote antimicrobial immunity and bacterial clearance,” said Raquel Hontecillas, associate director of MIEP and lead investigator of the EAEC project.

Studying EAEC and the ways in which PPAR γ can modulate immune responses in the gut may help researchers develop new therapeutic strategies to address such debilitating infections. This new work has enabled the MIEP team to test new therapies that may promote bacterial clearance.

Learn more about prior VBI research on PPAR γ.

Learn about how VBI helped annotate and positively identify the German strain of EAEC.

Please visit the MIEP Web Portal.
MIEP is funded by the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, under Contract No. HHSN272201000056C. PI: Josep Bassaganya-Riera.

The Nutritional Immunology and Molecular Medicine Laboratory (NIMML) conducts translational research aimed at developing novel therapeutic and prophylactic approaches for modulating immune and inflammatory responses. The Laboratory has over 20 researchers and combines computational modeling, bioinformatics approaches, pre-clinical experimentation and human clinical studies to better understand the mechanisms of immune regulation at mucosal surfaces and ultimately accelerate the development of novel treatments for infectious and immune-mediated diseases. In addition, the NIMML team leads the NIAID-funded Center for Modeling Immunity to Enteric Pathogens.

The Virginia Bioinformatics Institute at Virginia Tech is a premier bioinformatics, computational biology and systems biology research facility that uses transdisciplinary approaches to science, combining information technology, biology and medicine. These approaches are used to interpret and apply vast amounts of biological data generated from basic research to some of today’s key challenges in the biomedical, environmental and agricultural sciences. With more than 240 highly trained multidisciplinary, international personnel, research at the institute involves collaboration in diverse disciplines such as mathematics, computer science, biology, plant pathology, biochemistry, systems biology, computational immunology, statistics, economics, synthetic biology and medicine. The large amounts of data generated by this approach are analyzed and interpreted to create new knowledge that is disseminated to the world’s scientific, governmental and wider communities.


Tiffany Trent

March 20, 2013