Defective phagocytic ability of epithelioid cells reversed by levamisole

Both E-macrophages and E-macrophage polykaryons (epithelioid cells) obtained from subcutaneous glass coverslips fail to express IgG (Fe) surface receptors as assessed by phagocytosis of SRBC coated with specific IgG(E(IgG)). When, however, these cells were incubated with E(IgG) in the presence of levamisole, their capacity to ingest these particles returned. It is concluded that loss of FC receptor activity during epithelioid transportation is a reversible phenomenon possibly associated with changes in cyclic AMP.