Featured Research

from universities, journals, and other organizations

Protein In Deer Tick Saliva Prevents HIV-1 From Attaching To T Cells

Date:
February 21, 2008
Source:
University of Massachusetts Amherst
Summary:
The HIV-1 virus cripples the human immune system by targeting white blood cells called T cells that form the body's first line of defense in fighting infections. A recent study shows that a protein found in the saliva of deer ticks prevents the HIV-1 virus from attaching to the surface of T cells, which is the critical first step in the virus' attack strategy. Since the protein suppresses the action of T cells, it may also prove to be an effective treatment for autoimmune diseases like asthma and multiple sclerosis caused by an overactive immune system that mounts an attack against the body's own cells and tissues, and it could be useful to suppress the immune system to prevent the rejection of transplanted organs.

Deer tick.
Credit: NOAA

The HIV-1 virus cripples the human immune system by targeting white blood cells called T cells that form the body’s first line of defense in fighting infections. A recent study by researchers from the University of Massachusetts Amherst shows that a protein found in the saliva of deer ticks prevents the HIV-1 virus from attaching to the surface of T cells, which is the critical first step in the virus’ attack strategy.

Related Articles


Since the protein suppresses the action of T cells, it may also prove to be an effective treatment for autoimmune diseases like asthma and multiple sclerosis caused by an overactive immune system that mounts an attack against the body’s own cells and tissues, and it could be useful to suppress the immune system to prevent the rejection of transplanted organs.

When the HIV-1 virus enters a human host, it attaches to the surface of T cells before fusing with the cell membrane and injecting its DNA into the nucleus. “This allows the virus to use the machinery of the T cell to copy itself and multiply,” says Juan Anguita of the UMass Amherst department of veterinary and animal sciences. “Deer ticks, which are carriers of Lyme disease, produce a protein that can interfere with the initial attachment of the HIV-1 virus, which could lead to new treatments that stop the infection process before it begins.” Additional members of the research team include Ignacio Juncandella, Tonya Bates and Elias Olivera of veterinary and animal sciences.

Deer tick saliva contains the protein Salp15, which stops T cells from activating by binding to a specific site on their surface called the CD4 receptor. Since T cells initiate the body’s immune response to invading viruses and bacteria, this strategy allows the tick to evade a host’s immune system as it feeds for up to seven days. As it turns out, the CD4 receptor is also the site used by the HIV-1 virus to attach to T cells.

“Salp15 binds to proteins in the CD4 receptor that are furthest from the cell membrane in both mouse and human cells,” says Anguita. “This region overlaps with the binding region used by a protein on the envelope of the HIV-1 virus called gp120, making Salp15 one of several potential molecules being studied as entry-targeting inhibitors.”

Laboratory studies showed that the presence of Salp15 could inhibit the attachment of HIV-1 by almost 70 percent at the highest concentration tested. This effect may result from changes in the shape of the CD4 receptor caused by the binding of Salp15. Additional studies showed that Salp15 was also able to bind gp120, making it unable to attach to the CD4 receptor.

Since gp120 can only attach to one site on the CD4 receptor, and its shape has to fit exactly into the receptor’s proteins, this interaction is as specific as opening a lock with a key. Salp15 changes the shape of the key and the lock, preventing the system from working.

Anguita and Juncandella were also part of a study performed in cooperation with the Vermont Lung Center and the University of Vermont showing that Salp15 inhibited the development of asthma in mice. The researchers induced asthma in a group of mice that also received Salp15 and compared them to a control group. Mice that received Salp15 had airways that were less reactive, and showed lower levels of several biochemical markers that indicate a T cell response. Results were published in June 2007 in The Journal of Immunology.

“The activation of T Cells is necessary for the development of allergic airway disease in mice, which shares many features of human allergic asthma,” says Anguita. “Effectively controlling the activities of these cells could be a panacea for asthma therapy.”

Anguita believes that Salp15 may lead to treatments for HIV-1, transplant rejection and autoimmune diseases with fewer side effects than traditional medications like steroids and protease inhibitors, partly because its action is so specific. “HIV-1 and transplant patients are on powerful medications for life, and most of these have secondary effects like nerve damage and liver problems, says Angiuta. “This makes the development of new treatments an important area of research.”

Results were published in the February 2008 issue of Biochemical and Biophysical Research Communications.


Story Source:

The above story is based on materials provided by University of Massachusetts Amherst. Note: Materials may be edited for content and length.


Cite This Page:

University of Massachusetts Amherst. "Protein In Deer Tick Saliva Prevents HIV-1 From Attaching To T Cells." ScienceDaily. ScienceDaily, 21 February 2008. <www.sciencedaily.com/releases/2008/02/080217224459.htm>.
University of Massachusetts Amherst. (2008, February 21). Protein In Deer Tick Saliva Prevents HIV-1 From Attaching To T Cells. ScienceDaily. Retrieved December 19, 2014 from www.sciencedaily.com/releases/2008/02/080217224459.htm
University of Massachusetts Amherst. "Protein In Deer Tick Saliva Prevents HIV-1 From Attaching To T Cells." ScienceDaily. www.sciencedaily.com/releases/2008/02/080217224459.htm (accessed December 19, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, December 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Best Tips to Curb Holiday Carbs

The Best Tips to Curb Holiday Carbs

Buzz60 (Dec. 19, 2014) It's hard to resist those delicious but fattening carbs we all crave during the winter months, but there are some ways to stay satisfied without consuming the extra calories. Vanessa Freeman (@VanessaFreeTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Sierra Leone Bikers Spread the Message to Fight Ebola

Sierra Leone Bikers Spread the Message to Fight Ebola

AFP (Dec. 19, 2014) More than 100 motorcyclists hit the road to spread awareness messages about Ebola. Nearly 7,000 people have now died from the virus, almost all of them in west Africa, according to the World Health Organization. Video provided by AFP
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Kids Die While Under Protective Services

Kids Die While Under Protective Services

AP (Dec. 18, 2014) As part of a six-month investigation of child maltreatment deaths, the AP found that hundreds of deaths from horrific abuse and neglect could have been prevented. AP's Haven Daley reports. (Dec. 18) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins