Humoral and cellular immune functions are not compromised by the anticarcinogenic Bowman-Birk inhibitor

Previous studies have demonstrated that the soybean-derived Bowman-Birk protease inhibitor (BBI) is effective as a cancer chemopreventive agent in several animal model systems. Proteases represent a key component of several aspects of immune function; therefore the immune system is a primary target for potential toxicity. The present investigation examines the effect of dietary and intraperitoneally administered BBI on antibody response to keyhole limpet hemocyanin and delayed-type hypersensitivity response to dinitrochlorobenzene. Primary antibody response was not altered by BBI treatment; however, an elevated secondary response was observed in animals receiving dietary BBI at two weeks of age. This effect was not observed at later time points. No change in delayed-type hypersensitivity response was observed in any of the treatment groups.