Human mononuclear cell antibody-dependent cell-mediated cytotoxicity toward red blood cells of various Rh genotypes.

Abstract

Antibody-dependent cell-mediated cytotoxicity (ADCC) mediated by human peripheral blood mononuclear cells (85 % lymphocytes and 15 % monocytes) or lymphocyte-enriched (98 % lymphocytes) effector cells against human red blood cell (HRBC) targets of various Rh genotypes, with or without papain treatment, was tested in an 18-hour 51Cr release assay. The HRBC were sensitized with Rh0GAM, an anti-Rh0 (D) IgG fraction. Mononuclear cell effectors were found to lyse papain treated Rh0 (D) homozygous cells to a greater degree than Rh0 (D) heterozygotes. The genotypes of the HRBC targets, in order of the amount of lysis from highest to lowest was R1R1, R2R2 or R1R2, R2 r, R1r, R0r, rr. When the target cells were not papain treated and mononuclear cell effectors were used, the amount of lysis was low and the % specific lysis for Rh0 (D) homozygote and heterozygote HRBC was equivalent. Lymphocyteenriched effector cells did not lyse the homozygous target cells to a greater degree than the heterozygotes, although the amount of lysis for both types of HRBC was greater than that noted using mononuclear cells as effectors.