The development of the most successful cancer immunotherapies in solid tumors, immune-checkpoint blockade, has focused on factors regulating T-cell activation. Until recently, the field has ...maintained a predominately T-cell centric view of immunotherapy, leaving aside the impact of innate immunity and especially myeloid cells. Dendritic cells (DC) are dominant partners of T cells, necessary for initiation of adaptive immune responses. Emerging evidence supports a broader role for DCs in tumors including the maintenance and support of effector functions during T-cell responses. This relationship is evidenced by the association of activated DCs with immune-checkpoint blockade responses and transcriptional analysis of responding tumors demonstrating the presence of type I IFN transcripts and DC relevant chemokines. T-cell-inflamed tumors preferentially respond to immunotherapies compared with non-T-cell-inflamed tumors and this model suggests a potentially modifiable spectrum of tumor microenvironmental immunity. Although host and commensal factors may limit the T-cell-inflamed phenotype, tumor cell intrinsic factors are gaining prominence as therapeutic targets. For example, tumor WNT/β-catenin signaling inhibits production of chemokine gradients and blocking DC recruitment to tumors. Conversely, mechanisms of innate immune nucleic acid sensing, normally operative during pathogen response, may enhance DC accumulation and make tumors more susceptible to cancer immunotherapy. Elucidating mechanisms whereby DCs infiltrate and become activated within tumors may provide new opportunities for therapeutic intervention. Conceptually, this would facilitate conversion of non-T-cell-inflamed to T-cell-inflamed states or overcome secondary resistance mechanisms in T-cell-inflamed tumors, expanding the proportion of patients who benefit from cancer immunotherapy.
Cancer metastasis as a non-healing wound Deyell, Matthew; Garris, Christopher S; Laughney, Ashley M
British journal of cancer,
04/2021, Letnik:
124, Številka:
9
Journal Article
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Most cancer deaths are caused by metastasis: recurrence of disease by disseminated tumour cells at sites distant from the primary tumour. Large numbers of disseminated tumour cells are released from ...the primary tumour, even during the early stages of tumour growth. However, only a minority survive as potential seeds for future metastatic outgrowths. These cells must adapt to a relatively inhospitable microenvironment, evade immune surveillance and progress from the micro- to macro-metastatic stage to generate a secondary tumour. A pervasive driver of this transition is chronic inflammatory signalling emanating from tumour cells themselves. These signals can promote migration and engagement of stem and progenitor cell function, events that are also central to a wound healing response. In this review, we revisit the concept of cancer as a non-healing wound, first introduced by Virchow in the 19th century, with a new tumour cell-intrinsic perspective on inflammation and focus on metastasis. Cellular responses to inflammation in both wound healing and metastasis are tightly regulated by crosstalk with the surrounding microenvironment. Targeting or restoring canonical responses to inflammation could represent a novel strategy to prevent the lethal spread of cancer.
Monoclonal antibodies (mAbs) targeting the immune checkpoint anti-programmed cell death protein 1 (aPD-1) have demonstrated impressive benefits for the treatment of some cancers; however, these drugs ...are not always effective, and we still have a limited understanding of the mechanisms that contribute to their efficacy or lack thereof. We used in vivo imaging to uncover the fate and activity of aPD-1 mAbs in real time and at subcellular resolution in mice. We show that aPD-1 mAbs effectively bind PD-1
tumor-infiltrating CD8
T cells at early time points after administration. However, this engagement is transient, and aPD-1 mAbs are captured within minutes from the T cell surface by PD-1
tumor-associated macrophages. We further show that macrophage accrual of aPD-1 mAbs depends both on the drug's Fc domain glycan and on Fcγ receptors (FcγRs) expressed by host myeloid cells and extend these findings to the human setting. Finally, we demonstrate that in vivo blockade of FcγRs before aPD-1 mAb administration substantially prolongs aPD-1 mAb binding to tumor-infiltrating CD8
T cells and enhances immunotherapy-induced tumor regression in mice. These investigations yield insight into aPD-1 target engagement in vivo and identify specific Fc/FcγR interactions that can be modulated to improve checkpoint blockade therapy.
