Characterization of two plasmacytoma fractions and their RNA capable of changing lymphocyte surface immunoglobulins (cell conversion)

Extracellular nucleic acids as possible messengers in regulatory information transfer from immune system to non-lymphoid tissues

The goal of this review is to connect the information on the regulation of growth and differentiation of non-lymphoid tissues by the immune system and the release/uptake of nucleic acids by living cells (especially by lymphocytes). Nucleic acids are suggested to be the messengers in regulatory information transfer from the immune system to other cells.

Immunoglobulin expression on theta-positive leukemic cells in AKR/J mice

The expression of surface immunoglobulin was studied on cells of theta-positive AKR leukemia during repeated weekly passages of ascitic cells. It could be shown that the percentage of Ig-positive cells varied considerably (0-25%) and that this was accompanied by variations in the expression of theta-antigen on the cell surface. This was interpreted as repression and derepression of genes coding for surface antigen possibly at the translational level.

Some perspectives on the transfer of cell-mediated immunity by immune-RNA

Ribonucleic acid extracts of lymphoid cells from immune hosts were used to transfer in vivo and in vitro cell-mediated immune reactivity to a variety of antigens. The in vivo immune responses transferred by RNA included the delayed cutaneous hypersensitivity reaction to fungal and chemically-defined antigens and the tumor-rejection reaction to guinea pig hepatoma antigens. The in vitro immune responses transferred by RNA included macrophage migration inhibition by fungal, chemically-defined, and tumor antigens. The transfer activity of RNA preparations was contained in the 8 s to 18 s species of RNA and was sensitive to RNase but not to DNase or trypsin. Antigen was not detectable in the RNA preparations and appeared to have no role in the transfer activity. Syngeneic, allogeneic, or xenogeneic sources of RNA could transfer immune reactivity. In each system tested, the transfer of cell-mediated reactivity by RNA was specific for the antigen used to sensitize the RNA donor. The potential use of RNA-mediated transfer of immunity is discussed.