Allograft reactivity in chick embryos

Abstract

FRANK SET0 Zoology D e p a r t m e n t , U~z i v e r s i t y of O k l a k o m a , Nornznn, O k l a h o m c~ 73069 ABSTRACTKinetic studies with the splenomegaly assay and the in vivo antibody assay of marker allogeneic immunocompetent cells were made to ascertain when in embryonic development the capacity to actively reject foreign cells is manifested by the chick embryo. It was found that (1) the splenomegaly response elicited with equivalent amounts of immunologically competent cells was high in 14-day embryo hosts but much less in embryo hosts 16-, and 18day of age. Whereas the GVH reaction was effectively reduced in cyclophosphamide-pretreated 14-day hosts, no such effect was observed in older hosts;(2) the antibody production by allogeneic immunocytes, as measured with the in vivo assay, was high in 14-and 16-day embryo hosts, but significantly reduced in 18-day embryo and day-old chick hosts. In contrast the antibody output remained high in all cyclophosphamide-pretreated hosts; and (3) the marker immunocytes, cultured in embryo hosts for several days, maintained their antigen-responsive capacity unimpaired up to the seventeenth day of incubation but showed some loss by the eighteenth day. The experimental findings indicate that the host response during splenomegaly in young embryo hosts is not associated with graft rejection. However, coinciding with the reduction in splenomegaly in older hosts is rejection of donor cells. Alloimmune responsiveness exists as early as the development.

Chick embryo pancreatic transplants reverse experimental diabetes of rats.

“…Work is in progress to determine the threshold glucose concentration necessary to stimulate insulin release from a chick embryonic pancreas because the plasma glucose level of the embryo is below that of the adult I grafts such as the Krebs ascites tumor cells of mice (51) and lymphoid and bone marrow tissues of pigeons (52). However by the 18th d of incubation, allogeneic cells were rejected, indicating that the fate of grafted cells differed in 14-and 18-d embryo hosts (53).…”

Interaction of Embryonic Chicken Spleen Cells and Adult Allogeneic Leucocytes

“…The young embr>o, being immunologically incompetent, would be unai)le to stimulate adult allogeneie eells, but would be responsive to the stimulus provided by these adult celts. However, sinee inunune competence arises in the chicken embryo around 17-18 days of incubation (Seto, 1971), embryos at this stage would also develop the ability to stimulate responsive eells in the donor cell inoculum.…”

Early Development of the Avian Immune System

“…The antibody output was considerably improved, however, if the older hosts were pretreated with the immunosuppressant drug cyclophosphamide (Cy) (Seto, 1971). The antibody output was considerably improved, however, if the older hosts were pretreated with the immunosuppressant drug cyclophosphamide (Cy) (Seto, 1971).…”

“…The antibody output was considerably improved, however, if the older hosts were pretreated with the immunosuppressant drug cyclophosphamide (Cy) (Seto, 1971). ) In contrast among the hosts given cells from B-antigen mismatched donors, with the exception of the 13-day age group, the antibody output was significantly greater in hosts pretreated with Cy (Seto, 1971;1974). 3).…”