Immunity in humans: training T cells (Introduction)

by David Turell , Wednesday, June 14, 2017, 00:23 (2511 days ago) @ David Turell

Newly formed T cells, a major part of the immune defense system have to undergo training to be effective!

https://www.sciencedaily.com/releases/2017/06/170613120523.htm

"A healthy gut requires a molecule called gp96 to train the immune system to tolerate food and normal microbes, report researchers at the Medical University of South Carolina (MUSC). The study emphasizes the importance of gp96 in maintaining a balanced immune system in the gut.

"A healthy gut depends on a balance of inflammatory and tolerant T cells, which make up part of the adaptive immune system. In patients with colitis, inflammatory T cells in the lower intestines mistake the molecular structures of food or healthy gut bacteria for dangerous pathogens that must be destroyed. To determine how this happens, Bei Liu, M.D., associate professor in the MUSC Department of Microbiology and Immunology, considered the idea that these patients' adaptive immune systems might be poorly trained.

"T cells are trained by professional antigen-presenting cells (pAPCs) in the gut. pAPCs express toll-like receptors on their surfaces that recognize and trap molecular patterns called antigens on bacteria, food and our own cells. A pAPC that has trapped a specific antigen will travel to a lymph node and display that antigen to a naive, untrained T cell.

"The T cell then differentiates to a mature state and travels throughout the body to locate its antigen. Tolerogenic pAPCs train tolerant T cells to accept harmless antigens, while inflammatory pAPCs train inflammatory T cells to attack harmful antigens on microbes or molecules that may enter the gut.

"Liu and her team found that without gp96-a molecule inside most cells that helps Toll-like receptors and integrins fold and function properly-pAPCs in the gut were more inflammatory.

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"This is the first study to describe the roles of the molecular chaperone gp96 in maintaining gut homeostasis. Although this study offered proof that gp96 is required to prevent colitis, further study is needed to connect the loss of gp96 to the development of colitis in human patients. Yet this ubiquitous molecule may have a fundamental responsibility to maintain proper immune balance in the gut. In fact, gp96 is tasked with folding a number of proteins that immune cells need to function."

Comment: Another complex biological mechanism that cannot develop by chance mutations. Since dangerous bacteria have existed since the beginning of life, with the development of multicellular organisms with digestive systems, this defense mechanism had to be present. Complexity of this type demands a designer mind is behind its development. Why not God?