Characterization of Fc receptors associated with human malignant tumors.

Fc receptors from human tumors were isolated by sucrose gradient fractionation and affinity chromatography techniques. The isolated Fc receptors showed specificity for IgG(Fc) in the closed chamber hemadsorption technique and also in the inhibition experiments using radiolabeled Fc receptors. The results indicate that Fc receptors isolated from tumor tissue are similar to Fc receptors isolated from normal human spleen, dog macrophages, and peripheral white blood cells (WBCs). However, the Fc receptors isolated from macrophages are more potent inhibitors when compared with tumor, spleen, and peripheral WBC Fc receptors. Also, Fc receptors isolated from the various sources are independent of species specificity.