Explore the vast range of titles available.

Somatic gene mutations can alter the vulnerability of cancer cells to T-cell-based immunotherapies. Here we perturbed genes in human melanoma cells to mimic loss-of-function mutations involved in resistance to these therapies, by using a genome-scale CRISPR–Cas9 library that consisted of around 123,000 single-guide RNAs, and profiled genes whose loss in tumour cells impaired the effector function of CD8 + T cells. The genes that were most enriched in the screen have key roles in antigen presentation and interferon-γ signalling, and correlate with cytolytic activity in patient tumours from The Cancer Genome Atlas. Among the genes validated using different cancer cell lines and antigens, we identified multiple loss-of-function mutations in APLNR , encoding the apelin receptor, in patient tumours that were refractory to immunotherapy. We show that APLNR interacts with JAK1, modulating interferon-γ responses in tumours, and that its functional loss reduces the efficacy of adoptive cell transfer and checkpoint blockade immunotherapies in mouse models. Our results link the loss of essential genes for the effector function of CD8 + T cells with the resistance or non-responsiveness of cancer to immunotherapies. The authors describe a two-cell-type CRISPR screen to identify tumour-intrinsic genes that regulate the sensitivity of cancer cells to effector T cell function. CRISPR screen identifies genes driving resistance to cancer immunotherapy Some mutations in cancer cells make them resistant to immunotherapy. Nicholas Restifo and colleagues designed a 'two-cell-type' CRISPR–Cas9 screen to identify tumour-intrinsic genetic mutations associated with the sensitivity of melanoma cells to effector T cell function. The candidate genes identified included mediators of MHC class I antigen presentation and genes unknown to be involved in these immunity processes. The authors highlight the interaction between T-cell-secreted apelin and its receptor APLNR on tumour cells as a node for potent T-cell-mediated killing of cancer cells.

Effective eradication of leukemic stem cells (LSCs) remains the greatest challenge in treating acute myeloid leukemia (AML). The immune receptor LAIR-1 has been shown to regulate LSC survival; however, the therapeutic potential of this pathway remains unexplored. We developed a therapeutic LAIR-1 agonist antibody, NC525, that induced cell death of LSCs, but not healthy hematopoietic stem cells in vitro, and killed LSCs and AML blasts in both cell- and patient-derived xenograft models. We showed that LAIR-1 agonism drives a unique apoptotic signaling program in leukemic cells that was enhanced in the presence of collagen. NC525 also significantly improved the activity of azacitidine and venetoclax to establish LAIR-1 targeting as a therapeutic strategy for AML that may synergize with standard-of-care therapies.

Although prostate cancer typically runs an indolent course, a subset of men develop aggressive, fatal forms of this disease. We hypothesize that germline variation modulates susceptibility to aggressive prostate cancer. The goal of this work is to identify susceptibility genes using the C57BL/6-Tg(TRAMP)8247Ng/J (TRAMP) mouse model of neuroendocrine prostate cancer. Quantitative trait locus (QTL) mapping was performed in transgene-positive (TRAMPxNOD/ShiLtJ) F2 intercross males (n = 228), which facilitated identification of 11 loci associated with aggressive disease development. Microarray data derived from 126 (TRAMPxNOD/ShiLtJ) F2 primary tumors were used to prioritize candidate genes within QTLs, with candidate genes deemed as being high priority when possessing both high levels of expression-trait correlation and a proximal expression QTL. This process enabled the identification of 35 aggressive prostate tumorigenesis candidate genes. The role of these genes in aggressive forms of human prostate cancer was investigated using two concurrent approaches. First, logistic regression analysis in two human prostate gene expression datasets revealed that expression levels of five genes (CXCL14, ITGAX, LPCAT2, RNASEH2A, and ZNF322) were positively correlated with aggressive prostate cancer and two genes (CCL19 and HIST1H1A) were protective for aggressive prostate cancer. Higher than average levels of expression of the five genes that were positively correlated with aggressive disease were consistently associated with patient outcome in both human prostate cancer tumor gene expression datasets. Second, three of these five genes (CXCL14, ITGAX, and LPCAT2) harbored polymorphisms associated with aggressive disease development in a human GWAS cohort consisting of 1,172 prostate cancer patients. This study is the first example of using a systems genetics approach to successfully identify novel susceptibility genes for aggressive prostate cancer. Such approaches will facilitate the identification of novel germline factors driving aggressive disease susceptibility and allow for new insights into these deadly forms of prostate cancer.

