July 15, 2013

 

 Modified cell line helps identify FMD

Posted July 1, 2013

 

Department of Agriculture researchers have developed a line of cells that can be continuously grown in culture and modified to be more easily infected with foot-and-mouth disease virus, aiding in virus identification.

The cattle kidney cell line produced by the USDA Agricul­tural Research Service can be used to identify all seven FMD serotypes. The cell line is described in an article published in June in the Journal of Clinical Microbiology (J Clin Microbiol 2013;51:1714-1720), which is available here.

Dr. Luis L. Rodriguez, the ARS research leader at Plum Island Animal Disease Center, New York, said the agency’s research shows the cell line is as sensitive to FMD virus or more so than cells derived directly from animals, and that sensitivity has remained in more than 100 generations of the cells grown in culture.

“They were developed based on knowledge that we had in our research as to how foot-and-mouth disease infects cells and what kind of receptor it uses, and, based on that, we designed these cells to express these receptors and be more receptive in the presence of the virus,” Dr. Rodriguez said.

Currently, identifying FMD virus serotypes requires killing an animal prior to the test and extracting primary cells sensitive to the virus, he said. Examples include calf thyroid cells and lamb kidney cells. Although these cells can be grown in culture, they often lose sensitivity to the FMD virus after a few generations.

The new cell line also can be infected with viruses that cause clinical signs similar to those of FMD, such as vesicular stomatitis, Dr. Rodriguez said. But the ARS does not have information indicating whether the cells have increased sensitivity to any viruses other than FMD viruses.

The ARS has been letting other organizations use the cells for diagnostic or disease research purposes, provided those organizations agree not to use the cell line itself for commercial purposes, Dr. Rodriguez said. The cell line has been added to the American Type Culture Collection, and the agency is seeking a patent on the line.

The research that led to development of the cell line began with the discovery about 40 years ago of a precursor to the bovine kidney cell line and continued with more recent studies of the cell surface receptors.

“This is just an example of how long-term research and basic research can be applied to solve very specific problems in agriculture,” Dr. Rodriguez said.