Preliminary characterization of lymphoid hybridoma cell lines derived from the pregnant mouse uterus

Seven independent cell lines were derived from the fusion of migratory cells recovered from explant cultures of metrial glands to SP 2/0, a non-Ig secreting B cell myeloma. The migrating cells came from a pool of metrial glands from day 6-8 pregnant random bred CD1 mice and were assumed to be cells early in the differentiation pathway to granulated metrial gland (GMG) cells. The fused cells were cloned twice at the limiting dilution. Hybridization was confirmed by quantitation of cellular DNA using propidium iodide staining and by karyotyping. Electron microscopy revealed that each of the hybrid cell lines was composed of cells which were lymphoid in appearance, but lacked the granules found in mature GMG cells. The surface phenotype of all lines is CD45+, LGL-1-, asialo GM-1-, IgG-, IgM-, CD3- and CD25- (p55 of IL-2 receptor). Although the hybridomas lack those phenotypic markers which were used to show that GMG cells are related to the natural killer (NK) cell lineage (ie LGL-1, asialo GM-1), they do express the pan-leukocyte marker CD45 as well as the lytic protein, perforin, at levels intermediate to those of SP 2/0 cells and GMG cells. In addition, the hybridomas were observed to preferentially bind the NK target cell YAC and to be capable of lytic activity at temperatures below 30 degrees C. Because these hybridomas may represent fusion to an early progenitor cell of the NK/GMG cell lineage, their continued characterization is of merit.