Publication
Immunologic effector mechanisms of a standardized mistletoe extract on the function of human monocytes and lymphocytes in vitro, ex vivo, and in vivo
Journal Paper/Review - Jul 1, 2006
Heinzerling Lucie, von Baehr Volker, Liebenthal Christa, von Baehr Rüdiger, Volk Hans-Dieter
Units
PubMed
Doi
Citation
Type
Journal
Publication Date
Issn Print
Pages
Brief description/objective
Even though mistletoe extracts have been in clinical use for centuries their exact mode of action is still unknown. Currently, the application scheme for registered preparations is a dose-escalating scheme to thus reduce side effects. In this study, healthy controls and patients were evaluated for their immunologic response to treatment with a standardized mistletoe extract (Iscador). It shows a strong effect as adjuvant that induces TNF-alpha and IL-12, which was partly mediated via CD14. Desensitization of the TNF-alpha response could be shown after repeated application in vitro and in vivo. Furthermore, Iscador induces a specific lymphocyte sensitization upon multiple injections and production of IgG1- and IgG3 -mistletoe antibodies. Remarkably, a systemic bystander effect (heterologous immunity against other recall antigens) was observed after long-term treatment. In conclusion, dose-escalation reduces the monocyte-related clinical side effects. A T-lymphocyte sensitization stimulates mainly a specific Th1 response. The most interesting clinical long-term effect is the bystander stimulation of various memory T cells that might mediate in vivo antitumor and antiinfectious T-cell response under mistletoe-extract immunization.