Adoptive immunotherapy based on Tr1 cells is a growing field of investigation. In disorders's models, administration of Tr1 cells has proven efficacy for treating pathologies such as experimental colitis, multiple sclerosis, type I diabetes and atherosclerosis.

The activation of Tr1 cells in vivo was carried out by administering regularly the antigen to the model (for example, ovalbumin in the drinking water for colitis) or by the local presence of an auto-antigen in vivo (for example, Type II collagen already present in the joints, for rheumatoid arthritis).

Indeed, based on the mechanism of action of Tr1 cells, the presence of the specific antigen in the inflamed tissue is mandatory for a complete suppressive effect. Since Tr1 cells display a specific tropism for the inflamed tissues, administration of Tr1 cells in non-inflamed animals will also preclude the action of the cells.

Tr1 cells have interesting biological properties:
- Migrate within the inflamed tissues
- Become activated due to the specific antigen presented by dendritic cells within the inflamed tissue
- Secrete locally anti-inflammatory mediators such as IL-10 and TGF-β

From this perspective, Tr1 cells can be considered as an immunosuppressive cytokines delivery tool into inflammatory tissues.