Influence of Trypanosoma infection on the formation of E, EA, and EAC rosettes with peripheral blood lymphocytes from calves.

Peripheral blood lymphocyte (PBL) from calves infected with T. brucei and T. congolense or T. congolense alone were tested for their capacity to form E, EA, and EAC rosettes. The results obtained indicate that early in the infection a slight increase in the number of T and B cells has occurred as indicated by the increase in E and EAC rosette formation. At the same time EA rosette forming cells were also increased and persisted during the whole time of the infection. The EA rosette forming cells were more likely null cells, because later in the infection neither E nor EAC rosette forming cells showed any increase.