[Suppressive effects of graft versus host reaction on humoral immunity: consequences of homograft of chicken spleen on differentiation of the bursa of Fabricius].

By engrafting the chorio-allantoïs of Chick embryos with spleen fragments from homologous adult donors, one elicits a graft-versus-host disease. When the graft is performed before the bursa of Fabricius has reached the lymphoid differentiation state, the final follicular organization is greatly reduced. It seems that this suppression effect cannot be related to a diminution of the stem cell compartment available in the anlage but is a result of a direct impact on the mesenchyme and/or the epithelium of the bursa.