Cell hybridization and cell agglutination. I. Enhancement of cell hybridization by lectins.

A great increase in hybridization frequency of cultured rodent cells was obtained when conventional cell fusion using 50% polyethylene glycol (PEG) was combined with a cell agglutination produced by plant lectins. The rate of appearance of hybrid colonies was found to be correlated with the extent of cell agglutination by lectin, as well as with cell fusion induced by subsequent PEG treatment. Phytohemagglutinin (PHA), wheat germ agglutinin, Wistaria floribunda agglutinin and concanavalin A were all active; the most effective was PHA. When parental cells in a monolayer were treated with PHA followed by PEG, the resulting hybridization frequency was very low because of markedly decreased viability, whereas the same cells in suspension yielded hybrid colonies at a higher rate. These results suggest that the enhancement of hybridization by PHA/PEG treatment was brought about by the ability of lectin to agglutinate cells.