Anti-PD-1 immune checkpoint blockers can induce sustained clinical responses in cancer but how they function in vivo remains incompletely understood. Here, we combined intravital real-time imaging ...with single-cell RNA sequencing analysis and mouse models to uncover anti-PD-1 pharmacodynamics directly within tumors. We showed that effective antitumor responses required a subset of tumor-infiltrating dendritic cells (DCs), which produced interleukin 12 (IL-12). These DCs did not bind anti-PD-1 but produced IL-12 upon sensing interferon γ (IFN-γ) that was released from neighboring T cells. In turn, DC-derived IL-12 stimulated antitumor T cell immunity. These findings suggest that full-fledged activation of antitumor T cells by anti-PD-1 is not direct, but rather involves T cell:DC crosstalk and is licensed by IFN-γ and IL-12. Furthermore, we found that activating the non-canonical NF-κB transcription factor pathway amplified IL-12-producing DCs and sensitized tumors to anti-PD-1 treatment, suggesting a therapeutic strategy to improve responses to checkpoint blockade.
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•Effective anti-PD-1 anti-tumor responses require IL-12-producing dendritic cells•Anti-PD-1 indirectly activates IL-12 through IFN-γ produced from CD8+ T cells•Agonizing the non-canonical NF-κB pathway enhances dendritic cell IL-12 production•Combining aPD-1 with non-canonical NF-κB agonism enhances checkpoint immunotherapy
Anti-PD-1 mAbs can induce sustained clinical responses in cancer but how they function in vivo remains incompletely understood. Garris et al. show that effective anti-PD-1 immunotherapy requires intratumoral dendritic cells (DCs) producing IL-12. Anti-PD-1 indirectly activates DCs through IFN-γ released from drug-activated T cells. Furthermore, agonizing the non-canonical NF-κB pathway activates DCs and enhances aPD-1 therapy in an IL-12-dependent manner.
Tumour-associated macrophages are abundant in many cancers, and often display an immune-suppressive M2-like phenotype that fosters tumour growth and promotes resistance to therapy. Yet, macrophages ...are highly plastic and can also acquire an anti-tumorigenic M1-like phenotype. Here, we show that R848, an agonist of the toll-like receptors TLR7 and TLR8 identified in a morphometric-based screen, is a potent driver of the M1 phenotype in vitro and that R848-loaded β-cyclodextrin nanoparticles (CDNP-R848) lead to efficient drug delivery to tumour-associated macrophages in vivo. As a monotherapy, the administration of CDNP-R848 in multiple tumour models in mice altered the functional orientation of the tumour immune microenvironment towards an M1 phenotype, leading to controlled tumour growth and protecting the animals against tumour rechallenge. When used in combination with the immune checkpoint inhibitor anti-PD-1, we observed improved immunotherapy response rates, including in a tumour model resistant to anti-PD-1 therapy alone. Our findings demonstrate the ability of rationally engineered drug-nanoparticle combinations to efficiently modulate tumour-associated macrophages for cancer immunotherapy.
Myeloid cells are abundant, create a highly immunosuppressive environment in glioblastoma (GBM), and thus contribute to poor immunotherapy responses. Based on the hypothesis that small molecules can ...be used to stimulate myeloid cells to elicit anti‐tumor effector functions, a synthetic nanoparticle approach is developed to deliver dual NF‐kB pathway‐inducing agents into these cells via systemic administration. Synthetic, cyclodextrin‐adjuvant nanoconstructs (CANDI) with high affinity for tumor‐associated myeloid cells are dually loaded with a TLR7 and 8 (Toll‐like receptor, 7 and 8) agonist (R848) and a cIAP (cellular inhibitor of apoptosis protein) inhibitor (LCL‐161) to dually activate these myeloid cells. Here CANDI is shown to: i) readily enter the GBM tumor microenvironment (TME) and accumulate at high concentrations, ii) is taken up by tumor‐associated myeloid cells, iii) potently synergize payloads compared to monotherapy, iv) activate myeloid cells, v) fosters a “hot” TME with high levels of T effector cells, and vi) controls the growth of murine GBM as mono‐ and combination therapies with anti‐PD1. Multi‐pathway targeted myeloid stimulation via the CANDI platform can efficiently drive anti‐tumor immunity in GBM.
