Expression of the RT1A molecule of the class I major histocompatibility complex in a walker 256 tumor after transplantation into brattleboro rats with a genetic defect of arginine-vasopressin synthesis

The dynamics of expression of the RT1A antigen of the class I major histocompatibility complex (MHC) in a Walker 256 tumor after its transplantation into Brattleboro rats with a genetic defect of arginine-vasopressin synthesis in the hypothalamus was studied. Expression of the RT1A antigen was detected by means of Western-blotting and flow cytometry in the tumor cells on the 14th–17th days after transplantation. In addition, a simultaneous increase in the portion of cells that express the RT1A antigen and in the level of its expression per cell was observed. It is presupposed that at a deficiency of arginine-vasopressin, a renewal of expression of the class I MHC antigens, which results in an increase of immunogenicity of this tumor and regression, occurs in the Walker 256 tumor in the Brattleboro rats.