Prevention of Viral and Transplant Tumors in Hamsters Employing Killed and Fragmented Homologous Tumor Cell Vaccines ∗

Abstract

Summary

Studies were continued in SV₄₀ and adenovirus 7 hamster tumor systems to develop means for isolating tumor-specific transplant antigen, essentially free of normal tissue antigens, preparatory to consideration for vaccination experiments employing autochthonous tumor vaccines in man. Consistent with previous experiments, SV₄₀ virus-induced tumor cells lost their immunizing ability for the host when treated with formalin or disrupted by a French pressure cell or nitrogen decompression. By contrast, adenovirus 7 tumor cells treated with formalin or disrupted by freeze-thaw, by use of a French pressure cell, or by nitrogen decompression retained the ability to immunize against the same cell tumor challenge. The latter findings are regarded as a significant step toward eventual development of tumor cell vaccines employing fractionated and purified antigens.