Keeping the Balance in CytokinesKey to
Healthy Animals By Judy McBride
When a farm animals immune system reacts to viruses,
bacteria or parasites, good communication among cells turns what could be chaos
into coordination. Animals, like humans, rely on communication proteins called
cytokines to orchestrate an immune response.
Knowing which cytokines are key to maintaining a balanced
response will enable scientists to design therapies that stimulate the desired
response, or suppress an excessive response that can stress the animals and
steal farmers profits. And scientists will be able to select animals for
breeding that have the genetic background to respond appropriately.
Service scientists in the Immunology and Disease Resistance
Laboratory at Beltsville, Md., are using these cytokines to answer basic
questions about immune response in cattle and pigs. To do this, they prepare
reagents that can be used to measure either the cytokines themselves or changes
in their production.
To measure a cytokine directly, the researchers make monoclonal
antibodies, molecules that attach to specific sites on a particular cytokine.
Using these monoclonals, they can measure the amounts of cytokines produced at
each stage of an infection or a vaccine trial. They can even identify the exact
cell making the cytokine, according to research leader Joan K. Lunney, who has
produced antibody panels for two pig cytokines.
To measure cytokine production, researchers make DNA
competitors, which enable them to detect changes in expression of
the gene that codes for that cytokine. So far, laboratory personnel have
produced DNA competitors for 11 cytokines in pigs and 16 in cattle. And they
have sent competitors to hundreds of investigators around the world. The
researchers draw from the large database of human and mouse genes to prepare
Now microbiologist Dante S. Zarlenga is working to get the big
picture of immune response with third-generation assays that will
show changes in expression of many cytokines at once.
this research in the June issue of Agricultural Research
ARS is the U.S. Department of
Agricultures chief research agency.