Antigenicity of Pooled Human Malignant and Normal Tissues by Cyto-Immunological Technique: Presence of an Insoluble, Heat-Labile Tumor Antigen

Abstract

Pooled human malignant tissue (epithelial cancer) was used as antigen for preparing anti-cancer serum in horses. The resulting serum exhibited cytopathogenic activity on freshly obtained human malignant cells but not on freshly obtained fetal and adult human cells in tissue cultures. Anti-cancer serum exhibited a cytopathogenic effect on the strain HeLa grown on clot or directly on the glass wall in stationary tubes. The cytopathogenic effect, studied by time lapse motion pictures, was first seen in the ectoplasma, which became flattened to the cell. Retraction, clumping, and lysis were constant features in this reaction. The determining factor in the cytopathogenic reaction was the concentration of anti-cancer serum; the amount of serum or number of cells were not important. The cytopathogenicity of the anti-cancer serum toward the strain HeLa could be inhibited completely by absorption with cancer material but not by treatment under the same conditions with 15 pools of normal human tissues. The antigen responsible for the cytopathogenicity inhibition was not soluble in a series of solvents. It was destroyed by treatment with N, HC1 or NaOH for 48 hours at 35[degree]C. The antigen showed a considerable heat labilty. The cytopathogenicity inhibition reaction seems to be a useful tool for further studies of the antigenicity of normal and malignant tissues.