Effect of exogenous immunogenic RNA on the antibody synthesis in rat transplantable lymphosarcoma cells.

Cytoplasmic and nuclear RNA were isolated from sheep red cells immunized rat and mouse spleens. Rat spleen nuclear RNA was fractionated in the following steps: 1. thermal fractionation according to Georgiev, 2.

The ability of rat transplantable lymphosarcoma cells to synthesize immunoglobulins.

The hemolytic plaque assay of Jerne and Nordin has been used for the investigation of the ability of the transplantable rat lymphosarcoma cells to synthesize immunoglobulins. The data obtained indicate that in 3-4 days after antigen (sheep red blood cells) administration to the tumor-bearing rats, antibody (hemolysin) producers appear among lymphosarcoma cells. Most representative are the experiments on rats in which their own immune response was totally suppressed by X-ray irradiation.

Some antigenic similarity between nonhistone protein-DNA complexes from chromatin of the cells of Zajdela hepatoma and liver of rats subjected to a single 4-dimethylaminoazobenzene injection.

A comparative study of the antigenic properties of the nonhistone protein (NHP)-DNA complexes, isolated from liver and kidney chromatin of intact rats and from Zajdela hepatoma cells, revealed in the latter the presence of an antigenic component characteristic of kidney chromatin but never occurring in the liver chromatin of intact rats. A similar antigenic component is found in rat liver 4--7 days following a single injection of the hepatocarcinogen 4-dimethylaminoazobenzene and is not observed after an injection of the non-carcinogenic analogue 4-diethylaminoazobenzene. It is noteworthy, that this chromatin alteration resulting from carcinogen treatment is temporary, since on the 11th day following such treatment the kidney antigen is no longer found.