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Complex regulation of the immune response is necessary to support effective defense of an organism against hostile invaders and to maintain tolerance to harmless microorganisms and autoantigens. Recent studies revealed previously unappreciated roles of CD71 + erythroid cells (CECs) in regulation of the immune response. CECs physiologically reside in the bone marrow where erythropoiesis takes place. Under stress conditions, CECs are enriched in some organs outside of the bone marrow as a result of extramedullary erythropoiesis. However, the role of CECs goes well beyond the production of erythrocytes. In neonates, increased numbers of CECs contribute to their vulnerability to infectious diseases. On the other side, neonatal CECs suppress activation of immune cells in response to abrupt colonization with commensal microorganisms after delivery. CECs are also enriched in the peripheral blood of pregnant women as well as in the placenta and are responsible for the regulation of feto-maternal tolerance. In patients with cancer, anemia leads to increased frequency of CECs in the peripheral blood contributing to diminished antiviral and antibacterial immunity, as well as to accelerated cancer progression. Moreover, recent studies revealed the role of CECs in HIV and SARS-CoV-2 infections. CECs use a full arsenal of mechanisms to regulate immune response. These cells suppress proinflammatory responses of myeloid cells and T-cell proliferation by the depletion of ʟ-arginine by arginase. Moreover, CECs produce reactive oxygen species to decrease T-cell proliferation. CECs also secrete cytokines, including transforming growth factor β (TGF-β), which promotes T-cell differentiation into regulatory T-cells. Here, we comprehensively describe the role of CECs in orchestrating immune response and indicate some therapeutic approaches that might be used to regulate their effector functions in the treatment of human conditions., Competing Interests: Declaration of Competing Interest The authors declare that there are no conflicts of interest., (Copyright © 2021 Warszawski Uniwersytet Medyczny. Published by Elsevier Inc. All rights reserved.)

Richter syndrome (RS), an aggressive lymphoma occurring in the context of chronic lymphocytic leukaemia/small lymphocytic lymphoma, is associated with poor prognosis when treated with conventional immunochemotherapy, therefore, improved treatments are required. Immune checkpoint blockade has shown efficacy in some B-cell malignancies and modest responses in early clinical trials for RS. We investigated the immune checkpoint profile of RS as a basis to inform rational therapeutic investigations in RS. Formalin-fixed, paraffin-embedded biopsies of RS (n = 19), de novo diffuse large B-cell lymphoma (DLBCL; n = 58), transformed indolent lymphomas (follicular [tFL], n = 16; marginal zone [tMZL], n = 24) and non-transformed small lymphocytic lymphoma (SLL; n = 15) underwent gene expression profiling using the NanoString Human Immunology panel. Copy number assessment was performed using next-generation sequencing. Immunohistochemistry (IHC) for LAG3 and PD-1 was performed. LAG3 gene expression was higher in RS compared to DLBCL (P = 0·0002, log2FC 1·96), tFL (P < 0·0001, log2FC 2·61), tMZL (P = 0·0004, log2FC 1·79) and SLL (P = 0·0057, log2FC 1·45). LAG3 gene expression correlated with the gene expression of human leukocyte antigen Class I and II, and related immune genes and immune checkpoints. IHC revealed LAG3 protein expression on both malignant RS cells and tumour-infiltrating lymphocytes. Our findings support the investigation of LAG3 inhibition to enhance anti-tumour responses in RS., (© 2021 British Society for Haematology and John Wiley & Sons Ltd.)

Background: Hypoxia induced injury of pulmonary microvascular endothelial barrier is closely related to the pathogenesis of acute lung injury after lung transplantation. VE-cadherin is an important structural molecule for pulmonary microvascular endothelial barrier. In this study, we aim to investigate the roles of VE-cadherin in hypoxia induced injury of pulmonary microvascular endothelial barrier., Methods: Rat model of hypoxia and cultured pulmonary microvascular endothelial cells (PMVECs) were utilized. Determination of PMVECs apoptosis, skeleton combination was conducted to verify the effects of hypoxia on injury of pulmonary microvascular endothelial barrier. In addition, VE-cadherin expression was modulated by administration of siRNA in order to investigate the roles of VE-cadherin in hypoxia induced PMVECs apoptosis and skeleton recombination., Results: Our data indicated that expression of VE-cadherin was down-regulated in hypoxia-exposed PMVECs. Whereas, in the cells treated using siRNA, down-regulation of VE-cadherin did not trigger PMVECs apoptosis, but it increased the sensitivity of PMVECs to the hypoxia induced apoptosis. In cases of hypoxia, the expression of VE-cadherin was significantly down-regulated, together with endothelial skeleton recombination and increase of permeability, which then triggered endothelial barrier dysfunction., Conclusions: These data verify that VE-cadherin expression played an important role in hypoxia induced PMVECs apoptosis and cellular skeletal recombination.

