Any cell in the body is a potential target for one kind of virus or another. However, all cells express class I histocompatibility molecules at their surface. These can display antigenic fragments of viral components. T cells Graft Rejection Grafts of a kidney, heart, lung, liver, etc. If unchecked, this response will eventually lead to destruction of the graft.
Nude mice are homozygous for a gene that is essential for the development of a thymus.
Lacking a thymus they cannot produce T cells and hence are unable to reject grafts. Link to a view of nude mice carrying various skin grafts without rejecting them. Grafts of bone marrow can restore the patient. Sometimes the marrow must come from another person. In this case, there is no danger of rejecting the graft because the recipient has no functioning immune system.