For many animals, sleep is essential for healthy functioning; so too for T cells, warriors of the adaptive immune system.
T cells are normally quiescent until woke for work – sensing a molecular signal that pathogens may be on the prowl.
Rapid activation by immune cells is crucial for a timely response to pathogens. But, like all cells, T cells must have a quiet phase in its life cycle to properly replicate.
Overworked T cells go crazy and run amok. An overactive immune response is itself a dangerous disease.
References:
Soo Seok Hwang et al, “mRNA destabilization by BTG1 and BTG2 maintains T cell quiescence,” Science (13 March 2020).
Bill Hathaway, “How T cells make sure they have quiet time,” Phys.org (13 March 2020).
Ishi Nobu, The Ecology of Humans, BookBaby (2019).