Influence of ethylene-2,2'-bis (dithio)bis(ethanol) on certain human in vitro and in vivo lymphocyte functions

The influence of in vivo or in vitro exposure of human lymphocytes to ADA 202-718 (ethylene-2,2'-bis (dithio) bis (ethanol)) was tested. Evaluated were spontaneous, lectin, or alloantigen-induced proliferation as well as the release of IFN-alpha, gamma and of neopterin. The spontaneous cell mediated lysis (NK lysis) of K 562 tumor targets was also assessed. In vitro exposure to ADA 202-718 slightly enhanced lectin and alloantigen-induced human lymphocyte proliferation. IFN-gamma release was also slightly increased. These parameters were not clearly affected by in vivo treatment with ADA 202-718. In vitro and in vivo-treatment with this drug did not affect spontaneous lymphocyte blastogenesis. Statistically significant effects, however, were seen when NK activity was assessed. Preincubation of either effector or target cells with ADA 202-718 as well as in vivo treatment caused an increase of NK lysis. When these results obtained with human cells were compared with those previously seen in a murine system, immunostimulatory activity of ADA 202-718 was more pronounced in the murine system.