Table 1.

Targeting minor histocompatibility antigens vs. leukemia specific antigens.

	T Cells Targeting Minor Histocompatibility Antigens	T Cells Targeting Leukemia-specific Antigens
Targets	Minor histocompatibility proteins expressed as a result of genetic polymorphisms	Unique or upregulated proteins expressed specifically by tumors and not expressed or minimally expressed by healthy cells
HLA Restriction	Yes	No
Cell Source	Allogeneic only	Autologous and allogeneic
Other Advantages	Potent allogeneic T cells available in matched donors	Targets can be unique and required by tumors for malignant phenotype
Disadvantages	Antigens potentially present in all cells, thus may increase risks for GVHD Difficult to identify antigens for different donor-recipient pairs	Difficult to grow/not as immunogenic Downregulation by tumors occur Some expression in some healthy cells