Growth of the Reh cell line in diffusion chambers. Evidence for differentiation along the T- and B-cell pathway.

Cells of the Reh line, originally derived from an ALL of the 'Non-T, Non-B' type were cultured in diffusion chambers implanted intraperitoneally into perirradiated CBA mice. At different intervals over a period of 20 d changes in surface characteristics were examined by labelling the cells with AcALLG, ATCG as well as with polyvalent AIg. The evaluation was performed by using direct immunofluorescence. In addition, the ability to form rosetts with SRBC, AET-treated sheep erythrocytes, mouse red blood cells and EoxAC was tested. On day 0 of the diffusion chamber culture the cells only carried cALLA, and no rosette formation was observed. In the course of the diffusion chamber culture the cells unequivocally developed T-cell antigen, and in 1 of 2 experiments they further acquired a receptor for forming AET- and E-rosettes. Conversely, in the other experiment a receptor for mouse red blood cells was detected in a considerable portion of the cells. Our data show that the rather undifferentiated Reh line cells in vitro are able to develop features of mature T-cells and attributes of early B-cells during the diffusion chamber culture. In vitro they apparently retain a bivalent potentiality of lymphatic maturation. The diffusion chamber system proves to be a suitable tool for promoting differentiation in these cells.