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To the editor: Immune-related adverse events (irAEs) have emerged as a challenge for combination checkpoint blockade (CCB) in cancer (1). CTLA-4 and PD-1 checkpoints affect both B and T cell [...]

BACKGROUND. There is increasing evidence, in transgenic mice and in vitro, that inhibitory killer cell immunoglobulin-like receptors (iKIRs) can modulate T cell responses. Furthermore, we have previously shown that iKIRs are an important determinant of T cell-mediated control of chronic viral infection and that these results are consistent with an increase in the [CD8.sup.+] T cell lifespan due to iKIR-ligand interactions. Here, we tested this prediction and investigated whether iKIRs affect T cell lifespan in humans in vivo. METHODS. We used stable isotope labeling with deuterated water to quantify memory [CD8.sup.+] T cell survival in healthy individuals and patients with chronic viral infections. RESULTS. We showed that an individual's iKIR-ligand genotype was a significant determinant of [CD8.sup.+] T cell lifespan: in individuals with 2 iKIR-ligand gene pairs, memory [CD8.sup.+] T cells survived, on average, for 125 days; in individuals with 4 iKIR-ligand gene pairs, the memory [CD8.sup.+] T cell lifespan doubled to 250 days. Additionally, we showed that this survival advantage was independent of iKIR expression by the T cell of interest and, further, that the iKIR-ligand genotype altered the [CD8.sup.+] and [CD4.sup.+] T cell immune aging phenotype. CONCLUSIONS. Together, these data reveal an unexpectedly large effect of iKIR genotype on T cell survival. FUNDING. Wellcome Trust; Medical Research Council; EU Horizon 2020; EU FP7; Leukemia and Lymphoma Research; National Institute of Health Research (NIHR) Imperial Biomedical Research Centre; Imperial College Research Fellowship; National Institutes of Health; Jefferiss Trust., Introduction The human killer cell immunoglobulin-like receptors (KIRs) are a family of inhibitory and activating receptors. They are expressed predominantly by NK cells but are also found on T cells [...]

Tyrosine kinase inhibitors (TKIs) targeting epidermal growth factor receptor (EGFR) are effective for many patients with lung cancer with EGFR mutations. However, not all patients are responsive to EGFR TKIs, including even those harboring EGFR-sensitizing mutations. In this study, we quantified the cells and cellular interaction features of the tumor microenvironment (TME) using routine H&E-stained biopsy sections. These TME features were used to develop a prediction model for survival benefit from EGFR TKI therapy in patients with lung adenocarcinoma and EGFR-sensitizing mutations in the Lung Cancer Mutation Consortium 1 (LCMC1) and validated in an independent LCMC2 cohort. In the validation data set, EGFR TKI treatment prolonged survival in the predicted-to-benefit group but not in the predicted-not-to-benefit group. Among patients treated with EGFR TKIs, the predicted-to-benefit group had prolonged survival outcomes compared with the predicted not-to- benefit group. The EGFR TKI survival benefit positively correlated with tumor- tumor interaction image features and negatively correlated with tumor-stroma interaction. Moreover, the tumor-stroma interaction was associated with higher activation of the hepatocyte growth factor/MET-mediated PI3K/AKT signaling pathway and epithelial-mesenchymal transition process, supporting the hypothesis of fibroblast-involved resistance to EGFR TKI treatment., Introduction Tyrosine kinase inhibitors (TKIs) of the epidermal growth factor receptor (EGFR) have shown survival improvements in the treatment of patients with EGFR-mutant lung cancer as first line therapy. Erlotinib, [...]

Glioblastoma (GBM) is the most belligerent and frequent brain tumor in adults. Research over the past two decades has provided increased knowledge of the genomic and molecular landscape of GBM and highlighted the presence of a high degree of inter- and intratumor heterogeneity within the neoplastic compartment. It is now appreciated that GBMs are composed of multiple distinct and impressionable neoplastic and non-neoplastic cell types that form the unique brain tumor microenvironment (TME). Non-neoplastic cells in the TME form reciprocal interactions with neoplastic cells to promote tumor growth and invasion, and together they influence the tumor response to standard-of-care therapies as well as emerging immunotherapies. One of the most prevalent non-neoplastic cell types in the GBM TME are myeloid cells, the most abundant of which are of hematopoietic origin, including monocytes/monocyte-derived macrophages. Less abundant, although still a notable presence, are neutrophils of hematopoietic origin and intrinsic brain-resident microglia. In this Review we focus on neutrophils and monocytes that infiltrate tumors from the blood circulation, their heterogeneity, and their interactions with neoplastic cells and other non-neoplastic cells in the TME. We conclude with an overview of challenges in targeting these cells and discuss avenues for therapeutic exploitation to improve the dismal outcomes of patients with GBM., Introduction Considering the variety of unique and complex brain tumor microenvironments, this Review will mainly focus on research done in glioblastoma (GBM); results from extracranial tumors will occasionally be used [...]

