Immunity: new T cell controls found in lymph nodes (Introduction)

by David Turell , Wednesday, September 05, 2018, 23:39 (2059 days ago) @ David Turell

A surprise new finding:

https://www.sciencedaily.com/releases/2018/09/180905124743.htm

"Their research shows that the so-called Fibroblastic Reticular Cells (FRCs) that form the inner structure of human tonsils and lymph nodes exert control over T cells and their response to infection.

"These larger structural cells provide both structural support and guidance to immune cells while they spend time in lymph nodes, and the researchers' new work identifies four key mechanisms by which the FRCs act to dampen down T cell responses.

"The four mechanisms that FRCs use include pathways involving prostaglandin E2, the adenosine 2a receptor, indoleamine-2,3-dioxygenase, and transforming growth factor beta. The scientists were able to inhibit all four FRC mechanisms using existing drugs, and found that T cell responses were heightened in the process. Once T cells are no longer suppressed by FRCs they are readily able to expand and proliferate.

"Using an entirely novel approach, the researchers, in collaboration with University of Birmingham, examined the activation of T cells within live slices of human tonsil, and found that (in the presence or absence of key molecules), the T cells demonstrated a heightened response when FRCs were inhibited."

Comment: Suppression systems are part of the way the body balances reactions, just as feedback loops do. Since the T cells are designed to attack, controlling them had to be designed at the same time. No Darwin here.