Human dendritic cell models
Dendritic cells are considered the most potent antigen presenting cells of the immune system and are responsible for activation of the adaptive immune system in response to infections (figure 1). Dendritic cells are key regulators of the immune system in immunological disorders such as autoimmune and allergic diseases and are thus promising target cells for therapeutic treatment of these disorders (Steinman R:M., Banchereau J., Nature , 449, 419-426, 2007).
Figure 1: Activation of the adaptive immune system by dendritic cells (click figure for larger image)
Bioneer offers screening of compounds in the hDC model based on human dendritic cells derived from the blood of healthy human donors. We have experience with monocyte derived myeloid DCs as well as steady state myeloid and plasmacytoid DCs.
We apply our DC models under mainly two settings:
- Assessment of the overall immune modulation. This mostly applies to immune stimulation or modulating drugs or complex mixtures of e.g. natural extracts or microorganisms. The test reagent is added to immature DCs, and the response from the DC is measured in order to predict the effect of the reagent under in vivo conditions. Typical end-points are measurement of DC secreted cytokines or ability to induce T-cell differentiation towards a given T-helper cell (Th1, Th2, Treg or Th17 phenotype)
- Analyses of a compound or other reagent to suppress a specific immune response using our proprietary immune inducing cocktails (Th1, Th2 and Th17 responses). This mostly applies to screening of biologics, small molecule drugs or inhibitors of specific intracellular targets and pathways. The test compound is added with an immune stimulating cocktail, which is specifically designed to induce disease associated responses mimicking autoimmune (Th1 and Th17) or allergic/ezcema like responses (Th2). End-points are measurements of DC and T-cell secreted cytokines, FACS, T-cell proliferation or detection of intracellular targets.
Our immune directing cocktails consists of well defined reagents that upon addition to the DC culture causes maturation of DCs into Th1 promoting phenotypes (Figure 2), Th2 promoting phenotypes (figure 3), and Th17 promoting phenotypes (figure 4), when the cocktail treated DCs are co-cultured with naive CD4+ T-cells.
Figure 2: Development of Th1 inducing cocktails with readout on IL-12 secretion (from DCs) and IFN-gamma secretion from T-cells after co-culture with cocktail treated DCs (click figure for larger image)
Figure 3: Development of Th2 inducing cocktails with readout on IL-4, 5 and 13 as hall-mark Th2 cytokines. Cytokines are secreted from T-cells after co-culture with cocktail treated DCs (click figure for larger image)
Figure 4: Development of Th17 inducing cocktails with readout on IL-6, 23 secreted from DCs, and IL-17A from T-cells after co-culture with cocktail treated DCs (click figure for larger image)
Figure 5: Examples of cocktail validation using dexamethasone (Dex) for Th17 cocktail suppression (graphs 1 and 2) and suppression of Th1 activation using rapamycin in the DC-T-cell co-culture (click figure for larger image)
The model has been validated using known drugs like dexamethasone and rapamycin (figure 5)
Possible end-points includes:
- Cytokine and Chemokine readout (e.g. IL-1, 4, 5, 6, 8, 10, 12, 23, TNF, IFN)
- FACS analyses of maturation markers (e.g. CD40, 80, 86, MHC II)
- T-cell activation (proliferation and secreted cytokines)
- Intracellular markers of inflammation (e.g. COX2, iNOS, cytokines)
- Secreted lipid mediators of inflammation (e.g. prostaglandins)
Read more about Dendritic Cells in this article from European Biopharmaceutical Review, November 2008.
For further information, please contact Group Leader, Immune Targeting; Simon Skjøde Jensen by phone (+45 45160444) or email.