Cellular immunoabsorption using monoclonal antibodies. Selective removal of T cells from peripheral blood and bone marrow.

T cells can be selectively removed from human peripheral blood and bone marrow by passage over a column containing monoclonal anti-T-cell antibodies covalently attached to Sepharose 6MB gel. Effective depletion of T cells from peripheral blood mononuclear cells (PBMC) resulted in the appearance of Leu-2-positive cells, most of which do not express Leu-1 or Leu-4 antigens. Using a column containing anti-Leu-1 or anti-Leu-4 attached to Sepharose 6MB gel, depletion of 98.3% and 99% of T cells from bone marrow mononuclear cells (BMMC), respectively, was demonstrated with recovery of approximately 75% of non-T cells. These columns removed 92.3-98.4% T cells from PBMC with 43.5-74.8% recovery of non-T cells. Combining anti-Leu-1 and anti-Leu-4 antibodies on the same gel removed all detectable T cells from PBMC and BMMC. Proliferative responses to the T cell mitogen, phytohemagglutinin, were abolished from both PBMC and BMMC after column treatment. Preservation of hematopoietic progenitors was observed after treatment of bone marrow, with stem cell recovery averaging 83 +/- 26% for burst-forming units (erythroid), 86 +/- 14% for granulocyte-macrophage progenitors and 94 +/- 16% for granulocyte, erythroid macrophage, and megakaryocitic elements. These results suggest that clinical application of cellular immunoabsorption techniques using monoclonal antibodies will be useful in bone marrow transplantation.