Spatially resolved whole-transcriptomic and proteomic profiling of lung cancer and immune-microenvironment according to PD-L1 expression
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ABSTRACT: The expression of PD-L1 on tumor cells (TCs) is used as an immunotherapy biomarker in lung cancer, but heterogeneous intratumoral expression is often observed. Using a Digital Spatial Profiler, we performed proteomic and whole-transcriptomic analyses of TCs and immune cells (ICs) in spatially matched areas according to tumor PD-L1 expression and the status of the immune microenvironment. Several findings were validated using immunohistochemistry, The Cancer Genome Atlas, and immunotherapy cohorts. ICs in areas with high PD-L1 expression showed more features indicative of immunosuppression and exhaustion than ICs in areas with low PD-L1 expression. TCs highly expressing PD-L1 within immune-inflamed (IF) areas show up-regulation of pro-inflammatory processes, whereas TCs highly expressing PD-L1 within immune-deficient (ID) areas show up-regulation of various metabolic processes. Using differentially expressed genes of TCs between the IF and ID areas, we identified a novel prognostic gene signature for lung cancer. In addition, the high ratio of CD8+ cells to M2 macrophages was found to predict favorable outcomes in patients with PD-L1-expressing lung cancer after immune checkpoint inhibitor therapy. This study demonstrates that TCs and ICs have distinct spatial features within the tumor microenvironment that are related to tumoral PD-L1 expression and IC infiltration.
Project description:New therapeutics targeting immune checkpoint proteins have significantly advanced treatment of non-small cell lung cancer (NSCLC), but protein level quantitation of drug targets presents a critical problem. We used multiplexed, targeted mass spectrometry (MS) to quantify the immunotherapy target proteins PD-1, PD-L1, PD-L2, IDO1, LAG3, TIM-3, VISTA, GITR, and CD40 in formalin-fixed, paraffin-embedded (FFPE) NSCLC specimens. Immunohistochemistry (IHC) and MS measurements for PD-L1 were weakly correlated, but IHC did not distinguish protein abundance differences detected by MS. PD-L2 abundance exceeded PD-L1 in over half the specimens and the drug target proteins all displayed different abundance patterns. mRNA correlated with protein abundance only for PD-1, PD-L1, and IDO1 and tumor mutation burden did not predict abundance of any protein targets. Global proteome analyses identified distinct proteotypes associated with high PD-L1-expressing and high IDO1-expressing NSCLC. MS quantification of multiple drug targets and tissue proteotypes can improve clinical evaluation of immunotherapies for NSCLC.
Project description:Although the paradigm of cancer treatment has changed with the recent development of drugs targeting immune checkpoints (PD-1, PD-L1, etc.), there is still a need for new targets for anticancer drugs. To discover new potential targets for immunotherapy, we compared membrane protein expression in non-small cell lung cancer cells versus normal lung cancer cells and NSCLC cell lines with low and high PD-L1 expression using mass spectrometry. As a result, it was confirmed that membrane protein, which is one of the most highly expressed proteins in NSCLC cell lines, is highly expressed in normal cells and highly expressed in cells with low PD-L1 expression.
Project description:Lung cancer is a major global health problem, as it is the leading cause of cancer- related deaths worldwide. Non-small-cell lung cancer (NSCLC), the most common form, is a heterogeneous disease with adenocarcinoma and squamous cell carcinoma being the predominant subtypes. Immune-inhibiting interaction of Programmed cell death-ligand 1 (PD-L1) with programmed cell death-protein 1 (PD-1) causes checkpoint mediated immune evasion and is, accordingly, an important therapeutic target in cancer. In NSCLC, improved understanding of PD-1/PD-L1 checkpoint blockade-responsive biology is warranted. We aimed to identify the landscape of immune cell infiltration in primary lung adeno- carcinoma (LUAD) in the context of tumor PD-L1 expression and the extent of immune infiltration (“hot” vs. “cold” phenotype). Therefore, the study comprises LUAD cases (n=138) with “hot” and “cold” tumor immune phenotype and positive and negative tumor PD-L1 expression, respectively. Tumor samples were immunohistochemically analyzed for expression of PD-L1, CD4 and CD8 and further analyzed on transcriptomic level by Nanostring nCouter Pan Cancer Immune Profiling Panel. We detected significantly differentially expressed genes associated with PD-L1 positive and “hot” versus PD-L1 negative and “cold” phenotype. The presented study illustrates novel aspects of PD-L1 regulation, with potential biological relevance, as well as relevance for immunotherapy response stratification.
