Antigenic Differences between Leukemia L1210 and a Subline Resistant to Methylglyoxal-bis(guanylhydrazone)1

Cells from leukemia L1210 and a subline resistant to methylglyoxal-bis(guanylhydrazone) elicited a demonstrable humoral antibody response in DBA/2Ha-DD mice. Using paired-label 7-globulin mixtures containing '3 ' I-labeled normal and '2 5I-labeled immune 7-globulin, we showed that the specific uptake of antiresistant L1210 cell 7-globulin by resistant L1210 cells was consistently higher than that of anti-L1210 cell 7-globulin by LI210 cells. Moreover, above a certain level of cross-reactivity, the specific uptake of immune 7-globulin was 4 to 10 times higher with the cell type that was used to immunize the serum donors than with the other cell type. A greater uptake of 7-globulin by homologous cells was also found in vivo. The residual specific uptake of antiresistant L1210 cell 7-globulin by resistant L1210 cells was completely removed after 10 subsequent absorptions with resistant L1210 cells but not after 10 absorptions with L1210 cells. The data indicated that the resistant leukemic cells are more immunogenic than the LI 210 cells in DBA/2Ha-DD mice, that the two cell lines share some common antigens, and that, in addition, the two cell types have different antigenic components.