Neovascularization restores blood flow recovery after ischemia in peripheral arterial disease. The main two components of neovascularization are angiogenesis and arteriogenesis. Both of these processes contribute to functional improvements of blood flow after occlusion. However, discriminating between the specific contribution of each process is difficult. A frequently used model for investigating neovascularization is the murine hind limb ischemia model (HLI). With this model, it is difficult to determine the role of angiogenesis, because usually the timing for the sacrifice of the mice is chosen to be optimal for the analysis of arteriogenesis. More importantly, the occurring angiogenesis in the distal calf muscles is probably affected by the proximally occurring arteriogenesis. Therefore, to understand and subsequently intervene in the process of angiogenesis, a model is needed which investigates angiogenesis without the influence of arteriogenesis. In this study we evaluated the in vivo Matrigel plug assay in genetic deficient mice to investigate angiogenesis. Mice deficient for interferon regulatory factor (IRF)3, IRF7, RadioProtective 105 (RP105), Chemokine CC receptor CCR7, and p300/CBP-associated factor (PCAF) underwent the in vivo Matrigel model. Histological analysis of the Matrigel plugs showed an increased angiogenesis in mice deficient of IRF3, IRF7 , and RP105 , and a decreased angiogenesis in PCAF deficient mice. Our results also suggest an involvement of CCR7 in angiogenesis. Comparing our results with results of the HLI model found in the literature suggests that the in vivo Matrigel plug assay is superior in evaluating the angiogenic response after ischemia.

CD39 is an enzyme which is responsible, together with CD73, for a cascade converting adenosine triphosphate into adenosine diphosphate and cyclic adenosine monophosphate, ultimately leading to the release of an immunosuppressive form of adenosine in the tumor microenvironment. Here, we first review the environmental and genetic factors shaping CD39 expression. Second, we report CD39 functions in the T cell compartment, highlighting its role in regulatory T cells, conventional CD4 + T cells and CD8 + T cells. Finally, we compile a list of studies, from preclinical models to clinical trials, which have made essential contributions to the discovery of novel combinatorial approaches in the treatment of cancer.

Deleterious hyper-inflammation resulting from macrophage activation may aggravate sepsis and lead to lethality. Tumor endothelial marker 1 (TEM1), a type I transmembrane glycoprotein containing six functional domains, has been implicated in cancer and chronic sterile inflammatory disorders. However, the role of TEM1 in acute sepsis remains to be determined. Herein we explored the functional significance of the TEM1 lectin-like domain (TEM1D1) in monocyte/macrophage activation and sepsis using TEM1D1-deleted (TEM1 LeD/LeD ) transgenic mice and recombinant TEM1D1 (rTEM1D1) protein. Under stimulation with lipopolysaccharides (LPS) or several other toll-like receptor agonists, TEM1 LeD/LeD macrophages produced lower levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 than wild-type TEM1 wt/wt macrophages. Compared with TEM1 wt/wt macrophages, LPS-macrophage binding and intracellular mitogen-activated protein kinase (MAPK)/nuclear factor (NF)-κB activation were suppressed in TEM1 LeD/LeD macrophages. In vivo, TEM1D1 deletion improved survival in LPS-challenged mice with reduction of circulating TNF-α and IL-6 and alleviation of lung injury and pulmonary leukocyte accumulation. In contrast, rTEM1D1 could bind to LPS and markedly suppress LPS-macrophage binding, MAPK/NF-κB signaling in macrophages and proinflammatory cytokine production. Treatment with rTEM1D1 improved survival and attenuated circulating TNF-α and IL-6, lung injury and pulmonary accumulation of leukocytes in LPS-challenged mice. These findings demonstrated differential roles for the TEM1 lectin-like domain in macrophages and soluble TEM1 lectin-like domain in sepsis. TEM1 in macrophages mediates LPS-induced inflammation via its lectin-like domain, whereas rTEM1D1 interferes with LPS-induced macrophage activation and sepsis., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

