Targeting the innate immunoreceptor RIG-I overcomes melanoma-intrinsic resistance to T cell immunotherapy

Understanding tumor resistance to T cell immunotherapies is critical to improve patient outcomes. Our study revealed a role for transcriptional suppression of the tumor-intrinsic HLA class I (HLA-I) antigen processing and presentation machinery (APM) in therapy resistance. Low HLA-I APM mRNA levels in melanoma metastases before immune checkpoint blockade (ICB) correlated with nonresponsiveness to therapy and poor clinical outcome. Patient-derived melanoma cells with silenced HLA-I APM escaped recognition by autologous CD8+ T cells. However, targeted activation of the innate immunoreceptor RIG-I initiated de novo HLA-I APM transcription, thereby overcoming T cell resistance. Antigen presentation was restored in interferon-sensitive (IFN-sensitive) but also immunoedited IFN-resistant melanoma models through RIG-I–dependent stimulation of an IFN-independent salvage pathway involving IRF1 and IRF3. Likewise, enhanced HLA-I APM expression was detected in RIG-Ihi (DDX58hi) melanoma biopsies, correlating with improved patient survival. Induction of HLA-I APM by RIG-I synergized with antibodies blocking PD-1 and TIGIT inhibitory checkpoints in boosting the antitumor T cell activity of ICB nonresponders. Overall, the herein-identified IFN-independent effect of RIG-I on tumor antigen presentation and T cell recognition proposes innate immunoreceptor targeting as a strategy to overcome intrinsic T cell resistance of IFN-sensitive and IFN-resistant melanomas and improve clinical ou...
Source: Journal of Clinical Investigation - Category: Biomedical Science Authors: Source Type: research

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Activation of the stimulator of interferon gene (STING) pathway within the tumor microenvironment has been shown to generate a strong antitumor response. Although local administration of STING agonists has promise for cancer immunotherapy, the dosing regimen needed to achieve efficacy requires frequent intratumoral injections over months. Frequent dosing for cancer treatment is associated with poor patient adherence, with as high as 48% of patients failing to comply. Multiple intratumoral injections also disrupt the tumor microenvironment and vascular networks and therefore increase the risk of metastasis. Here, we develop...
Source: Science Translational Medicine - Category: Biomedical Science Authors: Tags: Research Articles Source Type: research
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Source: Oncology Times - Category: Cancer & Oncology Tags: News Source Type: research
ConclusionIncrease in pretreatment expression levels of PD-L1 on CD14+ monocytes is associated with the OS of patients treated with immune checkpoint inhibitors. Further evaluation of large sample size and each specific cancer type might clarify the predictive role of PBMC in patients.
Source: Cancer Immunology, Immunotherapy - Category: Cancer & Oncology Source Type: research
Abstract Approximately 40% of malignant melanomas are diagnosed in patients older than 65 years.Elderly patients with melanoma present clinico-pathological features related to a more aggressive biology and they are often diagnosed with advanced stage of disease. Interestingly, in older patients the immune system can be altered with changes both in the innate and adaptive immune system with the acquisition of a pro-inflammatory and immune suppressive phenotype. Immunotherapy with immune checkpoint inhibitors has reshaped the treatment strategies and prognosis of patients with melanoma and, particularly, older age s...
Source: Pigment Cell and Melanoma Research - Category: Cytology Authors: Tags: Pigment Cell Melanoma Res Source Type: research
Contributors : Tamara Ouspenskaia ; Aviv RegevSeries Type : Expression profiling by high throughput sequencingOrganism : Homo sapiensTumor epitopes – peptides that are presented on surface-bound MHC I proteins - provide targets for cancer immunotherapy and have been identified extensively in the annotated protein-coding regions of the genome. Motivated by the recent discovery of translated novel unannotated open reading frames (nuORFs) using ribosome profiling (Ribo-seq), we hypothesized that cancer-associated processes could generate nuORFs that can serve as a new source of tumor antigens that harbor somatic mutatio...
Source: GEO: Gene Expression Omnibus - Category: Genetics & Stem Cells Tags: Expression profiling by high throughput sequencing Homo sapiens Source Type: research
Basel, 31 July 2020 - Roche (SIX: RO, ROG; OTCQX: RHHBY) today announced that the U.S. Food and Drug Administration (FDA) approved Tecentriq ® (atezolizumab) plus Cotellic® (cobimetinib) and Zelboraf® (vemurafenib) for the treatment of BRAF V600 mutation-positive advanced melanoma patients.  The safety profile observed in the Tecentriq combination was consistent with the known safety profiles of the individual medicines. The supplemental Biologics License Application (sBLA) for Tecentriq was granted under priority review.   The review was also conducted under Project Orbis, an initiative of the FDA On...
Source: Roche Investor Update - Category: Pharmaceuticals Source Type: news
Management of PD-1 blockade resistance in metastatic melanoma (MM) remains challenging. Immunotherapy or chemotherapy alone provides limited benefit in this setting. Chemo-immunotherapy (CIT) has demonstrated favorable efficacy and safety profiles in lung cancer. Our pre-clinical study showed that in MM patients who have failed PD-1 blockade, the addition of chemotherapy increases CX3CR1+ therapy-responsive CD8+ T-cells with enhanced anti-tumor activity, resulting in improved clinical response. Here, we examined the clinical outcomes of CIT in MM patients after PD-1 blockade failure and the treatment-related changes in CX3...
Source: Melanoma Research - Category: Cancer & Oncology Tags: Original Articles: Clinical research Source Type: research
To evaluate factors affecting the utilization of immunotherapy and to stratify results based on the approval of ipilimumab in 2011 and PD-1 inhibitors in 2014, an analysis of available data from the National Cancer Database (NCDB) was performed. Stage IV melanoma patients were identified. Effects of immunotherapy on overall survival (OS) were assessed using Kaplan–Meier curves and Cox proportional hazards model. A total of 19 233 patients were analyzed and 1998 received immunotherapy. Between 2011 and 2013, and in 2014, 18.6 and 28.9% of patients received immunotherapy, respectively. Patients who received immu...
Source: Melanoma Research - Category: Cancer & Oncology Tags: Original Articles: Epidemiology Source Type: research
Response to talimogene laherparepvec (T-Vec) is difficult to assess as pigmented macrophages that have ingested melanoma cells (‘melanophages’) persist after injection, mimicking melanoma. We used quantitative immunofluorescence (qIF) to (1) distinguish melanophages from melanoma in biopsies from two patients treated with T-Vec and (2) evaluate the tumor microenvironment pretreatment and posttreatment. Tissues were stained with 4’,6-diamidino-2-phenylindole, cluster of differentiation (CD) 3, CD8, CD68, human leukocyte antigen-DR isotype (HLA-DR), and SRY-Box Transcription Factor 10 (SOX10), and multispec...
Source: Melanoma Research - Category: Cancer & Oncology Tags: Short Communications: Basic science Source Type: research
Abstract Brain metastasis (BM) is associated with a poor prognosis, with the typical overall survival rate ranging from weeks to months in the absence of treatment. Although the concept of immune privilege in the central nervous system has eroded over time, the advent of immunotherapy has opened a new set of potential therapeutic options for patients with BM. Recently, immunotherapy has been demonstrated to confer survival advantages to patients with multiple malignancies commonly associated with BMs. Data from a number of clinical trials have demonstrated that immune checkpoint inhibitors are effective for patien...
Source: International Journal of Oncology - Category: Cancer & Oncology Authors: Tags: Int J Oncol Source Type: research
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