Immune tolerance maintenance system [17]
| No. | Category | Members | References |
| 1 | Main cell lineages | Tolerogenic dendritic cells | [50, 51] |
| Peripheral (pTreg) Foxp3+ cells | [2, 45, 52] | ||
| 2 | pTreg subsets on mucosal surfaces (they do not express Foxp3) | Type 1 regulatory T cell (Tr1) | [53] |
| Type 3 helper T cell (Th3) | |||
| 3 | Other cell lineages | M2a macrophages | [54–56] |
| Myeloid-derived suppressor cells | [57] | ||
| Regulatory B cells | [58, 59] | ||
| 4 | Own body-derived molecules | Immunosuppressive cytokines (IL-10, TGF-β, IL-35) | [45, 60, 61] |
| Coinhibitory molecules | [62, 63] | ||
| Blocking antibodies | [64] | ||
| Protolerogenic neurotransmitters and neuropeptides | [4, 65–68] | ||
| 5 | Other | Tolerogenic microbiota | [38, 41] |