The Production of “Delayed Type” Cutaneous Hypersensitivity to Human Donor Leukocytes as a Result of the Rejection of Skin Homografts*

SUMMARY The immunity occasioned by the rejection of askin homograft in man is manifested by delayedintradermal sensitivity following injection of do-nor white blood cells. Unlike the immunity oc-casioned by the rejection of a previous skin homo-graft itself, under the conditions of our experi-ments, this reaction is not specific for donorleukocytes but may be elicited by the injection ofnondonor leukocytes into a sensitized recipient. ACKNOWLEDGM ENT The authors gratefully acknowledge the invaluable as- sistance of Miss Audrey Jean Clemens in carrying out this study.REFERENCES1. Lawrence, H. S. Homograft sensitivity. An expres-sion of the immunologic origins and consequencesof individuality. Physiol. Rev. 1959, 39, 811.2. Brent, L., Brown, J., and Medawar, P. B. Skin transplantation immunity in relation to hyper-sensitivity. Lancet 1958, 2, 561. 3. Billingham, R. E., Brent, L., and Medawar, P. B.The antigenic stimulus in transplantation im- munity. Nature (Lond.) 1956, 178, 514.4. Friedman,