calcein-am and nafamostat

The effects of clinical grade serine protease inhibitors on natural killer (NK) activity were compared. Cytotoxicity was measured with the Calcein-AM release method, using K562, Raji as a target. There is a significant correlation between measurements of NK activity by the Calcein-AM method and the 51Cr release assay. Cytotoxicity was inhibited with a calcium chelating agent or a perform inhibitor. Although up to 65% of cytotoxicity was inhibited by nafamostat mesilate with an E/T ratio of 10:1, and by 55% by ulinastatin, neither gabexate mesilate nor antithrombin III inhibited any cytotoxicity. None of these agents inhibited lymphokine-activated killer cell activity. In clinical applications, it should be noted that some protease inhibitors have been proven to have immunosuppressive effects.

Topics: Anti-Bacterial Agents; Antithrombin III; Benzamidines; Calcium; Cytotoxicity Tests, Immunologic; Cytotoxicity, Immunologic; Fluoresceins; Gabexate; Glycoproteins; Guanidines; Humans; Killer Cells, Lymphokine-Activated; Killer Cells, Natural; Macrolides; Serine Proteinase Inhibitors; Tumor Cells, Cultured