Therapy of Established Tumors with Rationally Designed Multiple Agents Targeting Diverse Immune–Tumor Interactions: Engage, Expand, Enable (original) (raw)
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Journal for ImmunoTherapy of Cancer, 2021
BackgroundDifferent types of tumors have varying susceptibility to immunotherapy and hence require different treatment strategies; these cover a spectrum ranging from ‘hot’ tumors or those with high mutational burden and immune infiltrates that are more amenable to targeting to ‘cold’ tumors that are more difficult to treat due to the fewer targetable mutations and checkpoint markers. We hypothesized that an effective anti-tumor response requires multiple agents that would (1) engage the immune response and generate tumor-specific effector cells; (2) expand the number and breadth of the immune effector cells; (3) enable the anti-tumor activity of these immune cells in the tumor microenvironment; and (4) evolve the tumor response to widen immune effector repertoire.MethodsA hexatherapy combination was designed and administered to MC38-CEA (warm) and 4T1 (cool) murine tumor models. The hexatherapy regimen was composed of adenovirus-based vaccine and IL-15 (interleukin-15) superagonist...
Cancer Research Communications
Cancer cell heterogeneity and immunosuppressive tumor microenvironment (TME) pose a challenge in treating solid tumors with adoptive cell therapies targeting limited tumor-associated antigens (TAAs), such as CAR T-cell therapy. We hypothesize that oncolytic adenovirus Delta-24-RGDOX activates the TME and promote antigen spread to potentiate the abscopal effect of adoptive TAA-targeting T-cells in localized intratumoral treatment. Herein, we used C57BL/6 mouse models with disseminated tumors derived from B16 melanoma cell lines to assess therapeutic effects and antitumor immunity. gp100-specific pmel-1 or OVA-specific OT-I T-cells were injected into the first subcutaneous (s.c.) tumor, followed by three injections of Delta-24-RGDOX. We found TAA-targeting T-cells injected into one s.c. tumor showed tumor tropism. Delta-24-RGDOX sustained the systemic tumor regression mediated by the T-cells, leading to improved survival rate. Further analysis revealed that, in mice with disseminated ...
Cancer Research, 2011
Low antigen expression and an absence of coimmunostimulatory signals may be partly responsible for the low immunogenicity of many tumors. It may be possible to overcome this situation by defining a combination of adjuvants and antigens that can activate a high-avidity antitumor response. Using the poorly immunogenic B16-OVA melanoma cells as tumor model, we tested different combinations of adjuvants and antigens to treat established tumors. In the absence of exogenous antigens, repeated administration of the TLR7 ligand Imiquimod together with anti-CD40 agonistic antibodies activated only innate immunity, which was insufficient to reject intradermal tumors. Administering this adjuvant combination together with OVA as a tumor antigen induced T-cell responses that delayed tumor growth. However, administering a combination of anti-CD40 plus TLR3 and TLR7 ligands, together with antigen targeting to dendritic cells through TLR4, was sufficient to induce tumor rejection in 50% of mice. This response was associated with a greater activation of innate immunity and induction of high-avidity polyfunctional CD8(+) T-cell responses, which each contributed to tumor rejection. This therapy activated T-cell responses not only against OVA, which conferred protection against a rechallenge with B16-OVA cells, but also activated T-cell responses against other melanoma-associated antigens. Our findings support the concept that multiple adjuvant combination and antigen targeting may be a useful immunotherapeutic strategy against poorly immunogenic tumors.
Oncoimmunology, 2017
The progressive tumor microenvironment (TME) coordinately supports tumor cell expansion and metastasis, while it antagonizes the survival and (poly-)functionality of antitumor T effector cells. There remains a clear need to develop novel therapeutic strategies that can transform the TME into a pro-inflammatory niche that recruits and sustains protective immune cell populations. While intravenous treatment with tumor-primed CD4(+) T cells combined with intraperitoneal delivery of agonist anti-glucocorticoid-induced TNF receptor (α-GITR) mAb results in objective antitumor responses in murine early stage disease models, this approach is ineffective against more advanced tumors. Further subcutaneous co-administration of a vaccine consisting of tumor antigen-loaded dendritic cells (DC) failed to improve the antitumor efficacy of this approach. Remarkably, these same three therapeutic agents elicited significant antitumor benefits when the antitumor CD4(+) T cells and tumor antigen-loaded...
