Characterization and comparison of the lytic function of NKR-P1+ and NKR-P1-rat natural killer cell clones established from NKR-P1bright/TCR alpha beta-cell lines.

From sorted rat NKR-P1bright/T cell receptor (TCR) alpha beta-cells, we established interleukin (IL)-2-dependent cell lines with the morphology, phenotype and function of natural killer (NK) cells. The cell lines NKbr11.3 and NKbr1.28 had large-granular-lymphocyte morphology, were capable of lysing NK-and lymphokine-activated-killer-susceptible target cells, and had the phenotype NKR-P1bright/CD3-/CD4-/CD5-/CD25-/gp42+/TCR alpha beta-. Both cell lines mediated reverse antibody-dependent cellular cytotoxicity via NKR-P1. NKR-P1-subpopulations, identical in all other aspects of phenotype, spontaneously developed in both cell lines. Cloning of NKbr11.3 and NKbr1.28 by limiting dilution resulted in two NKR-P1+ clones, 11.3(6B) and 1.28(3D), and three NKR-P1- clones, 11.3(8A), 11.3(10B), and 1.28(9F). The NKR-P1- clones were lytic and their target preference resembled that of the parental lines, except that C1498 and P815 appeared to be poor targets for 11.3(8A) and 11.3(10B). These cells represent the first reported rat IL-2-dependent NK cell lines and clones. They will be useful for the study of NK cell function as well as the function and expression of NKR-P1.