Induction of anti-mistletoe lectin antibodies in relation to different mistletoe-extracts.

Mistletoe extracts are frequently applied in adjuvant cancer treatment. The mistletoe lectins are especially suggested to mediate an antitumorous effect. During treatment with mistletoe lectin-rich extracts, anti-mistletoe lectin antibodies preferentially of the immunoglobulin G type are produced against mistletoe lectin (ML)-1. Interestingly, after application of mistletoe extracts containing natural micelles, anti-mistletoe lectin antibodies of the immunoglobulin G as well as one of the immunoglobulin E type were induced in parallel, suggesting that the nature and preparation of the antigens within the extract modifies immune responses. Anti-mistletoe lectin antibodies were shown to neutralize the cytotoxic effect of mistletoe lectin on peripheral blood mononuclear cells in vitro. Thus, the mode of application of these extracts seems to be of importance with respect to the therapeutic effect.