Dose and time related effects of T-2 toxin on mitogenic response of murine splenic cells in vitro.

The effects of T-2 toxin in vitro on murine splenic cells were investigated. Cells from syngeneic male NFS/N mice were cultured with three concentrations of either lipopolysaccharide (LPS), pokeweed mitogen (PWM), phytohaemagglutinin (PHA), or concanavalin A (Con A), for 48 h. T-2 toxin (10(-12)-10(-8)M) was added at the beginning or 24 h after initiation of the cultures. Exposure to T-2 toxin (10(-11)-10(-10)M) after 24 h increased 3H-thymidine uptake by splenic cells. Stimulation by PWM increased dramatically while the response to LPS was increased to a lesser extent in this system. Conversely, exposure to T-2 toxin decreased T-cell responses to both PHA and Con A. Exposing cells to T-2 toxin at the initiation of culture increased Con A stimulation; LPS and PWM responses decreased following 48 h exposure. When splenic cells were pre-treated for 60 or 90 min at 0 degrees C with 10(-9)M T-2 toxin the responses to both PWM and LPS increased. Increased 3H-thymidine uptake was also observed following 90 min exposure to T-2 toxin alone at either 0 or 37 degrees C. The increased PWM response and the mitogenic phenomenon observed when cells were exposed only to T-2 toxin were consistent with previously observed effects of in vivo T-2 toxin exposure.