Natural killer cells could be key to anthrax defense

October 27, 2011, University of Texas Medical Branch at Galveston

One of the things that makes inhalational anthrax so worrisome for biodefense experts is how quickly a relatively small number of inhaled anthrax spores can turn into a lethal infection. By the time an anthrax victim realizes he or she has something worse than the flu and seeks treatment, it's often too late; even the most powerful antibiotics may be no help against the spreading bacteria and the potent toxins they generate.

Now, though, University of Texas Medical Branch at Galveston researchers have found new allies for the fight against anthrax. Known as natural killer cells, they're a part of the immune system normally associated with eliminating and cells infected by viruses. But also attack bacteria -- including anthrax, according to the UTMB group.

"People become ill so suddenly from inhalational anthrax that there isn't time for a T cell response, the more traditional cellular immune response," said UTMB assistant professor Janice Endsley, lead author of a paper now online in the journal Infection and Immunity. "NK cells can do a lot of the same things, and they can do them immediately."

In test-tube experiments, a collaborative team led by Endsley and Professor Johnny Peterson profiled the NK cell response to anthrax, documenting how NK cells successfully detected and killed cells that had been infected by anthrax, destroying the bacteria inside the cells along with them. Surprisingly, they found that NK cells were also able to detect and kill outside of .

"Somehow these NK cells were able to recognize that there was something hostile there, and they actually caused the death of these bacteria," Endsley said.

In further experiments, the group compared the responses of normal mice and mice that were given a treatment to remove NK cells from the body. All the mice died with equal rapidity when given a large dose of , but the non-treated (NK cell-intact) mice had much lower levels of bacteria in their blood. "This is a significant finding," Endsley said. "Growth of bacteria in the bloodstream is an important part of the disease process."

The next step, according to Endsley, is to apply an existing NK cell-augmentation technique (many have already been developed for cancer research) to mice, in an attempt to see if the more numerous and active NK cells can protect them from anthrax. Even if the augmented don't provide enough protection by themselves, they could give a crucial boost in combination with antibiotic treatment.

"We may not be able to completely control something just by modulating the immune response," Endsley said. "But if we can complement antibiotic effects and improve the efficiency of antibiotics, that would be of value as well."

Related Stories

Recommended for you

Researchers devise decoy molecule to block pain where it starts

January 16, 2018
For anyone who has accidentally injured themselves, Dr. Zachary Campbell not only sympathizes, he's developing new ways to blunt pain.

Scientists unleash power of genetic data to identify disease risk

January 16, 2018
Massive banks of genetic information are being harnessed to shed new light on modifiable health risks that underlie common diseases.

Blood-vessel-on-a-chip provides insight into new anti-inflammatory drug candidate

January 15, 2018
One of the most important and fraught processes in the human body is inflammation. Inflammatory responses to injury or disease are crucial for recruiting the immune system to help the body heal, but inflammation can also ...

Molecule produced by fat cells reduces obesity and diabetes in mice

January 15, 2018
UC San Francisco researchers have discovered a new biological pathway in fat cells that could explain why some people with obesity are at high risk for metabolic diseases such as type 2 diabetes. The new findings—demonstrated ...

Obese fat becomes inflamed and scarred, which may make weight loss harder

January 12, 2018
The fat of obese people becomes distressed, scarred and inflamed, which can make weight loss more difficult, research at the University of Exeter has found.

Optimized human peptide found to be an effective antibacterial agent

January 11, 2018
A team of researchers in the Netherlands has developed an effective antibacterial ointment based on an optimized human peptide. In their paper published in the journal Science Translational Medicine, the group describes developing ...

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.