To better elucidate epigenetic mechanisms that correlate with the dynamic gene expression program observed upon T-cell differentiation, we investigated the genomic landscape of histone modifications in naive and memory CD8＋ T cells. Using a ChlP-Seq approach coupled with global gene expression profiling, we generated genome-wide histone H3 lysine 4 （H3K4me3） and H3 lysine 27 （H3K27me3） trimethylation maps in naive, T memory stem cells, central memory cells, and effector memory cells in order to gain insight into how histone architecture is remodeled during T cell differentiation. We show that H3K4me3 histone modifications are associated with activation of genes, while H3K27me3 is negatively correlated with gene expression at canonical loci and enhancers associated with T-cell metabolism, effector function, and memory. Our results also reveal histone modifications and gene expression signatures that distinguish the recently identified T memory stem cells from other CD8＋ T-cell subsets. Taken together, our results suggest that CD8＋ lymphocytes undergo chromatin remodeling in a progressive fashion. These findings have major implications for our understanding of peripheral T-cell ontogeny and the formation of immunological memory.

The immune system has a powerful ability to recognize and kill cancer cells, but its function is often suppressed within tumors, preventing clearance of disease. Functionally diverse innate and adaptive cellular lineages either drive or constrain immune reactions within tumors. The transcription factor (TF) BACH2 regulates the differentiation of multiple innate and adaptive cellular lineages, but its role in controlling tumor immunity has not been elucidated. Here, we demonstrate that BACH2 is required to establish immunosuppression within tumors. Tumor growth was markedly impaired in Bach2-deficient mice and coincided with intratumoral activation of both innate and adaptive immunity. However, augmented tumor clearance in the absence of Bach2 was dependent upon the adaptive immune system. Analysis of tumor-infiltrating lymphocytes from Bach2-deficient mice revealed high frequencies of rapidly proliferating effector CD4+ and CD8+ T cells that expressed the inflammatory cytokine IFN-γ. Effector T cell activation coincided with a reduction in the frequency of intratumoral Foxp3+ Tregs. Mechanistically, BACH2 promoted tumor immunosuppression through Treg-mediated inhibition of intratumoral CD8+ T cells and IFN-γ. These findings demonstrate that BACH2 is a key component of the molecular program of tumor immunosuppression and identify therapeutic targets for the reversal of immunosuppression in cancer.

Potassium ions released by necrotic cells in tumours impair T cell function by increasing the intracellular potassium concentration in vitro and in vivo . Influence of cell death on anti-tumour defences Cell death in tumours is frequently associated with a poor prognosis, a phenomenon that has previously been attributed to rapidly dividing cancer cells in a resource-limited environment. Robert Eil et al . demonstrate that intratumoural cell death in fact plays an active part in suppressing anti-tumour immunity. They show that elevated extracellular potassium in human and mouse tumour interstitial fluid inhibits T-cell-receptor-induced anti-tumour functions in human and mouse T cells. In addition, this immune suppression can be reversed by enabling tumour-specific T cells to efflux potassium through overexpression of the exporter Kcna3 . Tumours progress despite being infiltrated by tumour-specific effector T cells 1 . Tumours contain areas of cellular necrosis, which are associated with poor survival in a variety of cancers 2 . Here, we show that necrosis releases intracellular potassium ions into the extracellular fluid of mouse and human tumours, causing profound suppression of T cell effector function. Elevation of the extracellular potassium concentration ([K + ] e ) impairs T cell receptor (TCR)-driven Akt–mTOR phosphorylation and effector programmes. Potassium-mediated suppression of Akt–mTOR signalling and T cell function is dependent upon the activity of the serine/threonine phosphatase PP2A 3 , 4 . Although the suppressive effect mediated by elevated [K + ] e is independent of changes in plasma membrane potential ( V m ), it requires an increase in intracellular potassium ([K + ] i ). Accordingly, augmenting potassium efflux in tumour-specific T cells by overexpressing the potassium channel K v 1.3 lowers [K + ] i and improves effector functions in vitro and in vivo and enhances tumour clearance and survival in melanoma-bearing mice. These results uncover an ionic checkpoint that blocks T cell function in tumours and identify potential new strategies for cancer immunotherapy.

T lymphocytes are powerful immune cells that can destroy tumors, but cancers have developed tricks to evade killing. Vodnala et al. found that potassium ions in the tumor microenvironment serve a dual role of influencing T cell effector function and stemness (see the Perspective by Baixauli Celda et al. ). Increased potassium impairs T cell metabolism and nutrient uptake, resulting in a starvation state known as autophagy. The increased potassium can also preserve T cells in a stem-like state where they retain the capacity to divide. These seemingly divergent processes are linked to the cellular distribution of acetyl–coenzyme A, which, when manipulated, can restore the ability of human T cells to eliminate tumors in mice. Science , this issue p. eaau0135 ; see also p. 1395 Potassium in the tumor microenvironment metabolically reprograms tumor-infiltrating immunological T cells. A paradox of tumor immunology is that tumor-infiltrating lymphocytes are dysfunctional in situ, yet are capable of stem cell–like behavior including self-renewal, expansion, and multipotency, resulting in the eradication of large metastatic tumors. We find that the overabundance of potassium in the tumor microenvironment underlies this dichotomy, triggering suppression of T cell effector function while preserving stemness. High levels of extracellular potassium constrain T cell effector programs by limiting nutrient uptake, thereby inducing autophagy and reduction of histone acetylation at effector and exhaustion loci, which in turn produces CD8 + T cells with improved in vivo persistence, multipotency, and tumor clearance. This mechanistic knowledge advances our understanding of T cell dysfunction and may lead to novel approaches that enable the development of enhanced T cell strategies for cancer immunotherapy.

