Antibody-Dependent Monocyte-Mediated Cytotoxicity

Monocyte-mediated-antibody-dependent cellular cytotoxicity in malignant lymphoma and solid tumors

Monocyte-mediated-antibody-dependent cellular cytotoxicity (MO-ADCC) was studied in 21 patients with Hodgkin's disease (HD), 15 patients with a long-lasting remission of HD, 11 patients with non-Hodgkin's lymphoma (NHL), 11 patients with solid tumors, and 15 normal controls. Lymphocyte ADCC (LY-ADCC) was evaluated in 12 patients with HD and 9 normal controls. Monocytes lymphocytes were isolated with cell-scatter monitored counterflow centrifugation providing high purity and yield. Antibody-dependent cellular cytotoxicity was evaluated by means of DNA flowcytometry, using antibody-coated chicken erythrocyte targets (CRBC). In comparison with normal controls MO-ADCC was significantly increased in HD (P less than 0.0005), NHL (P less than 0.005), and solid tumors (P less than 0.005). In patients in long-lasting complete remission of HD, MO-ADCC was in the normal range. Lymphocyte-ADCC of 12 patients with HD was similar to that of 9 normal controls. In all experiments LY-ADCC was invariably lower than MO-ADCC of the same donor, indicating the monocyte as the most potent effector cell towards CRBC targets. Results indicate the following: (1) purified cell suspensions of both lymphocytes and monocytes are essential to unravel their role as effector cells; (2) LY-ADCC in HD is similar to normal controls; (3) MO-ADCC enhancement is not uncommon in malignant lymphoma and several solid tumors; (4) normal MO-ADCC in a group of successfully treated patients with HD suggests a disease-related induction of enhanced MO-ADCC.

Depression of monocyte-mediated cytotoxicity by renal carcinoma and restoration through therapy

The cytotoxic ability of freshly isolated monocytes against the tumor cell line K-562 was severely depressed in patients with renal cell carcinoma. The impaired cytotoxicity was partly restored 2 weeks after nephrectomy. Production of monocyte-activating lymphokine, measured as ability to activate tumor cytotoxicity in control monocytes, was depressed in lymphocytes from patients with tumor burden. The impaired lymphokine production seemed to be due to factors in patient serum. Patient monocytes showed an impaired ability to be activated by lymphokines. Products from patient lymphocytes were not able to activate the tumor cytotoxicity of patient monocytes.

Inhibitory effect on monocyte-mediated cytotoxicity of sera from patients with multiple myeloma and malignant lymphoma

There was no difference in monocyte-mediated cytotoxicity between monocytes from patients with multiple myeloma or malignant lymphomas and monocytes from control persons after in vitro culture for 5 d. Cytostatic and cytolytic ability of lymphokine-activated monocytes cultured in medium with patient serum was significantly depressed compared to the ability of monocytes cultured with normal serum. A similar depression of cytostasis was found with non-activated monocytes of both patient and control origin. Sera from myeloma and lymphoma patients impaired the monocyte-mediated cytotoxicity equally.

Monocyte cytotoxicity after splenectomy

Antibody-dependent cell-mediated cytotoxicity (ADCC) by monocytes was determined in 45 adults approximately 4 years after splenectomy for either abdominal trauma or accidental injury during operation for benign gastroduodenal ulcer. Compared to controls, both groups of splenectomized persons showed increased numbers of monocytes and decreased monocyte ADCC. The decrease of monocyte ADCC was only significant in those splenectomized persons in whom accessory splenic tissue was not detectable by isotope scanning. Addition of the spleen-dependent peptide tuftsin to monocytes in vitro did not augment their ADCC. An increase serum concentration of immune complexes was neither related to the presence of splenic tissue nor to the monocyte cytotoxicity. Vaccination with pneumococcal polysaccharide had no effect on monocyte ADCC. It is suggested that the defective monocyte cytotoxicity observed in splenectomized persons without detectable splenic tissue might be relevant to post splenectomy infectious susceptibility.

Decreased antibody-dependent cellular cytotoxicity in various types of leukaemia in man

Antibody-dependent cellular cytotoxicity (ADCC) by cells from peripheral blood was studied in patients with; chronic lymphocytic leukaemia (CLL), chronic granulocytic leukaemia (CGL), acute lymphoblastic leukaemia (ALL), acute non-lymphoid leukaemia (ANLL) and compared with that of healthy donors. The ADCC activity in all the types of leukaemia was on the average lower as compared with the control values, being especially low in both CLL and CGL. Further, it has also been shown that the ADCC activity of non-leukaemic blood cells in ANLL was lower as compared with control values. The latter observation indicates that, at least in ANLL, the reduced ADCC potential of peripheral blood cells is not due to dilution of effector cells by poorly- or non-active leukaemic cells.