Lymphoid precursor cell lines have capacity to migrate to multiple lymphoid sites.

Cell lines have been isolated which phenotypically resemble natural killer (NK)/lymphoid precursor cells. These cell lines were derived by in vitro culture and represent continuously replicating cell lines. Since they do not grow as tumours in vivo, it was anticipated that they may have maintained the migratory capacity of their normal cell counterpart. Capacity to migrate to various lymphoid sites, i.e. spleen, bone marrow, thymus and mesenteric lymph node, has been analysed in a short-term 3-hr homing assay following intravenous injection of cells into a syngeneic irradiated host. Frequency of cells localizing in these organs was estimated by limit dilution cloning analysis. Three out of four cell lines were found to migrate to all four organs, while the C6VL/1 T-cell lymphoma was detected in spleen and bone marrow only, and did not enter thymus and mesenteric lymph nodes. This suggests that NK/lymphoid precursor cells may exist which have capacity to recirculate widely through the lymphoid system.