The demonstration in vitro of the mitogenic effects of trypanosomal antigen on the spleen cells of normal, athymic and cyclophosphamide-treated mice

When the spleen cells of normal NIH mice were cultured with pokeweed mitogen (PWM), staphylococcal filtrate (SF) and trypanosomal antigen (TAg), and tritiated thymidine (³H]Tdr) incorporation was used as a measure of mitogenic activity, the TAg (at a level of 25 μg/ml of spleen cell suspensions containing 2–3 × 10⁶ cells/ ml) was found to be a better mitogen than SF. PWM, however, was more effective than either of the two. ³H]Tdr incorporation by the spleen cells of Nu/nu (`athymic') mice was greater than that by the spleen cells of normal NIH mice when equal numbers of both cells were cultured with TAg. Pretreatment of NIH mice with cyclophosphamide suppressed ³H]Tdr incorporation by their cells when TAg was added to the cultures. The TAg used was derived from T. brucei TREU 226 obtained from Edinburgh University.