Project description:Cancer cells express high levels of PD-L1, a ligand of the PD-1 receptor on T cells, allowing tumors to suppress T cell activity 1-3. Clinical trials utilizing monoclonal antibodies that disrupt the PD-1/PD-L1 immune checkpoint have yielded remarkable results, with PD-1 immunotherapy approved as a first-line therapy for human lung cancer patients 4-6. Despite significant progress in targeting this pathway, the mechanisms through which PD-L1 is upregulated in non-small cell lung cancer (NSCLC) and other tumor types remain incompletely understood. Here we used CRISPR-based screening to identify regulators of PDL1 in human lung cancer cells, revealing potent induction of PD-L1 levels upon disruption of the heme biosynthesis pathway. Impairment of heme production activates the integrated stress response (ISR), allowing bypass of inhibitory upstream open reading frames in the PD-L1 5¢ UTR, resulting in enhanced PD-L1 translation and suppression of anti-tumor immunity. We further demonstrated that ISR-dependent translation of PD-L1 requires the translation initiation factor EIF5B. EIF5B overexpression, which is frequent in human lung cancers and is associated with poor prognosis, is sufficient to induce PD-L1. These findings uncover a new mechanism of immune checkpoint activation and suggest novel targets for therapeutic intervention.
Project description:Programmed cell death 1 ligand 1 (PD-L1) is known to suppress immune system and to be an unfavorable prognostic factor in ovarian cancer. The purpose of this study was to elucidate the function of PD-L1 in peritoneal dissemination. Tumor cell lysis by CTLs was attenuated when PD-L1 on tumor cells was overexpressed and promoted when it was silenced. PD-L1 overexpression also inhibited gathering and degranulation of CTLs. Gene expression profile of mouse CTLs caused by PD-L1-overexpressing ovarian cancer was related to human CTLs exhaustion. In mouse ovarian cancer dissemination models, depleting PD-L1 expression on tumor cells resulted in inhibited tumor growth in the peritoneal cavity and prolonged survival. Restoring immune function by inhibiting immune-suppressive factors such as PD-L1 may be a promising therapeutic strategy for peritoneal dissemination. Genome-wide transcriptional changes in OT-1 mouse CD8+ T cells that were co-incubated with OVA peptide-loaded ID8 mouse ovarian cancer cell lines. CTLs from 4 mice were devided into 2 groups, and co-incubated with PD-L1-overexpressed ID8 or PD-L1-depleted ID8.
Project description:Targeting the PD-1/PD-L1 axis has transformed the field of immune-oncology. While conventional wisdom initially postulated that PD-L1 serves as the inert ligand for PD-1, an emerging body of literature suggests that PD-L1 has cell‑intrinsic functions in immune and cancer cells. In line with these studies, here we show that PD-L1 potently inhibits the type I interferon pathway in cancer cells. Hampered type I interferon responses in PD-L1-expressing cells resulted in enhanced infection with oncolytic viruses in cancer cells in vitro and in vivo. PD-L1 expression marks tumor explants from cancer patients that are best infected by oncolytic viruses. Agonistic antibodies targeting PD-L1 further reduced type I IFN responses and enhanced oncolytic virus infection. Mechanistically, PD-L1 suppressed type I interferon by promoting Warburg metabolism, characterized by enhanced glucose uptake and glycolysis rate. Lactate generated from glycolysis was the key metabolite responsible for inhibiting type I interferon responses and enhancing oncolytic virus infection in PD‑L1‑expressing cells. In addition to adding mechanistic insight into PD-L1 intrinsic function and showing that PD-L1 has a broader impact on immunity and cancer biology besides acting as a ligand for PD-1, our results will also help guide the numerous efforts currently ongoing to combine PD-L1 antibodies with oncolytic virotherapy in clinical trials.
Project description:Ovarian cancer often progresses by disseminating to the peritoneal cavity, but how the tumor cells evade host immunity during this process is poorly understood. Programmed cell death 1 ligand 1 (PD-L1) is known to suppress immune system and to be an unfavorable prognostic factor in ovarian cancer. The purpose of this study was to elucidate the function of PD-L1 in peritoneal dissemination. Positive cytology in ascites was a significant poor prognostic factor in ovarian cancer. Microarray profiles of cytology-positive cases showed significant correlations with Gene Ontology terms related to immune system process. Microarray and immunohistochemistry in human ovarian cancer revealed significant correlation between PD-L1 expression and positive cytology. PD-L1 expression on mouse ovarian cancer cells was induced upon encountering lymphocytes in the course of peritoneal spread in vivo and upon co-culturing with lymphocytes in vitro. Tumor cell lysis by CTLs was attenuated when PD-L1 was overexpressed and promoted when it was silenced. PD-L1 overexpression also inhibited gathering and degranulation of CTLs. In mouse ovarian cancer dissemination models, depleting PD-L1 expression on tumor cells resulted in inhibited tumor growth in the peritoneal cavity and prolonged survival. Restoring immune function by inhibiting immune-suppressive factors such as PD-L1 may be a promising therapeutic strategy for peritoneal dissemination. Genome-wide transcriptional changes in human ovarian cancer tissue from ascites-cytology-positive or -negative patients.
