TRANSFER OF DELAYED HYPERSENSITIVITY TO SKIN HOMOGRAFTS WITH LEUKOCYTE EXTRACTS IN MAN*

Abstract
Skin homograft sensitivity (accelerated homograft rejection) has been transferred to nonsensitive recipients with deoxyribonuclease-treated leucocyte extracts prepared from sensitive donors: (a) in 4 out of 4 consecutive attempts by local transfer technique and a dosage of 2 grafts to sensitize the leukocyte donor; (b) in 6 out of 6 attempts by systemic transfer technique and a dosage of 4 grafts to sensitize the leukocyte donor. Dosage of 1 or 2 grafts is not sufficient to sensitize the leukocyte donor so as to allow systemic transfer of sensitivity. Dosage of 4 successive grafts sensitizes donor leukocytes so as to permit systemic transfer of sensitivity only if the repeat-set grafts undergo accelerated rejection, and not if white graft reactions are produced. Serum from sensitized donors or leukocytes from nonsensitive donors do not transfer homograft sensitivity. The results of transfer of homograft sensitivity by means of leukocyte extracts generally parallel those obtained in man following similar transfers of bacterial (tuberculin, streptococcal proteins, diphtheria toxoid) and fungal (coccidioidin) hypersensitivities of the delayed type. This finding fulfills a critical criterion relating delayed hypersensitivity of the tuberculin type to homograft sensitivity.