Development of natural killer cells: comparison of the maturation rates in different lymphoid compartments

By means of semisyngeneic bone marrow transplantation, the appearance of donor-type natural killer (NK) cells in different organs (spleen, blood, lungs) of the recipients was studied. Seven days after the transplantation the first donor-type NK cells appeared in all these organs, and adult NK levels were reached simultaneously within a couple of days. The first NK cells to appear in every organ divided rapidly (sensitive to hydroxyurea) and contained a high proportion of Thy-1+ cells. These data suggest that NK cell precursors mature locally and simultaneously in different organs.