ONTOGENY OF CELLS INVOLVED IN THE SUPPRESSOR CIRCUIT OF THE IMMUNE-RESPONSE

Some macrophage (MΦ) cell surface structures which bind T cell‐derived factors remain intact after the MΦ are killed by heating at 56°C(but not 72°C) for 45 min. As a result, appropriately killed MΦ (HK MΦ) can act as competitive antagonists for those MΦ functions which are involved in binding and active presentation of T cell derived regulatory signals. By blocking the transmission of these signals with HK MΦ, we have found that the spleens of newborn mice contain considerable numbers of “latent” helper cells whose activity is not ordinarily seen because it is overridden by suppressor mechanisms. Similarities between these neonatal helper cells and a subset of adult T helper “inducer” cells (cell surface phenotype Ly‐1+; Ly‐2−,3−; IJ+; Qa l+), whose activity appears in significant numbers only after immunization, are described. Copyright © 1979 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim