[Effect of a deficiency in the mononuclear phagocyte system and the administration of yeast polysaccharide on the development of a heterotopic source of hematopoiesis].

Mononuclear phagocyte system (MPS) deficiency was induced by repeated peritoneal lavage in (C57Bl x CBA) F1 mice. The animals were then used as donors or recipients in heterotopic bone marrow transplantation. Yeast polysaccharide (YP) produced by Cryptococcus luteolus strain 228 was injected weekly (25 mg/kg) during 30 days after bone marrow transplantation under the kidney capsule. Bone marrow transplantation from MPC-deficient mice to intact mice 30 days later resulted in no variations from the control in cellularity and ossicle weight. YP produced an increase in cellularity, but not in ossicle weight. In the opposite experimental scheme (transplantation from intact mice to MPS-deficient mice) an increase in both cellularity and weight was not noticed. YP injections in this case resulted in the reduction of heterotopic organ size to the control level. Possible mechanisms of this phenomenon are discussed.