Mercaptoethanol-Sensitive Antibody Production in Germ-Free Mice and Guinea Pigs

Summary Germ-free and nongerm-free guinea pigs and mice were injected intraperitoneally or in the footpads with soluble I131 bovine γ-globulin (BγG) or BγG precipitated with alum. The germ-free guinea pigs responded to these injections in a manner similar to the nongerm-free guinea pigs. Germ-free mice injected intraperitoneally also responded in the same manner as nongerm-free mice, but germ-free mice injected in the footpads produced only a delayed 19 S antibody response while nongerm-free mice injected in the footpads demonstrated a prompt antibody response with a 19 S-to-7 S conversion. It is suggested that this difference in antibody response in germ-free mice after different routes of injection indicates that the number of “potentially competent” cells available to a given antigen may determine the type of antibody produced.