Biological complexity: immunity feedback loop (Introduction)

by David Turell , Sunday, August 06, 2017, 18:41 (2447 days ago) @ David Turell

A new immune T cell has been found which tends to keep regular T cells under control. All of life's processes has activator and depressor controls to keep everything within proper limits. Both have to be developed simultaneously or new processes would act out of control:

https://www.sciencedaily.com/releases/2017/08/170804124005.htm

"Type 1 regulatory (Tr1) cells are a type of regulatory immune cell that help suppress immune responses, including inflammation and tissue damage, but very few details were known about their development and function.

"A new study with mice and humans, published in the journal Nature Communications, describes how an enzyme called ITK plays a crucial role in the development of Tr1 cells during an immune response. The enzyme offers an entry point for researchers to manipulate the development of Tr1 cells to enhance them to treat allergies, for instance, or block their development to treat viral and bacterial infections.

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"Doctors employ antigen immunotherapy to treat allergies by administering a regimen that exposes a patient to increasing doses of an allergen over a period of months. Since allergies are caused by an overactive immune response to an allergen, the treatment works because Tr1 cells help suppress the immune system and lower inflammation. In the future, clinicians may want to enhance the pathway to produce more Tr1 cells, August said.

"But when treating viral infections such as the flu, bacterial infections and tumors, clinicians may want to selectively block the pathway to lower the number of Tr1 cells. In experiments with mice, August and colleagues found that Tr1 cells increase when a mouse is infected with viruses or bacteria or when fighting tumors.

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"This is a balance because these cells are there for a purpose, and we think their purpose is to make sure the immune system doesn't destroy and cause pathology in an immune response," August said. (my bold)

"The danger with flu, for example, is that at a certain point other types of immune system T cells, whose purpose is to kill infected cells, start to destroy tissue. In such cases, an overactive immune response can lead to death.

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"In the study, August, Huang and their colleagues bred genetically altered mice so they carried a gene that makes Tr1 cells glow green when they develop, which allows for easy tracking. They then bred another type of mouse that had fluorescent Tr1 cells and also allowed the researchers to specifically block the enzymatic activity of ITK. Using the same protocol, they created a third type of mouse that lacked ITK.

"In both the mice where ITK was inhibited and the mice that lacked ITK, Tr1 cells failed to develop. Using blood cells from anonymous human volunteers, they got the same results.

"In a second experiment, the researchers identified a second critical enzyme in the pathway that leads to the development of Tr1 cells. This other enzyme, called IRF4, is a transcription factor that regulates the expression of a number of genes and proved key for controlling whether Tr1 cells developed. The team also confirmed that the same pathway exists in people.:

Comment: To my mind the evidence of design is overwhelming. There are two enzymes to develop Tr1 cells. These specialized giant molecules must be created and the Tr1 feedback control must be put in place for the system to work. All multicellular animal life has inflammatory reactions to fight infections. Only design saltation fits this process.