Regulatory T cells in Multiple Sclerosis – Indications of impaired function of suppressive capacity and a role for chemokines

• BACKGROUND Regulatory T cells (Treg) are critical for immune regulation and homeostasis. In multiple sclerosis (MS), the function of these cells has been shown to be impaired, although the underlying mechanism has yet to be shown. In the current study, we aimed to characterize and assess the phenotypical, functional and transcriptional characteristics of memory and naïve Treg in MS patients and controls.MATERIAL AND METHODS 27 patients with relapsing-remitting disease were included, along with 29 healthy controls. Flow cytometry was used for detailed phenotyping of Treg subpopulations CD4+CD45RA+/- and CD4dimCD25++ and their expression of FOXP3, CD39 and HELIOS. CFSE (proliferation marker) and CD69 (activation marker) were used to investigate the functional capacity of Treg. A microarray was employed for genome-wide transcriptional characterization of isolated Treg.RESULTS CD4+CD45RA–CD25++ activated Treg displayed a higher expression of FOXP3 and CD39 than resting CD4+CD45RA+CD25+ Treg, while no significant phenotypical differences were observed in Treg subpopulations between patients and controls. However, a lower anti-proliferative capacity was observed in activated Treg of MS patients compared with those of controls (p<0.05), while suppression of activation was similar to controls. Gene set enrichment analysis (GSEA) of microarray data revealed enrichment for the GO gene set ‘chemokine receptor binding’ in MS Treg.CONCLUSION Although numerical phenotypical assessment of resting and activated Tregs did not reveal any significant difference between patients and controls, functional co-culturing experiments showed an impaired function in activated Treg of MS patients. Furthermore, GSEA revealed immune-related gene sets overexpressed in Treg of MS patients, possibly containing clues to the functional impairment. In particular over-activity in chemokine signalling in Treg would be of interest for further investigation.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine (hsv//eng)

Keyword

EBI3

FOXP3

multiple sclerosis

RORC

T cells

transcription factors

Publication and Content Type

vet (subject category)

ovr (subject category)