Studies on the immune response to fixed antigens. Preferential induction of helper function with heavily trinitrophenylated sheep erythrocytes, and glutaraldehyde treated sheep erythrocytes

Mice primed with heavily trinitrophenylated sheep red cells (TNP₁₂₈SRC) or glutaraldehyde treated sheep red cells (G SRC) developed an early helper function mediated by thymus derived cells. Such mice were able to produce high secondary responses to both hapten and carrier after challenge 2 days after priming, with lightly trinitrophenylated SRC (TNP(0.14) SRC). However, the primary responses of the TNP₁₂₈SRC or G SRC primed mice were very low to undetectable, and their secondary responses were also low when the challenge antigen was administered 4 days after priming or later. Inhibitory humoral factor(s) which were induced in the primed animals appeared responsible for the decreased capacity of primed mice to mount a secondary response when challenged later than 2 days after priming. Transfer of spleen cells from TNP₁₂₈SRC primed mice to sublethally irradiated recipients circumvents their exposure to inhibitory humoral factor(s) present in intact animals allowing them to react with challenge antigen. Enriched populations of T cells, but not B cells, were able to transfer this early immunologic memory to irradiated recipients. The theoretical and practical implications of these results are discussed.