READING NO. 5: Counterintuitive Cure: A nanovaccine that stops autoimmune disease by boosting the immune system

Counterintuitive Cure: A Nanovaccine That Stops Autoimmune Disease by Boosting the Immune System

A new treatment prevents type 1 diabetes in mice by turning the immune system on itself

The human body's immune system can quickly track down and kill cells that don't belong. Take certain kinds of bacteria: molecules on their surfaces flag them as foreign invaders, alerting the body's defenders to the breach and drawing a full-fledged attack on anything waving that molecular flag. But sometimes the system mistakenly attacks the body's own cells. The result is autoimmune disease, such as type 1 diabetes, in which the insulin-producing beta cells of the pancreas are attacked and destroyed by T cells.

Scientists have struggled to find ways to treat autoimmune disease without compromising overall immunity. Therapies that suppress the immune system carry the risk of letting infections and even tumors go unchecked. But researchers in Canada have found a way to prevent type 1 diabetes in mice by doing just the opposite—vaccinating to boost the immune system.

The approach, published April 8 in Immunity, exploits the immune system's built-in safety mechanism—a group of regulatory T cells whose job is to squelch overactive immune responses.

"Essentially, there is an internal tug-of-war between aggressive T cells that want to cause [an autoimmune response] and weaker T cells that want to stop it from occurring," says study senior author Pere Santamaria from the Julia McFarlane Diabetes Research Center at the University of Calgary in Alberta. Although they have seemingly opposite effects, these different classes of T cells are "musicians in the same orchestra," Santamaria explains. And they take directions from the same conductor—the antigen-presenting cell (APC).

APCs are specialized white blood cells that grab tiny bits of protein off the surfaces of other cells (like invaders or, in the case of diabetes, beta cells), chop them into pieces (antigens) and present them to T cells to instigate the immune response. "T cells have to be fed," Santamaria says. "If there is no antigen-presenting cell, there is no immune response."

When the aggressive, autoimmune disease-causing T cells are presented with antigens from dying beta cells, they keep attacking and killing the beta cells. But when the weak T cells that want to stop the disease are presented with those same antigens, they kill the APC. "A single weak T cell can blunt the problem by killing the orchestra leader," Santamaria says. And unlike aggressive T cells that die shortly after killing their targets, weak T cells proliferate. "They become long-living cells that attempt to regulate the disease," Santamaria says.

Santamaria designed a "vaccine" to boost the activity of the weak T cells. He used nanoparticles—spheres thousands of times smaller than a single cell—that were coated with beta cell antigens. In doing so, he created an APC doppelganger that could repeatedly activate the weak T cells, causing them to proliferate and kill the real APCs. The nanoparticles shield the antigens from degradation, meaning they stay in the system much longer, so they can be delivered at fewer intervals and at lower doses.

The nanovaccine prevented diabetes in a prediabetic mouse model and restored normal blood sugar levels in diabetic mice. Santamaria hopes to translate his exciting finding into human clinical trials. "We know what we want the compound to look like for use in humans—it's not a pie in the sky," he says. "But launching a clinical trial is not a trivial task. It requires that we do our homework properly."

Over 23 million people in the U.S. have diabetes, according to the most recent report jointly produced by the U.S. Centers for Disease Control, the National Institutes of Health (NIH) and the American Diabetes Association, although only 5 to 10 percent of those cases are thought to be autoimmune (type 1 diabetes). Type 1 diabetics have to carefully monitor their blood glucose levels and routinely administer insulin to keep them down. They have a heightened risk for kidney failure, heart and eye problems, and nerve disease.

Autoimmune disease affects up to 23.5 million Americans, according to the NIH, and it is one of the top 10 leading causes of death in female children and women in all age groups up to 64 years. Santamaria plans to test his approach in models of other autoimmune diseases, such as multiple sclerosis and rheumatoid arthritis. "We're trying to extend this paradigm to see if it applies to other autoimmune disorders, as well. We think it will but that remains to be seen. That’s our hope and dream."

VOCABULARY

track down sb/sth or track sb/sth down

to find someone or something after searching for them in many different places 
I'm trying to track down one of my old school friends.
They've finally managed to track down that book I wanted.

flag verb (MARK) 

/flæg/ (-gg-)

•

[T] to put a mark on something so it can be found easily among other similar things

Flag any files which might be useful later.

