KEY POINTS:
Bleach is a key weapon used by white blood cells to control bacterial infections in the body, New Zealand scientists have discovered.
Exactly how the hard-working white blood cells of the immune system control and kill invading bacteria has long been an area of controversy in medical research.
Now Otago University Associate Professor Tony Kettle and Professor Christine Winterbourn have detailed in international journals Biochemistry and The Journal of Biological Chemistry research which shows exactly how the cells use bleach to control infection.
The Christchurch-based medical scientists have been locked in debate with other international research teams, trying to explain how and why white blood cells, or neutrophils, are so effective in declaring war on bacteria.
Researchers at The University College of London argued recently that enzymes, not bleach, inside white blood cells digest and kill bacteria they have trapped, but the Christchurch results do not support that.
The New Zealand researchers demonstrated for the first time that bleach is the key element, by studying all the chemical reactions in the cell pathways, including the use of oxygen and the manufacture and use of large amounts of bacteria-killing chlorine bleach.
"This is a significant finding because it demonstrates that chlorine bleach is a major weapon white blood cells use to kill bacteria," Kettle said.
"Our experiments show that white blood cells first trap bacteria, and then produce bleach to zap the invaders. This happens millions of times in a healthy immune system fighting an infection."
But the production of bleach by white blood cells could also cause problems for some people.
Especially vulnerable were those with particular inflammatory diseases like cystic fibrosis, rheumatoid arthritis and blood poisoning.
"Bleach with these conditions tends to exacerbate rather than protect, and in the case of cystic fibrosis, damages lung tissue."
However, with the knowledge of the exact mechanisms used by white blood cells to produce bleach, scientists could now develop drugs that targeted the enzyme that produced bleach in an attempt to combat inflammation in these chronic diseases, Kettle said.
- NZPA