Tumor‐associated immunoglobulins. enhancement of syngeneic tumors by igg2‐containing tumor eluates

The present study was intended to establish whether IgG2‐containing eluates, dissociated from carcinogen‐induced tumors by a low pH buffer, have tumor‐enhancing properties. Threshold amounts of cells from mouse tumor lines originally induced by benzo (a)‐pyrene or by methylcholanthrene were mixed and incubated, prior to inoculation, with IgG2‐containing eluates, originating either from the corresponding tumors (autologous eluates) or from other syngeneic tumors (isologous eluates). Tumor cells incubated and injected together with autologous eluates gave in some experiments a higher yield of tumors in syngeneic mice than did cells not subjected to this treatment. Some isologous eluates originating from several primary tumors or from syngeneic tumors belonging to a different line from the one tested, were also capable of enhancing tumor growth.