Project description:Disrupting PD-1/PD-L1 interaction rejuvenates antitumor immunity. Clinical successes by blocking PD-1/PD-L1 binding have grown across wide-ranging cancer histologies, but innate therapy resistance is evident in the majority of treated patients1. Cancer cells can express robust surface levels of PD-L1 to tolerize tumor-specific T cells, but regulation of PD-L1 protein levels in the cancer cell is poorly understood. Quasi-mesenchymal tumor cells up-regulate PD-L1/L2 and induce an immune-suppressive microenvironment, including expansion of M2-like macrophages and regulatory T cells and exclusion of CD8+ T-cell infiltration2. Targeted therapy, including MAPK inhibitor therapy in melanoma, leads to quasi-mesenchymal transitions and resistance3, and both MAPK inhibitor treatment and mesenchymal signatures are associated with innate anti-PD-1 resistance4,5. Here we identify ITCH as an E3 ligase that downregulates tumor cell-surface PD-L1/L2 in PD-L1/L2-high cancer cells, including MAPK inhibitor-resistant melanoma, and suppresses acquired MAPK inhibitor resistance in and only in immune-competent mice. ITCH interacts with and poly-ubiquitinates PD-L1/L2, and ITCH deficiency increases cell-surface PD-L1/L2 expression and reduces T cell activation. Mouse melanoma tumors grow faster with Itch knockdown only in syngeneic hosts but not in immune-deficient mice. MAPK inhibitor therapy induces tumor cell-surface PD-L1 expression in murine melanoma, recapitulating the responses of clinical melanoma3, and this induction is more robust with Itch knockdown. Notably, suppression of ITCH expression first elicits a shift toward an immune-suppressive microenvironment and then accelerates resistance development. These findings collectively identify ITCH as a critical negative regulator of PD-L1 tumor cell-surface expression and provide insights into previously unexplained role of PD-L1 in adaptive resistance to therapy.
Project description:The growing tumor avoids recognition and destruction by immune system. During continuous stimulation of tumor infiltrating lymphocytes (TILs) by tumor, TILs become functionally exhausted. Thus, they become unable to kill tumor cells and to produce some cytokines, and lose their ability to proliferate. It collectively results in the immune escape of cancer cells. Here, we show that breast cancer cells expressing PD-L1 can accelerate exhaustion of persistently activated human effector CD4+ T cells, manifesting in high PD-1 and PD-L1 expression level on cell surface, decreased glucose metabolism genes, strong downregulation of SWI/SNF chromatin remodeling complex subunits and p21 cell cycle inhibitor upregulation. This results in inhibition of T cell proliferation and reduction of T cells number. The RNAseq analysis on exhausted CD4+ T cells indicated strong overexpression of IDO1 and genes encoding pro-inflammatory cytokines and chemokines. The PD-L1 overexpression was also observed in CD4+ T cells after co-cultivation with other cell line overexpressing PD-L1 that suggested the existence of general mechanism of CD4+ T cell exhaustion induced by cancer cells. The ChIP analysis on PD-L1 promoter region indicated that the strong BRM recruitment in control CD4+ T cells is replaced by BRG1 and EZH2 in CD4+ T cells strongly exhausted by cancer cells. These findings suggest that such epi-drugs as EZH2 inhibitors may be used as immunomodulators in cancer treatment.
Project description:Background: Immune checkpoint inhibitors (ICIs) have transformed lung cancer treatment, yet their effectiveness appears restricted to certain patient subsets. Current clinical stratification based on PD-L1 expression offers limited predictive value. Given the mechanism of action, directly detecting spatial PD1–PD-L1 interactions might yield more precise insights into immune responses and treatment outcomes. Methods: We applied a second-generation in situ proximity ligation assay (PLA) to detect PD1–PD-L1 interactions in diagnostic tissue samples from 16 different cancer types, a tissue microarray from 352 surgically resected early-stage non-small cell lung cancer (NSCLC) patients, and finally diagnostic biopsies from 242 advanced NSCLC patients with and without ICI treatment. RNAseq analysis was used to identify potential resistance mechanisms. Results: In the early-stage NSCLC,only about half of the cases with detectable PD-L1 and PD1 expression showed PD1–PD-L1 interactions, with significantly lower levels in EGFR-mutated tumors. Interaction levels varied across cancer types, aligning with reported ICI response rates. In ICI-treated NSCLC patients, higher PD1–PD-L1 interactions were linked to complete responses and longer survival, outperforming standard PD-L1 expression assays. Patients who, despite high PD1–PD-L1 interactions, did not respond to ICIs, showed additional expression of stromal immune mediators (EOMES, HAVCR1/TIM-1, JAML, FCRL1). Conclusion: Our study proposes a diagnostic shift from static biomarker quantification to assessing active immune pathways, providing more precise ICI treatment. This functional concept applies to tiny lung biopsies and can be used to further immune checkpoints. Accordingly, our results indicate concerted ICI resistance mechanisms, highlighting a need for combination diagnostics and therapies.