List regulatory T cells in immunology.

1. Natural regulatory T cells (nTregs)
2. Induced regulatory T cells (iTregs)
3. Tr1 cells
4. Th3 cells
5. CD8+ regulatory T cells
6. B regulatory cells (Bregs)
7. γδ T cells
8. iNKT cells
9. T regulatory type 1 (Tr1) cells
10. T regulatory type 3 (Th3) cells

- Central regulatory T cells (cTregs): These cells are generated in the thymus and express the transcription factor Foxp3. They are responsible for maintaining immune tolerance by suppressing the activation and proliferation of autoreactive T cells.
- Peripheral regulatory T cells (pTregs): These cells are generated in the periphery after activation of naive T cells. They also express Foxp3 and have similar suppressive functions as cTregs.
- Induced regulatory T cells (iTregs): These cells are generated in vitro by stimulating naive T cells with specific antigens in the presence of immunosuppressive cytokines such as interleukin-2 (IL-2) or transforming growth factor-beta (TGF-β). They express Foxp3 and have suppressive functions similar to cTregs and pTregs.
- Tr1 cells: These cells are a type of regulatory T cell that is characterized by the production of interleukin-10 (IL-10). They are involved in the suppression of immune responses to microbial antigens and in the maintenance of immune tolerance.
- Th3 cells: These cells are a type of regulatory T cell that is characterized by the production of transforming growth factor-beta (TGF-β). They are involved in the suppression of immune responses to self-antigens and in the maintenance of immune tolerance.