Activation of dendritic cells by an aqueous mistletoe extract and mistletoe lectin-3 in vitro.
BACKGROUND
The function of dendritic cells (DC), the most important cell population for the induction of specific immune responses, is often altered in cancer patients. Since mistletoe extracts are applied to tumour patients, their influence on the activation/generation of DC was investigated.


METHODS
Monocytes from healthy individuals were stimulated with the mistletoe extract (HM) or the mistletoe lectin 3 (ML-3) in the presence or absence of GM-CSF/IL-4.


RESULTS
HM slightly but significantly stimulated the expression of CD83 but not CD1a in the presence of GM-CSF/IL-4, while in their absence only CD86 was activated. In pre-generated immature DC, HM and ML-3 enhanced the expression of CD86 but did not significantly activate CD83/CD1a. There was no relevant influence on the expression of HLA-class-I or class-II molecules.


CONCLUSIONS
For the first time, our data demonstrate an influence of a mistletoe extract on the activation/generation of DC, but it remains to be elucidated whether the function of DC is also activated and especially whether this rather slight effect is of importance for tumour patients.
Stein
Gerburg M
GM
Krebsforschung Herdecke, Department of Applied Immunology, University Witten/Herdecke, Community Hospital, Germany. stein.g@debitel.net
Büssing
Arndt
A
Schietzel
Michael
M
D015703:Antigens, CD / Q000096:biosynthesis; D051940:B7-2 Antigen; D002470:Cell Survival / Q000187:drug effects; D003713:Dendritic Cells / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006680:HLA Antigens / Q000096:biosynthesis; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis; D015847:Interleukin-4 / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D014784:Mistletoe / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology*; D028321:Plant Preparations; D010940:Plant Proteins; D054790:Ribosome Inactivating Proteins, Type 2; D014118:Toxins, Biological / Q000494:pharmacology*; D014867:Water / Q000737:chemistry; D000097802:CD83 Antigen
D015703:Antigens, CD; D051940:B7-2 Antigen; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006680:HLA Antigens; D007136:Immunoglobulins; D015847:Interleukin-4; D008562:Membrane Glycoproteins; D010936:Plant Extracts; D028321:Plant Preparations; D010940:Plant Proteins; D054790:Ribosome Inactivating Proteins, Type 2; D014118:Toxins, Biological; D014867:Water; D000097802:CD83 Antigen; C497964:CD86 protein, human; C009674:ribosome inactivating protein, Viscum