Dried-out human cells can come back to life

April 17, 2001

NORMAL human cells have been dried out and revived eight days later using a trick evolved by a bacterium that can survive for centuries without water. The technique could have all sorts of medical uses.

Blood for transfusions could be stored for long periods, for example, or carried to remote disasters without having to be kept cool. Antibodies and vaccines would have an almost unlimited shelf life, making them easier to distribute in developing countries.

Desiccated medical supplies could even be sent on long space missions. And it should become possible to make cell-based biosensors to detect poisons such as nerve gas. "You could rehydrate them when you needed the sensor," says Malcolm Potts of the Virginia Tech Center for Genomics in Blacksburg, who developed the technique.

Our cells usually die within seconds without water. But Potts and his colleague David Helm knew of a photosynthetic bacterium, or cyanobacterium, called Nostoc commune, that can survive such harsh conditions. N. commune lives on exposed rock surfaces, where it often dries out. When the rock gets wet again the cells come back to life, swelling up to form gel-like masses whose sudden appearances led to the popular names "star jelly" and "witches butter".

N. commune survives by surrounding itself with a slimy substance called glycan, Potts says. "It forms a woolly overcoat for the cells." Glycan is thought to protect cell membranes, as well as slowing the rate of drying.

So Potts and Helm tried mixing purified glycan with human kidney cells and drying them out at room temperature. When they rehydrated the cells 8 days later, half of the cells recovered and started dividing again, Potts told a meeting of Britain's Society for Experimental Biology in Canterbury earlier this month. "It's a breakthrough," says Potts. "By applying the techniques we have found in cyanobacteria, we can dry out human cells. It's very exciting."

Alan Tunnacliffe of the Institute of Biotechnology at Cambridge University says he's surprised the cells survived with only glycan to protect them, as it does not get inside the cells. "I am a little sceptical," he says. "But if it does work, it is a major achievement."

Last year, Fred Levine of the University of California in San Diego reported that he had revived dried human cells after 5 days (New Scientist, 19 February 2000, p 11). But this technique doesn't work for normal cells-Levine's team had to genetically modify the cells to make a sugar called trehalose, which protects cells against freezing and drying from the inside.

Other researchers have failed to repeat Levine's results. But he insists the technique works. "We have been drying cells, putting them in a standard cardboard container, sending them [from California] to the East Coast and having them successfully rehydrated," he says. Potts and Helm hope that one day tissues and perhaps even organs could be dried out and revived. But this won't be achieved with glycan alone, Potts says. "In the end it's bound to require a combination of different approaches."
Author: Joanna Marchant

New Scientist issue: 21st April 2001


New Scientist

Related Bacterium Articles from Brightsurf:

Root bacterium to fight Alzheimer's
A bacterium found among the soil close to roots of ginseng plants could provide a new approach for the treatment of Alzheimer's.

Tuberculosis bacterium uses sluice to import vitamins
A transport protein that is used by the human pathogen Mycobacterium tuberculosis to import vitamin B12 turns out to be very different from other transport proteins.

Bacterium makes complex loops
A scientific team from the Biosciences and Biotechnology Institute of Aix-Marseille in Saint-Paul lez Durance, in collaboration with researchers from the Max Planck Institute of Colloids and Interfaces in Potsdam and the University of Göttingen, determined the trajectory and swimming speed of the magnetotactic bacterium Magnetococcus marinus, known to move rapidly.

Researchers show how opportunistic bacterium defeats competitors
The researchers discovered that Stenotrophomonas maltophilia uses a secretion system that produces a cocktail of toxins and injects them into other microorganisms with which it competes for space and food.

Genetic typing of a bacterium with biotechnological potential
Researchers at Kanazawa University describe in Scientific Reports the genetic typing of the bacterium Pseudomonas putida.

How the strep bacterium hides from the immune system
A bacterial pathogen that causes strep throat and other illnesses cloaks itself in fragments of red blood cells to evade detection by the host immune system, according to a study publishing December 3 in the journal Cell Reports.

The cholera bacterium can steal up to 150 genes in one go
EPFL scientists have discovered that predatory bacteria like the cholera pathogen can steal up to 150 genes in one go from their neighbors.

Exploiting green tides thanks to a marine bacterium
Ulvan is the principal component of Ulva or 'sea lettuce' which causes algal blooms (green tides).

The cholera bacterium's 3-in-1 toolkit for life in the ocean
The cholera bacterium uses a grappling hook-like appendage to take up DNA, bind to nutritious surfaces and recognize 'family' members, EPFL scientists have found.

Excellent catering: How a bacterium feeds an entire flatworm
In the sandy bottom of warm coastal waters lives Paracatenula -- a small worm that has neither mouth, nor gut.

Read More: Bacterium News and Bacterium Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.