 Interleukin2 IL2 was initially discovered and used as a stimulator of effector T lymphocytes Teffs, but is now viewed as a very promising immunoregulatory drug having the capacity to stimulate regulatory T cells Tregs. At low dose, Il-2 tips the TregTeff balance towards Tregs. Recently, it has been shown that Tregs of MS patients have reduced proliferative potential. MS-IL2 will assess the safety and biological efficacy of low-dose IL2 as a Treg inducer in a Relapsing-Remitting Multiple Sclerosis RRMS, with the aim to stimulate Treg and define potential clinical benefits 