Nitrotyrosine production following the interaction between autologous human B lymphocytes and natural killer cells

It has been suggested that nitric oxide (NO) and superoxide anion may be in volved in heterotypic interactions. We have now assessed nitrotyrosine, one of the products of peroxynitrite (ONOO-), by a specific sandwich ELISA, in the supernatants of autologous B lymphocytes and natural killer (NK) cells that were cultured for 48 h alone or mixed in different ratios (5:1, 2.5:1 and 1:1). There were no significant differences in nitrotyrosine concentra tion independently of the conditions used. However, when cultures were esta blished with allogeneic cells at a B: NK ratio of 1:1, nitrotyrosine levels markedly increased from 11.2 +/- 3.5 up to 32.0 +/- 4.8 ng/ml (P < 0.0001) . We conclude that without allogeneic stimuli, there is no net increase in nitrotyrosine production, suggesting that cell survival may depend on perox ynitrate production. Med Sci Res 27:589-590 (C) 1999 Lippincott Williams & Wilkins.