Health & Medicine - Posted by Leigh MacMillan-Vanderbilt on Monday, August 13, 2012 10:07 - 0 Comments
Imaging combo spots infection in 3D
VANDERBILT (US) — Scientists have combined MRI and imaging mass spectrometry to visualize the body’s inflammatory response to a bacterial infection in 3D.
The techniques, described in Cell Host & Microbe, offer opportunities for discovering proteins not previously implicated in the inflammatory response.
Straight from the Source
Eric Skaar, chair in pathology at Vanderbilt University and his team were interested in imaging infection in three dimensions—in the whole animal—while also being able to identify the proteins that are produced at sites of infection.
MRI provides detailed anatomical images of tissue damage, while imaging mass spectrometry directly measures proteins, lipids, and other metabolites and maps their distribution in a biopsy or other tissue sample.
Ahmed Attia, a former member of Skaar’s group now on the faculty at Cairo University, Egypt, infected mice with Staphylococcus aureus, a major cause of human disease.
He then delivered the infected animals to Daniel Colvin, in the Vanderbilt University Institute of Imaging Science (VUIIS), who imaged them with MRI. Kaitlin Schroeder and Erin Seeley, in the Mass Spectrometry Research Center (MSRC) then conducted imaging mass spectrometry studies.
Putting together the two technologies and multiple data sets accurately required the expertise of Kevin Wilson, who developed algorithms to show consolidated 3D views of the inflammatory response.
The technologies allow the investigators to see a single image of an infected animal, look at how proteins of the immune system are responding, and identify where the infected tissue is located, Skaar says.
“Part of the strength of this work is not where the research is now, but where it allows us to go from here.”
His team plans to identify “proteins that are important at the interface between the host and the pathogen—the battleground between the immune system and the bacteria,” Skaar says.
The researchers will study the proteins they identify to discover new biomarkers for infection, which could improve diagnostic tools, or new targets for therapeutic intervention.
And although the technology is not non-invasive because imaging mass spectrometry requires tissue sections, it could be applied to tissues removed from patients, such as tumors.
“Imaging mass spectrometry is extremely valuable for the discovery process because it does not require a target-specific reagent such as an antibody—that is, you do not have to know in advance what you’re looking for in order to correlate molecular changes with disease outcome,” says Richard Caprioli, director of MRSC a senior co-author of the paper. “An area of intense interest is the application of this technology to molecular pathology.”
The research was supported by grants from the National Institutes of Health, the establishment of an NIH-funded National Resource for Imaging Mass Spectrometry, and a Pfizer 2009 ASPIRE research award.
Skaar is a Burroughs Wellcome Fellow in the Pathogenesis of Infectious Diseases and is associate professor of Pathology, Microbiology and Immunology. John Gore, director of VUIIS, is professor of radiology and radiological sciences and a third senior co-author of the paper.
More news from Vanderbilt University: http://news.vanderbilt.edu/research/