Humoral immunodepression following acute NO2 exposure in normal and adrenalectomized mice

The effects following 20 ppm NO2 exposure on humoral immunity were investigated in C57Bl/6 mice after 48, 72, and 96 h exposure. Both spleen plaque-forming cell (PFC) responses and serum hemagglutinins (HA) using sheep red blood cells (SRBC) as antigen were studied. Splenic and thymic weight and cellularity decreased on acute exposure to NO2. PFC were markedly depressed after 48 h exposure and continued to decrease as exposure time was lengthened. HA titers were also depressed. The same significant suppression of PFC and HA titers was observed in adrenalectomized mice after 96 h NO2 exposure. The depression of humoral immunity in NO2-exposed mice was independent of stress-induced endogenous steroids.