Immunomodulating properties of cianidanol on responsiveness and function of human peripheral blood T-cells and...

Cianidanol (Ci) [(+)-catechin] is a lipophilic compound which interacts with membrane lipids and affects responsiveness and function of immunocompetent cells. We therefore studied the immunomodulating properties of Ci on the proliferative response of human peripheral T-cells in one-way mixed lymphocyte reaction (1-MLR) and autologous mixed lymphocyte reaction (AMLR); on the generation of cytotoxic T-cells (Tc-cells), suppressor T-cells (Ts-cells, comprising radiosensitive as well as radioresistant suppressor T-cells) and radioresistant suppressor T-cells (rrTs) in 1-MLC; and on the cytolytic activity of Tc-cells and K-cells. In 1-MLR we observed a small stimulation of cell proliferation at Ci concentrations up to 108 microM whereas higher concentrations led to a marked suppression (100% at 435 microM). The generation of Ts-cells and rrTs-cells in 1-MLR was clearly suppressed at Ci-concentrations above 435 microM and 108 microM, respectively. The timing of Ts-cell formation was not influenced. The Tc-cell generation in 1-MLR was inhibited at high doses, and at 870 microM 59% suppression was observed. A similar dose-dependent suppressive effect of Ci was seen by testing for the cytolytic activity of ADCC-reactive K-cells and of CML-reactive Tc-cells generated in 1-MLR in the absence of Ci. At the highest concentration used (870 microM) the CML was suppressed by 45% and the ADCC by 46%. Our investigation on Ci's influence on the efferent and afferent part of immune responses in vitro demonstrated both stimulatory and inhibitory effects usually occurring at low and high concentrations, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)