Antibody-dependent and -independent cytotoxic activity of spleen cells for Plasmodium berghei from susceptible and resistant rats.

Antibody-dependent cell cytotoxicity (ADCC) mediated by spleen cells from 30- or 50-day old rats against 51Cr-labelled rat erythrocytes parasitized by Plasmodium berghei in the presence of anti-P. berghei antibody showed only slight age differences. However, in the absence of specific antibody, the total cell-mediated cytotoxicy (CMC) per spleen was four times higher in the spleen cells from 50-day-old rats compared with those from 30-day-old rats. CMC accounted for about 50% of total cytotoxic activity in 50-day-old rat spleens. Spleen cells mediating ADCC and CMC are Thy-1.1 positive, and those mediating ADCC are nearly all non-adherent to Sephadex G-10 columns.