Nature sub-journal: Previously unknown function of immune cells - T cell void

T cells are part of the adaptive immune system that recognizes foreign antigens and specifically fights pathogens
.
Different T cells perform different functions
in this process.
So-called T helper cells secrete cytokines that attract other immune cells to the site of infection and trigger inflammation
there.
However, T helper cells can also fight inflammation
.
A better understanding of these mechanisms can help develop treatments
against pathogens or autoimmune diseases.
          

Study leader Christina Zielinski explains: "We found a cytokine in Th17 cells, a subset of T helper cells, which was previously thought to be part of the
innate immune system.
" She is the Head of the Department of Infectious Immunology at Leibniz-HKI and Professor at
Friedrich Schiller University Jena.
Cytokines, called IL-1α, are strong pro-inflammatory factors
.
"It's a signal molecule
for danger.
Even the smallest dose is enough to trigger a fever"
.
It is thought to be associated with
autoimmune diseases such as rheumatoid arthritis in children.
"We don't know how IL-1α is made in T cells and how it is released from the cell," said
first author Chao Ying-Yin.
The research was part of her doctoral dissertation, and she now works at an international biotech company in Munich, Germany, developing T-cell therapies
.

Through numerous experiments, the researchers eventually discovered that IL-1α, unlike other cytokines, is produced
by a multiprotein complex in T cells called inflammasomes.
This protein complex has very different roles
in other cells.
Zielinski said: "Until now, it was not known that human T cells had such an inflammatory body, and that it could be repurposed to produce IL-1α
.
"

Equally unexpected is the extracellular transport pathway
.
Alisa Puhach, the second author of the study, explains: "We found through knockout experiments that gasdermin E is the cause of
this.
" This molecule forms stomata
on the cell membrane.
The mechanism by which this inflammatory mediator is exported from T cells was previously unknown
.