[CD4.sup.+] Th cells play a key role in orchestrating immune responses, but the identity of the [CD4.sup.+] Th cells involved in the antitumor immune response remains to be defined. We analyzed the immune cell infiltrates of head and neck squamous cell carcinoma and colorectal cancers and identified a subset of [CD4.sup.+] Th cells distinct from FOXP3* Tregs that coexpressed programmed cell death 1 (PD-1) and ICOS. These tumor-infiltrating lymphocyte [CD4.sup.+] Th cells ([CD4.sup.+] Th TILs) had a tissue-resident memory phenotype, were present in MHC class II-rich areas, and proliferated in the tumor, suggesting local antigen recognition. The T cell receptor repertoire of the PD-1*ICOS* [CD4.sup.+] Th TILs was oligoclonal, with T cell clones expanded in the tumor, but present at low frequencies in the periphery. Finally, these PD-1*ICOS* [CD4.sup.+] Th TILs were shown to recognize both tumor-associated antigens and tumor-specific neoantigens. Our findings provide an approach for isolating tumor-reactive [CD4.sup.+] Th TILs directly ex vivo that will help define their role in the antitumor immune response and potentially improve future adoptive T cell therapy approaches., Introduction The realization that the immune system can recognize and kill cancer cells led to a paradigm shift in the therapeutic approach for patients with cancer. Instead of directly targeting [...]

Cardiovascular disease (CVD) accounts for almost half of all deaths related to non-communicable disease worldwide, making it the single largest global cause of mortality. Although the risk factors for coronary artery disease--the most common cause of CVD--are well known and include hypertension, high cholesterol, age, and genetics, CVDs are now recognized as chronic inflammatory conditions. Arterial blockages, known as atherosclerosis, develop dueto excess cholesterol accumulating within the arterial wall, creating a perpetually inflammatory state. The normally quiescent intimal layer of the vessel wall becomes laden with inflammatory cells, which alters the surrounding endothelial, smooth muscle, and extracellular matrix components to propagate disease. Macrophages, which can be either tissue resident or monocyte derived, are a key player in atherosclerotic disease progression and regression, and the understanding of their functions and origins continues to evolve with the use of deep phenotyping methodologies. This Review outlines how macrophages interact with each layer of the developing atherosclerotic plaque and discusses new concepts that are challenging our previous views on how macrophages function and our evolving understanding of the contribution of macrophages to disease., Macrophages and their classification Since their initial description in the late 19th century, the role of macrophages in inflammation and disease has been studied in depth; however, owing to their [...]

T cell immunoglobulin mucin domain-containing protein 3 (Tim-3) negatively regulates innate and adaptive immunity in cancer. To identify the mechanisms of Tim-3 in cancer immunity, we evaluated the effects of Tim-3 blockade in human and mouse melanoma. Here, we show that human programmed cell death 1-positive ([PD-1.sup.+]) [Tim-3.sup.+][CD8.sup.+] tumor-infiltrating lymphocytes (TILs) upregulate phosphatidylserine (PS), a receptor for Tim-3, and acquire cell surface myeloid markers from antigen-presenting cells (APCs) through transfer of membrane fragments called trogocytosis. Tim-3 blockade acted on [Tim-3.sup.+] APCs in a PS-dependent fashion to disrupt the trogocytosis of activated tumor antigen-specific [CD8.sup.+] T cells and [PD-1.sup.+][Tim-3.sup.+] [CD8.sup.+] TILs isolated from patients with melanoma. Tim-3 and PD-1 blockades cooperated to disrupt trogocytosis of [CD8.sup.+] TILs in 2 melanoma mouse models, decreasing tumor burden and prolonging survival. Deleting Tim-3 in dendritic cells but not in [CD8.sup.+] T cells impeded the trogocytosis of [CD8.sup.+] TILs in vivo. Trogocytosed [CD8.sup.+] T cells presented tumor peptide-major histocompatibility complexes and became the target of fratricide T cell killing, which was reversed by Tim-3 blockade. Our findings have uncovered a mechanism Tim-3 uses to limit antitumor immunity., Introduction During chronic viral infection and cancer, tumor antigen-specific (TA-specific) [CD8.sup.+] T cells become dysfunctional and upregulate multiple inhibitory receptors, including programmed cell death 1/programmed death ligand 1 (PD-1/PD-L1) and [...]

Cellular senescence is a fundamental aging mechanism that is currently the focus of considerable interest as a pathway that could be targeted to ameliorate aging across multiple tissues, including the skeleton. There is now substantial evidence that senescent cells accumulate in the bone microenvironment with aging and that targeting these cells prevents age-related bone loss, at least in mice. Cellular senescence also plays important roles in mediating the skeletal fragility associated with diabetes mellitus, radiation, and chemotherapy. As such, there are ongoing efforts to develop 'senolytic' drugs that kill senescent cells by targeting key survival mechanisms in these cells without affecting normal cells. Because senescent cells accumulate across tissues with aging, senolytics offer the attractive possibility of treating multiple age-related comorbidities simultaneously., Introduction The past 30 years has witnessed an explosion in our understanding of bone biology that has provided insights into the pathophysiology of skeletal diseases and driven new therapeutic advances. [...]