Featured Research

from universities, journals, and other organizations

UT Southwestern Researchers Develop Vaccine Against Deadly Bioterrorism Toxin Ricin

Date:
September 9, 2002
Source:
University Of Texas Southwestern Medical Center At Dallas
Summary:
UT Southwestern Medical Center at Dallas researchers have developed a vaccine in mice against the deadly toxin ricin. Ricin has been used as a biological weapon in many parts of the world.

DALLAS – Sept. 4, 2002 – UT Southwestern Medical Center at Dallas researchers have developed a vaccine in mice against the deadly toxin ricin. Ricin has been used as a biological weapon in many parts of the world.

"Ricin is not only dangerous, but it is also cheap and easy to make," said Dr. Ellen Vitetta, director of the Cancer Immunobiology Center at UT Southwestern and senior author of the study to be published in the Sept. 10 issue of the journal Vaccine.

Large stockpiles of ricin have been found in several countries in the Middle East, Vitetta said. It is a protein produced by castor beans. A single ricin molecule inside a cell shuts down protein synthesis, killing the cell. Ricin can be administered in foods and water or sprayed as an aerosol. A small dose can produce flulike symptoms and result in death in a few days.

Because of its ease of production and high toxicity, ricin has found its way into the arsenals of extremist individuals, groups and governments. Iraq is known to have ricin as part of its biological weapons program, and it is believed that at least one group linked to the terrorist organization al-Qaeda also has experimented with the poison as a weapon. Domestically, several individuals have been arrested and convicted of ricin possession in recent years under the 1989 Biological Weapons Antiterrorism Act.

In creating the new vaccine, UT Southwestern researchers, led by Vitetta, mutated the DNA encoding the active A chain of the toxin. They took out the site that inhibits protein synthesis, as well as the site responsible for inducing vascular leak. The latter was identified by Vitetta's group several years ago in its ongoing efforts to produce safer immunotoxins containing the A chain. Immunotoxins are anti-cancer drugs that have been used by Vitetta and her colleagues in more than 200 cancer patients. The new recombinant A chain induces a protective immune response in mice and protects them against very high doses of ricin. There were no vaccine-related side effects.

The UT Southwestern scientists created three recombinant versions of ricin A chain, two of which were effective as vaccines in mice. Vitetta said E. coli bacteria are used to produce the recombinant DNA, making vaccine production cheap and safe. The researchers believe one or both of the vaccines would be safe and effective in humans.

Vitetta said tests against airborne ricin will be initiated as soon as the experiments can be safely done in a biosafety level 3 facility, which is currently in the planning stage.

Once immunized mice have been subjected to an aerosol challenge, the next step would be to optimize production, formulation and storage of the vaccine. Then 10 human volunteers would be vaccinated. Their sera would be injected into mice and tested for its ability to protect mice from ricin aerosols.

Vitetta said a large government agency, such as the Army or National Institutes of Health, or a well-funded private company would then have to step in and take the vaccine through clinical trials. Such trials are well beyond our resources, she said.

"We have only tested it against injected ricin, but, based on past experience, there's every reason to believe it will be protective against aerosolized ricin," Vitetta said.

Ricin was used in the 1978 murder of Georgi Markov, a Bulgarian author and dissident. Markov, who had defected nine years earlier, was assassinated while waiting for a bus in London when he took an apparently accidental poke from another man's umbrella. Four days later Markov was dead, and it was only upon autopsy that ricin poisoning was revealed as the cause. The lethal dose, estimated at 450 micrograms, was delivered in a pinhead-sized hollow pellet, discovered during the autopsy.

The Centers for Disease Control and Prevention ranks ricin on its "B" list of biowarfare or bioterrorist agents – placing it in the category of a moderate threat.

Other contributors to the Vaccine study, all from the Cancer Immunobiology Center, were first author Dr. Joan E. Smallshaw, postdoctoral researcher; research assistants Ana Firan, John R. Fulmer, Stephen L. Ruback; and Dr. Victor Ghetie, professor.

The work was supported by a National Institutes of Health grant.


Story Source:

The above story is based on materials provided by University Of Texas Southwestern Medical Center At Dallas. Note: Materials may be edited for content and length.


Cite This Page:

University Of Texas Southwestern Medical Center At Dallas. "UT Southwestern Researchers Develop Vaccine Against Deadly Bioterrorism Toxin Ricin." ScienceDaily. ScienceDaily, 9 September 2002. <www.sciencedaily.com/releases/2002/09/020909065008.htm>.
University Of Texas Southwestern Medical Center At Dallas. (2002, September 9). UT Southwestern Researchers Develop Vaccine Against Deadly Bioterrorism Toxin Ricin. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2002/09/020909065008.htm
University Of Texas Southwestern Medical Center At Dallas. "UT Southwestern Researchers Develop Vaccine Against Deadly Bioterrorism Toxin Ricin." ScienceDaily. www.sciencedaily.com/releases/2002/09/020909065008.htm (accessed September 1, 2014).

Share This




More Health & Medicine News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Liberia Continues Fight Against Ebola

Liberia Continues Fight Against Ebola

AFP (Aug. 30, 2014) Authorities in Liberia try to stem the spread of the Ebola epidemic by raising awareness and setting up sanitation units for people to wash their hands. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
California Passes 'yes-Means-Yes' Campus Sexual Assault Bill

California Passes 'yes-Means-Yes' Campus Sexual Assault Bill

Reuters - US Online Video (Aug. 30, 2014) California lawmakers pass a bill requiring universities to adopt "affirmative consent" language in their definitions of consensual sex, part of a nationwide drive to curb sexual assault on campuses. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
New Drug Could Reduce Cardiovascular Deaths

New Drug Could Reduce Cardiovascular Deaths

Newsy (Aug. 30, 2014) The new drug from Novartis could reduce cardiovascular deaths by 20 percent compared to other similar drugs. Video provided by Newsy
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:
from the past week

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