Methods for human allografting

A method of preparing a human recipient for a graft from a human donor, without administering irradiation to promote the formation of mixed chimerism and without thymic irradiation, the method comprising:

• administering to the recipient an anti-CD2 monoclonal antibody;
• administering to the recipient, donor peripheral blood progenitor in an amount sufficient to form mixed chimerism in the absence whole body irradiation and thymic irradiation;
• administering to the recipient, a non-chronic course of an immunosuppressant;
• and
• administering to the recipient, one or both of a blocker of the CD40 ligand-CD40 interaction and a blocker of the CD28-B7 interaction.