T-cell exhaustion

https://longcovidatlas.org/glossary/t-cell-exhaustion

In plain language

What it is

A worn-out state of immune cells that have been activated for too long and stop working well.

Why it matters

It is one sign that the immune system in long COVID is stuck on rather than resolving.

Think of it like

A guard kept on duty so long they can no longer do the job properly.

For specialists

Formal definition

A dysfunctional T-cell state marked by inhibitory receptors such as PD-1 and CTLA-4 and reduced effector function, reported in long COVID.

Mechanism

Chronic antigen exposure, possibly from a viral reservoir, can drive exhaustion and a miscoordinated adaptive response.

Sources

Long COVID T cell dysregulation and uncoordinated adaptive response (Nat Immunol 2024) free full text ›