IMMUNOLOGICAL STIMULATION OF EARLY MURINE HEMATOPOIESIS AND ITS ABROGATION BY CYCLOSPORIN-A

  • 1 January 1982
    • journal article
    • research article
    • Vol. 59  (4) , 851-856
Abstract
Mice injected chronically with antiplatelet serum develop an increase in the number of megakaryocytic progenitor cells compared to animals given normal rabbit serum. To examine the specificity of this response, progenitor cells giving rise to megakaryocyte, granulocyte-macrophage, erythroid and mixed-cell colonies were assayed after injection of various heterosera or saline. All 4 colony types increased in the serum-treated groups. Since the in vitro proliferation of hematopoietic progenitor cells is promoted by supernatants of mitogen-stimulated spleen cells, the immune response following antiserum administration may result in the in vivo activation of T lymphocytes which produce or lead to the production of colony stimulating activities. Cyclosporin A, a preferential inhibitor of T lymphocyte function, was given to mice concurrently with antiserum and also added to spleen cell cultures in the presence of pokeweed mitogen. Cyclosporin A abrogated the antiserum-related increases in progenitor cell numbers in vivo and the production of colony stimulating activity in vitro. The immune response related to antiserum administration probably results in the in vivo production of hematopoietic colony stimulating activities that may be identical to those produced in vitro by mitogen-stimulation of spleen cells.