X-ray enhancement of splenic rosette-forming cells in nonimmune mice.

The formation of rosettes between spleen cells from nonimmune mice and sheep red blood cells (SRBC) has been investigated. The number of splenic rosette-forming cells (RFC) in the intact spleen was very low but greatly increased after sublethal whole body x-irradiation. These cells were inhibited by pretreatment of the cells with AKR anti-C3H- antigen antiserum, in the presence of fresh guinea pig serum, but not with rabbit anti-mouse immunoglobulin antiserum. The splenic RFC also increased after cortisone acetate administration into mice. These results suggest that the RFC are a T cell sub-population having x-ray resistant and cortisone-insensitive characteristics. The x-irradiation of mice in vivo selectively increased the number of splenic RFC in consequence of reduction in the number of cells having non-T cell characteristics. These RFC are presumably antigen-specific sheep red blood cell rosettes, a quite different situation as in the case of human T lymphocyte rosette formation.