Enhancement of anti-tumor immunity by tumor cells transfected with the secondary lymphoid tissue chemokine EBI-1-ligand chemokine and stromal cell-derived factor-1alpha chemokine genes.
ABSTRACT Several new lymphocyte-specific chemokines, which attract naive and memory T cells, B cells, dendritic cells and natural killer cells, have been isolated. We have found evidence of the anti-tumor effects of 3 major lymphocyte-specific chemokines, secondary lymphoid tissue chemokine (SLC), EBI-1-ligand chemokine (ELC) and stromal cell-derived factor (SDF)-1alpha, in murine models (Meth A fibrosarcoma and HM-1 ovarian tumor). In both naive and immunized mice, tumors expressing SLC, ELC or SDF-1alpha showed delayed progression compared with control tumors. In mice immunized with tumor cells expressing 1 of these 3 chemokine genes, challenge with parental tumor cells resulted in slightly slower progression than in control mice, while in mice immunized with tumor cells transfected to co-express IL-2 or granulocyte-macrophage colony-stimulating factor (GM-CSF) as well as these chemokines, all tumors regressed. Furthermore, spleen cells from mice immunized with these "double-transfected" tumor cells exhibited higher proliferative responses and greater cytotoxic activity against parental tumor cells. These anti-tumor effects were associated with profound alterations in the leukocyte populations within the tumors and regional lymph nodes, and this was due to activation of type I T cell-dependent responses that produced high levels of IFN-gamma. These findings show that SLC, ELC and SDF-1alpha enhance anti-tumor immunity both systemically and locally and that these chemokines may be clinically useful, especially when combined with IL-2 and GM-CSF.
Article: Regulated expression of CCL21 in the prostate tumor microenvironment inhibits tumor growth and metastasis in an orthotopic model of prostate cancer.[show abstract] [hide abstract]
ABSTRACT: Currently there are no curative therapies available for patients with metastatic prostate cancer. Thus, novel therapies are needed to treat this patient population. Immunotherapy represents one promising approach for the elimination of occult metastatic tumors. However, the prostate tumor microenvironment (TME) represents a hostile environment capable of suppressing anti-tumor immunity and effector cell function. In view of this immunosuppressive activity, we engineered murine prostate cancer cells with regulated expression (tet-on) of CCL21. Prostate tumor cells implanted orthotopically produced primary prostate tumors with predictable metastatic disease in draining lymph nodes and distant organs. Expression of CCL21 in the prostate TME enhanced survival, inhibited tumor growth and decreased the frequency of local (draining lymph node) and distant metastasis. Therefore, these studies provide a strong rationale for further evaluation of CCL21 in tumor immunity and its use in cancer immunotherapy.Cancer Microenvironment 06/2009; 2(1):59-67.
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ABSTRACT: Immune cells, such as cytotoxic T lymphocytes, natural killer cells, B cells, and dendritic cells, have a central role in cancer immunotherapy. Conventional studies of cancer immunotherapy have focused mainly on the search for an efficient means to prime/activate tumor-associated antigen-specific immunity. A systematic understanding of the molecular basis of the trafficking and biodistribution of immune cells, however, is important for the development of more efficacious cancer immunotherapies. It is well established that the basis and premise of immunotherapy is the accumulation of effective immune cells in tumor tissues. Therefore, it is crucial to control the distribution of immune cells to optimize cancer immunotherapy. Recent characterization of various chemokines and chemokine receptors in the immune system has increased our knowledge of the regulatory mechanisms of the immune response and tolerance based on immune cell localization. Here, we review the immune cell recruitment and cell-based systems that can potentially control the systemic pharmacokinetics of immune cells and, in particular, focus on cell migrating molecules, i.e., chemokines, and their receptors, and their use in cancer immunotherapy.Pharmaceutical Research 05/2008; 25(4):752-68. · 4.09 Impact Factor
Article: CXC chemokine ligand 12 (stromal cell-derived factor 1 alpha) and CXCR4-dependent migration of CTLs toward melanoma cells in organotypic culture.[show abstract] [hide abstract]
ABSTRACT: Studies in experimental animal models have demonstrated that chemokines produced by tumor cells attract chemokine receptor-positive T lymphocytes into the tumor area, which may lead to tumor growth inhibition in vitro and in vivo. However, in cancer patients, the role of chemokines in T lymphocyte trafficking toward human tumor cells is relatively unexplored. In the present study, the role of chemokines and their receptors in the migration of a melanoma patient's CTL toward autologous tumor cells has been studied in a novel organotypic melanoma culture, consisting of a bottom layer of collagen type I with embedded fibroblasts followed successively by a tumor cell layer, collagen/fibroblast separating layer, and, finally, a top layer of collagen with embedded fibroblasts and T cells. In this model, CTL migrated from the top layer through the separating layer toward tumor cells, resulting in tumor cell apoptosis. CTL migration was mediated by chemokine receptor CXCR4 expressed by the CTL and CXCL12 (stromal cell-derived factor 1alpha) secreted by tumor cells, as evidenced by blockage of CTL migration by Abs to CXCL12 or CXCR4, high concentrations of CXCL12 or small molecule CXCR4 antagonist. These studies, together with studies in mice indicating regression of CXCL12-transduced tumor cells, followed by regression of nontransduced challenge tumor cells, suggest that CXCL12 may be useful as an immunotherapeutic agent for cancer patients, when transduced into tumor cells, or fused to anti-tumor Ag Ab or tumor Ag.The Journal of Immunology 06/2005; 174(9):5856-63. · 5.79 Impact Factor