Bab 3: Responder

Responder and stimulator splenocytes were either pretreated with carbonyl iron particles and magnetism or filtered through Sephadex G-10 columns to remove phagocytic and other adherent cells. There is no doubt that both procedures removed conventional macrophages since the frequency of cells ingesting latex particles decreased from ∼7 to <1%. There is evidence, however, that the carbonyl iron procedure also removes nonphagocytic adherent cells (23) and that both procedures remove nonviable and broken cells (unpublished observations). As to the competence for F1 antiparent CML of the depleted populations, results of two representative experiments are shown in Table 1. Treatment of the responder or stimulator population alone consistently resulted in the development of reduced albeit substantial cytotoxicity, but treatment of both populations entirely prevented the generation of CTL. The carbonyl iron procedure was somewhat inferior to Sephadex G-10 filtration, mainly because the effectiveness of adherent cell removal was more batch-dependent for carbonyl iron (Lymphocyte Separator Reagent, Technicon Instrument Co., Tarrytown, New York) than for Sephadex G-10. No attempts were made in these experiments to remove extensively adherent cells by repeated exposures to carbonyl iron or serial fìltrations through Sephadex G-10. In fact, mixed allogeneic cultures of treated splenocytes were often not as incompetent as F1-parent cultures, an indication that enough adherent cells were left behind to support allogeneic CML, the less demanding response with regard to accessory cells.