Cancer research, 2017
Oncolytic viruses selectively lyse tumor cells, disrupt immunosuppression within the tumor and reactivate anti-tumor immunity, but they have yet to live up to their therapeutic potential. Immune checkpoint modulation has been efficacious in a variety of cancer with an immunogenic microenvironment, but is associated with toxicity due to nonspecific T-cell activation. Therefore, combining these two strategies would likely result in both effective and specific cancer therapy. To test the hypothesis, we first constructed oncolytic adenovirus Delta-24-RGDOX expressing the immune co-stimulator OX40 ligand (OX40L). Like its predecessor Delta-24-RGD, Delta-24-RGDOX induced immunogenic cell death and recruit lymphocytes to the tumor site. Compared to Delta-24-RGD, Delta-24-RGDOX exhibited superior tumor-specific activation of lymphocytes and proliferation of CD8+ T cells specific to tumor-associated antigens, resulting in cancer-specific immunity. Delta-24-RGDOX mediated more potent anti-gli...
Cancer Immunology Research, 2019
In cancers with tumor-infiltrating lymphocytes (TILs), monoclonal antibodies (mAbs) that block immune checkpoints such as CTLA-4 and PD-1/PD-L1 promote antitumor T-cell immunity. Unfortunately, most cancers fail to respond to single-agent immunotherapies. T regulatory cells, myeloid derived suppressor cells (MDSCs), and extensive stromal networks within the tumor microenvironment (TME) dampen antitumor immune responses by preventing T-cell infiltration and/or activation. Few studies have explored combinations of immune-checkpoint antibodies that target multiple suppressive cell populations within the TME, and fewer have studied the combinations of both agonist and antagonist mAbs on changes within the TME. Here, we test the hypothesis that combining a T-cell-inducing vaccine with both a PD-1 antagonist and CD40 agonist mAbs (triple therapy) will induce T-cell priming and TIL activation in mouse models of nonimmunogenic solid malignancies. In an orthotopic breast cancer model and both subcutaneous and metastatic pancreatic cancer mouse models, only triple therapy was able to eradicate most tumors. The survival benefit was accompanied by significant tumor infiltration of IFNg-, Granzyme Band nd TNFa-secreting effector T cells. Further characterization of immune populations was carried out by high-dimensional flow-cytometric clustering analysis and visualized by t-distributed stochastic neighbor embedding (t-SNE). Triple therapy also resulted in increased infiltration of dendritic cells, maturation of antigen-presenting cells, and a significant decrease in granulocytic MDSCs. These studies reveal that combination CD40 agonist and PD-1 antagonist mAbs reprogram immune resistant tumors in favor of antitumor immunity.
Clinical Cancer Research, 2012
The efficacy of oncolytic viruses (OVs) depends on multiple actions including direct tumor lysis, modulation of tumor perfusion and stimulation of tumordirected immune responses. In this study, we investigated whether a sequential combination of immunologically distinct viruses might enhance antitumor efficacy through the induction of tumor-specific immunity and circumvention or mitigation of antiviral immune responses. Experimental Design: The Syrian hamster as an immune-competent model that supports replication of both adenovirus and vaccinia virus was evaluated in vitro and in vivo. The antitumor efficacy of either virus alone or sequential combination of the two viruses was examined in pancreatic and kidney cancer models. The functional mechanism of the regime developed here was investigated by histopathology, immunohistochemistry staining, CTL assay and T-cell depletion. Results: The Syrian hamster is a suitable model for assessment of oncolytic adenovirus and vaccinia virus. Three low doses of adenovirus followed by three low doses of vaccinia virus resulted in a superior antitumor efficacy to the reverse combination, or six doses of either virus alone, against pancreatic and kidney tumors in Syrian hamsters. 62.5% of animals bearing either tumor type treated with the sequential combination became tumor-free, accompanied by the induction of effective tumor-specific immunity. This enhanced efficacy was ablated by CD3+ T cell depletion, but was not associated with humoral immunity against the viruses. Conclusion: These findings demonstrate that sequential treatment of tumors with oncolytic adenovirus and vaccinia virus is a promising approach for cancer therapy and that T cell responses play a critical role.
