Anticellular serum inhibited phagocytosis of colloidal gold and staphylococci by HeLa cells. This inhibition of phagocytosis was reversed by conditions which allowed the antibody to elute from the cell. Concentrations of antiserum that inhibited phagocytosis did not interfere with the transport of tritiated thymidine and uridine across the cell membrane, and their incorporation into cell nucleic acids was unaltered as evaluated by autoradiography. These results indicate that thymidine and uridine were taken into cells independently of phagocytosis.
Morphologic changes induced in the cells by antibody suggest that the antibody agglutinates adjacent portions of the cell membrane. This agglutination of the cell membrane by antibody would be expected to interfere with the continuous evagination and invagination of the cell membrane associated with phagocytosis.
The inhibition of virus infection by anticellular antibody may be a result of the effect of the antiserum upon phagocytosis.