Trypanosoma lewisi: In vitro behavior of rat spleen cells

Dissociated splenic cells from rats infected with Trypanosoma lewisi were cultured in vitro for short periods of time. The macrophages showed a capability to be activated as early as the second day. Somewhat later, lymphocytes and young cells formed clusters surrounding larger phagocytic cells. This phenomenon, maximal at the peak of the infection, was accompanied by an increase in the number of blast cells and young cells. Dividing or mature trypanosomes, when placed in culture with splenic cells from infected hosts, generally continued to divide or began to divide. However, some selection by adhesion to the splenic cells occurred, so that the percentage of dividing forms was reduced in the supernatant fluid. This effect could be made more prominent by utilizing only those splenic cells-clusters and macrophages-which were adherent to glass.