International Journal of Oncology, 2018
The objective of cancer immunotherapy is to prime the host's immune system to recognize and attack malignant tumor cells. IMO-2125, a Toll-like receptor 9 (TLR9) agonist, exhibited potent antitumor effects in the murine syngeneic A20 lymphoma and the CT26 colon carcinoma models. IMO-2125 exhibited superior A20 antitumor activity when injected intratumorally (i.t.) compared with equivalent subcutaneous doses. In mice bearing dual CT26 grafts, the i.t. injection of right flank tumors elicited infiltration of cluster of differentiation (CD)3 + T lymphocytes into tumors, resulting in the regression of injected and uninjected left flank tumors. Depletion of CD8 + , but not CD4 + , T-cells abrogated the IMO-2125-mediated antitumor response, suggesting that CD8 + lymphocytes are required for the antitumor activity. In mice harboring right flank CT26 and left flank β-galactosidase (β-gal)-expressing CT26.CL25 grafts, the i.t. administration of IMO-2125 to the CT26 graft resulted in potent and dose-dependent antitumor activity against the two grafts. Splenic T-cells isolated from these mice responded to AH1 antigen (present in the two tumors) and β-gal antigen (present only in CT26. CL25) in an interferon γ enzyme-linked immunospot assay, suggesting the clonal expansion of T-cells directed against antigens from the two tumors. Mice with ablated CT26 tumors by previous IMO-2125 treatment rejected re-implanted CT26 tumor cells, but not A20 tumor cells, demonstrating that the initial IMO-2125 treatment created a long-lived tumor-specific immune memory of CT26 antigens. A quantitative increase in CD3 + T lymphocytes in injected A20 tumors and an upregulation of selected checkpoint genes, including indoleamine 2,3-dioxygenase (IDO)-1, IDO-2, programmed cell death protein-1 (PD-1); programmed cell death protein ligand 1 (PD-L1), carcinoembryonic antigen-related cell adhesion molecule 1, tumor necrosis factor receptor superfamily member 4 (OX40), OX40 ligand, T-cell immunoglobulin and mucin-domain-containing 3 protein, lymphocyte-activation gene 3, cytotoxic T-lymphocyte-associated protein 4, were observed following IMO-2125 treatment. IMO-2125 also increased immune checkpoint gene expression in injected and uninjected contralateral CT26 tumors, suggesting that the co-administration of anti-CTLA-4, anti-PD-1 or anti-PD-L1 therapies with IMO-2125 may provide additional therapeutic efficacy.
Nature Communications, 2019
Virus-based vaccines and appropriate costimulation potently enhance antigen-specific T cell immunity against cancer. Here we report the use of recombinant modified vaccinia virus Ankara (rMVA) encoding costimulatory CD40L against solid tumors. Therapeutic treatment with rMVA-CD40L-expressing tumor-associated antigens results in the control of established tumors. The expansion of tumor-specific cytotoxic CD8+ T cells is essential for the therapeutic antitumor effects. Strikingly, rMVA-CD40L also induces strong natural killer (NK) cell activation and expansion. Moreover, the combination of rMVA-CD40L and tumor-targeting antibodies results in increased therapeutic antitumor efficacy relying on the presence of Fc receptor and NK cells. We describe a translationally relevant therapeutic synergy between systemic viral vaccination and CD40L costimulation. We show strengthened antitumor immune responses when both rMVA-CD40L-induced innate and adaptive immune mechanisms are exploited by comb...