Correlation between killing activity towards the murine L929 cell line and expression of membrane-associated lymphotoxin-related molecule of human lymphokine-activated killer cells.
Human lymphokine-activated killer (LAK) cells expressed a membrane-associated lymphotoxin-related molecule (mLT) which was detected by flow cytometric analysis with anti-lymphotoxin antibody. Upon removal of exogenous interleukin-2 from LAK cell culture medium and another 24 h cultivation, the expression of mLT was decreased. Corresponding to the decrease of mLT expression, the killing activity of LAK cells towards L929 cells was remarkably reduced and killing of MIA PaCa-2 and U937 cells was moderately reduced, whereas killing of Daudi and K562 cells was fully restored. The supernatant of mLT-expressing LAK cells had no cytotoxic activity towards L929 cells in the absence of actinomycin D. Moreover, not only the killing of L929 cells but also that of human tumor cell lines (MIA PaCa-2, U937) by mLT-expressing LAK cells was partially inhibited in the presence of anti-lymphotoxin antibody. These results suggest an involvement of mLT in the killing of some tumor target cells by LAK cells.
Miyake
M
M
Second Department of Surgery, Ehime University School of Medicine, Japan.
Horiuchi
A
A
Kimura
K
K
Abe
Y
Y
Kimura
S
S
Hitsumoto
Y
Y
D000818:Animals; D000954:Antigens, Surface / Q000032:analysis; D002462:Cell Membrane / Q000737:chemistry; D003602:Cytotoxicity, Immunologic; D006801:Humans; D015979:Killer Cells, Lymphokine-Activated / Q000502:physiology*; D008233:Lymphotoxin-alpha / Q000032:analysis / Q000502:physiology*; D051379:Mice; D009374:Neoplasms, Experimental / Q000276:immunology; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology
D000954:Antigens, Surface; D008233:Lymphotoxin-alpha; D014409:Tumor Necrosis Factor-alpha