Project description:Evidence from mouse chronic viral infection models suggests that CD8+ T cell subsets characterized by distinct expression levels of the receptor PD-1 diverge in their state of exhaustion and potential for reinvigoration by PD-1 blockade. However, it remains unknown whether T cells in human cancer adopt a similar spectrum of exhausted states based on PD-1 expression levels. We compared transcriptional, metabolic, and functional signatures of intratumoral CD8+ T lymphocyte populations with high (PD-1T), intermediate (PD-1N) and no PD-1 expression (PD-1-) from non-small cell lung cancer patients. We observed that, PD-1T T cells show a markedly different transcriptional and metabolic profile as compared to PD-1N and PD-1- lymphocytes, as well as an intrinsically high capacity for tumor recognition. Furthermore, while PD-1T lymphocytes are impaired in classical effector cytokine production, they produce CXCL13 that mediates immune cell recruitment to tertiary lymphoid structures. Strikingly, the presence of PD-1T cells was strongly predictive for both response and survival in a small cohort of non-small cell lung cancer patients treated with PD-1 blockade. The characterization of a distinct state of tumor-reactive, PD-1 bright lymphocytes in human cancer, which only partially resembles that seen in chronic infection, provides novel potential avenues for therapeutic intervention.
Project description:IIn contrast to the young mice treated with anti-PD-1 therapy, aged mice exhibited immune-related adverse event (irAE)-like symptoms in the lung when treated with anti-PD-1 therapy. To understand the molecular events underlying the development of anti-PD-1 therapy-induced irAE, we employed deep RNA sequencing of whole lung transcript from anti-PD-1 therapy-treated young and aged mice. In order to further evaluate the effect of IL-21 signal on PD-1-blockade-mediated immune response, gene expression profile in lung tissue from aged mice twith the blockade of IL-21 activity was also assessed.
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:We sought to more precisely characterize the different alpha-synuclein (aSyn) 3M-bM-^@M-^YUTR mRNA species in normal and PD human brain. High-throughput, whole-transcriptome sequencing of the 3M-bM-^@M-^YUTR ends of polyadenylated mRNA transcripts (termed pA-RNAseq; see Methods) was performed on a cohort of 17 unaffected and 17 PD cerebral cortical tissue samples. This revealed 5 aSyn 3M-bM-^@M-^YUTR isoforms, with lengths of 290, 480, 560, 1070 and 2520 nt. Of these, the 560 nt and 2520 nt forms were predominant. The existence and relative preponderance of these species was further confirmed by Northern Blot. We next hypothesized, that aSyn 3M-bM-^@M-^YUTR selection might be altered in PD. Comparison of pA-RNAseq profiles from PD and unaffected cerebral cortex samples revealed an increase in the preponderance of the long 3M-bM-^@M-^YUTR species (>560 nt) relative to shorter species (<560 nt). Such a relative increase in aSynL was confirmed by Quantitative real-time RT-PCR (rt-qPCR) and appeared specific for PD, as the increase was also observed by comparison to RNA from amyotrophic lateral sclerosis patient samples. We note that the modified aSyn 3M-bM-^@M-^YUTR selection associated with PD patient tissue was detected in cerebral cortex tissue, which typically harbors pathological evidence of the disease process without frank cell loss; thus, this phenotype is unlikely to be a secondary consequence of neurodegeneration. Comparison of 3'UTR ends of alpha-synuclein in PD and unaffected brain cortex
Project description:Cancer immunotherapy has focused on inhibitors of checkpoint proteins, such as Programmed Death Ligand 1 (PD-L1). Unlike RAS-mutated lung cancers, EGFR mutant tumors have generally low response to immunotherapy. Because treatment outcomes vary by EGFR allele, we assumed that intrinsic and microenvironmental factors are involved. Among all non-immunological signaling pathways we surveyed in patients’ datasets, EGFR signaling best associated with high PD-L1. Correspondingly, active EGFRs stabilized PD-L1’s transcripts and depleting PD-L1 severely inhibited EGFR-driven tumorigenicity and metastasis in mice. The underlying mechanisms involve recruitment of phospholipase C-g1 (PLC-g1) to a cytoplasmic motif of PD-L1, which enhances PLC-g1 activation by EGFR. Once stimulated, PLC-g1 activates calcium flux, RHO GTPases and protein kinase C, which promotes an aggressive phenotype. Furthermore, anti-PD-L1 antibodies can inhibit these intrinsic functions of PD-L1. Our results portray PD-L1 as a molecular amplifier of EGFR signaling and lay the foundation for understanding resistance of EGFR+ tumors to immunotherapy.
