Setback for New Stem Cell Treatment

The research involved so-called induced pluripotent stem cells, or iPS cells, which can be made from skin cells and which appear to have the characteristics of embryonic stem cells. That means they can theoretically be turned into nerve, heart, liver or other types of cells and transplanted to repair damaged organs.

The initial creation of human iPS cells in 2007 electrified scientists because the cells seemed to have two big advantages over embryonic stem cells. They were not controversial, because their creation did not entail the destruction of human embryos. And since the stem cells could be made from a particular patient’s skin cells, they could be used to make tissues that presumably would not be rejected by that patient’s immune system.

But that latter assumption was never really tested, until now. When Yang Xu, a biologist at the University of California, San Diego, and colleagues did so, they found that iPS cells made from mouse skin cells were nonetheless rejected by genetically identical mice.

Other scientists said the results, published online on Friday in the journal Nature, were surprising.

“The path to the clinic has just gotten a lot murkier,” said Dr. Robert Lanza, chief scientific officer of Advanced Cell Technology, a company trying to develop medical treatments using both embryonic stem cells and induced pluripotent stem cells.

He said it was not clear that the results in mice would hold true for humans, though some other scientists said they assumed they would.

The new report is just the latest to take some of the shine off iPS cells. In recent months other researchers have reported that the cells are prone to various types of genetic abnormalities.

“As with any new technology, there is always this initial phase of infatuation, and then the reality sets in,” said Dr. George Q. Daley, director of the stem cell transplantation program at Children’s Hospital Boston. “I think it goes to the heart of the issue of how ignorant we really are in understanding these cells.”

Dr. Daley said the finding about the immune reactions “happened to be a particularly startling result that I wasn’t anticipating.”

Still, he added, years of work lie ahead before iPS cells would be ready to use in treating people, so it is too early to be discouraged. Many scientists say iPS cells for now will be used to create cells — like brain cells from someone with Alzheimer’s disease — that can be used to study diseases in the laboratory.

Dr. Xu, whose research was paid for by the National Institutes of Health and by California’s stem cell program, created both embryonic stem cells and iPS cells from an inbred strain of mice and implanted those stem cells into other mice of the same strain.

The mice did not have an immune response to the implanted embryonic stem cells. But their immune systems attacked the implanted iPS cells.

Further experiments suggested that the reaction was caused by the abnormal activation of certain genes in the iPS cells, resulting in the production of proteins that seemed foreign to the immune systems of the mice.

The degree of immune response depended on how the iPS cells were made. The strongest response was to cells made by incorporating genes for certain growth factors into the DNA of the skin cells. Cells made that way are not likely to be used for medical treatments anyway because at least one of the inserted genes can cause cancer.

Dr. Rudolf Jaenisch, a professor of biology at the Massachusetts Institute of Technology and a founding member of the Whitehead Institute, said that in practice, iPS cells themselves would not be implanted into people. Rather, the stem cells would first be turned into specific types of cells, like brain cells or heart cells. He said it was unclear whether such differentiated cells would elicit the same immune response as the stem cells did in the mice.

Jeanne F. Loring, director of the center for regenerative medicine at the Scripps Research Institute, said the new findings would not preclude use of the iPS cells for therapy because immune-suppressing drugs could always be used.

But the potential problem with iPS cells might make some scientists take another look at making patient-specific tissues by creating an embryo from a patient’s cell through so-called therapeutic cloning. That approach, which is not known to have been accomplished using human cells, is controversial because the same technique might also be used to create a baby.

“This reopens the whole need for S.C.N.T, which will be controversial,” said Dr. Lanza of Advanced Cell Technology, referring to somatic cell nuclear transfer, the scientific term for cloning. “We had thought we had put that aside with this technology.”

 

Taliban Prison Break May Lead to Military and Political Setback

The plan for the prison break , which led the prisoners through a tunnel dug over more than five months and equipped with electricity and air pipes, was so closely held that one young Taliban fighter who got out said he knew nothing of it until a fellow inmate tugged his sleeve to wake him in the night and led him to the three-foot-wide tunnel, which ran more than half a mile from a hole in a cell’s floor, under security posts, tall concrete walls and a highway, and came up in a nearby house. From there, a waiting car took the fighter a few miles away, where he hailed a taxi to safety.

“I was just praying to God that he would free me,” said the fighter, Allah Mohammed Agha, 22, recounting his escape from Sarposa Prison, where he had been held for 28 days. “Last night was the night that my dream was made true.” He spoke by phone from Spinbaldak, near the Pakistani border.

