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ODU'S HYNES AWARDED GRANT FOR TICK-BORNE DISEASES

Wayne Hynes, professor of biological sciences at Old Dominion University, is the winner of one of four 2006 grants awarded by the National Research Fund for Tick-Borne Diseases (NRFTD). The award will fund research related to the mechanisms of transmission of the Lyme disease-causing bacterium, Borrelia burgdorferi.

Together with Daniel Sonenshine, professor emeritus of biological sciences, Hynes has helped ODU gain international prominence in tick-borne disease research. This latest award to Hynes for $60,000 is designed to advance their recent investigations of the ability of some ticks to transmit the Lyme disease bacterium.

The ultimate goal of all NRFTD awards is to boost the sponsored projects to the point that they can obtain long-term funding.

ODU researchers have been interested for years in how Borrelia burgdorferi bacteria survive and behave as they move from the original host, such as a deer, on which a tick feeds, to another mammal bitten by the infected tick. Why, for example, aren't the bacteria killed by the immune system of the tick? How can the bacteria stay in the tick without harming or killing the tick?

Antimicrobial proteins, known as defensins, are found in the hemolymph (blood) of the dog tick, and these defensins can kill bacteria such as Borrelia burgdorferi. No such defensins, however, are found in the deer tick. This difference may help explain why the deer tick, but not the dog tick, is able to transmit the bacteria that cause Lyme disease.

Hynes, working with Sonenshine, proposes to use RNA interference to block the dog ticks' production of defensin in order to address questions about how bacteria survive in ticks' hemolymph and move to the salivary glands, where they can be transmitted to another host, such as a human.

In earlier research on Lyme disease, the ODU faculty members have looked at challenges scientists encounter in replicating the progression of the bacteria from mammal to tick to mammal. This might involve artificially infecting a first group of mice with the bacteria, introducing ticks to feed on the mouse's blood, and then moving the ticks to a second group of mice that can be infected by tick bites.

The process is time-consuming and hard to control. But when scientists take a shortcut and focus their Lyme disease studies on mammals that have been artificially infected using cultured bacteria and a syringe, they may be compromising their results, the ODU researchers point out. Culture-grown bacteria and bacteria delivered by ticks can produce different antigens, and therefore, laboratory mice infected by tick bites can have a different immune response than mice infected by syringe inoculation.

"To accurately reproduce events that occur during and after transmission of Borrelia burgdorferi, animal models of Lyme disease should be based on animals infected by tick bite," states a 2002 research article whose authors include Sonenshine and Hynes.

The researchers have been part of a multi-institutional team that has developed procedures for artificially infecting the tiny deer ticks with Borrelia burgdorferi and documented the ability of the ticks to maintain the infection and transmit it to mice.

The 2006 awards from the NRFTD were announced Dec. 1.

Hynes' work in molecular microbiology includes studies in streptococcal pathogenesis and also extends to interdisciplinary ODU research projects in bioelectrics and oceanography.

Sonenshine's definitive two-volume text, "The Biology of Ticks," was published in 1991 and 1993, followed by "Dynamics of Tick-Borne Zoonoses" in 1994. He received Virginia's Outstanding Scientist award in 1994.

This article was posted on: December 6, 2006

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