[Absence of a stimulating effect of T-lymphocytes on the colony-forming activity of splenic hematopoietic stem cells].

Interaction of thymocytes with polypotent stem hemopoietic cells (PSHC) from the bone marrow and spleen was studied in the syngeneic system with the use of a model of an intermediate lethally irradiated recipient, in the spleen of which there is a contact between the test populations, as well as in the donor-recipient semi-allogeneic system. The PSHC of the bone marrow were found to differ in principle from those of the spleen. The difference concerned the regulatory importance of T-cells for stem hemopoietic elements. Thymocytes examined in both the systems stimulated proliferation of bone marrow PSHC but did not affect proliferation of spleen stem cells.