Immunity system complexity: T cell gene control (Introduction)

by David Turell , Tuesday, July 07, 2020, 21:45 (1386 days ago) @ David Turell

More found in fine tuning of the immune system genetics:

https://www.sciencedaily.com/news/strange_offbeat/bizarre_things/

"The human immune system is a finely-tuned machine, balancing when to release a cellular army to deal with pathogens, with when to rein in that army, stopping an onslaught from attacking the body itself. Now, Salk researchers have discovered a way to control regulatory T cells, immune cells that act as a cease-fire signal, telling the immune system when to stand down.

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"Regulatory T cells are responsible for reining in the activity of other cells in the immune system. They prevent the immune system from attacking the body's own tissues, and tell the immune response to fade when it is no longer needed, acting like an all-clear signal. Underactive regulatory T cells are associated with autoimmune diseases where the immune system attacks the body, including rheumatoid arthritis, multiple sclerosis, inflammatory bowel disease and lupus.

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"Researchers already knew that the gene called Foxp3 is a key player in the development and function of regulatory T cells. If regulatory T cells are like the lead peacekeepers, Foxp3 is like the UN, encouraging the peacekeeping force to organize. Without Foxp3, the body doesn't form regulatory T cells. So Zheng's group set out to find other genes that impacted levels of Foxp3. They used CRISPR gene-editing technology to test which genes throughout the genome affected Foxp3. This screen turned up hundreds of genes, including a handful that encoded different subunits of the SWI/SNF complex, a group of proteins that plays a role in turning many other genes on and off by physically making DNA accessible to cellular machinery.

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"Hargreaves and her group were already studying a number of genes in the SWI/SNF complex, including a new variant that the lab identified in 2018 called the ncBAF comple

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"'There was already data to show how the SWI/SNF complex is important for the development of cells, but not much data in regulatory T cells specifically," says Salk postdoctoral researcher Jovylyn Gatchalian, co-first author of the new work.

"The researchers used CRISPR to selectively remove the SWI/SNF complex genes from regulatory T cells. They found that the deletion of one gene in the ncBAF complex, called Brd9, had a particularly strong effect on the immune cells; regulatory T cells without Brd9 had lower levels of Foxp3 and weakened function."

Comment: A highly complex system of controls requiring a designer. Chance cannot develop this degree of complex controls to start systems and stop systems as required by pathogenic attacks. This had to develop early in the evolution of life for living organisms to survive and evolve into today's complex organisms..