Procedure for immunomagnetic removal of CD4 cells and partial depletion of CD8 cells from the marrow. Erythrocytes were removed and mononuclear cells were enriched by centrifugation using a Cobe Spectra (Step 1). Cells were incubated with CD4-specific immunomagnetic beads and exposed to a magnetic field in a first cycle of CD4 depletion (Step 2). A preliminary aliquot containing the desired number of CD8 cells was removed from the CD4 partially depleted marrow and subjected to a second cycle of CD4 depletion (Step 3b), and the remaining CD8 cells were enumerated (Step 4). The bulk marrow graft remaining after removal of the preliminary CD8 aliquot was subjected to a second cycle of CD4 depletion combined with CD8 depletion (Step 3a). The CD4/CD8-depleted bulk marrow was combined with the counted CD8 aliquot (Step 5) to yield the final graft containing the desired number of CD8 cells. For dose level 0, the entire marrow was subjected to 2 cycles of CD4 depletion with no removal of CD8 cells.