Mechanism of interferon gamma-induced protection of human gliosarcoma cells from lymphokine-activated killer lysis: division of lymphokine-activated killer cells into natural killer- and T-like cells.
The mechanism by which interferon gamma (IFN-gamma) decreases the susceptibility of the established cultured gliosarcoma line Gl-1 to lymphokine-activated killer (LAK) lysis was analyzed. The results of monolayer depletion and lectin-dependent cellular cytotoxicity assays by LAK cells revealed that the resistance to LAK lysis of IFN-gamma-treated Gl-1 cells is manifested at the stage of LAK cell target recognition alone. We have also divided LAK cells into populations of phenotypically natural killer (NK)- and T-like cells with monoclonal antibodies and complement, respectively. We have used these cells to examine the mechanism of IFN-gamma-induced protection of Gl-1 cells from LAK lysis in cold target inhibition, monolayer depletion, and direct binding assays. The results revealed that NK-like cells do not recognize IFN-gamma-treated Gl-1 cells as efficiently as they do untreated targets, whereas T-like cells show the opposite tendency. In conclusion, we have demonstrated that the IFN-gamma induced protection of tumor cells from LAK lysis is predominantly regulated by the target recognition of NK-like cells. On the other hand, IFN-gamma-treated tumor cells may bind to T-like cells but fail to trigger them to initiate further stages for lysis as effectively as NK-like cells.
Kondo
S
S
Department of Neurosurgery, Faculty of Medicine, Kyoto University, Japan.
Miyatake
S
S
Kikuchi
H
H
Oda
Y
Y
Iwasaki
K
K
Ohyama
K
K
Namba
Y
Y
D002455:Cell Division; D003584:Cytological Techniques; D005910:Glioma / Q000473:pathology*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D015979:Killer Cells, Lymphokine-Activated / Q000473:pathology / Q000502:physiology*; D007694:Killer Cells, Natural / Q000473:pathology*; D037102:Lectins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000473:pathology*; D014407:Tumor Cells, Cultured / Q000187:drug effects
D037102:Lectins; D007371:Interferon-gamma