The midbody at the center of the intercellular bridge connecting dividing cells recruits the machinery essential for the final steps of cytokinesis. 1-5 Successive abscission on both sides of the midbody generates a free midbody remnant (MBR) that can be inherited and accumulated in many cancer, immortalized, and stem cells, both in culture and in vivo. 6-12 Strikingly, this organelle was recently shown to contain information that induces cancer cell proliferation, influences cell polarity, and promotes dorso-ventral axis specification upon interaction with recipient cells. 13-16 Yet the mechanisms by which the MBR is captured by either a daughter cell or a distant cell are poorly described. 10 , 14 Here, we report that BST2/tetherin, a well-established restriction factor that blocks the release of numerous enveloped viruses from the surface of infected cells, 17-20 plays an analogous role in retaining midbody remnants. We found that BST2 is enriched at the midbody during cytokinesis and localizes at the surface of MBRs in a variety of cells. Knocking out BST2 induces the detachment of MBRs from the cell surface, their accumulation in the extracellular medium, and their transfer to distant cells. Mechanistically, the localization of BST2 at the MBR membrane is both necessary and sufficient for the interaction between MBRs and the cell surface. We thus propose that BST2 tethers post-cytokinetic midbody remnants to the cell surface. This finding reveals new parallels between cytokinesis and viral biology 21-26 that unexpectedly extend beyond the ESCRT-dependent abscission step., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Lymphocyte activation gene 3 (LAG-3) is a cell surface inhibitory receptor with multiple biological activities over T cell activation and effector functions. LAG-3 plays a regulatory role in immunity and emerged some time ago as an inhibitory immune checkpoint molecule comparable to PD-1 and CTLA-4 and a potential target for enhancing anti-cancer immune responses. LAG-3 is the third inhibitory receptor to be exploited in human anti-cancer immunotherapies, and it is considered a potential next-generation cancer immunotherapy target in human therapy, right next to PD-1 and CTLA-4. Unlike PD-1 and CTLA-4, the exact mechanisms of action of LAG-3 and its relationship with other immune checkpoint molecules remain poorly understood. This is partly caused by the presence of non-conventional signaling motifs in its intracellular domain that are different from other conventional immunoregulatory signaling motifs but with similar inhibitory activities. Here we summarize the current understanding of LAG-3 signaling and its role in LAG-3 functions, from its mechanisms of action to clinical applications.

Early and accurate diagnosis of prostate cancer (PCa) is extremely important, as metastatic PCa remains hard to treat. EWI-2, a member of the Ig protein subfamily, is known to inhibit PCa cell migration. In this study, we found that EWI-2 localized on both the cell membrane and exosomes regulates the distribution of miR-3934-5p between cells and exosomes. Interestingly, we observed that EWI-2 is localized not only on the plasma membrane but also on the nuclear envelope (nuclear membrane), where it regulates the nuclear translocation of signaling molecules and miRNA. Collectively, these functions of EWI-2 found in lipid bilayers appear to regulate PCa cell metastasis through the epidermal growth factor receptor-mitogen-activated protein kinase-extracellular-signal-regulated kinase (EGFR-MAPK-ERK) pathway. Our research provides new insights into the molecular function of EWI-2 on PCa metastasis, and highlights EWI-2 as a potential PCa biomarker., (© 2021 The Authors. Molecular Oncology published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Aims: The present study aimed to investigate the role and underlying mechanisms of CD166 in cancer stem cell-like (CSCs) phenotype of the radioresistant nasopharyngeal carcinoma cell CNE-2R., Main Methods: Established CD166-shRNA- CNE-2R cell line by lentivirus-mediated silencing CD166. Then, CSC-related genes mRNAs and proteins, and EGFR/ERK1/2 signaling pathway were detected using RT-PCR and western blot. Sphere formation assay was performed to evaluate the sphere formation capacity in CD166-shRNA- CNE-2R cells. The tumorigenesis ability in vivo was examined in nude mice mode., Key Findings: Downregulation of CD166 inhibited the expression of the CSC-related genes, pEGFR and pERK in vitro and vivo. The capacity to form spheres and tumorigenesis was significantly decreased in CD166-shRNA cells. Furthermore, EGF-stimulated CD166-shRNA cells exhibited an increase in CSC-like traits by activating EGFR/ERK1/2 signaling., Significance: CD166 induced CSCs formation by activating the EGFR/ERK1/2 signaling pathway in nasopharyngeal carcinoma, which may serve as a critical molecular target for NPC therapeutic strategies., (Copyright © 2021 Elsevier Inc. All rights reserved.)

