Immunity system complexity: attack bacteria not self cells (Introduction)

by David Turell , Tuesday, May 07, 2019, 19:04 (1810 days ago) @ David Turell

The attack pauses to be sure only bacteria are affected:

https://www.sciencedaily.com/releases/2019/05/190506093419.htm

"To kill bacteria in the blood, our immune system relies on nanomachines that can open deadly holes in their targets. UCL scientists have now filmed these nanomachines in action, discovering a key bottleneck in the process which helps to protect our own cells.

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"In earlier research, the scientists imaged the hallmarks of attack in live bacteria, showing that the immune system response results in 'bullet holes' spread across the cell envelopes of bacteria. The holes are incredibly small with a diameter of just 10 nanometres -- about 1/10,000 of the width of a human hair.

"For this study, the researchers mimicked how these deadly holes are formed by the membrane attack complex (MAC) using a model bacterial surface. By tracking each step of the process, they found that shortly after each hole started to form, the process stalled, offering a reprise for the body's own cells.

"'It appears as if these nanomachines wait a moment, allowing their potential victim to intervene in case it is one of the body's own cells instead of an invading bug, before they deal the killer blow," explained Dr Edward Parsons (UCL London Centre for Nanotechnology).

"The team say the process pauses as 18 copies of the same protein are needed to complete a hole. Initially, there's only one copy which inserts into the bacterial surface, after which the other copies of the protein slot into place much more rapidly.

"'It is the insertion of the first protein of the membrane attack complex which causes the bottleneck in the killing process. Curiously, it coincides with the point where hole formation is prevented on our own healthy cells, thus leaving them undamaged," said Professor Bart Hoogenboom (UCL Physics & Astronomy)."

Comment: Immunity is so vital, this complex process had to be designed as a whole intact system as life started. There is no other logical way, certainly not stepwise development. Obviously a designer is required