News / Health

'Serial Killer' Cells Demolish Leukemia Tumors

Test patients show complete remission or significant improvement

This microscopy image provided by Dr. Carl June on Wednesday, Aug. 10, 2011 shows immune system T-cells, center, binding to beads which cause the cells to divide. The beads, depicted in yellow, are later removed, leaving pure T-cells which are then ready
This microscopy image provided by Dr. Carl June on Wednesday, Aug. 10, 2011 shows immune system T-cells, center, binding to beads which cause the cells to divide. The beads, depicted in yellow, are later removed, leaving pure T-cells which are then ready

Multimedia

Audio
Jessica Berman

U.S. researchers say they've been able to modify a patient's immune system T cells, turning them into “serial killer” cells which zero in on cancer and obliterate it.

It’s being called a breakthrough in the treatment of a form of leukemia, a hard to treat and usually fatal blood cancer.  

Chronic lymphocytic leukemia (CLL) is marked by a slow increase in immune system white blood cells, called B lymphocytes. These B cells, as they're known, are manufactured by the bone marrow, the spongy tissue inside bones that also manufactures red blood cells.

Eventually, the healthy blood cells are crowded out by the proliferating B cells, the patient experiences bone marrow failure, and - without a bone marrow transplant - dies.

A transplant of healthy bone marrow from a donor has been the only treatment and potential cure for chronic lymphocytic leukemia. But it is very difficult to find a match and many people with CLL die while waiting. Even with a transplant, experts say only about half of CLL patients survive the procedure.

Three CLL patients who had run out of treatment options were selected for an experiment at the University of Pennsylvania. Researchers genetically engineered another one of their immune system cells, the T lymphocytes, to attack cancerous B cells.

Carl June, a professor of pathology and laboratory medicine at the school’s Abramson Cancer Center, was the study’s lead author.  

“The actual trial exceeded our wildest outcome and imagination actually," says Carl June, professor of pathology and laboratory medicine, who was the study’s lead author, "because what we found is all three patients have had a remarkable anti-tumor response and that literally pounds of leukemia have been eradicated in all three patients.”

Two of the three CLL patients had a complete remission of their disease and there was a significant improvement in the third.

Watch related video story by Vidushi Sinha

The T cells were genetically modified using a harmless virus, which carried an anti-body called a chimeric antigen receptor (CAR). Antibodies are immune system proteins which are produced in response to an infection.  

The CAR was engineered to bind to another protein called CD19 that’s present on the surface of normal B lymphocytes and all CLL tumor cells.  

Scientists say the modified T cells, injected into the patients following standard chemotherapy, homed in on the cancerous B cells inside the bone marrow, each T lymphocyte killing thousands of tumor cells.  

Researcher Michael Kalos says the team also engineered a signaling molecule that binds to CD19, triggering the continued production of thousands of T cells. The genetically engineered cells act as sentries against cancerous B cells should they return.

“We saw a substantial number of cells remaining circulating and in the marrow of patients very, very late after infusion, nine to 12 months, entirely unprecedented in the field," says Kalos. "And finally we saw that those cells, not only did they remain there, but they were able to be triggered, recognize and kill cancer cells when they encountered them again.”

In a report describing the so-called “serial killer” T cell therapy in the New England Journal of Medicine, researchers say it completely obliterated cancer cells in a 64-year-old man with CLL three weeks after treatment, and three to six months later, researchers could detect no sign of disease.

The patient’s marrow began manufacturing healthy B cells to replace the ones that were destroyed as "collateral damage" by the therapy. Cells that did not express CD19 were unaffected.


You May Like

Photogallery South Africa Bans Travelers From Ebola-stricken Countries

South Africans returning from affected West African countries will be thoroughly screened, required to fill out medical questionnaire, health minister says More

Multimedia UN Launches ‘Biggest Aid Operation in 30 Years’ in Iraq

Move aims to help thousands of Iraqi religious minorities who fled their homes as Kurdish, Iraqi government forces battle Sunni insurgents More

Video African Media Tries to Educate Public About Ebola

IT specialists, together with radio and TV reporters, are battling misinformation and prejudice about disease More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Gaza Conflict, Hamas Popularity Challenge Abbasi
X
Scott Stearns
August 21, 2014 9:20 PM
The Palestinian unity government of Mahmoud Abbas has failed to convince Hamas to agree to Egyptian-negotiated terms with Israel on a Gaza cease-fire. VOA State Department Correspondent Scott Stearns reports on what the Gaza conflict means for President Abbas, with whom U.S. officials have worked for years on a two-state solution to the Israeli-Palestinian conflict.
Video

Video Gaza Conflict, Hamas Popularity Challenge Abbas

The Palestinian unity government of Mahmoud Abbas has failed to convince Hamas to agree to Egyptian-negotiated terms with Israel on a Gaza cease-fire. VOA State Department Correspondent Scott Stearns reports on what the Gaza conflict means for President Abbas, with whom U.S. officials have worked for years on a two-state solution to the Israeli-Palestinian conflict.
Video

