Tick saliva may be a secret ingredient to help HIV patients

September 7, 2017 by Jill Daly, Pittsburgh Post-Gazette
HIV infecting a human cell. Credit: NIH

The black-legged tick -loaded with bacteria causing Lyme disease - may have some good qualities: its spit.

Tick saliva - the same fluid that sets the stage for feeding on their hosts by blocking blood coagulation - is now part of experiments examining ways to reduce heart disease in people living with HIV. Their risk of heart attack and stroke is nearly double that of the general population, according to a study last year. That risk was found even in people whose virus is undetectable in their blood because of .

Chronic inflammation is suspected as the cause of the cardiovascular disease, and researchers in the HIV field are trying to find out what causes it, according to Ivona Pandrea, professor of pathology in the Center for Vaccine Research at the University of Pittsburgh.

Although HIV patients are treated with antiretroviral drugs and the virus is well controlled, Pandrea said, "Patients develop other issues, comorbidities that affect organs and systems that reduce longevity. They develop health problems that old people have. The aging process is accelerated in HIV patients. The main cause is inflammation."

Pandrea is co-senior author of recently published research that says the increased can be linked to an overabundance of a type of immune cell in people with HIV.

Irini Sereti, of the National Institute of Allergy and Infectious Diseases, was also co-senior author, and her team found that in human blood samples, people with HIV share an elevated number of the immune cells called monocytes that continue to express a protein that triggers blood clotting and inflammation even if the HIV virus is under control.

Pandrea found the same cells in monkeys that progress to AIDS after infection with SIV, the primate form of HIV. The cells taken from a different species of monkey, which usually doesn't develop when infected with SIV, didn't express the protein involved with clotting and inflammation.

As reported in Science Translational Medicine last week, the human blood samples were exposed to Ixolaris, a synthetic version of the small molecule found in the saliva of the tick (scientific name: Ixodes scapularis), and the team found the protein activity was blocked. Then a small group of lab monkeys, including the two different species and both with an early infection of SIV, were treated with the drug.

"Both models replicated very well the virus," Pandrea said, "but one did not have hypercoagulation; the other had high coagulation and high ." The levels of the inflammatory proteins in the high-coagulation species were lowered with the Ixolaris treatment.

The study concluded that "targeting the coagulation pathway in HIV-infected patients may be effective in reducing the immune activation and inflammation that are linked to cardiovascular comorbidities in HIV infection." It may also help as therapy in other inflammatory diseases, the study said.

NIH holds the patent for Ixolaris, which in the past was tested to treat blood clots in animals. More work needs to be done to confirm the research findings and study the effectiveness and safety of treatment with Ixolaris, Pandrea said.

The study is a step forward. She said, "It's about a new cause of inflammation in the HIV patient: hypercoagulation. It establishes a clear connection with hypercoagulation and ."

Tick saliva alone won't do the trick, however:

"I wouldn't recommend people getting bitten by ticks. They'll still get Lyme disease."

Explore further: Tick saliva may hold potential treatment for reducing HIV-linked heart disease risk

Related Stories

Tick saliva may hold potential treatment for reducing HIV-linked heart disease risk

August 30, 2017
Scientists may have found a clue to why people living with HIV have double the likelihood of developing heart disease. The findings, made by researchers at the University of Pittsburgh Center for Vaccine Research and National ...

Breakthrough in HIV/AIDS research gives hope for improved drug therapy

May 16, 2014
The first direct proof of a long-suspected cause of multiple HIV-related health complications was recently obtained by a team led by the University of Pittsburgh Center for Vaccine Research (CVR). The finding supports complementary ...

From bug to drug—tick saliva could be key to treating heart disease

June 27, 2017
Proteins found in tick saliva could be used to treat a potentially fatal form of heart disease, according to new Oxford University research.

High-fat diet leads to same intestinal inflammation as a virus

June 22, 2017
A new study by scientists at UCLA found that when mice eat a high-fat diet, the cells in their small intestines respond the same way they do to a viral infection, turning up production of certain immune molecules and causing ...

A tick's spit leads to an entire lesson in blood clotting

July 1, 2013
There really is such a thing as tick spit – that is, the saliva of a tick. And there's something about it that might help fight heart disease and stroke.

AIDS resistance secret may be in blood

February 12, 2007
U.S. scientists say the absence of a specific marker in the blood and tissues of certain monkeys might be part of the key to understanding AIDS resistance.

Recommended for you

New hope for cystic fibrosis

October 19, 2018
A new triple-combination drug treatment being trialled at the Mater Hospital in Brisbane could increase the life expectancy of patients with cystic fibrosis.

Bug guts shed light on Central America Chagas disease

October 18, 2018
In Central America, Chagas disease, or American trypanosomiasis, is spread by the "kissing bug" Triatoma dimidiata. By collecting DNA from the guts of these bugs, researchers reporting in PLOS Neglected Tropical Diseases ...

Rapid genomic sequencing of Lassa virus in Nigeria enabled real-time response to 2018 outbreak

October 18, 2018
Mounting a collaborative, real-time response to a Lassa fever outbreak in early 2018, doctors and scientists in Nigeria teamed up with researchers at Broad Institute of MIT and Harvard and colleagues to rapidly sequence the ...

Infectious disease consultation significantly reduces mortality of patients with bloodstream yeast infections

October 17, 2018
In a retrospective cohort study conducted at the University of Alabama at Birmingham Division of Infectious Diseases, patients with candidemia—a yeast infection in the bloodstream—had more positive outcomes as they relate ...

How drug resistant TB evolved and spread globally

October 17, 2018
The most common form of Mycobacterium tuberculosis (TB) originated in Europe and spread to Asia, Africa and the Americas with European explorers and colonialists, reveals a new study led by UCL and the Norwegian Institute ...

Marker may help target treatments for Crohn's patients

October 16, 2018
Crohn's disease (CD), a chronic inflammatory condition of the intestinal tract, has emerged as a global disease, with rates steadily increasing over the last 50 years. Experts have long suspected that CD likely represents ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.