Antibody‐dependent, cell‐mediated cytotoxicity against human red blood cells: correlation of effector cell type with enzymatic alteration of the target cell surface

Abstract

Target cell factors, which contribute to the determination of the effector cell type in an antibody-dependent, cell-mediated cytotoxicity system were studied. Human red blood cells (RBC) were treated with papain and investigated by transmission and scanning electron microscopy (TEM and SEM). Both untreated (native) and treated 0 Rh+ RBC were labeled with 51Cr, sensitized with anti-D immunoglobulin and incubated with unfractionated autologous peripheral blood mononuclear cells. With native RBC, immune lysis was proportional to the number of phagocytes: enrichment of effectors in phagocytes increased lysis, while depletion of phagocytes from effectors decreased lysis. Following papain treatment of target RBC, lysis by unfractionated mononuclear effectors was markedly augmented; since this effect was not diminished by decrease of phagocytes to less than 2%, the augmented lysis was not due to the number of phagocytic effectors. TEM and SEM of enzyme-treated RBC showed spherocytosis with varying degrees of crenation and blurring and irregularities of the cellular membranes. The results suggest that papain-induced alterations in the target RBC rendered them susceptible to lysis by interaction between anti-D antibody and peripheral blood lymphocytes.

Mapping the functional topography of Fcγ with monoclonal antibodies: localization of epitopes interacting with the binding sites of Fc receptor on human K cells

“…Effector cells were added to the targets at different ratios. The plates were centrifugated at 200 x g for 5 min, then incubated at 37°C in 5% C 0 2 atmosphere for 3 h. Monocyte-mediated lysis was performed as described before, except that PBMC were used as effectors and the erythrocytes were not pretreated with papain [19]. The results were calculated according to the formula:…”

“…The purity of the Fab fraction was controlled by polyacrylamide electrophoresis according to the method of Weber and Osborn [19].…”

Immunology

“…These investigators hypothesized that this shift toward lymphocyte-mediated killing was due to a reduction in the surface charge density on the erythrocyte membrane as a consequence of the loss of sialic acid residues. In a more recent report, Yust et al (1980a) confirmed that papain treatment of RBCs resulted in lysis by lymphocytes as weH as monocytes; however, it did not appear to be the sole result of a reduction in surface charge. Using both transmission and scanning electron microscopy these investigators documented that enzyme treatment resulted in morphological changes in the RBCs which altered antigenic configuration and therefore antibody orientation.…”

Antibody‐dependent Cell‐mediated Cytotoxicity (ADCC) of Penicillin‐treated Human Red Blood Cells

“…Recently it has been shown that lymphocytes and granulocytes can also mediate lysis of antibody sensitized RBC. Urbaniak (1976), and later others (Milgrom 8i Shore, 1978;Yust et al, 1980b), found that papain-treated anti-D coated Rh(+) RBC were lysed by lymphocytes. Shaw et a1 (1978) showed that 0 Rh(+) (RIR,CDF/?DE) RBC treated with Ripley anti-CD serum and -D-RBC treated with anti-D serum were susceptible to lysis by monocytes, granulocytes and lymphocytes.…”