Video Nigeria's 'Nollywood' Movie Industry Rolls in High Gear

Twenty years after its birth in a video shop in Lagos, Nigeria's "Nollywood" is one of the most prolific film industries on earth. Despite low budgets and whirlwind production schedules, Nigerian films are wildly popular in Africa and industry professionals say they hope, in the future, their films will be as great in quality as they are in quantity. Heather Murdock has more for VOA from Lagos.
Video

Video UN Launches 'Biggest Aid Operation in 30 Years' in Iraq

The United Nations has launched what it describes as one of the biggest aid operations in 30 years in northern Iraq, as hundreds of thousands of refugees flee the extremist Sunni militant group calling itself the Islamic State. As Kurdish and Iraqi forces battle the Sunni insurgents, the fighting has forced more people to flee their homes. Kurdish authorities say the international community must act now to avert a humanitarian catastrophe. Henry Ridgwell reports for VOA from London.
Video

Video Cambodian American Hip Hop Artist Sings of Personal Struggles

A growing underground movement of Cambodian American hip hop artists is rapping about the struggles of living in urban America. Most, if not all of them, are refugees or children of refugees who came to the United States from Cambodia to escape the Khmer Rouge genocide of the 1970s. Through their music, the artists hope to give voice to immigrants who have been struggling quietly for years. Elizabeth Lee reports from Long Beach, California.
Video

Video African Media Tries to Educate Public About Ebola

While the Ebola epidemic continues to claim lives in West Africa, information technology specialists, together with radio and TV reporters, are battling misinformation and prejudice about the disease - using social media to educate the public about the deadly virus. VOA’s George Putic has more.
Video

Video Ferguson Calls for Justice as Anger, Violence Grips Community

Violence, anger and frustration continue to grip the small St. Louis suburb of Ferguson, Missouri. Protests broke out after a white police officer fatally shot an unarmed black teenager on August 9. The case has sparked outrage around the nation and prompted the White House to send U.S. Attorney Eric Holder to the small community of just over 20,000 people. VOA’s Mary Alice Salinas has more from Ferguson.
Video

Video Beheading Of US Journalist Breeds Outrage

U.S. and British authorities have launched an investigation into an Islamic State video showing the beheading of kidnapped American journalist James Foley by a militant with a British accent. The extremist group, which posted the video on the Internet Tuesday, said the murder was revenge for U.S. airstrikes on militant positions in Iraq - and has threatened to execute another American journalist it is holding. Henry Ridgwell has more from London.
Video

Video Family Robots - The Next Big Thing?

Robots that can help us with daily chores like cooking and cleaning are a long way off, but automatons that serve as family companions may be much closer. Researchers in the United States, France, Japan and other countries are racing to build robots that can entertain and perform some simpler tasks for us. VOA’s George Putic reports.
Video

Video In Ukraine, Fear and Distrust Remain Where Fighting has Stopped

As the Ukrainian military reclaims control of eastern cities from pro-Russian separatists, residents are getting a chance to rebuild their lives. VOA's Gabe Joselow reports from the town of Kramatorsk in Donetsk province, where a sense of fear is still in the air, and distrust of the government in Kyiv still runs deep.
Video

Video Five Patients Given Experimental Ebola Drug Said to Be Improving

The World Health Organization has approved the use of experimental treatments for Ebola patients in West Africa. The Ebola outbreak there is unprecedented, the disease deadly. The number of people who have died from Ebola has surpassed 1,200. VOA's Carol Pearson reports on the ethical considerations of allowing experimental drugs to be used.
Video

Video China Targets Overseas Assets of Corrupt Officials

As China presses forward with its anti-graft effort, authorities are targeting corrupt officials who have sent family members and assets overseas. The efforts have stirred up a debate at home on exactly how many officials take that route and how likely it is they will be caught. Rebecca Valli has this report.
Video

Video Leading The Fight Against Islamic State, Kurds Question Iraqi Future

Western countries including the United States have begun arming the Kurdish Peshmerga forces in northern Iraq to aid their battle against extremist Sunni militants from the Islamic State. But there are concerns that a heavily-armed Kurdistan Regional Government, or KRG, might seek to declare independence and cause the break-up of the Iraqi state. As Henry Ridgwell reports from London, the KRG says it will only seek greater autonomy from Baghdad.
Video

Video In Rural Kenya, Pressure Builds Against Female Circumcision

In some Kenyan communities, female genital mutilation remains a rite of passage. But activists are pushing back, with education for girls and with threats of punishment those who perform the circumcision. Mohammed Yusuf looks at the practice in the rural eastern community of Tharaka-Nithi.

AppleAndroid