Peripheral membrane molecules of leukocytes and NK cytotoxicity.
Some leukocyte effector cell-surface molecules movement toward the adjoining target cells takes place during the reaction of NK cytotoxicity (NK R). The majority of the moving molecules are usually anchored via a divalent-ion-dependent interaction (PMM-M2+). The released PMM-M2+ can interact also with the secreted tumor necrosis factor alfa (TNF-alpha). In agreement with PMM-M2+ movement, the number of TNF-alpha binding sites on the target cell surface increases during NK R. In addition, antibodies against PMM-M2+, as well as D-mannose- or N-acetyl-D-glucosamine-terminated oligosaccharides of PMM-M2+ inhibit NK R. A more detailed analysis of PMM-M2+ with monoclonal antibodies used flow cytometry and cell-surface biotinylation. Only 3 of 31 tested CD antigens (CD2, LAK-1 and CD45) were passed through this first strongly restricted experimental screening. The EDTA-released LAK-1 antigen, but not CD2 and CD45, interact with TNF-alpha and cell surface via a mannose-inhibitable interaction dependent on the presence of Ca2+ ions. The mechanism of possible participation of PMM-M2+ in cytotoxic events is discussed in relation to Ca2+ influx and subsequent cytolysin secretion.
Kubrycht
J
J
Department of Immunology, Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague.
Malíková
P
P
Huan
N H
NH
Fiserová
A
A
Bezouska
K
K
Kruzík
P
P
Stajner
K
K
Moravec
V
V
Pospísil
M
M
D000920:Antibody-Dependent Cell Cytotoxicity / Q000502:physiology; D000954:Antigens, Surface / Q000032:analysis; D002462:Cell Membrane / Q000276:immunology; D003602:Cytotoxicity, Immunologic / Q000502:physiology*; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D007962:Leukocytes / Q000276:immunology*; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
D000954:Antigens, Surface; D014409:Tumor Necrosis Factor-alpha