Data from: Human blood and mucosal regulatory T cells express activation markers and inhibitory receptors in inflammatory bowel disease

Background: FOXP3+ regulatory T cells (Tregs) are critical for preventing
intestinal inflammation. However, FOXP3+ T cells are paradoxically
increased in the intestines of patients with the inflammatory bowel
disease (IBD) ulcerative colitis (UC) or Crohn's disease (CD). We
determined whether these FOXP3+ cells in IBD patients share or lack the
phenotype of such cells from patients without IBD. Methods: We quantified
and characterized FOXP3+ Treg populations, as well as FOXP3- CD4+ T cells,
in the lamina propria lymphocytes (LPL) of intestine surgically resected
from patients with and without IBD, and in the blood of controls or
Crohn's patients with or without disease activity. Results: In all
samples, a similar fraction of FOXP3+ cells expressed the
"natural" Treg (nTreg) marker Helios, suggesting that, in IBD,
these cells are not entirely "induced" Tregs (iTregs) derived
from activated effector T cells. Helios+ and Helios- FOXP3+ T cells
demonstrated similar expression of maturation markers, activation markers,
and inhibitory molecules between IBD patients and controls, while FOXP3-
cells paradoxically expressed more of the inhibitory receptors CD39,
CTLA4, and PD-1 in inflamed mucosa. Greater expression of activation
markers was also seen in both Helios+ and Helios- Tregs, relative to
FOXP3- cells, in both IBD patients and controls, indicating that Tregs are
effectively activated by antigen in IBD. Conclusions: Extensive
immunophenotyping revealed that Helios+ and Helios- mucosal Tregs exist at
a similar frequency, and have a similar expression of inhibitory molecules
and activation markers in patients with IBD as in healthy controls.