Inhibition of human lymphokine-activated killer activity by smokeless tobacco (snuff) extract.
Chronic snuff dipping has been associated with oral cancer in man and experimental animals. Here, the effects of a water-extract of snuff on the in-vitro development of human lymphokine-activated killer (LAK) activity were examined. The snuff extract inhibited both LAK cytotoxicity and DNA synthesis in a dose-dependent fashion at concentrations of 0.125 to 2.0 per cent; above 2.0 per cent, cell viability decreased significantly. In contrast, the snuff extract had no effect on natural killer-cell cytotoxicity when incubated with fresh peripheral blood lymphocytes in a standard 4 h assay, or on LAK cytotoxicity when incubated only during the final 4 h effector phase. Lymphocyte protein synthesis was generally unaffected by the addition of this extract. Thus, a water-soluble snuff extract appears to suppress LAK activity by inhibiting DNA synthesis. Altered LAK function in the oral mucosa might permit the development of snuff-associated carcinogenesis.
Lindemann
R A
RA
Section of Oral Diagnosis, Oral Medicine, Oral Pathology, UCLA School of Dentistry.
Park
N H
NH
D003602:Cytotoxicity, Immunologic / Q000187:drug effects*; D004247:DNA / Q000096:biosynthesis; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000276:immunology* / Q000378:metabolism; D008213:Lymphocyte Activation; D010936:Plant Extracts / Q000494:pharmacology; D014030:Tobacco, Smokeless
D007376:Interleukin-2; D010936:Plant Extracts; D004247:DNA