Subsets of T regulatory cells

Are all T reg cells Foxp3 positive?

No.

T regulatory cells (Treg) are distinguished by CD4+, CD25+, GITR+, CTLA-4+. Some of T regs also express the transcription factor Foxp3 (nTreg).

Treg subsets

- Natural Tregs (nTreg)

nTregs develop in the thymus and constitutively express Foxp3 and CD25. They depend upon IL-2 for their survival.

- Induced Tregs (iTreg)

iTregs are induced from naïve CD4 in the periphery. They express Foxp3 only after development by TGF-b.

- T Regulatory 1 (Tr1)

Tr1 do not express CD25 or Foxp3. They depend on IL-10 from DCs for development. Tr1 produce high levels of IL-10.



Regulatory T cells - 6 groups have been described as of year 2010 (click to enlarge the image).

References:
T Cells. Jordan S. Orange MD/PhD. ACAAI/ACAAI Certification/Maintenance of Certification Board Review Course, 2008.