LAG3 is an important immune checkpoint with relevance in cancer, infectious disease and autoimmunity. However, despite LAG3's role in immune exhaustion and the great potential of LAG3 inhibition as treatment, much remains unknown about its biology, particularly its mechanism of action. This review describes the knowns, unknowns and controversies surrounding LAG3. This includes examination of how LAG3 is regulated transcriptionally and post-translationally by endocytosis and proteolytic cleavage. We also discuss the interactions of LAG3 with its ligands and the purpose thereof. Finally, we review LAG3's mechanism of action, including the roles of LAG3 intracellular motifs and the lack of a role for CD4 competition. Overall, understanding the biology of LAG3 can provide greater insight on LAG3 function, which may broaden the appreciation for LAG3's role in disease and potentially aid in the development of targeted therapies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Graydon, Mohideen and Fowke.)

Background & Aims: The reason why small intestinal cancer is rarer than colorectal cancer is not clear. We hypothesized that intraepithelial lymphocytes (IELs), which are enriched in the small intestine, are the closest immune cells to epithelial cells, exclude tumor cells via cell-to-cell contact., Methods: We developed DPE-green fluorescent protein (DPE-GFP) × adenomatous polyposis coli; multiple intestinal neoplasia (APC min ) mice, which is a T-cell-reporter mouse with spontaneous intestinal tumors. We visualized the dynamics of IELs in the intestinal tumor microenvironment and the interaction between IELs and epithelial cells, and the roles of cell-to-cell contact in anti-intestinal tumor immunity using a novel in vivo live-imaging system and a novel in vitro co-culture system., Results: In the small intestinal tumor microenvironment, T-cell movement was restricted around blood vessels and the frequency of interaction between IELs and epithelial cells was reduced. Genetic deletion of CD103 decreased the frequency of interaction between IELs and epithelial cells, and increased the number of small intestinal tumors. In the co-culture system, wild-type IELs expanded and infiltrated to intestinal tumor organoids from APC min mice and reduced the viability of them, which was cell-to-cell contact and CD103 dependent., Conclusions: The abundance of IELs in the small intestine may contribute to a low number of tumors, although this system may not work in the colon because of the sparseness of IELs. Strategies to increase the number of IELs in the colon or enhance cell-to-cell contact between IELs and epithelial cells may be effective for the prevention of intestinal tumors in patients with a high cancer risk., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Ewing sarcoma (ES) is a type of highly aggressive pediatric tumor in bones and soft tissues and its metastatic spread remains the most powerful predictor of poor outcome. We previously identified that the transcription factor hepatoma-derived growth factor (HDGF) promotes ES tumorigenesis. However, the mechanisms underlying ES metastasis remain unclear. Here, we show that HDGF drives ES metastasis in vitro and in vivo, and HDGF reduces metastasis-free survival (MFS) in two independent large cohorts of human ES patients. Integrative analyses of HDGF ChIP-seq and gene expression profiling in ES cells reveal that HDGF regulates multiple metastasis-associated genes, among which activated leukocyte cell adhesion molecule (ALCAM) emerges as a major HDGF target and a novel metastasis-suppressor in ES. HDGF down-regulates ALCAM, induces expression and activation of the downstream effectors Rho-GTPase Rac1 and Cdc42, and promotes actin cytoskeleton remodeling and cell-matrix adhesion. In addition, repression of ALCAM and activation of Rac1 and Cdc42 are required for the pro-metastatic functions of HDGF in vitro. Moreover, analyses in murine models with ES tumor orthotopic implantation and experimental metastasis, as well as in human ES samples, demonstrate the associations among HDGF, ALCAM, and GTPases expression levels. Furthermore, high HDGF/low ALCAM expression define a subgroup of patients harboring the worst MFS. These findings suggest that the HDGF/ALCAM/GTPases axis represents a promising therapeutic target for limiting ES metastasis.

