Solano, S. (Sarai)

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    Carcinoma-derived interleukin-8 disorients dendritic cell migration without impairing T-cell stimulation
    (Public Library of Science, 2011) Dubrot, J. (Juan); Martinez-Forero, I. (Iván); Alfaro, C. (Carlos); Solano, S. (Sarai); Perez-Gracia, J.L. (Jose Luis); Rouzaut, A. (Ana); Bolaños, E. (Elixabet); Gonzalez-Hernandez, A. (Alvaro); Gurpide, A. (Alfonso); Hervas-Stubbs, S. (Sandra); Erro, L. (Lorena); Melero, I. (Ignacio); Palazon, A. (Asís); Suarez, N. (Natalia); Feijoo, E. (Esperanza)
    BACKGROUND: Interleukin-8 (IL-8, CXCL8) is readily produced by human malignant cells. Dendritic cells (DC) both produce IL-8 and express the IL-8 functional receptors CXCR1 and CXCR2. Most human colon carcinomas produce IL-8. IL-8 importance in malignancies has been ascribed to angiogenesis promotion. PRINCIPAL FINDINGS: IL-8 effects on human monocyte-derived DC biology were explored upon DC exposure to recombinant IL-8 and with the help of an IL-8 neutralizing mAb. In vivo experiments were performed in immunodeficient mice xenografted with IL-8-producing human colon carcinomas and comparatively with cell lines that do not produce IL-8. Allogenic T lymphocyte stimulation by DC was explored under the influence of IL-8. DC and neutrophil chemotaxis were measured by transwell-migration assays. Sera from tumor-xenografted mice contained increasing concentrations of IL-8 as the tumors progress. IL-8 production by carcinoma cells can be modulated by low doses of cyclophosphamide at the transcription level. If human DC are injected into HT29 or CaCo2 xenografted tumors, DC are retained intratumorally in an IL-8-dependent fashion. However, IL-8 did not modify the ability of DC to stimulate T cells. Interestingly, pre-exposure of DC to IL-8 desensitizes such cells for IL-8-mediated in vitro or in vivo chemoattraction. Thereby DC become disoriented to subsequently follow IL-8 chemotactic gradients towards malignant or inflamed tissue. CONCLUSIONS: IL-8 as produced by carcinoma cells changes DC migration cues, without directly interfering with DC-mediated T-cell stimulation.
  • Therapeutic antitumor efficacy of anti-CD137 agonistic monoclonal antibody in mouse models of myeloma
    (American Association for Cancer Research, 2008) Dubrot, J. (Juan); Alfaro, C. (Carlos); Solano, S. (Sarai); McCluskey, B. (Brandon); Perez-Gracia, J.L. (Jose Luis); Oyahobi, B.O. (Babatunde O.); Murillo, O. (Oihana); Gupta, A. (Anjana); Azpilicueta, A. (Arantza); Hervas-Stubbs, S. (Sandra); Ochoa, M.C. (María Carmen); Melero, I. (Ignacio); Palazon, A. (Asís); Arina, A. (Ainhoa)
    PURPOSE: Eradication of post-treatment residual myeloma cells is needed to prevent relapses, and immunostimulatory monoclonal antibodies (mAb) such as anti-CD137, CTLA-4, CD40, etc., which enhance the immune response against malignancies, represent a means of achieving this purpose. This study explores anti-CD137 mAbs for multiple myeloma treatment in preclinical models of the disease because they safely augment tumor immunity and are in clinical trials for other cancers. EXPERIMENTAL DESIGN: The antitumor effect of anti-CD137 mAb on mouse plasmacytomas derived from HOPC and NS0 cell lines was studied and compared with that of anti-CTLA-4, anti-CD40, and anti-ICAM-2 mAbs. The antitumor effect of anti-CD137 mAb was also examined in a mouse syngeneic disseminated myeloma (5TGM1) model, which more closely resembles human multiple myeloma. Depletions of specific cell populations and gene-targeted mice were used to unravel the requirements for tumor rejection. RESULTS: Agonistic mAb against CD137 and blocking anti-CTLA-4 mAb showed activity against i.p. HOPC tumors, resulting in extended survival of mice that also became immune to rechallenge. Anti-CD137 mAbs induced complete eradications of established s.c. NS0-derived tumors that were dependent on IFN-gamma, natural killer cells, and CD8(+) T lymphocytes. Natural killer cells accumulated in tumor draining lymph nodes and showed increased IFN-gamma production. Antitumor efficacy of anti-CD137 mAb was preserved in CD28-deficient mice despite the fact that CD28 signaling increases the expression of CD137 on CD8(+) T cells. Importantly, anti-CD137 mAb treatment significantly decreased systemic tumor burden in the disseminated 5TGM1 model. CONCLUSIONS: The immune-mediated antitumor activity of anti-CD137 mAb in mouse models holds promise for myeloma treatment in humans.