Neuroendocrine (NE) differentiation has gained increased attention as a prostate cancer (PC) prognostic marker. The aim of this study is to determine whether host germline genetic variation influences tumor progression and metastasis in C57BL/6-Tg(TRAMP)8247Ng/J (TRAMP) mouse model of aggressive NEPC. TRAMP mice were crossed to the eight progenitor strains of the Collaborative Cross recombinant inbred panel to address this. Tumor growth and metastasis burden were quantified in heterozygous transgene positive F1 male mice at 30 weeks of age. Compared to wild-type C57BL/6J-Tg(TRAMP)824Ng/J males, TRAMP x CAST/EiJ, TRAMP x NOD/ShiLtJ and TRAMP x NZO/HlLtJ F1 males displayed significant increases in tumor growth. Conversely, TRAMP x WSB/EiJ and TRAMP x PWK/PhJ F1 males displayed significant reductions in tumor growth. Interestingly, despite reduced tumor burden, TRAMP x WSB/EiJ males had an increased nodal metastasis burden. Patterns of distant pulmonary metastasis tended to follow the same patterns as that of local dissemination in each of the strains. All tumors and metastases displayed positive staining for NE markers, synaptophysin, and FOXA2. These experiments conclusively demonstrate that the introduction of germline variation by breeding modulates tumor growth, local metastasis burden, and distant metastasis frequency in this model of NEPC. These strains will be useful as model systems to facilitate the identification of germline modifier genes that promote the development of aggressive forms of PC.

T cell activation upon TCR signaling can lead to development of effector and memory cells. Roychoudhuri and colleagues show that the transcription factor BACH2 promotes memory CD8 + T cell generation by blocking access to genomic regulatory sites recognized by AP-1. T cell antigen receptor (TCR) signaling drives distinct responses depending on the differentiation state and context of CD8 + T cells. We hypothesized that access of signal-dependent transcription factors (TFs) to enhancers is dynamically regulated to shape transcriptional responses to TCR signaling. We found that the TF BACH2 restrains terminal differentiation to enable generation of long-lived memory cells and protective immunity after viral infection. BACH2 was recruited to enhancers, where it limited expression of TCR-driven genes by attenuating the availability of activator protein-1 (AP-1) sites to Jun family signal-dependent TFs. In naive cells, this prevented TCR-driven induction of genes associated with terminal differentiation. Upon effector differentiation, reduced expression of BACH2 and its phosphorylation enabled unrestrained induction of TCR-driven effector programs.

Prostate cancer (PC) is very common in developed countries. However, the molecular determinants of PC metastasis are unclear. Previously, we reported that germline variation influences metastasis in the C57BL/6-Tg(TRAMP)8247Ng/J (TRAMP) mouse model of PC. These mice develop prostate tumors similar to a subset of poor outcome, treatment-associated human PC tumors. Here, we used TRAMP mice to nominate candidate genes and validate their role in aggressive human PC in PC datasets and cell lines. Candidate metastasis susceptibility genes were identified through quantitative trait locus (QTL) mapping in 201 (TRAMP × PWK/PhJ) F2 males. Two metastasis-associated QTLs were identified; one on chromosome 12 (LOD = 5.86), and one on chromosome 14 (LOD = 4.41). Correlation analysis using microarray data from (TRAMP × PWK/PhJ) F2 prostate tumors identified 35 metastasis-associated transcripts within the two loci. The role of these genes in susceptibility to aggressive human PC was determined through in silico analysis using multiple datasets. First, analysis of candidate gene expression in two human PC datasets demonstrated that five candidate genes were associated with an increased risk of aggressive disease and lower disease-free survival. Second, four of these genes ( GNL3 , MAT1A , SKA3 , and ZMYM5 ) harbored SNPs associated with aggressive tumorigenesis in the PLCO/CGEMS GWAS of 1172 PC patients. Finally, over-expression of GNL3 and SKA3 in the PC-3 human PC cell line decreased in vitro cell migration and invasion. This novel approach demonstrates how mouse models can be used to identify metastasis susceptibility genes, and gives new insight into the molecular mechanisms of fatal PC.