White blood cells move like millipedes, scientists show

May 4, 2009

How do white blood cells - immune system 'soldiers' - get to the site of infection or injury? To do so, they must crawl swiftly along the lining of the blood vessel - gripping it tightly to avoid being swept away in the blood flow - all the while searching for temporary 'road signs' made of special adhesion molecules that let them know where to cross the blood vessel barrier so they can get to the damaged tissue.

In research recently published in the journal Immunity, Prof. Ronen Alon and his research student Ziv Shulman of the Weizmann Institute's Immunology Department show how advance along the length of the lining the blood vessels.

Current opinion maintains that advance like inchworms, but Alon's new findings show that the rapid movement of the white blood cells is more like that of millipedes. Rather than sticking front and back, folding and extending to push itself forward, the cell creates numerous tiny 'legs' no more than a micron in length - adhesion points, rich in adhesion molecules (named LFA-1) that bind to partner adhesion molecules present on the surface of the blood vessels. Tens of these legs attach and detach in sequence within seconds - allowing them to move rapidly while keeping a good grip on the vessels' sides.

Next, the scientists turned to the Institute's Unit. Images produced by scanning and transmission electron microscopes, taken by Drs. Eugenia Klein and Vera Shinder, showed that upon attaching to the blood vessel wall, the white blood cell legs 'dig' themselves into the endothelium, pressing down on its surface. The fact that these legs - which had been thought to appear only when the cells leave the blood vessels - are used in crawling the vessel lining suggests that they may serve as probes to sense exit signals.

The researchers found that the shear force created by the blood flow was necessary for the legs to embed themselves. Without the thrust of the rushing blood, the white blood cells couldn't sense the exit signals or get to the site of the injury. These results explain Alon's previous findings that the blood's shear force is essential for the white blood cells to exit the blood vessel wall. The present study suggests that shear forces cause their adhesion molecules to enter highly active states. The scientists believe that the tiny legs are trifunctional: Used for gripping, moving and sensing distress signals from the damaged tissue.

In future studies, the scientists plan to check whether it is possible to regulate aggressive immune reactions (such as in autoimmune diseases) by interrupting the 'digging' of immune cell legs into the endothelium. They also plan to investigate whether cancerous blood cells metastasize through the blood stream using similar mechanisms in order to exit the vessels and enter different tissues.

Source: Weizmann Institute of Science (news : web)


Rank 5 /5 (1 vote)
Relevant PhysicsForums posts
  • Is Everyday Technology Killing Us?
    createdFeb 08, 2012
  • Exercise and weight loss
    createdFeb 08, 2012
  • Why do we have head aches? Our brains can't feel anything.
    createdFeb 07, 2012
  • "The end of diseases" by David Agus, interview from Daily Show with Jon Stewart
    createdFeb 04, 2012
  • Oncolytic adenovirus
    createdFeb 04, 2012
  • Nutrition label stuffs and diets
    createdFeb 02, 2012
  • More from Physics Forums - Medical Sciences

More news stories

Discovery paves way for salmonella vaccine

(Medical Xpress) -- An international research team led by a University of California, Davis, immunologist has taken an important step toward an effective vaccine against salmonella, a group of increasingly antibiotic-resistant ...

Medicine & Health / Research

created 42 minutes ago | popularity 5 / 5 (2) | comments 0 | with audio podcast

First-of-its-kind stem cell study re-grows healthy heart muscle in heart attack patients

Results from a Cedars-Sinai Heart Institute clinical trial show that treating heart attack patients with an infusion of their own heart-derived cells helps damaged hearts re-grow healthy muscle.

Medicine & Health / Cardiology

created 48 minutes ago | popularity 5 / 5 (1) | comments 2 | with audio podcast

Ovarian cancer arises in fallopian tube of knockout mice

(Medical Xpress) -- The most deadly form of "ovarian" cancer arises in the fallopian tubes – not the ovaries – of knockout mice that lack two genes associated with the disease, said researchers led by Baylor College ...

Medicine & Health / Cancer

created 43 minutes ago | popularity not rated yet | comments 0 | with audio podcast

Smoking bans lead to less, not more, smoking at home: study

Smoking bans in public/workplaces don't drive smokers to light up more at home, suggests a study of four European countries with smoke free legislation, published online in Tobacco Control.

Medicine & Health / Health

created 48 minutes ago | popularity not rated yet | comments 0

UK cases of progressive sight loss condition set to rise a third by 2020

New cases of the progressive sight loss condition, known as age-related macular degeneration, or AMD for short, are set to rise by a third in the UK over the next decade, reveals research published online in the British Jo ...

Medicine & Health / Diseases

created 47 minutes ago | popularity not rated yet | comments 0


Time of year important in projections of climate change effects on ecosystems

(PhysOrg.com) -- Does it matter whether long periods of hot weather, such as last year's heat wave that gripped the U.S. Midwest, happen in June or July, August or September?

Medical school link to wide variations in pass rate for specialist exam

Wide variations in doctors' pass rates, for a professional exam that is essential for one type of specialty training, seem to be linked to the particular medical school where the student graduated, indicates research published ...

Scientists discover reason for Mt. Hood's non-explosive nature

(PhysOrg.com) -- For a half-million years, Mount Hood has towered over the landscape, but unlike some of its cousins in Oregon’s Cascade Mountains and many other volcanoes around the Pacific “Rim ...

Missing dark matter located: Intergalactic space is filled with dark matter

Researchers at the University of Tokyo’s Institute for the Physics and Mathematics of the Universe (IPMU) and Nagoya University used large-scale computer simulations and recent observational data of gravitational ...

Plants use circadian rhythms to prepare for battle with insects

In a study of the molecular underpinnings of plants' pest resistance, Rice University biologists have shown that plants both anticipate daytime raids by hungry insects and make sophisticated preparations to ...

Sensing self and non-self: New research into immune tolerance

At the most basic level, the immune system must distinguish self from non-self, that is, it must discriminate between the molecular signatures of invading pathogens (non-self antigens) and cellular constituents that usually ...