Immunosuppressant effect of IDS 30, a stinging nettle leaf extract, on myeloid dendritic cells in vitro.
OBJECTIVE
Dendritic cells are important antigen presenting cells that play a role in the initiation of rheumatoid arthritis (RA). The stinging nettle leaf extract IDS 30 (Hox alpha) has been recommended for adjuvant therapy of rheumatic diseases. We investigated the immunomodulating effect of IDS 30 extract on the maturation of hematopoietic dendritic cells.


METHODS
Human dendritic cells were generated from peripheral blood mononuclear cells cultured in granulocyte macrophage-colony stimulating factor and interleukin 4 (IL-4). Dendritic cell maturation was induced by keyhole limped hemocyanin (KLH). Dendritic cell phenotype was characterized by flow cytometric analysis; dendritic cell cytokine production was measured by ELISA. The ability of dendritic cells to activate naive autologous T cells was evaluated by mixed leukocyte reaction.


RESULTS
IDS 30 prevented the maturation of dendritic cells, but did not affect their viability. IDS 30 reduced the expression of CD83 and CD86. It increased the expression of chemokine receptor 5 and CD36 in a dose dependent manner. The secretion of tumor necrosis factor-alpha was reduced. Application of IDS 30 to dendritic cells in culture caused a high endocytosis of dextran and a low capacity to stimulate T cell proliferation.


CONCLUSIONS
Our in vitro results showed the suppressive effect of IDS 30 on the maturation of human myeloid dendritic cells, leading to reduced induction of primary T cell responses. This may contribute to the therapeutic effect of IDS 30 on T cell mediated inflammatory diseases like RA.
Broer
Johanna
J
Strathmann Biotec GmbH, Hamburg, Germany.
Behnke
Bert
B
D015703:Antigens, CD / Q000032:analysis; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000187:drug effects* / Q000276:immunology / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007959:Lymphocyte Culture Test, Mixed; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D019713:Receptors, CCR5 / Q000032:analysis; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis; D015854:Up-Regulation; D026982:Urtica dioica / Q000737:chemistry*
D015703:Antigens, CD; D007166:Immunosuppressive Agents; D010936:Plant Extracts; D019713:Receptors, CCR5; D014409:Tumor Necrosis Factor-alpha