Birt-Hogg-Dubé (BHD) syndrome is a multiorgan disorder caused by inactivation of the folliculin (FLCN) protein. Previously, we identified FLCN as a binding protein of Rab11A, a key regulator of the endocytic recycling pathway. This finding implies that the abnormal localization of specific proteins whose transport requires the FLCN-Rab11A complex may contribute to BHD. Here, we used human kidney-derived HEK293 cells as a model, and we report that FLCN promotes the binding of Rab11A with transferrin receptor 1 (TfR1), which is required for iron uptake through continuous trafficking between the cell surface and the cytoplasm. Loss of FLCN attenuated the Rab11A-TfR1 interaction, resulting in delayed recycling transport of TfR1. This delay caused an iron deficiency condition that induced hypoxia-inducible factor (HIF) activity, which was reversed by iron supplementation. In a Drosophila model of BHD syndrome, we further demonstrated that the phenotype of BHD mutant larvae was substantially rescued by an iron-rich diet. These findings reveal a conserved function of FLCN in iron metabolism and may help to elucidate the mechanisms driving BHD syndrome., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Metastasis is the leading cause of death in lung adenocarcinomas. Identifying potential prognostic biomarkers and exploiting regulatory mechanisms could improve the diagnosis and treatment of lung cancer patients. We previously found that cluster of differentiation 109 (CD109) was upregulated in lung tumor tissues, and CD109 overexpression was correlated with the invasive and metastatic capacities of lung adenocarcinoma cells. However, the contribution of CD109 to lung tumorigenesis remains to be elucidated. In the present study, we identified that CD109 was upregulated in metastatic lung adenocarcinoma cells, and elevation of CD109 was correlated with epithelial-to-mesenchymal transition (EMT) traits in patients with lung adenocarcinoma. Functionally, CD109 expression was crucial for EMT gene expressions, tumor invasiveness, and cancer stemness properties. Moreover, elevation of CD109 was accompanied by upregulation of the yes-associated protein (YAP) signature in metastatic lung cancer cells and lung cancer patients, and activation of YAP was demonstrated to participate in CD109-elicited EMT gene expressions and tumor invasiveness. Our study reveals the molecular mechanism underlying CD109 in lung tumor aggressiveness, and CD109 could be a potential diagnostic and therapeutic target for lung cancer patients.

Siglecs (sialic acid-binding immunoglobulin-like lectins) are single-pass cell surface receptors that have inhibitory activities on immune cells. Among these, Siglec-8 is a CD33-related family member selectively expressed on human mast cells and eosinophils, and at low levels on basophils. These cells can participate in inflammatory responses by releasing mediators that attract or activate other cells, contributing to the pathogenesis of allergic and non-allergic diseases. Since its discovery in 2000, initial in vitro studies have found that the engagement of Siglec-8 with a monoclonal antibody or with selective polyvalent sialoglycan ligands induced the cell death of eosinophils and inhibited mast cell degranulation. Anti-Siglec-8 antibody administration in vivo to humanized and transgenic mice selectively expressing Siglec-8 on mouse eosinophils and mast cells confirmed the in vitro findings, and identified additional anti-inflammatory effects. AK002 (lirentelimab) is a humanized non-fucosylated IgG1 antibody against Siglec-8 in clinical development for mast cell- and eosinophil-mediated diseases. AK002 administration has safely demonstrated the inhibition of mast cell activity and the depletion of eosinophils in several phase 1 and phase 2 trials. This article reviews the discovery and functions of Siglec-8, and strategies for its therapeutic targeting for the treatment of eosinophil- and mast cell-associated diseases.

In vertebrates, the semaphorin family of proteins is composed of 21 members that are divided into five subfamilies, i.e. classes 3 to 7. Semaphorins play crucial roles in regulating multiple biological processes, such as neural remodeling, tissue regeneration, cancer progression, and, especially, in immunological regulation. Semaphorin 4D (SEMA4D), also known as CD100, is an important member of the semaphorin family and was first characterized as a lymphocyte-specific marker. SEMA4D has diverse effects on immunologic processes, including immune cell proliferation, differentiation, activation, and migration, through binding to its specific membrane receptors CD72, PLXNB1, and PLXNB2. Furthermore, SEMA4D and its underlying signaling have been increasingly linked with several immunological diseases. This review focuses on the significant immunoregulatory role of SEMA4D and the associated underlying mechanisms, as well as the potential application of SEMA4D as a diagnostic marker and therapeutic target for the treatment of immunological diseases., (© 2020 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.)

