IMMUUNIJÄRJESTELMÄ - BAKTEERIT

[Bb]

Lähettäjä: Soijuv Lähetetty: 26.8.2005 19:50

Uuden tutkimuksen mukaan bakteerit käyttävät elimistön omaa immuunijärjestelmää taistelussa toisia bakteereita vastaan. Ihmisen nenässä ja ylemmissä hengitysteissä on koko ajan miljoonia bakteereita valmiina tunkeutumaan laajemmalle elimistöön.


Bacteria use your immune system to kill each other

http://www.world-science.net/othernews/ ... actfrm.htm

July 22, 2005
Courtesy the Public Library of Science and World Science staff

Bacteria don't wage a lonely, one-on-one struggle against your immune system: rather, they deviously use it as a weapon against each other, new research has found.

Millions of bacteria live within the recesses of our noses and upper respiratory tracts, waiting for a chance to infiltrate and infect.

But long before these bacteria break through our immune defenses, they must first compete against other bacterial species to colonize the mucus-lined surfaces of our noses.

Competition between two common nose bacteria involves some trickery, according to the study, slated to appear in the Sept. 30 issue of the research journal PLoS Pathogens.

"We're looking at how bacteria use their host, and we've found that the presence of one species leads to the elimination of another," said Jeffrey Weiser, coauthor of the study and professor of pediatrics and microbiology at the University of Pennsylvania, School of Medicine.

In mice, Haemophilus influenzae-a common bacterium that infects children-stimulates the immune system to send out specialized white blood cells that attack its competitor, Streptococcus pneumoniae, the researchers found. This competitor is a leading cause of pneumonia.

"It is striking that the host's response can so completely eliminate the competitor," said Weiser.

The findings also demonstrate how antibiotics and vaccines that target one microbe might inadvertently alter the competitive interactions among other species present.