Enhancing Effects ofGammaInterferon on Phagocytic Cell Association withandKilling ofTrypanosoma cruzi

TheP388D1cells werepretreatedwith250UofRec.IFN--ypermlfor72hand washed before the parasites were added. After the nonbound organismswere removed, half of the cultures (0 time) were interrupted by fixation,whereasthe otherhalfreceived fresh mediumandfurther incubation for6 h.c Given in brackets is the absolute increase or decrease in the numberofparasites per 100 cells observed at the endofthe 6-h period.d Onlythe differences betweenthese values and the correspondingcontrolvalues measured at zero time were statistically significant.e Catalase (8,000