Evaluation of Acute Immunotoxicity of Aerosolized Aflatoxin B1 in Female C57BL/6N Mice

There is evidence for immunotoxicity of aflatoxin B1 (AFB1) in chronic animal feeding studies; however, little information is available as to the effects of inhalation exposure. This study evaluated the acute affects of aerosolized AFB1 on systemic immune function of female C57BL/6N mice following a single aerosol exposure. Mice were exposed in nose-only inhalation tubes to 0, 2.86, 6.59 and 10 μg AFB1 aerosol/L air for 90 minutes. A negative control group of untreated mice and a positive control group of cyclophosphamide-treated mice were included to account for day to day variation. Three days following exposure, mice were sacrificed and body, liver, lung, thymus and spleen weights, and complete blood counts and white blood cell differentials were measured. Splenocytes were isolated for flow cytometric analysis of CD4+ and CD8+ lymphocytes, CD19+ B-cells and natural killer cells (NK 1.1+). The effect of AFB1 on humoral immunity was assessed by measuring serum anti-keyhole limpet hemocyanin (KLH) IgM lev...