The present invention relates to regulatory T cell and uses thereof. By their immunosuppressive and anti-inflammatory activities, regulatory T cells play a central role in peripheral tolerance and thus critically prevent the development of autoimmune and inflammatory disorders. The inventors showed that Foxp3+CD4+ Tregs express high levels of LTα, which negatively regulates their immunosuppressive signature. They demonstrated that the adoptive transfer of LTα-/- Tregs or the adoptive transfer of Tregs previously incubated with soluble lymphotoxin-β receptor in mice protects from dextran sodium sulfate (DSS)-induced colitis and attenuates inflammatory bowel disease (IBD), multi-organ autoimmunity and the development of CAC. The inventors also showed that by mixed bone marrow chimeras that LTα expression specifically in hematopoietic cells negatively controls the immunosuppressive signature of Tregs. In particular, the present invention relates to a method of treating or preventing autoimmune disorders and inflammatory-associated cancers in a subject in need thereof comprising the step of administrating to the subject a therapeutically effective amount of regulatory T cells which have been previously incubated with effective amount of soluble lymphotoxin-β receptor.