MACROPHAGE REQUIREMENTS OF PPD-INDUCED BLASTOGENIC FACTOR PRODUCTION BY LYMPHOCYTE-T AND LYMPHOCYTE-B IN THE GUINEA-PIG

An attempt has heen made to characterize the cell type which releases blastogenie ractor(s) (BF) on purified protein derivative (PPD) stimulation in complete Freund's atijuvant (CFA)‐sensitized guinea‐pig system and, further, to examine whether macrophages (Mφ) are required for antigen activation of T or B lymphocytes to produce this lyniphokine. Both T and B lymphocyte populations from guinea‐pigs 2–3 weeks after CFA sensitization (early‐stage T and B cells) failed to produce significant amounts of BF in response to PPD, whereas both the populations from 10 to 14 weeks after sensitizalion (late‐siage T and B cells) acquired the ability to produce BF by themselves. It is noteworthy that readded auiologous Mφ not only functioned well to augment BF production by the late‐stage T and B cells but also completely made up for the inability of the early‐stage T and B cells to produce BF. From these data it is reasonable to conclude that in the guinea‐pig sensitized T and B cells can both release BF on exposure to PPD and that Mtp either reconstitute or augment the BF synthetic response of T and B cells. Copyright © 1979, Wiley Blackwell. All rights reserved