•

[T] specialized to mark computer information with one of two possible values so that you can process it later

We'll flag the records of interest in the database and then we can give you a print-out.

breach noun (OPENING) 

/briːtʃ/ [C]

formal a hole that is made in a wall or another structure used for protection during an attack

A cannon ball had made a breach in their castle walls. 

fully-fledged adjective 

/ˌfʊ.liˈfledʒd/ UK (US full-fledged)

completely developed or trained

What started as a small business is now a fully-fledged company.

After years of study, Tim is now a fully-fledged architect.

boost verb 

/buːst/ [T]

to improve or increase something

The theatre managed to boost its audiences by cutting ticket prices.

Share prices were boosted by reports of the President's recovery.

I tried to boost his ego (= make him feel more confident) by praising his cooking.

built-in adjective 

/ˌbɪltˈɪn/

If a place or piece of equipment has built-in objects, they are permanently connected and cannot be easily removed

All the rooms have built-in cupboards/wardrobes

squelch verb (STOP) 

/skweltʃ/

•

[T] US to quickly end something that is causing you problems

A spokeswoman at the White House has squelched rumors about the president's ill-health.

•

[T] US to silence someone by criticizing them

The senator thoroughly squelched the journalist who tried to interrupt him during his speech.

tug-of-war noun 

/ˌtʌg.əv ˈwɔːr//-ˈwɔːr/ [C usually singular]

a type of sport in which two teams show their strength by pulling against each other at the opposite ends of a rope, and each team tries to pull the other over a line on the ground

chop verb 

/tʃɒp//tʃɑːp/ [T] (-pp-)

•

to cut something into pieces with an axe, knife or other sharp instrument

He was chopping wood in the yard.

Add some fresh parsley, finely chopped.

Chop (up) the onions and carrots roughly.

informal Laura had her hair chopped (= cut) yesterday.

•

If something is chopped in finance or business, it is stopped or reduced

Because of lack of funding many long-term research projects are being chopped.

blunt verb 

/blʌnt/ [T]

•

to make something less sharp

•

to make a feeling less strong

My recent bad experience has rather blunted my enthusiasm for travel.

doppelgänger noun 

/ˈdɒp.əlˌgæŋ.ər //ˈdɑː.pəlˌgæŋ.ɚ/ [C]

a spirit that looks exactly like a living person, or a person who looks exactly like someone else but who is not related to them

a pie in the sky

A fanciful notion; ludicrous concept; the illusory promise of a desired outcome that is unlikely to happen

LISTENING COMPREHENSION

After closely reading the text, see how many questions you can answer correctly:

1) Enumerate the risks that are mentioned in the text as being associated with therapies that suppress the immune system

2) Say when and where this approach was published

3) Explain how regulatory T cells halt the immune system

4) How does the vaccine act?

5) How did the nanovaccine perform in both a prediabetic mouse model and in diabetic mice?

6) Which 3 organizations agree on the figure of 23 million people in the US with diabetes?

7) What percentage of this population is thought to be type 1 diabetes?

8) What other autoimmune diseases are planned to be tested following this same approach?

READING NO. 3: Effects of Global Warming

The planet is warming, from North Pole to South Pole, and everywhere in between. Globally, the mercury is already up more than 1 degree Fahrenheit (0.8 degree Celsius), and even more in sensitive polar regions. And the effects of rising temperatures aren’t waiting for some far-flung future. They’re happening right now. Signs are appearing all over, and some of them are surprising. The heat is not only melting glaciers and sea ice, it’s also shifting precipitation patterns and setting animals on the move.

Some impacts from increasing temperatures are already happening.

• Ice is melting worldwide, especially at the Earth’s poles. This includes mountain glaciers, ice sheets covering West Antarctica and Greenland, and Arctic sea ice.
• Researcher Bill Fraser has tracked the decline of the Adélie penguins on Antarctica, where their numbers have fallen from 32,000 breeding pairs to 11,000 in 30 years.
• Sea level rise became faster over the last century.
• Some butterflies, foxes, and alpine plants have moved farther north or to higher, cooler areas.
• Precipitation (rain and snowfall) has increased across the globe, on average.
• Spruce bark beetles have boomed in Alaska thanks to 20 years of warm summers. The insects have chewed up 4 million acres of spruce trees.

Other effects could happen later this century, if warming continues.

• Sea levels are expected to rise between 7 and 23 inches (18 and 59 centimeters) by the end of the century, and continued melting at the poles could add between 4 and 8 inches (10 to 20 centimeters).
• Hurricanes and other storms are likely to become stronger.
• Species that depend on one another may become out of sync. For example, plants could bloom earlier than their pollinating insects become active.
• Floods and droughts will become more common. Rainfall in Ethiopia, where droughts are already common, could decline by 10 percent over the next 50 years.
• Less fresh water will be available. If the Quelccaya ice cap in Peru continues to melt at its current rate, it will be gone by 2100, leaving thousands of people who rely on it for drinking water and electricity without a source of either.
• Some diseases will spread, such as malaria carried by mosquitoes.
• Ecosystems will change—some species will move farther north or become more successful; others won’t be able to move and could become extinct. Wildlife research scientist Martyn Obbard has found that since the mid-1980s, with less ice on which to live and fish for food, polar bears have gotten considerably skinnier.  Polar bear biologist Ian Stirling has found a similar pattern in Hudson Bay.  He fears that if sea ice disappears, the polar bears will as well.

Source for climate information: IPCC, 2007

VOCABULARY

far-flung: /ˌfɑːˈflʌŋ/ US /ˌfɑːr-/ adj literary

describes places that are a great distance away, or something that is spread over a very large area

e.g. The news spread to all corners of our far-flung empire.

 

shifting (to shift):/ʃɪft/ v

•  [I or T] to (cause something or someone to) move or change from one position or direction to another, especially slightly

She shifted (her weight) uneasily from one foot to the other.

The wind is expected to shift (to the east) tomorrow.

Media attention has shifted recently onto environmental issues.

• [T] mainly US to move the gears of a vehicle into different positions in order to make it go faster or slower

In cars that are automatics, you don't have to bother with shifting gears.

breeding: /ˈbriː.dɪŋ/ n [U]

•  the keeping of animals or plants in order to breed from them

The family's business was horse-breeding.

We used to keep pigs for breeding purposes.

• when animals have sex and reproduce

The penguins' breeding season has begun.

bark: /bɑːk/ US /bɑːrk/ n

[U] the hard outer covering of a tree

boomed: /buːm/ v

[I] to increase or become successful and produce a lot of money very quickly

OFTEN in continuous tenses

The leisure industry is booming.

booming

adjective /ˈbuː.mɪŋ/

chewed: /tʃuː/ v [I or T]

•  to crush food into smaller, softer pieces with the teeth so that it can be swallowed

This meat is difficult to chew.

You don't chew your food enough - that's why you get indigestion.

•  to bite something with your teeth, usually in order to taste its flavour

Would you like some gum to chew?

She gave the children some sweets to chew (on) during the long car journey.

She sat in the dentist's waiting room, nervously chewing (at) (= biting) her nails.

out of sync: (in/out of sync)

If two things are in/out of sync, they reach the same or related stage at the same time/at different times.

bloom: /bluːm/ v [I]

When a flower blooms, it opens or is open, and when a plant or tree blooms it produces flowers

These flowers will bloom all through the summer.

droughts: /draʊt/ n [C or U]

a long period when there is little or no rain

This year (a) severe drought has ruined the crops.

cap: /kæp/ n [C]

• a small usually protective lid or cover

The camera has a lens cap to protect the lens surface.

• an artificial protective covering on a tooth

• a mass of ice and snow that permanently covers a large area of land (e.g., the polar regions or a mountain peak)

•  a soft flat hat which has a curved part sticking out at the front, often worn as part of a uniform

•  a thin hat that stops your hair getting wet when swimming or taking a shower

a shower/swimming cap

• UK a hat given to someone who plays for their national team in a particular sport, or a player who receives this

Davis has 17 Scottish caps (= has played for Scotland 17 times).

The team contains five international caps.

spread: /spred/ v [I or T] (spread, spread)

• to (cause to) cover, reach or have an effect on a wider or increasing area

The fire spread very rapidly because of the strong wind.

It started off as cancer of the liver but it spread to other areas of the body.

The redundancies are spread across the clothing, banking and building industries.

We spread the picnic rug out on the ground and sat down to eat.

The AIDS virus is spread (= given to other people) through contact with blood and other body fluids.

Are you spreading (= telling a lot of people) gossip/rumours again?

If we spread (= divide) the work between us, it won't seem so bad.

She spread her toast with a thick layer of butter./She spread a thick layer of butter on her toast.

It's a special sort of butter that spreads easily even when cold.

The suburbs spread (out) for miles to either side of the city.

Slowly a smile spread across her face.

skinnier (skinny): /ˈskɪn.i/ adj

•  (mainly disapproving) very thin

You should eat more, you're much too skinny.

 

LISTENING COMPREHENSION

1. What effects that are currently happening because of global warming can you remember?

2. What animals have been mentioned in the text?

3. How many effects of the global warming can you remember that may happen in this century?

4. How much will sea level rise?

5. How may polar bears be affected?