T. Mariani

Induction of Immunological Tolerance to Male Skin Isografts in Female Mice Subsequent to Neonatal Period.

Summary (1) Acquired tolerance of male skin isografts has been produced in females of inbred A and C57Bl (subline 1) strains, over a wide age range, either by injection of viable male spleen cells or by placing females in parabiosis with males. (2) Attention is directed to the importance of age and degree of histocompatibility difference in susceptibility to induction of acquired tolerance. (3) The implications of these observations are discussed.

Effect of Hypophysectomy on Immunological Recovery after Sublethal Irradiation of Adult Rats

Summary Recovery of total leukocyte count, hemagglutinating antibody formation to sheep erythrocytes, and skin allograft rejection was defective after sublethal irradiation in adult hypophysectomized rats. These findings could possibly be interpreted as interference of thymus function by hypophysectomy in immunologic recovery after irradiation.

Transfer of acquired tolerance to skin homografts in mice.

Summary Newborn mice of the ZBC strain injected intravenously with living spleen cells taken from donors of the same strain in which tolerance to Ce tissues was previously induced, became tolerant to this strain and accepted homologous skin grafts from Ce donors. This would indicate that acquired tolerance can be transferred to an isologous individual at birth by the intravenous injection of spleen cells taken from a tolerant donor.

Immunological Tolerance to Male Skin Isografts in Female Mice.

Summary 1) Acquired tolerance to isolo-gous male skin may be produced in female mice of the A and C57 Bl (subline I) strains by injection at birth of living spleen cells taken from isologous adult male donors. The results show that by this procedure sex-determined incompatibility observed between male and female mice of these 2 strains may be overcome. 2) These observations are interpreted as providing evidence for the immunological basis of male skin graft rejection by isologous females.

Analogies between experimental and human lymphoma cutis.

An experimental model system of cutaneous lymphoma has been developed in an inbred mouse system. This utilizes skin isografts from donors which received transplants earlier of a passage ascites lymphoma. Tumor develops in the graft site and follows a development pattern which shows many analogies with human lymphoma cutis.

Comparison of the effects of inoculation routes and viral preparations on leukemogenesis.

Summary Two preparations of Gross passage A virus (one from leukemic tissues and the other from cell-free peritoneal fluid from mice bearing transplantable Gross lymphoma in the ascites form) were used to compare the effectiveness of the intrathymic route of injection with that of the intraperitoneal route. With both preparations, the intrathymic route of inoculation produced a shorter latent period and a higher incidence of leukemia than did the intraperitoneal route. These findings further support the hypothesis that the thymus is a site of primary virus-cell interaction during leukemogenesis. Intraperitoneal injection of virus from peritoneal fluid was more effective in leukemogenesis than similarly administered virus derived from leukemic tssues. Several hypotheses are suggested to explain this phenomenon. It could be the result of the virus titer or a heightened infectivity of the virus in the ascites form. It might also result from the combination of the virus with a helper virus or tissue components that foster infectivity. Or, perhaps, some transport mechanism reflecting a recognition phenomenon is involved.

Age of Donor and Host in Sex Histo-Incompatibility to Skin Isografts.

Summary 1) Age, as a factor in immunological maturity of both donor and recipient, is presented as a possible controlling factor in acceptance or rejection of skin isotransplants in the inbred A strain of mice. 2) The age factor does not play a significant role in skin isotransplants of the inbred C57Bl (subline 1) strain. 3) A sex histo-incompatibility exists in inbred mice of the NH and Ce strains.

Similarities Between Experimental Mouse Lymphoma Cutis and Human Disease

Lymphoma cutis was studied in mice and compared to its manifestations in man. In some cases the disease may be extremely chronic and limited to the skin for many years, while in others it may become disseminated to involve the lymph nodes, viscera, and bone marrow. Fractionated irradiation to a total dose of 2,500–3,000 rads is sufficient to clear the skin lesions in man.

Induction of Leukemia in Weanling C3H/Bi Mice by Means of Skin Transplantation from Preleukemic Donors

Summary C3H/Bi weanling mice were grafted with skin taken from 4-week-old preleukemia, syngeneic mice (GPA virus system) which had been inoculated at birth with Gross passage A virus. Careful analysis of the tissues of the grafted weanlings (carried out after natural death of the animals) revealed a high incidence of thymus enlargement and a 100% incidence of disseminated lymphoma. This indicates that leukemogenesis was induced by means of skin transplantation in 100% of the weanling animals by the skin grafting of preleukemia skin.