The Afghan government called the breach a disaster. The breach called into question the extent of the gains made against the Taliban in 18 months of hard fighting in Kandahar Province, and whether any progress would be sustainable once NATO troops began to reduce their numbers as planned this summer, members of Parliament, tribal leaders and Western officials said in interviews.

Some worried that the jailbreak might strengthen the Taliban in the coming weeks as the spring fighting season began. Having so many fighters back in circulation — possibly including hard-core commanders — also threatened to undermine efforts to bring Taliban fighters over to the government side, Afghan officials and former Taliban said.

There is no doubt that the incident demonstrated the ability of the Taliban to organize such an elaborate operation, even after they were driven largely underground in Kandahar and Helmand Provinces, and despite police and prison guards, prison visits by NATO mentors, and sophisticated NATO surveillance in Kandahar.

The prison break comes after four recent attacks by the Taliban, in which they used suicide bombers, often disguised as police officers or soldiers, to penetrate secure buildings, including an Afghan army corps’ headquarters in Laghman Province and the Ministry of Defense headquarters in the capital, Kabul.

Members of Parliament and others were scathing about the lapses. Some questioned whether the prison guards or police officers were bribed not to notice the tunnel’s construction.

“It’s a big achievement for the Taliban and shows a big failure and weakness in the government,” said Muhammad Naiem Lalay Hamidzai, a Parliament member from Kandahar and chairman of the internal security committee.

“The Taliban gain two things from this jailbreak,” he said. “First, coming after the incidents in Kunduz, Laghman, Kandahar and at the Ministry of Defense headquarters, it sends a message that they can do whatever they want, even at the heart of the most secure and important jail, and it allows them to strengthen their ranks with more manpower.”

The Afghan government was reeling Monday as details of the escape emerged. “This is bad news for the government and the people of Afghanistan,” the spokesman for President Hamid Karzai, Waheed Omar, said at a news conference. “This shows a vulnerability on the part of the government.” He called the prison break a disaster.

One unexplained question was why the cells where prisoners were supposed to sleep were left open so that they could make their way to the cell with the tunnel. It also seemed that none of the guards checked on the prisoners during the night, even though Afghan intelligence officials and Western military officials said that there had been intelligence about the possibility of a security breach.

“This is absolutely the fault of the ignorance of the security forces,” said the Kandahar provincial governor, Tooryalai Wesa. “This was not the work of a day, a week or a month of activities. This was actually months of work they spent to dig and free their men.”

Clearly embarrassed, Afghan officials had little else to say, other than to acknowledge that the prison break showed unexpected weaknesses in security. Since the Taliban engineered a major break at the same prison in 2008 — freeing 1,200 prisoners — Canadian forces have mentored the Afghans who run the prison and NATO countries have spent several million dollars upgrading and training the prison administration, according to a Western official in Kabul.

“There are a lot of people asking questions today,” said a NATO officer at the coalition’s headquarters in Kabul.

There was no official comment from the NATO command. Two Western officials described the break as “at least partially an inside job,” but both said they could not be named because of the delicacy of the situation.

Of the 488 men who escaped, fewer than 20 were from the criminal section of the prison; the rest were security detainees believed to be Taliban fighters and commanders.

An escapee, who asked not to be identified, said that among those freed were two shadow governors and 14 shadow district governors. The Taliban have a shadow government that has varying influence in different provinces.

However, Muhammad Qasim Hashimzai, a deputy justice minister, said that the government did not yet know who had escaped. “The detainees included all kinds of people,” he said, and he promised to have more information on Tuesday.

Mr. Wesa, the Kandahar provincial governor, said a manhunt was on and that 26 escapees had been captured by late afternoon.

The security section of the prison was eerily empty on Monday when reporters were shown around. Prisoners’ belongings were strewn about, but appeared heaped in the cell with the tunnel in an effort to obscure the entrance. A second tunnel branched off to the criminal side of the prison, according to the warden, Gen. Ghulam Dastagir Mayar, and Mr. Wesa.

Now, with so many Taliban back in the fight, it will be even harder to convince Taliban fighters that they will be safe if they defect to the government, a former Taliban commander said.

“The prison break will slow down the peace process,” said Mullah Noorul Aziz Agha, a Taliban member who recently decided to lay down his arms and work with the government. “I was talking to Taliban on the phone to try to persuade them to come over, but now with this, how can we promise them that we can offer them security and protection?”

Taimoor Shah reported from Kandahar, and Alissa J. Rubin from Kabul, Afghanistan. Sangar Rahimi contributed reporting from Kabul.