Project description:Cancer testis antigens (CTAs) are of clinical interest as biomarkers and present valuable targets for immunotherapy. To comprehensively characterize the CTA landscape of non-small cell lung cancer (NSCLC), we compared RNAseq data of 199 NSCLC tissues to the normal transcriptome of 142 samples from 32 different normal organs. Of 232 CTAs currently annotated in the CTdatabase, 96 were confirmed in NSCLC. To obtain an unbiased CTA profile of NSCLC, we applied stringent criteria on our RNAseq data set and defined 90 genes as CTAs, of which 55 genes were not annotated in the CTdatabase. Cluster analysis revealed that CTA expression is histology-dependent and concurrent expression is common. Immunohistochemistry confirmed tissue specific protein expression of selected genes. Furthermore, methylation was identified as a regulatory mechanism of CTA expression based on independent data from the Cancer Genome Atlas. The proposed prognostic impact of CTAs in lung cancer, was not confirmed, neither in our RNAseq-cohort nor in an independent meta-analysis of 1117 NSCLC cases. Fresh frozen tumor tissue from 199 patients diagnosed with NSCLC and surgically treated 2006-2010 at the Uppsala University Hospital, Uppsala, Sweden and 19 paired normal lung tissues. Clinical data were retrieved from the regional lung cancer registry. Several of the new CTAs are poorly characterized Sample characteristics values represent; pTNM: decided by Hans Brunnstrom, pathologist in Lund Spring 2013 Stage according to pTNM: 1=1a 2=1b 3=2a 4=2b 5=3a 6=3b 7=IV Histology diagnosis spring 2013 HB: 1=squamous cell cancer 2=AC unspecified 3=Large cell/ NOS Surgery date: the date when sample arrived at Patologen UAS Age: age when surgery was performed Vital date: day of death or latest contact Dead: 0=no 1= yes Smoking history : 1=current 2=ex >1year 3=never WHO performance status: Performance status 0-4 Please note that the L608T_2122, L771T_1 data columns (in the processed data files) are associated with L608T and L771T samples, respectively.
Project description:The identification of novel therapeutic strategies to overcome the intrinsic or acquired resistance to trametinib in mutant KRAS lung adenocarcinoma (LUAD) is a major challenge. This study analyzes the effects of trametinib in Id1, a key factor involved in the oncogenic KRAS pathway, and investigates the Id1 role in acquire resistance and synergy with immunotherapy in KRAS-driven LUAD. Restoring the antitumor immune response by blocking programmed-cell death protein 1 (PD-1) and programmed-cell death-ligand 1 (PD-L1) pathway represents a major breakthrough in non-small-cell lung cancer (NSCLC) treatment. Nevertheless, a high proportion of LUAD patients with KRAS alterations remain refractory to this therapy. Material and Methods: To explore whether MEK1/2 inhibition reduces Id1 expression, in vitro and in vivo experiments were conducted in KRAS-mutant NSCLC cells and murine models. RNAseq analysis was performed to elucidate the pathways involved in Id1 inhibition. Apoptosis and PD-L1 expression was measured by flow cytometry. Synergy of trametinib combined with anti-PD1 was investigated in KRAS-mutant LUAD mouse models. Results: Using preclinical syngeneic KRAS-mutant lung cancer mouse models, we demonstrate that trametinib synergizes with PD-1 blockade to reduce lung cancer progression and increase mice overall survival. This antitumor activity was linked to the degradation of Id1 via proteasome, and an enhanced INF-Y-mediated PD-L1 tumor cell expression in KRAS-mutant tumor cells. This effect required CD8+ T cells, boosted the intratumoral CD8+/Treg ratio, reducing the intratumoral Treg/CD4+ ratio. Conclusions: Our data may support the role of Id1 in the trametinib antitumoral effect, sustaining the mitogen-activated protein kinases (MAPK) signaling pathway involved in the trametinib acquired resistance cells and sensitizing KRAS-mutant lung tumors to PD-1 inhibitors, through PD-L1 overexpression.
Project description:Targeting checkpoint blockade to rescue exhausted regulatory T cells (Tregs) has become an essential immunotherapy strategy in treating cancer. Until now, the CD4+ Tregs and PD-1+CD8+ T cells were demonstrated to reduce immunogenic responses. In contrast, little is known about the PD-L1 graphic pattern and characteristics in CD8+ T cells. We performed two high-throughput analysis approaches on tumor-infiltrating CD8+ T cells in lung cancers. We discovered PD-L1+CD8+ T cells enriched in tumor lesions, localized with PD-1+CD8+ affected T cells, and owned regulatory functions. Moreover, tumor-derived IL-27 promoted the development of PD-L1+CD8+ T cells through STAT1/STAT3 signaling. Single-cell RNA sequencing data analysis further clarified the enrichment of PD-L1+CD8+ T cells related to the downregulation of adaptive immune response. Additionally, enrichment of this subset was correlated with poor survival of lung cancer patients. Our data collectively demonstrated that PD-L1+CD8+ T cells potentially become a prognostic biomarker in lung cancer.