Conversion of Non-Immune Rabbit Spleen Cells by Ribonucleic Acid of Lymphoid Cells from an Immunized Rabbit to Produce IgM and IgG Antibody of Foreign Heavy-Chain Allotype

Abstract

Abstract Spleen cells (SpC) from non-immunized rabbits homozygous for one allotype at the a heavy-chain locus of immunoglobulins were incubated with RNA extracts of lymph nodes from immunized homozygous rabbits of a different genotype to yield IgM “direct” plaque-forming cells (PFC) or IgG “indirect” PFC. The heavy-chain allotype of the antibody in the plaques was identified by radioautography and by inhibition of plaque formation using anti-allotype antibodies. The allotype of the RNA donor rabbit was identified in 75% to 86% of the IgM “direct” plaques and in 43% to 62% of the IgG “indirect” plaques. The allotype of the SpC donor rabbit was found in 2% to 12% of the IgM “direct” plaques and in 24% to 39% of the IgG “indirect” plaques. The lysates of “RNA-converted” SpC were analyzed for immunoglobulins of each heavy-chain allotype by immunodiffusion. Allotypes of both RNA and SpC donor rabbits were found in the lysates, whereas only that of the SpC donor was found in the lysates of untreated SpC, and neither allotype was found in the RNA extracts. These results were similar to those reported previously for light-chain allotypes and indicated that a component of the RNA extract provided information for synthesis of at least part of the heavy chains as well as the light chains of the IgM and IgG antibody molecules.