Naturally occurring antibodies against fibrosarcoma and glioma cells in rats
Itaya, T.; Moriuchi, T.; Kodama, T.; Sendo, F.; Kobayashi, H.
Gan 73(3): 454-461
1982
ISSN/ISBN: 0016-450X PMID: 7129010 Document Number: 190846
The presence of natural antibodies (NA) against fibrosarcoma and glioma cell [of 20 transplantable tumors and 2 rat tumor lines] was detected in the normal sera of 10 different strains of rats. By a complement-dependent cytotoxicity test and an absorption test, the NA-reactive antigens were detected in all investigated syngeneic and allogeneic fibrosarcoma lines and 1 glioma line, but not in hepatoma, lymphoma, leukemia and neurinoma lines. The cytotoxic activity of NA was significantly absorbed by normal brain, lung, kidney, skin homogenates and cultured fibroblasts of syngeneic rats, but not by liver homogenates, thymus, spleen, lymph node or red blood cells. With the exception of a Donryu rat strain, there were no strain or sex differences in the NA levels among the investigated strains of rats. The NA were biochemically identified as being IgM and were stable at 56.degree. for 30 min. The level of NA correlated with the in vivo anti-tumor response: when NA-reactive fibrosarcoma or glioma cells were implanted into syngeneic WKA/Hok rats, groups of rats with high NA levels showed suppression of tumor growth and prolongation of survival time compared to groups of rats with low NA levels, while there was no difference in survival time of rats transplanted with NA nonreactive hepatoma or lymphoma lines. When 3-methylcholanthrene was inoculated into rats, the tumor incidence in the group of rats with high NA levels was significantly suppressed compared to the group of rats with low NA levels.