Detection of interleukin-6 and interleukin-2 in serum of rhesus monkeys exposed to a nonlethal dose of staphylococcal enterotoxin B.

The immune response to a nonlethal dose of aerosolized staphylococcal enterotoxin B (SEB) was studied in nonhuman primates to define the potential human host response to a nonlethal exposure of SEB on the battlefield. Serum levels of the cytokines interleukin 2 (IL-2) and interleukin 6 (IL-6) increased significantly (p < 0.01) in six juvenile rhesus monkeys 4 hours after receiving a nonlethal, inhaled dose of SEB. The mean (+/-SD) peak serum levels of IL-2 and IL-6 were 63 +/- 39 units/ml and 514 +/- 234 pg/ml, respectively, post-SEB treatment. Tumor necrosis factor, known to be associated with SEB-mediated lethal toxic shock, was undetectable in all samples. gamma-Interferon concentrations were also elevated, but not significantly [p < 0.089]. Hence, elevated levels of IL-2 and IL-6 might be used as a serological marker for a nonlethal, incapacitating exposure to SEB.