Semaphorins were originally identified as axon-guidance molecules that function during neuronal development. However, cumulative evidence indicates that semaphorins also participate in immune ...responses, both physiological and pathological, and they are now considered to be potential diagnostic and/or therapeutic targets for a range of diseases. The primary receptors for semaphorins are neuropilins and plexins, which have cell type-specific patterns of expression and are involved in multiple signalling responses. In this Review, we focus on the roles of neuropilin 1 (NRP1) and plexins in the regulation of the immune system, and we summarize recent advances in our understanding of their pathological implications.
Abstract
Macrophages are heterogeneous and plastic, and play several diverse functions in immune responses. Emerging data provide evidence of multiple roles for metabolic pathways in the control of ...macrophage effector functions. The diverse functions of macrophages are categorized into two main subsets: classical activated macrophages (M1) and alternative activated macrophages (M2). M1 macrophages secrete pro-inflammatory cytokines and reactive oxygen species and migrate into inflamed sites as a part of host defenses. On the other hand, M2 macrophages are involved in immune homeostasis by producing anti-inflammatory cytokines and phagocytosing apoptotic cells. Metabolic reprogramming of environmental or cellular nutrients such as glucose, lipids and amino acids supports this diversity. Mechanistically, the mammalian target of rapamycin (mTOR) network plays important roles in the effector functions of macrophages by modulating cellular metabolism and regulating gene expression at the transcriptional and translational levels. In this review, we outline immunometabolism and provide insights into metabolic regulation by mTOR in macrophages.
Abstract
Semaphorins were originally identified as axon-guidance molecules essential for neural development. In addition to their functions in the neural system, members of the semaphorin family have ...critical functions in many pathophysiological processes, including immune responses, bone homeostasis, cancer and metabolic disorders. In particular, several lines of evidence indicate that mammalian/mechanistic target of rapamycin (mTOR), a central regulator of cell metabolism, regulates the functions of semaphorins in various types of cells, revealing a novel link between semaphorins and cell metabolism. In this review, we discuss recent advances in the immunometabolic functions of semaphorins, with a particular focus on mTOR signaling.
The purpose of this study was to compare a manual bronchoscopic navigation technique, the direct oblique method (DOM), with conventional virtual bronchoscopic navigation software in terms of ...bronchial identification ability involving reconstruction of a whole bronchial tree from identical CT images. A whole bronchial tree was drawn using manual bronchial recognition with the DOM. The tree was compared with that reconstructed by SYNAPSE VINCENT bronchoscopic navigation-dedicated software. The number of bronchial generations at each terminal tip was then compared between the two approaches. Physicians spent 20 h tracing all bronchi on CT scan images and obtained a bronchial tree. The hand-made bronchial tree had five times the number of tips as that reconstructed by automatic bronchial recognition (1482 vs. 279 tips, respectively). The number of bronchial generations prior to each terminal tip was larger with the DOM than with VINCENT (median, 10; interquartile range (IQR), 9-11 vs. median, 5; IQR, 5-7, respectively; p-value < 0.001). Using the CT image data in this case, manual bronchial recognition with the DOM identified more bronchi than automatic bronchial recognition. This result implies that manual bronchial recognition is a valid basis for detailed bronchoscopic navigation analysis.
Numbers of blood central memory T cells increase in responders to anti-PD-1 therapy
Abstract
Cancer immunotherapy that blocks immune checkpoint molecules, such as PD-1/PD-L1, unleashes dysfunctional ...antitumor T-cell responses and has durable clinical benefits in various types of cancers. Yet its clinical efficacy is limited to a small proportion of patients, highlighting the need for identifying biomarkers that can predict the clinical response by exploring antitumor responses crucial for tumor regression. Here, we explored comprehensive immune-cell responses associated with clinical benefits using PBMCs from patients with malignant melanoma treated with anti-PD-1 monoclonal antibody. Pre- and post-treatment samples were collected from two different cohorts (discovery set and validation set) and subjected to mass cytometry assays that measured the expression levels of 35 proteins. Screening by high dimensional clustering in the discovery set identified increases in three micro-clusters of CD4+ T cells, a subset of central memory CD4+ T cells harboring the CD27+FAS−CD45RA−CCR7+ phenotype, after treatment in long-term survivors, but not in non-responders. The same increase was also observed in clinical responders in the validation set. We propose that increases in this subset of central memory CD4+ T cells in peripheral blood can be potentially used as a predictor of clinical response to PD-1 blockade therapy in patients with malignant melanoma.
Despite the importance of type I interferon (IFN-I) in systemic lupus erythematosus (SLE) pathogenesis, the mechanisms of IFN-I production have not been fully elucidated. Recognition of nucleic acids ...by DNA sensors induces IFN-I and interferon-stimulated genes (ISGs), but the involvement of cyclic guanosine monophosphate (GMP)-AMP synthase (cGAS) and stimulator of interferon genes (STING) in SLE remains unclear. We studied the role of the cGAS-STING pathway in the IFN-I-producing cascade driven by SLE serum.
