Dependence on macrophages of the guinea pig T-cell immune response to Herpetomonas samuelpessoai.

The specific in vitro activation of guinea pig T-lymphocytes by Herpetomonas samuelpessoai and its dependence upon macrophages was studied. Peritoneal exudate T-cells from guinea pigs sensitized against intact H. samuelpessoai organisms were activated specifically in vitro as measured by 3H thymidine incorporation. These same T-cells also were activated by Trypanosoma cruzi extracts, indicating cross reactivity at the cellular level between the two protozoan antigens. The T-cell specific response was found to be dependent on adherent cells. Moreover, macrophages that had been "pulsed" in vitro with H. samuelpessoai organisms were able to induce the specific T-cell activation.