DDVP markedly decreases the expression of granzyme B and granzyme 3/K in human NK cells.
Natural killer (NK), lymphokine-activated killer (LAK), and cytotoxic T lymphocyte (CTL) cells kill target cells by the directed release of cytolytic granules that contain perforin, granzymes, and granulysin. We have found previously that dimethyl 2,2-dichlorovinyl phosphate (DDVP, dichlorvos), an organophosphorus pesticide, significantly decreased the expression of perforin, granzyme A (GrA), and granulysin and inhibited NK, LAK, and CTL activities. To further explore the mechanism of organophosphorus pesticide-induced inhibition of cell-mediated cytolysis, we examined whether organophosphorus pesticides affect the expression of GrB and Gr3/K in NK cells. We used an interleukin-2 (IL-2) independent human NK cell line, NK-92CI. We confirmed that NK-92CI cells express intracellular GrB and Gr3/K by flow cytometry, that NK-92CI cells are highly cytotoxic to K562 cells with a chromium release assay, and that DDVP significantly inhibited cytolytic activity of NK-92CI cells in a dose- and time-dependent manner. We found that DDVP significantly decreased the expression of GrB and Gr3/K in NK-92CI cells in a dose- and time-dependent manner by flow cytometry. Immunocytochemical results showed that DDVP significantly decreases the level of GrB positive granules in NK-92CI cells, which may be due to degranulation. Taken together, DDVP significantly inhibits NK activity and reduces the intracellular GrB and Gr3/K levels in NK cells.
Li
Qing
Q
Department of Hygiene and Public Health, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan. qing-li@nms.ac.jp
Kobayashi
Maiko
M
Kawada
Tomoyuki
T
D002460:Cell Line; D002860:Chromium Radioisotopes; D004006:Dichlorvos / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D053804:Granzymes / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007694:Killer Cells, Natural / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D008856:Microscopy, Fluorescence; D013997:Time Factors
D002860:Chromium Radioisotopes; D004006:Dichlorvos; D053804:Granzymes; D016650:Fluorescein-5-isothiocyanate