Rosette-forming cell and cytophilic antibody.

Abstract

AbstractImmunization of mice with two non‐cross‐reacting erythrocytes results in the appearance of double rosettes. Injection of sera from doubly immunized animals into normal mice also results in double rosette appearance when spleen cells are examined after rosette formation and incubation at 0 °C for 1 h. However, passive rosettes entirely disappear after overnight incubation at 4 °C or after incubation for 1 h at 37 °C, whereas active ones persist in significant numbers. These treatments therefore provide an accurate discrimination between cells passively sensitized by cytophilic antibody and cells actively forming antibody.Removal of cells adhering to plastic surfaces from spleen cells of doubly immunized animals provokes a decrease of simple rosettes and a disappearance of doubles among non‐adherent cells.When adherent cells are tested for existence of hemolytic plaque‐forming cells (PFC), it was found that PFC also adhere. Conversely, the non‐adherent cell population is severely depleted of such cells. Moreover, double PFC, again found in initial cell populations, were recovered with adherent cells but were absent in the final non‐adherent population.