Cluster of differentiation (CD) 166 or activated leukocyte cell adhesion molecule (ALCAM) is a transmembrane molecule known to be an intercellular adhesion factor. The expression and function of ALCAM in medulloblastoma (MB), a pediatric brain tumor with highly advanced molecular genetics, remains unclear. Therefore, this study aimed to clarify the significance and functional role of ALCAM expression in MB. ALCAM expression in 45 patients with MB was evaluated by immunohistochemical analysis of formalin-fixed paraffin-embedded clinical specimens and the relationship between ALCAM expression and pathological type/molecular subgroup, such as WNT, SHH, Group 3, and Group 4, was examined. Eight ALCAM positive (18%), seven partially positive (16%), and 30 negative (67%) cases were detected. All seven cases of the WNT molecular subgroup were ALCAM positive and ALCAM expression strongly correlated with this subgroup (P < 0.0001). In addition, functional studies using MB cell lines revealed ALCAM expression affected proliferation and migration as a positive regulator in vitro. However, ALCAM silencing did not affect survival or the formation of leptomeningeal dissemination in an orthotopic mouse model, but did induce a malignant phenotype with increased tumor cell invasion at the dissemination sites (P = 0.0029). In conclusion, our results revealed that ALCAM exhibited highly specific expression in the WNT subgroup of MB. Furthermore, we demonstrated that the cell kinetics of MB cell lines can be altered by the expression of ALCAM., Competing Interests: The authors have declared that no competing interests exist.

Aim: The study aims to investigate the roles of LncRNA and miRNA in ferroptosis in brain ischemia/reperfusion (I/R) in vivo and in vitro., Materials and Methods: qPCR assay was used to analyze lncRNA PVT1 and miR-214 expressions in acute ischemic stroke (AIS) patients. Then, we established brain I/R mice models and OGD/R PC12 cell models to analyze the mechanism of ferroptosis. I/R mice were treated by lncRNA PVT silencing or miR-214 overexpressing lentivirus via lateral ventricles. Infarct size was analyzed by TTC staining, accompanied by the detection of ferroptosis indicators through Perls'Prussian blue staining, iron kit, MDA kit, glutathione kit, GPx activities kit and Western blotting (WB). Dual luciferase reporter assay was used to assess whether miR-214 bound to PVT1, TP53 or TFR1. Co-IP analyzed the interplay of p53 with SLC7A11., Key Findings: We found that the levels of PVT1 were upregulated and miR-214 levels were downregulated in plasma of AIS patients. NIHSS score was positively correlated with PVT1 levels but was negatively with miR-214 levels. PVT1 silencing or miR-214 overexpression significantly reduced infarct size and suppressed ferroptosis in vivo. miR-214 overexpression markedly decreased PVT1 levels. Specifically, miR-214 could bind to 3'untranslated region (3'UTR) of PVT1, TP53 or TFR1. PVT1 overexpression or miR-214 silencing markedly abolished the effects of Ferrostatin-1 on ferroptosis indicators except for TFR1 expression. Besides, miR-214 silencing counteracted the effects of PVT1 knockdown on the ferroptosis-related proteins., Conclusion: PVT1 regulated ferroptosis through miR-214-mediated TFR1 and TP53 expression. There was a positive feedback loop of lncRNA PVT1/miR-214/p53 possibly., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Atherosclerosis is an inflammatory disease characterized by the accumulation of macrophages in the vessel wall. Macrophages depend on their polarization to exert either pro-inflammatory or anti-inflammatory effects. Macrophages of the anti-inflammatory phenotype express high levels of CD163, a scavenger receptor for the hemoglobin-haptoglobin complex. CD163 can also bind to the pro-inflammatory cytokine TWEAK. Using ApoE-deficient or ApoE/CD163 double-deficient mice we aim to investigate the involvement of CD163 in atherosclerosis development and its capacity to neutralize the TWEAK actions. ApoE/CD163 double-deficient mice displayed a more unstable plaque phenotype characterized by an increased lipid and macrophage content, plaque size, and pro-inflammatory cytokine expression. In vitro experiments demonstrated that the absence of CD163 in M2-type macrophages-induced foam cell formation through upregulation of CD36 expression. Moreover, exogenous TWEAK administration increased atherosclerotic lesion size, lipids, and macrophages content in ApoE -/- /CD163 -/- compared with ApoE -/- /CD163 +/+ mice. Treatment with recombinant CD163 was able to neutralize the proatherogenic effects of TWEAK in ApoE/CD163 double-deficient mice. Recombinant CD163 abolished the pro-inflammatory actions of TWEAK on vascular smooth muscle cells, decreasing NF-kB activation, cytokines and metalloproteinases expression, and macrophages migration. In conclusion, CD163-expressing macrophages serve as a protective mechanism to prevent the deleterious effects of TWEAK on atherosclerotic plaque development and progression., (© 2020 The Authors. The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.)

