Hamster monoclonal antibodies to murine natural killer cells

To further the study of natural killer (NK) cells we have produced hamster monoclonal antibodies (MAbs) with reactivities to mouse NK cells. MAbs 4A2 and 3C2 were obtained by fusing spleen cells from Syrian hamsters immunized with IL-2-activated NK cells with Fox-NY myeloma cells. 4A2 antigen was expressed by bone marrow (BM)-derived IL-2-responsive NK cell precursors, by mature NK cells of the BM, and by a highly lytic subset of splenic NK cells, in addition to IL-2-activated NK cells. 3C2 antigen was also expressed by BM-derived NK cell precursors, by mature NK cells in the BM, at low levels by splenic NK cells, and at high levels by IL-2-activated NK cells. These MAbs are likely to provide useful reagents for the study of the life history and functional significance of NK cells.