This invention relates to a therapeutic molecule capable of suppressing an immune response against an organ or tissue transplantation in a patient. In particular, the invention relates to a conjugate comprising a first portion connected to a second portion, wherein the first portion binds to an MHC Class I molecule and the second portion has HLA-G activity. This conjugate may be used as a medicament to modulate immune responses and induce immunological tolerance specific to allogenic MHC complexes.