The influence of the age of donors and recipients on the regional graft-versus-host reaction in mice.

Regional graft versus host (GVH) reaction in mice induced by injection of parental strain spleen cells into the footpad of F1, recipients, was measured 7 days later by a popliteal lymph node (PLN) enlargement index. Young, 6-week-old F1 hosts can be used for studying the age- and sex-dependent GVH reactivity of parental strain donors. On the other hand, senescent, 21-24-month-old F1 recipients are able to mount a host versus graft response against parental antigens which may obscure the typical GVH reaction. The PLN enlargement in syngeneic old F1 mice points to an autoimmune mechanism of this phenomenon.