Graft versus host response as influenced by the origin of the cell, age of chicken, and cellular interactions.

Mononuclear cells collected by Ficoll-paque or T cells collected by nylon wool elicited the same magnitude of graft versus host (GvH) response as mononuclear cells collected from the buffy coat (BC). Bone marrow, spleen, or thymic BC cells from day-old chickens did not produce a GvH response. The GvH ability of spleen and bone marrow BC cells increased rapidly during the first 4 weeks and then plateaued. Although at 4 and 12 weeks of age the GvH response produced by thymic BC cells was significantly less than spleen or bone marrow BC cells, thymic BC cells did produce a significant GvH response at these ages. Thymic BC cells from 11-month-old chickens showed significantly higher GvH response than those of previous ages. Corticosterone treatment of chickens eliminated the thymic cortex but did not enhance the GvH reactivity of thymic BC cells. Suppressor effect of thymic BC cells from day-old chickens was not detected. A synergistic effect was noted in the GvH reaction when thymic cells were combined with bone marrow or splenic BC cells of 4-week-old chickens.