Modulation of specific protein expression in teratocarcinoma cell aggregates by antibodies affecting cell-cell...

Decompacting Fab were used as tools to modify cell interactions during embryoid body formation and differentiation of the embryonal carcinoma (EC) PSMB. Two kinds of Fab were used: anti-uvomorulin Fab which recognize only the adhesion glycoprotein uvomorulin and Fab from an anti-EC serum which recognizes a series of molecules including uvomorulin. Both types of Fab led to decompaction and formation of loose aggregates with abnormal deposition of extracellular matrix (ECM) components. Anti-uvomorulin Fab did not affect the pattern of embryoid body differentiation. In contrast Fab anti-EC induced a differentiation of most of the cells in the aggregate into an endoderm-like phenotype. This effect was observed only when anti-EC Fab were added to aggregates and not to monolayer cultures.