Methods and compositions for infusion of transiently engrafting, selected populations of allogeneic lymphocytes to treat cancer

The invention provides methods and compositions for administration of allogeneic lymphocytes as an exogenous source of CD4+ T cell help for endogenous, tumor-reactive CD8+ T cells. Depletion of CD8+ T cells from the donor lymphocyte infusion reduces the risk of sustained engraftment and graft-versus-host disease. Removal of regulatory T cells from the infused population may augment the ability of non-regulatory T cells to provide help for endogenous effectors of anti-tumor immunity. Allogeneic T cell therapy is typically given in the context of allogeneic stem cell transplantation, in which the patient receives highly immunosuppressive conditioning followed by an infusion of a stem cell graft containing unselected populations of mature T cells. In the treatment described here, the graft is engineered to minimize the possibility of sustained donor cell engraftment, and the anti-tumor effector T cells derive from the host.