Immunity complexity: control of immature immune proteins (Introduction)

by David Turell , Tuesday, September 24, 2019, 21:30 (1675 days ago) @ David Turell

The immune proteins are allowed to leave the cell only when mature:

https://www.sciencedaily.com/releases/2019/09/190924133250.htm

"The cells of our immune system constantly communicate with one another by exchanging complex protein molecules. A team has now revealed how dedicated cellular control proteins, referred to as chaperones, detect immature immune signaling proteins and prevent them from leaving the cell.

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"A team led by researchers from the Technical University of Munich (TUM) has now revealed how dedicated cellular control proteins, referred to as chaperones, detect immature immune signaling proteins and prevent them from leaving the cell.

"The body's defenses systems have to react quickly whenever pathogens enter the organism. Intruders are identified by white blood cells which pass on the information to other immune cells. Information is transmitted via secreted signaling proteins, the interleukins, which dock onto the matching receptors on the recipient cells and for example make the target cells divide and release antibodies.

"Researchers from TUM, the Helmholtz Zentrum München and Stanford University have, by studying interleukin 23, been able to show how cells ensure that the interleukin signalling proteins are built correctly.

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"Interleukin 23 is composed of two proteins, which have to combine in the cell to form an active complex in order to be able to trigger the desired signals. As the scientists have demonstrated in their study, molecules referred to as chaperones retain one part of the interleukin known as IL23-alpha in the cell until it has been incorporated into the complete complex. This way the cell makes sure that it does not secrete any unpaired IL23-alpha and thus controls the biosynthesis of this important interleukin and accordingly of the messages it sends. Chaperones are molecular protein machines that ensure that other proteins are built correctly.

"'We were able to show that unbound IL23-alpha has chemical bonds which are prone to interaction with chaperones," Feige explains. In the completed interleukin 23 these bonds are closed, so that the chaperon no longer is able to interact and hence the complete molecule can leave the cell."

Comment: the immune system is vital to protect organisms from attack. Proper targets must be identified accurately, and release of antibodies controlled and prompt. This protection must have been designed in the beginning of life as all organisms need ways to block infections