We collected sera from patients with SLE (n=64), patients with other autoimmune diseases (n=31) and healthy controls (n=35), and assayed them using a cell-based reporter system that enables highly sensitive detection of IFN-I and ISG-inducing activity. We used Toll-like receptor-specific reporter cells and reporter cells harbouring knockouts of cGAS, STING and IFNAR2 to evaluate signalling pathway-dependent ISG induction.
IFN-I bioactivity and ISG-inducing activities of serum were higher in patients with SLE than in patients with other autoimmune diseases or healthy controls. ISG-inducing activity of SLE sera was significantly reduced in STING-knockout reporter cells, and STING-dependent ISG-inducing activity correlated with disease activity. Double-stranded DNA levels were elevated in SLE. Apoptosis-derived membrane vesicles (AdMVs) from SLE sera had high ISG-inducing activity, which was diminished in cGAS-knockout or STING-knockout reporter cells.
AdMVs in SLE serum induce IFN-I production through activation of the cGAS-STING pathway. Thus, blockade of the cGAS-STING axis represents a promising therapeutic target for SLE. Moreover, our cell-based reporter system may be useful for stratifying patients with SLE with high ISG-inducing activity.
Monocytes and macrophages comprise a variety of subsets with diverse functions. It is thought that these cells play a crucial role in homeostasis of peripheral organs, key immunological processes and ...development of various diseases. Among these diseases, fibrosis is a life-threatening disease of unknown aetiology. Its pathogenesis is poorly understood, and there are few effective therapies. The development of fibrosis is associated with activation of monocytes and macrophages. However, the specific subtypes of monocytes and macrophages that are involved in fibrosis have not yet been identified. Here we show that Ceacam1
Msr1
Ly6C
F4/80
Mac1
monocytes, which we term segregated-nucleus-containing atypical monocytes (SatM), share granulocyte characteristics, are regulated by CCAAT/enhancer binding protein β (C/EBPβ), and are critical for fibrosis. Cebpb deficiency results in a complete lack of SatM. Furthermore, the development of bleomycin-induced fibrosis, but not inflammation, was prevented in chimaeric mice with Cebpb
haematopoietic cells. Adoptive transfer of SatM into Cebpb
mice resulted in fibrosis. Notably, SatM are derived from Ly6C
FcεRI
granulocyte/macrophage progenitors, and a newly identified SatM progenitor downstream of Ly6C
FcεRI
granulocyte/macrophage progenitors, but not from macrophage/dendritic-cell progenitors. Our results show that SatM are critical for fibrosis and that C/EBPβ licenses differentiation of SatM from their committed progenitor.
Sema4D, also known as CD100, is a protein belonging to class IV semaphorin. Its physiologic roles in the immune and nervous systems have been extensively explored. However, the roles of Sema4D have ...extended beyond these traditionally studied territories. Via interaction with its high affinity receptor Plexin-B1, Sema4D-Plexin-B1 involvement in tumor progression is strongly implied. Here, we critically review and delineate the Sema4D-Plexin-B1 interaction in many facets of tumor progression: tumor angiogenesis, regulation of tumor-associated macrophages and control of invasive growth. We correlate the in vitro and in vivo experimental data with the clinical study outcomes, and present a molecular mechanistic basis accounting for the intriguingly contradicting results from these recent studies.
Semaphorins were originally identified as guidance molecules in neural development. However, accumulating evidence indicates that ‘immune semaphorins’ are critically involved in regulating immune ...cell activation, differentiation, mobility and migration. Semaphorins are also intimately associated with the pathogenesis of allergic diseases including asthma, allergic rhinitis, atopic dermatitis, allergic conjunctivitis, and eosinophilic chronic rhinosinusitis. Interestingly, reflecting their function in positive or negative regulation of immune cells, levels of some semaphorins are increased while others are decreased in patients with allergic diseases. This review presents the pathogenic functions of immune semaphorins in allergic inflammation and discusses the potential use of these molecules as therapeutic targets for allergic diseases.
The aim of this study was to investigate the clinical impact of sarcopenia on the efficacy of programmed death (PD)-1 inhibitors. We retrospectively reviewed the medical records of all patients ...treated with nivolumab or pembrolizumab between January 2016 and September 2018 for previously treated advanced non-small cell lung cancer (NSCLC). The cross-sectional area of the psoas muscle at the level of the third lumbar vertebra on baseline computed tomography was assessed to calculate the psoas muscle index (PMI). Sarcopenia was defined based on PMI cut-off values for Asian adults (6.36 cm
/m
for males and 3.92 cm
/m
for females). A total of 42 patients were analysed. The prevalence of sarcopenia was 52.4%. Sarcopenia was significantly associated with poorer progression-free survival (PFS) (median, 2.1 vs. 6.8 months, p = 0.004). Compared to patients with sarcopenia, those without sarcopenia had a higher overall response rate (40.0% vs. 9.1%, p = 0.025) and 1-year PFS rate (38.1% vs. 10.1%). In conclusion, sarcopenia at baseline as determined using computed tomography is a significant predictor of worse outcome in patients with advanced NSCLC receiving PD-1 blockade. Screening for sarcopenia may help identify patients more likely to achieve a long-term response in routine clinical practice.
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