"`The work that Dr. Wikel is doing is the most exciting research I've seen so far. It holds real promise toward prevention of tick-borne diseases in our lifetimes,' said Jill Auerbach, the chairwoman of the Hudson Valley Lyme Disease Association, which is hosting Wikel. `Perhaps the children will be able to roll in the grass and leaves as we were able to without fear of ticks.'" ****
Any one of the 17,530 Dutchess County residents who has been so unfortunate as to have contracted Lyme disease after the stealthy bite of a tick has probably had a thought like this:
Why didn't I feel it bite?
Stephen K. Wikel, a professor of immunology in the School of Medicine at the University of Connecticut Health Center in Farmington, has spent more than 30 years asking questions like that. His work has been to uncover the "incredibly clever" way a tick -- and more to the point, its spit -- outwits our immune system.
And since 2004, he's been working with a team to decipher the genetic code for the black-legged tick in hopes a vaccine or pesticide can be developed to thwart tick spit. That's right: A Tick Genome Project.
Later this month, Wikel will come to Poughkeepsie to discuss his research, its potential for preventing disease, and its implications for world health and for the prevention of bioterrorism. Yes, federal counterterrorism officials have identified ticks and diseases far more deadly than Lyme as a threat to be reckoned with.
"The work that Dr. Wikel is doing is the most exciting research I've seen so far. It holds real promise toward prevention of tick-borne diseases in our lifetimes," said Jill Auerbach, the chairwoman of the Hudson Valley Lyme Disease Association, which is hosting Wikel. "Perhaps the children will be able to roll in the grass and leaves as we were able to without fear of ticks."
After as many as 250 million years of evolution, the black-legged tick has developed an array of strategies for attaching to animals and drawing their blood undetected. Its success opened up an avenue for a variety of diseases.
Bite with no pain
The spit suppresses the body's pain and itch responses so you don't know it's there. It simultaneously draws blood and prevents that blood from coagulating.
Ever pulled a tick off your pet, and wonder why the wound takes so long to heal? The answer is tick spit -- the stuff suppresses the immune system.
Mosquitoes, the only bug responsible for more disease than ticks, have a mere 70 proteins in their saliva to get past our impressive defenses. Ticks have 500.
That's one of the things that makes the Tick Genome Project so promising, Wikel said. If scientists can understand the molecules in tick saliva, they are that much closer to identifying ways to manipulate, disrupt or destroy them.
The Lyme vaccine that hit the market with fanfare unequaled until it was withdrawn from the market, was only effective preventing one disease. Wikel is hopeful the next decade will see the development of a vaccine that prevents tick bites altogether. That would stop Lyme, babesiosis, anaplasmosis (the disease formerly known as ehrlichiosis) and anything else ticks start to spread.
"This is a quantum leap in our understanding, and it's going to open the door to so many new opportunities to understand what's going on and to understand how to control tick-borne disease," Wikel said. "It's another tool, but it's a very very powerful tool."
****TOIL for Lyme**** T == Teach tolerance 0 == Overcome ignorance I == Initiate insurance reform L == Labor for Lyme literacy/advocacy
[Non-text portions of this message have been removed]
=== The mission of LymeInfo is to keep you informed of issues that might be of interest to Lyme disease patients. Postings are not meant to imply that we agree with the content of all items we distribute.
OspA is an adhesin that selectively binds to tick gut epithelial cells (13). The reason OspA-producing bacteria rarely entered the salivary glands and the host may be that OspA-producing bacteria are selectively retained in the tick gut.
Especially striking was the sudden burst of OspC synthesis by spirochetes in the tick gut, which peaked at 48 hr, just before infectious spirochetes entered the host. Previous studies pointed to OspC playing an important role in early infection in the mammal because infected animals readily seroconvert to OspC (22).
However, this study has demonstrated that the protein was not produced by most spirochetes that actually entered the salivary glands and moved into the host. On the basis of this pattern of expression, we propose that OspC may play a role in allowing the bacteria to escape from the gut into the hemocele.
Once they exit the gut, the bacteria may begin to down-regulate OspC production (Fig. 7). The recent report by Gilmore and Piesman (29) that OspC antibodies block the movement of spirochetes from the tick gut to the salivary glands supports this hypothesis.
Even though most bacteria invading the salivary glands and entering the host did not produce OspC, small numbers of bacteria did have the protein on their surface, and this may be sufficient to stimulate the early OspC antibody response that is regularly observed.
The OspC immune response in mice wanes over time (30, 31), possibly because the rodent immune response is due to a small number of OspC-producing bacteria being carried over from the tick to the host.
Our working model that OspA serves to retain bacteria in the tick gut and that OspC facilitates transfer from the gut lumen to the hemocele is a simplification and does not explain all our observations.
Small numbers of OspA-producing bacteria were observed in the salivary glands, and many OspC-producing bacteria remained confined to the gut. Many individual bacteria within the feeding tick produced both OspA and OspC, and the location of these double-positives may depend on the actual level of OspA and -C on individual bacteria.
Furthermore, in addition to OspA and -C, other bacterial proteins may control transmission, and their expression pattern may explain the apparent mislocalization of some of the spirochetes.
Dr. Burgdorfer found that during this soft tick's feeding period (10-30 minutes) (Figure 10), it ingests spirochetes into the midgut (Figure 11). Within hours, these spirochetes accumulate in the tick's gut epithelium and subsequently enter the body cavity, where they begin multiplying by binary fission (Figure 12). From there, the spirochetes invade various other tissues. Only in nymphal ticks does the salivary gland become heavily infected.
Once a tick reaches the adult stage, the salivary glands are free of spirochetes or are only mildly infected. Thus, nymphs can transmit spirochetes by bite (via saliva) or excretion of coxal fluid shortly before feeding ends (Figure 13). Adult ticks, on the other hand, transmit spirochetes through infected coxal fluid and only rarely via saliva.
Yes, even if it doesn't take too long to really develop it, it will probably take a long time to get FDA approval. THe government ALWAYS holds thing up. SOmetimes that is good, but most of the time not for some people.
The Lyme Disease Network is a non-profit organization funded by individual donations. If you would like to support the Network and the LymeNet system of Web services, please send your donations to:
The
Lyme Disease Network of New Jersey 907 Pebble Creek Court,
Pennington,
NJ08534USA http://www.lymenet.org/
UBBFriend: Email this page to someone!
Printer-friendly view of this topic