Cytotoxicity of plant lectins for mouse embryonal carcinoma cells

The cytotoxicity of 10 plant lectins with different carbohydrate recognition properties towards a number of mouse embryonal carcinoma (EC) cell lines (F9, OTF9-63, PCC4, PCC3/A/1, P19, and P19S1801A1) has been examined. Six of the lectins are toxic for the majority of the cell types at concentrations of ≤100 μg/ml and should be useful as direct selective agents for the isolation of EC glycosylation mutants (see accompanying manuscript). However, the concentration of the various lectins required to kill 90% of the cell population differs markedly between EC cell lines, the greatest variation being observed with the lectins from T. vulgaris (wheat germ agglutinin; WGA) and G. simplicifolia (GS-I). The lectin-binding abilities of different EC cell lines also vary and do not necessarily correlate with their relative lectin sensitivities. Certain lectins which are not toxic even at concentrations of 200 μg/ml, nevertheless exhibit significant binding at the cell surface. The extensive variation in lectin sensitivities and lectin-binding abilities between the EC cell lines is diagnostic of the expression of different carbohydrate structures at their respective cell surfaces. The results suggest that the EC lines examined will give rise to different families of glycosylation mutants.