Effect of temperature on suppressor cells in chicken spleen cell cultures.

The plaque forming cell (PFC) response of in vivo primed chicken spleen cells to sheep erythrocytes (SRBC) at 37 degrees C in vitro was much higher when antigen was added on Day 2 of culture than on Day 0, at the initiation of the incubation period. No such difference was observed when the cells were cultured at 40 degrees C, in which case both responses were low. As shown previously the effect of delayed exposure to SRBC at 37 degrees C was due to a disappearance of suppressor T cells in the absence of antigen, which did not occur at 40 degrees C. Addition of concanavalin A on Day 0 could, even in the absence of SRBC, maintain the suppressor cell activity at 37 degrees C. The results suggest that suppressor cell activity is very temperature dependent.