Response to Lyme Disease Determined by Individual's Genetic Makeup

Lyme disease can have dramatically different outcomes in different people. Symptoms range from debilitating disease to no symptoms at all and scientists have attributed the differences in people's response to Lyme disease to the unique genetic makeup of each individual.

In the United States and Europe, Lyme disease is caused by tick-borne bacteria called Borrelia. Testing is a challenge because symptoms vary and often mimic flu-like symptoms. The bite may not immediately result in antibody production so early negative diagnosis is not definitive. The organism is also difficult to culture and is slow growing, which complicate detection.

A team of scientists used a mice model to examine whether a person's immune response to Borrelia could determine the outcome of the disease. The team has identified and synthesized key peptides that are predicted to have high binding affinity to an individual's immune cells based on the genetic traits of his/her immune system. It has also tested the newly identified peptides in mouse models in which the immunological genes are very well characterized. Lastly, the team demonstrated that the "targeted, computationally predicted peptides" significantly reduce the number and "activation state" of the cells responding to Borrelia proteins.

"If infection is detected very early, a round of antibiotics sometimes is enough for some people. In other cases, even with antibiotics, the disease becomes chronic and includes symptoms like arthritis, heart disease, and harm to the nervous system," said Dr. M. Karen Newell, Ph.D., lead investigator of the study and a professor at the University of Colorado (Boulder, CO, USA).

Viral Genetics initially unveiled the new model and early findings on Saturday, October 18, 2008, at the International Lyme & Associated Diseases Society (ILADS) Scientific Session. The study model potentially applies to human immunodeficiency virus (HIV)/AIDS and other immune based diseases.

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University of Colorado