Studies on the antigenicity of bone. I. Freeze-dried and deep-frozen bone allografts in rabbits.

The antigenicity of deep-frozen and freeze-dried cortical and corticocancellous bone allografts placed orthotopically in rabbits was studied using a sensitive microcytotoxicity assay. Target cells were phytohemagglutinin-P-stimulated, 51chromium-labeled peripheral blood lymphocytes from the bone donors (Dutch belted rabbits), and sera or peripheral blood lymphocytes from the graft recipients (New Zealand white rabbits) were used as effectors of cytotoxicity. Fresh allografts and deep-frozen corticocancellous bone evoked detectable humoral and cell-mediated immunity,, whereas freeze-dried cortical bone allografts failed to sensitize the recipients and were the least antigenic of the allografts examined.