Studies on the properties of the immunologically effective anti-tumor substance from spleen cells of tumor-resistant rats.

ABSTRACT

The influence of physical and chemical treatments upon the immunologically effective subcellular fractions (5,000 X g supernatant and 105,000 X g sediment), which were prepared from the spleen cells of Yoshida sarcoma (YS)-resistant Donryu rats, was studied. The immunological activity of the 5,000 X g supernatant was stable to heating at 80 degrees C for 30 min. It was stable to alkali (pH 10) and less stable to acid (pH 2). It was labile to a ten-day storage at 4 degrees C, but relatively stable to a 30-day storage at -20 degrees C. When the 105,000 X g sediment was lyophilized and stored at -20 degrees C for 95 days, its immunological activity was well maintained. It was labile to 95% ethanol, 90% phenol and 2 M NaNO2, but relatively stable to 10% as well as 100% acetone, 10% phenol and 10% ethanol. It was labile to 0.1 M NaIO4 and relatively stable to 0.1 M K2Cr2O7 solution. It was labile to RNase but relatively stable to DNase.