Peculiar Gamma G in Tumour Cells and Depletion of Antibody Forming Organs in Tumour Bearing Mice

Abstract

Two findings made during a study of the antigenic composition of ascites cell extracts (unpublished results) may be causally related, (a) Extracts of ascites cells of the MCIA strain, kept bacteria-free in RIII mice¹, were subjected to immunoelectrophoresis against corresponding antiserum and revealed a slow moving protein which formed an arc at the edge of the cathodal field. Extracts of spontaneous mammary carcinomas of RIII mice and C3H strains tested against the same antiserum produced identical arcs (Fig. 1a). These arcs were not produced by anti-serum absorbed with living ascites cells, and they are apparently caused by an antigen of the tumour cell surface. This cell antigen, precipitating in the region of the gamma₂ globulins, did not cross-react with normal mouse serum globulins. When, however, the ascites-bearing mice lived for as long as 14–16 days after receiving a small inoculum, an identical or similar protein could be revealed in sera and ascites fluids, though only in the last 2 or 3 days.