Influence of cianidanol on specific and non-specific immune mechanisms.

The influence of Cianidanol (Ci), a cytoprotective radical scavenger, on peripheral blood mononuclear cells (PBMC) was assessed with respect to its immunomodulatory function. In previous studies performed in our laboratory, a bidirectional influence of Ci on the immune response was observed, depending on its concentration. In order to elucidate this effect, the influence of Ci on macrophage (M phi) and B-cell function was investigated. A marked dose-dependent suppression of M phi phagocytosis by Ci could be detected. Furthermore, PGE2 synthesis of non-activated and PHA-activated PBMC was inhibited in the presence of Ci. This effect was shown to be due to an inhibition of M phi cyclooxygenase. It was also demonstrated that neither spontaneous nor Staphylococcus aureus Cowan I induced proliferation of highly purified B-cells was enhanced by Ci. Similar results were obtained by measuring the influence of Ci on immunoglobulin secretion of purified B-cells, exposed to Klebsiella membrane preparations. From these data it can be concluded that the previously described enhancing effect of Ci on immunoglobulin secretion is probably T-cell mediated.