CD8A and disease arising from reactivation of latent virus: To test if direct antigen presentation by latently infected non-hematopoietic tissue cells also applies to latent infection with mCMV-Δm152, we compared CD8 T-cell responses in H-2dχd syngeneic chimeras, in which donor and recipient cells differ only epigenetically, with H-2dχdm2 allogeneic chimeras, in which only donor-derived pAPCs express the MHC class-I molecule Ld that presents the antigenic IE1 peptide (for the principle, see Figure 5A).