VOA慢速英語(yǔ):"大事件":治療艾滋新方法

Researchers in the United States are calling it a "BigDeal." Next year, human tests could lead to a newtreatment for AIDS. It is being called an innovative andcreative treatment. The treatment changes the DNA ofcells to make them HIV fighters. It has protectedmonkeys from a primate type of the immune disorder.

VOA's Jessica Berman reported this story fromWashington, D.C. for VOA News.

Researchers in the United States are changing healthymuscle cells to make them produce genetic informationthat could possibly neutralize HIV, the virus thatcauses AIDS in humans. Scientists at ScrippsResearch Institute in Jupiter, Florida, tested thetreatment on a type of monkey.

The immune systems of these monkeys wererepeatedly exposed to simian immunodeficiency virus(SIV), the primate version of HIV. The animals neverbecame infected after a treatment to change the musclecells.

Michael Farzan is the lead researcher on the project. He and his team administered the virus to the monkeysin increasing amounts. They started with a dose thateasily passes SIV to the untreated monkeys in thecontrol group. But the treated monkey remaineduninfected. Then, the scientists doubled the dose foreach re-exposure to the virus.

Mr. Farzan said even monkeys that received 16 timesthe usual dose were protected. They did not getinfected with SIV.

"We continued to administer the virus, doubling the dose each time. We'venow gone to -- with six doses that were capable of infecting control((untreated)) animals -- we've gone to 16 times that."

Making HIV kill itself

Traditional vaccines train the immune system to recognize and destroydisease. But experimental AIDS vaccines fail at this because the virus isalways mutating, or changing, to avoid destruction. HIV and SIV are bothable to do this because of a surface protein that mutates to avoid the body’simmune system.

Mr. Farzan says this new drug treatment is based on tricking HIV. The drugtricks HIV into exposing this important viral surface protein.

The experimental compound attaches to the part of the virus that is alwaysmutating to avoid the immune system. Once attached, a second proteinmakes the virus self-destruct. The virus never has a chance to infect cells.

"Because HIV is sort of fooled into thinking that it's binding the cell, itundergoes the changes that it would normally do when it's ready to enter acell. And those changes, um, if it's not near a cell, inactivate the virus."

The muscle cells continually produce cells that fool the virus into self-destruction.

Mr. Farzan says the compound has the potential both to protect againstinfection with HIV and to fight the virus in infected people. The team wants tobegin testing human patients who are not able to take antiretroviral drugs.

The researchers published their findings in the journal Nature.

According the World Health Organization, almost 78million people have been infected with the HIV virus.About 39 million people have died of HIV.

In 2013 alone, 35 million people were living with HIV orAIDS and 1.5 million died from AIDS.

The virus still affects Sub-Saharan Africa moreseverely than any other part of the world.

Nearly one in every 20 adults there is living with HIV. This represents almost 71% of the people living withHIV worldwide.

I’m Anna Matteo.

Jessica Berman reported this story for VOA News from Washington, DC. Anna Matteo wrote it for Learning English. Caty Weaver was the editor.

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Words in This Story

genetic – adj. of, relating to, or involving genes

neutralize – v. to stop (someone or something) from being effective orharmful

immune system – n. the system that protects your body from diseases andinfections

primate – n. any member of the group of animals that includes human beings,apes, and monkeys

dose­ – n. the amount of a medicine, drug, or vitamin that is taken at one time

expose – v. subject to risk from a harmful action or condition

mutate – v. biology to cause a gene to change and create an unusualcharacteristic in a plant or animal

antiretroviral – adj. acting, used, or effective against retroviruses