Abstract
Summary Studies have been carried out on the solubilization of the rabbit cell-antigen associated with rejection of transferred allogeneic lymph node cells. Using as a preliminary criterion serologic reaction vs cell-suppressive rabbit anti-rabbit-leucocyte sera, soluble antigen has appeared in low concentration in suspensions of liver cell-fragments from normal rabbits kept for some days at 4°C. The antigen was solubilized by the use of butanol at 20% by volume from suspensions of such liver cell-fragments, if the suspensions were previously maintained at 4°C for some time. Butanol extraction could also be applied to Triton-extracted lipoprotein of cell-fragments obtained from normal rabbit lymph node and spleen with serologically active material obtained in solution in about 10 times the yield obtained from liver, relative to mass of tissue. When the butanol-extracted soluble antigen from rabbit lymph node was injected twice into normal rabbits, the sera of the latter showed the property of suppressing antibody formation by transferred lymph node cells on incubation with the cells in vitro prior to transfer.