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

Abstract

It has been suggested that nitric oxide (NO) and superoxide anion may be involved 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 48h alone or mixed in different ratios (5: 1, 2 .5: 1 and 1: 1). There were no significant differences in nitrotyrosine concentration independently of the conditions used. However, when cultures were established with alIogeneic 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 < 0.000 1). We conclude that without alIogeneic stimuli, there is no net increase in nitrotyrosine production, suggesting that cell survival may depend on peroxynitrate production.