[Aune]

If they return to baseline in 30 minutes, was there even an increase to begin with? What is the mean lifetime of those cytotoxic cells, and would one expect such a decay in so short a time?

I understand that it is a very dynamic system but 30 minutes seems very short to me. So is the return a die-off or where do they go?

[biotechbio]

The lifespan of T cells varies from months to years (memory T cells). T cell development begins in the bone marrow and continues in the lymphatic tissue and periphery. During their lifespan, these cells circulate in the body and migrate based on chemical gradients.

What happens when you exercise? Blood pressure increases, blood vessels dilate. I honestly would not be surprised if what these authors observed was just existing T cells in capillary beds being kicked up into circulation, only to adhere and begin to intravasate a couple minutes later.

[Aune]

Excellent explanation, thanks.

That seems to translate well to my layman intuition. Would there actually be a health benefit with respect to cancer (or pathogenic disease) from this "T cell migration"? Is there a sense in which migration of T cells spread information to different parts of the body or is this just not how it works?