Wculek, S.K. (Stefanie K.)

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    The clinical application of cancer immunotherapy based on naturally circulating dendritic cells
    (BMJ, 2019) Dzionek, A. (Andrzej); Kandalaft, L.E. (Lana E.); Sancho, D. (David); Coukos, G. (George); Wculek, S.K. (Stefanie K.); Romero, P.J. (Pedro J.); Schwarze, J.K. (Julia Katharina); Schreibelt, G. (Gerty); Vries, J. (Jolanda) de; Neyns, B. (Bart); Melero, I. (Ignacio); Rabold, K. (Katrin); Bol, K.F. (Kalijn F.); Teijeira, A. (Álvaro)
    Dendritic cells (DCs) can initiate and direct adaptive immune responses. This ability is exploitable in DC vaccination strategies, in which DCs are educated ex vivo to present tumor antigens and are administered into the patient with the aim to induce a tumor-specific immune response. DC vaccination remains a promising approach with the potential to further improve cancer immunotherapy with little or no evidence of treatment-limiting toxicity. However, evidence for objective clinical antitumor activity of DC vaccination is currently limited, hampering the clinical implementation. One possible explanation for this is that the most commonly used monocyte-derived DCs may not be the best source for DC-based immunotherapy. The novel approach to use naturally circulating DCs may be an attractive alternative. In contrast to monocyte-derived DCs, naturally circulating DCs are relatively scarce but do not require extensive culture periods. Thereby, their functional capabilities are preserved, the reproducibility of clinical applications is increased, and the cells are not dysfunctional before injection. In human blood, at least three DC subsets can be distinguished, plasmacytoid DCs, CD141+ and CD1c+ myeloid/conventional DCs, each with distinct functional characteristics. In completed clinical trials, either CD1c+ myeloid DCs or plasmacytoid DCs were administered and showed encouraging immunological and clinical outcomes. Currently, also the combination of CD1c+ myeloid and plasmacytoid DCs as well as the intratumoral use of CD1c+ myeloid DCs is under investigation in the clinic. Isolation and culture strategies for CD141+ myeloid DCs are being developed. Here, we summarize and discuss recent clinical developments and future prospects of natural DC-based immunotherapy.
  • Thumbnail Image
    Effective cancer immunotherapy by natural mouse conventional type-1 dendritic cells bearing dead tumor antigen
    (BMJ, 2019) Conde-Garrosa, R. (Ruth); Sancho, D. (David); Wculek, S.K. (Stefanie K.); Khouili, S.C. (Sofía C.); Melero, I. (Ignacio); Amores-Iniesta, J. (Joaquín)
    Background: The manipulation of dendritic cells (DCs) for cancer vaccination has not reached its full potential, despite the revolution in cancer immunotherapy. DCs are fundamental for CD8+ T cell activation, which relies on cross-presentation of exogenous antigen on MHC-I and can be fostered by immunogenic cancer cell death. Translational and clinical research has focused on in vitro-generated monocyte-derived DCs, while the vaccination efficacy of natural conventional type 1 DCs (cDC1s), which are associated with improved anti-tumor immunity and specialize on antigen cross-presentation, remains unknown. Methods: We isolated primary spleen mouse cDC1s and established a protocol for fast ex vivo activation and antigen-loading with lysates of tumor cells that underwent immunogenic cell death by UV irradiation. Natural tumor antigen-loaded cDC1s were transferred and their potential for induction of endogenous CD8+ and CD4+ T cell responses in vivo, cancer prevention and therapy were assessed in three grafted cancer models. Further, we tested the efficacy of natural cDC1 vaccination in combination and comparison with anti-PD-1 treatment in two "wildtype" tumor models not expressing exogenous antigens. Results: Herein, we reveal that primary mouse cDC1s ex vivo loaded with dead tumor cell-derived antigen are activated and induce strong CD8+ T cell responses from the endogenous repertoire upon adoptive transfer in vivo through tumor antigen cross-presentation. Notably, cDC1-based vaccines enhance tumor infiltration by cancer-reactive CD8+ and CD4+ T cells and halt progression of engrafted cancer models, including tumors that are refractory to anti-PD-1 treatment. Moreover, combined tumor antigen-loaded primary cDC1 and anti-PD-1 therapy had strong synergistic effects in a PD-1 checkpoint inhibition susceptible cancer model. Conclusions: This preclinical proof-of-principle study is first to support the therapeutic efficacy of cancer immunotherapy with syngeneic dead tumor cell antigen-loaded mouse cDC1s, the equivalents of the human dendritic cell subset that correlates with beneficial prognosis of cancer patients. Our data pave the way for translation of cDC1-based cancer treatments into the clinic when isolation of natural human cDC1s becomes feasible.
  • Thumbnail Image
    Depletion of conventional type-1 dendritic cells in established tumors suppresses immunotherapy efficacy
    (AACR, 2022) Egea, J. (Josune); Berraondo, P. (Pedro); Kaisho, T. (Tsuneyasu); Cirella, A. (Assunta); Azpilikueta, A. (Arantza); Sancho, D. (David); Verkhusha, V. (Vladislav); Rouzaut, A. (Ana); Gato-Cañas, M. (María); Rodriguez, I. (Inmaculada); Wculek, S.K. (Stefanie K.); Garasa, S. (Saray); Molina, C. (Carmeen); Melero, I. (Ignacio); Valencia, K. (Karmele); Andrea, C.E. (Carlos Eduardo) de; Olivera, I. (Irene); Luri-Rey, C. (Carlos); Teijeira, A. (Álvaro)
    The ability of conventional type-1 dendritic cells (cDC1) to cross-present tumor antigens to CD8+ T cells is critical for the induction of antitumor CTLs. Mice that are constitutively deficient in cDC1 cells have been reported to fail to respond to immunotherapy strategies based on checkpoint inhibitors. However, further work is needed to clarify the precise time during immunotherapy treatment that cDC1 cells are required for the beneficial effect of treatment. Here, we used a refined XCR1-DTR-Venus transgenic mouse model to acutely deplete cDC1 cells and trace their behavior using intravital microscopy. Diphtheria toxin-mediated cDC1 depletion prior to immunotherapy treatment with anti-PD-1 and/or anti-CD137 immunostimulatory mAbs completely ablated antitumor efficacy. The efficacy of adoptive T-cell therapy was also hampered by prior cDC1 depletion. After the onset of immunotherapy treatment, depletion of cDC1s only moderately reduced the therapeutic efficacy of anti-PD-1 and anti-CD137 mAbs. Intravital microscopy of liver-engrafted tumors revealed changes in the intratumoral behavior of cDC1 cells in mice receiving immunotherapy, and treatment with diphtheria toxin to deplete cDC1s impaired tumor T-cell infiltration and function. These results reveal that the functional integrity of the cDC1 compartment is required at the onset of various immunotherapies to successfully treat established tumors.