Suppression of immune response in mice by navy bean lectin.

A cluster of cases of Hodgkin's disease was observed in a small town which contained a large navy bean elevator. In previous investigations a lectin was isolated from the navy beans and lymphocytes from town residents were shown to be sensitized to this lectin. Mice were exposed to 15 weekly injections of navy bean lectin. Splenic lymphocytes from injected mice incorporated greater amounts of thymidine than did controls when incubated with the lectin. Cell-mediated immunity as measured by a Concanavalin A dose-response curve was significantly suppressed (p < 0.01) in the injected mice. Long term studies are needed to see if the decreased Concanavalin A response in the mice chronically stimulated with navy bean lectin will predispose to lymphoreticular malignancies.