T cell recognizes which antigen in graft rejection

Both MHC I & II are recognizedThe major antigenic differences between a donor and recipient that result in rejection of transplants are differences in HLA allelesDendritic cells carried in the donor organs are the most impoant APCs for initiating the antigraft response, because they not only express high levels of class I and II MHC molecules but also are endowed with costimulatory molecules (e.g., B7-1 and B7-2). Ref: Robbins and Cotran Pathologic Basis of Disease; 9th edition; Page no: 230