Here immune stimulants delivered via this new platform called cyclodextrin‐adjuvant nanoparticle dual immunotherapy (CANDI) are shown to effectively target myeloid cells in glioblastoma multiforme (GBM) mouse models, and reverse immune suppression. This immunotherapy turns the “cold” GBM tumor microenvironment (TME) into a “hot” T cell inflamed TME, and leads to significant survival benefits in GBM.
Summary
Sphingosine‐1‐phosphate (S1P) is a lipid second messenger that signals via five G protein‐coupled receptors (S1P1–5). S1P receptor (S1PR) signalling is associated with a wide variety of ...physiological processes including lymphocyte biology, their recirculation and determination of T‐cell phenotypes. The effect of FTY720 (Fingolimod, Gilenya™) to regulate lymphocyte egress and to ameliorate paralysis in experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis led to the use of FTY720 as a first‐line oral agent for treatment of relapsing–remitting multiple sclerosis. However, a significant body of research suggests that S1P signalling may participate in diverse immune regulatory functions other than lymphocyte trafficking. This review article discusses the current knowledge of S1P signalling in the fate and function of T regulatory, T helper type 17 and memory T cells in health and disease.
Intravesical immunotherapy using Bacille Calmette-Guérin (BCG) attenuated bacteria delivered transurethrally to the bladder has been the standard of care for patients with high-risk ...non-muscle-invasive bladder cancer (NMIBC) for several decades. BCG therapy continues to be limited by high rates of disease recurrence and progression, and patients with BCG-unresponsive disease have few effective salvage therapy options besides radical cystectomy, highlighting a need for new therapies. We report that the immune-stimulatory receptor CD40 is highly expressed on dendritic cells (DCs) within the bladder tumor microenvironment of orthotopic bladder cancer mouse models, recapitulating CD40 expression by DCs found in human disease. We demonstrate that local CD40 agonism in mice with orthotopic bladder cancer through intravesical delivery of anti-CD40 agonist antibodies drives potent antitumor immunity and induces pharmacodynamic effects in the bladder tumor microenvironment, including a reduction in CD8
T cells with an exhausted phenotype. We further show that type 1 conventional DCs (cDC1) and CD8
T cells are required for both bladder cancer immune surveillance and anti-CD40 agonist antibody responses. Using orthotopic murine models humanized for CD40 and Fcγ receptors, we demonstrate that intravesical treatment with a fully human, Fc-enhanced anti-CD40 agonist antibody (2141-V11) induces robust antitumor activity in both treatment-naïve and treatment-refractory settings, driving long-term systemic antitumor immunity with no evidence of systemic toxicity. These findings support targeting CD40-expressing DCs in the bladder cancer microenvironment through an intravesical agonistic antibody approach for the treatment of NMIBC.
Tumor-associated macrophages (TAMs) are often abundant in solid cancers, assuming an immunosuppressive (M2-like) phenotype which supports tumor growth and immune escape. Recent methods have focused ...on identification of means (e.g., drugs, nanomaterials) that polarize TAMs to a tumor suppressive (M1-like) phenotype; however, reducing the systemic side effects of these therapies and enabling their delivery to TAMs has remained a challenge.
Here, we develop R848-Ad, an adamantane-modified derivative of the toll-like receptor (TLR) 7/8 agonist resiquimod (R848) through iterative drug screening against reporter cell lines. The adamantane undergoes guest-host interaction with cyclodextrin nanoparticles (CDNPs), enabling drug loading under aqueous conditions and TAM-targeted drug delivery. Therapeutic efficacy and systemic side effects were examined in a murine MC38 cancer model.
R848-Ad retained macrophage polarizing activity through agonization of TLR7/8, and the adamantane moiety improved drug affinity for the CDNP. In preclinical studies, nanoformulated R848-Ad resulted in a drastic reduction in measurable systemic effects (loss of body weight) relative to similarly formulated R848 alone while arresting tumor growth.
The findings demonstrate the ability of strong nanoparticle-drug interactions to limit systemic toxicity of TLR agonists while simultaneously maintaining therapeutic efficacy.
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