Type 1 regulatory T cell (Tr1) (Tr1)

Type 1 regulatory T (Tr1) cells are a distinct subset of CD4+ T cells characterized by their high production of the immunosuppressive cytokine interleukin-10 (IL-10) and their lack of constitutive FOXP3 expression (Roncarolo et al., 2018, Nature Reviews Immunology). Unlike thymus-derived regulatory T cells, Tr1 cells are induced in the periphery in response to chronic antigen stimulation in an IL-10-rich environment (Gagliani et al., 2013, Nature). They play a vital role in maintaining immune tolerance and preventing autoimmunity by suppressing the activity of effector T cells and antigen-presenting cells through cytokine secretion and direct cytolysis (Gregori et al., 2012, Blood). In therapeutic contexts, Tr1 cells are being investigated as both targets for induction and as adoptive cell therapies for conditions such as graft-versus-host disease (GvHD) and Crohn's disease (Bacchetta et al., 2014, Frontiers in Immunology). Drugs like anti-CD3 monoclonal antibodies (e.g., Otelixizumab) have been shown to promote the differentiation of Tr1 cells in vivo, while ex vivo expanded Tr1 cell products like T-allo10 are currently in clinical trials (Roncarolo et al., 2014, Pediatric Reports). However, the use of Tr1-targeted therapies must be carefully managed to avoid broad immunosuppression or the unintended promotion of tumor growth in oncology settings (Comi et al., 2018, Frontiers in Immunology).

Other names

Tr1 cellsIL-10-producing regulatory T cellsType 1 T regulatory cellsInduced regulatory T cells (subset)

Induction of Tr1 cell differentiation, expansion of Tr1 populations, or adoptive transfer of ex vivo generated Tr1 cells to suppress pathological immune responses.