Functional behaviour of skin allografts transplanted to rabbit deciduomata

The behaviour and fate of allogenic skin transplanted to rabbit deciduomata was investigated and compared with orthotopic and subcutaneous allografts. Allografts implanted in the decidua of non-sensitized hosts were alive and showed no evidence of immunological rejection 14 days after grafting. The surrounding decidual tissue showed no infiltration by lymphocytes. Allografts in the myometrium of nonsensitized hosts demonstrated immunological rejection as early as 7 days post grafting. Orthotopic allografts on non-sensitized hosts were rejected between 7 and 8 days. Allografts implanted in the decidua of pre-sensitized hosts were alive and histologically healthy 6 days after grafting but showed minimal survival at 8 days. Since rejected grafts were not usually infiltrated with lymphocytes it was concluded that humoral antibody, in the absence of a cell mediated effect, may have procured the destruction of grafts. Subcutaneous allografts in pre-sensitized hosts were rejected between 4 and 6 days after grafting and demonstrated a classical second set type of immunological reaction. The significance of these results was discussed and it as suggested that the decidua, possibly because of its structure, may serve to restrict invasion of its substance by maternal immunocompetent cells thus contributing to the immunologically privileged nature of pregnancy.