Sensitivity of murine hemopoietic stem cells to lectin cytotoxicity

The response of normal murine bone marrow and mastocytoma cells to the cytotoxic effect of the four lectins WGA, PHA, SBA and Con A was studied. It was found that the two types of cells had similar sensitivities to each of the four lectins, as judged by decreased ability to develop colony growth in soft agar. They differed, however, in their sensitivity to particular lectins. The cells were most sensitive to WGA, less sensitive to PHA and SBA, and least sensitive to Con A. In further experiments, carried out on bone marrow cells, it was found that pluripotent stem cells (CFU-S) and committed stem cells (CFU-C) were equally sensitive to the cytotoxic effect of WGA. Incubation of bone marrow cells with 12 mug/ml WGA at 37 degrees C for 30 minutes had no effect on CFU-C; incubation for 60 minutes produced a 70% decrease in CFU-C. Additional periods of incubation up to 120 minutes did not further affect CFU-C, suggesting that some particular phase of the cell cycle may be sensitive to the cytotoxic effect of lectins.