Graft versus tumor effect

Graft versus tumor effect (GvT) appears after allogeneic hematopoietic stem cell transplantation (HSCT). The graft contains donor T lymphocytes that are beneficial for recipient. Donor T-cells eliminate malignant residual host T-cells (graft versus leukemia) or eliminates diverse kinds of tumors. GvT might develop after recognizing tumor-specific or recipient-specific alloantigens.[99] It could lead to remission or immune control of hematologic malignancies. This effect applies in myeloma and lymphoid leukemias, lymphoma, multiple myeloma and possibly breast cancer. It is closely linked with graft versus host disease phenoma (GvHD). CD4+CD25+ regulatory T cells (Treg) can be used to suppress GvHD without loss of beneficial GvT effect. The biology of GvT response still isn’t fully understood but it is probable that the reaction with polymorphic minor histocompatibility antigens expressed either specifically on hematopoietic cells or more widely on a number of tissue cells or tumor-associated antigens is involved. This response is mediated largely by cytotoxic T lymphocytes (CTL) but it can be employed by natural killers (NK cells) as separate effectors, particularly in T-cell-depleted HLA-haploidentical HSCT.