  • In vivo depletion of DC impairs the anti-tumor effect of agonistic anti-CD137 mAb
    (Wiley-VCH Verlag Berlin, 2009) Berraondo, P. (Pedro); Dubrot, J. (Juan); Berasain, C. (Carmen); Alfaro, C. (Carlos); Solano, S. (Sarai); Gabari, I. (Izaskun); Perez-Gracia, J.L. (Jose Luis); Murillo, O. (Oihana); Azpilicueta, A. (Arantza); Hervas-Stubbs, S. (Sandra); Ochoa, M.C. (María Carmen); Melero, I. (Ignacio); Palazon, A. (Asís); Arina, A. (Ainhoa)
    Anti-CD137 mAb are capable of inducing tumor rejection in several syngeneic murine tumor models and are undergoing clinical trials for cancer. The anti-tumor effect involves co-stimulation of tumor-specific CD8(+) T cells. Whether antigen cross-presenting DC are required for the efficacy of anti-CD137 mAb treatment has never been examined. Here we show that the administration of anti-CD137 mAb eradicates EG7-OVA tumors by a strictly CD8beta(+) T-cell-dependent mechanism that correlates with increased CTL activity. Ex vivo analyses to determine the identity of the draining lymph node cell type responsible for tumor antigen cross-presentation revealed that CD11c(+) cells, most likely DC, are the main players in this tumor model. A minute number of tumor cells, revealed by the presence of OVA cDNA, reach tumor-draining lymph nodes. Direct antigen presentation by tumor cells themselves also participates in anti-OVA CTL induction. Using CD11c diphtheria toxin receptor-green fluorescent protein-->C57BL/6 BM chimeric mice, which allow for sustained ablation of DC with diphtheria toxin, we confirmed the involvement of DC in tumor antigen cross-presentation in CTL induction against OVA(257-264) epitope and in the antitumor efficacy induced by anti-CD137 mAb
  • Influence of bevacizumab, sunitinib and sorafenib as single agents or in combination on the inhibitory effects of VEGF on human dendritic cell differentiation from monocytes
    (Cancer Research UK, 2009) Dubrot, J. (Juan); Alfaro, C. (Carlos); Solano, S. (Sarai); Perez-Gracia, J.L. (Jose Luis); Lopez-Picazo, J.M. (José M.); Gonzalez-Hernandez, A. (Alvaro); Gurpide, A. (Alfonso); Hervas-Stubbs, S. (Sandra); Erro, L. (Lorena); Melero, I. (Ignacio); Palazon, A. (Asís); Suarez, N. (Natalia); Grande-Pulido, E. (E.)
    Vascular endothelial growth factor (VEGF) inhibits differentiation and maturation of dendritic cells (DC), suggesting a potential immunosuppressive role for this proangiogenic factor. Bevacizumab, sorafenib and sunitinib target VEGF-mediated angiogenesis and are active against several types of cancer, but their effects on the immune system are poorly understood. In this study, VEGF and supernatants of renal carcinoma cell lines cultured under hypoxia were found to alter the differentiation of human monocytes to DC. Resulting DC showed impaired activity, as assessed by the alloreactive mixed T-lymphocyte reaction. Bevacizumab and sorafenib, but not sunitinib, reversed the inhibitory effects of VEGF, but not of those mediated by tumour supernatants. Dendritic cells matured under the influence of VEGF expressed less human leukocyte antigen-DR (HLA-DR) and CD86, and this effect was restored by bevacizumab and sorafenib. Finally, tumour-cell supernatants decreased interleukin-12 (IL-12) production by mature DC, and such inhibition was not restored by any of the tested drugs, delivered either as single agents or in combination. The deleterious effects of tumour-cell supernatants were mainly mediated by thermostable molecules distinct from VEGF. These results indicate that inhibition of the differentiation of monocytes to DC is a multifactorial effect, and that they support the development of combinations of angiogenesis inhibitors with immunological modulators.