Discrepancy between direct and antibody-dependent cytotoxic activities of human LAK cells.
Human lymphokine-activated killer (LAK) cells display cytotoxic activity against natural killer (NK)-resistant tumor cells in an antibody-independent and -dependent manner. We compared LAK cell-mediated antibody-independent cytotoxicity (LAK activity) and antibody-dependent cellular cytotoxicity (ADCC) against untreated and antibody-coated Raji cells, respectively. Human lymphocytes showed drastically increased LAK activity after stimulation with interleukin-2 (IL-2) for 3 or 7 days when compared to non-activated cells. The level of ADCC was reduced for 3-day-generated LAK cells and augmented for 7-day-generated LAK cells as compared to non-activated cultured lymphocytes. Phenotypical analysis revealed IL-2-induced up-regulation of the proportion of CD11b+ (but not CD16+) lymphocyte subpopulation in 7-day-generated LAK cells. The data imply that human LAK cells exhibit antibody-dependent and -independent cytotoxic activities via distinct effector pathways at different stages of generation. These stages may be associated with changes in adhesion molecule (CD11b/CD18) expression on the surface of IL-2-activated lymphocytes.
Institute of Hematology and Blood Transfusion, Minsk, Belarus, Russia.
M P
MP
Potapnev
T S
TS
Garbuzenco
N V
NV
Goncharova
V D
VD
Zobnin
O V
OV
Shadrin
S N
SN
Bykovskaya
D000920:Antibody-Dependent Cell Cytotoxicity / Q000276:immunology*; D018845:CD11 Antigens / Q000276:immunology; D018821:CD18 Antigens / Q000276:immunology; D002478:Cells, Cultured; D006801:Humans; D016130:Immunophenotyping; D007376:Interleukin-2 / Q000494:pharmacology; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology*; D008213:Lymphocyte Activation / Q000187:drug effects; D017452:Receptors, IgG / Q000276:immunology; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
D018845:CD11 Antigens; D018821:CD18 Antigens; D007376:Interleukin-2; D017452:Receptors, IgG