Interferon-induced BST2 (bone marrow stromal cell antigen 2) inhibits viral replication by tethering enveloped virions to the cell surface to restrict viral release and by inducing the NFKB-dependent antiviral immune response. However, the mechanism by which BST2 uses the selective autophagy pathway to inhibit viral replication is poorly understood. In this study, we showed that BST2 expression was significantly increased during porcine epidemic diarrhea virus (PEDV) infection of Vero cells by IRF1 targeting its promoter. We also showed that BST2 suppressed PEDV replication by binding and degrading the PEDV-encoded nucleocapsid (N) protein. The downregulation of N protein was blocked by macroautophagy/autophagy inhibitors but not a proteasome inhibitor, implying that the N protein was degraded via the selective autophagy pathway. Both the BST2 and N protein interacted with the E3 ubiquitin ligase MARCHF8/MARCH8 and the cargo receptor CALCOCO2/NDP52, and the ubiquitination of N protein was necessary for the degradation of N mediated by the BST2-MARCHF8 axis. The knockdown of MARCHF8 or ATG5 with small interfering RNAs blocked the selective autophagy pathway, rescued the protein abundance of PEDV N in 293T cells, and prevented the inhibition of PEDV replication by BST2 in Vero cells. Together, our data demonstrate the novel mechanism of BST2-mediated virus restriction, in which BST2 recruits MARCHF8 to catalyze the ubiquitination of the PEDV N protein. The ubiquitinated N protein is then recognized by CALCOCO2/NDP52, which delivers it to autolysosome for degradation through the selective autophagy pathway. Abbreviations : 3MA: 3-methyladenine; ATG: autophagy-related; Baf A1: bafilomycin A 1 ; BST2: bone marrow stromal cell antigen 2; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; CC: coiled-coil; ChIP: chromatin immunoprecipitation; Co-IP: co-immunoprecipitation; CQ: chloroquine; CT: cytoplasmic tail; DAPI: 4',6-diamidino-2-phenylindole; GPI: glycosyl-phosphatidylinositol; hpi: hours post infection; IRF1: interferon regulatory factor 1; ISG: IFN-stimulated gene; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MARCHF8/MARCH8: membrane-associated ring-CH-type finger 8; MOI: multiplicity of infection; N protein: nucleocapsid protein; PED: porcine epidemic diarrhea; PEDV: porcine epidemic diarrhea virus; RT: room temperature; siRNA: small interfering RNA; STAT: signal transducer and activator of transcription; TCID 50 : 50% tissue culture infectious doses; TM: transmembrane.

Introduction: Psoriasis is a chronic inflammatory skin condition known to affect about 1%-3% of the global population. Psoriasis can be a serious burden to the patients, having deleterious effect on their physical, social and mental wellbeing. Systemic therapies consisting of methotrexate, cyclosporine, acitretin, PUVA, etc. used in moderate to severe psoriasis, are associated with end organ toxicity with long term use., Areas Covered: Role of Itolizumab, an anti CD6 biologic in regulation of lymphocyte development, selection, activation and differentiation in the set-up of psoriasis. We performed a literature review by searching online databases including PubMed and Google Scholar., Expert Opinion: There is emerging evidence to implicate CD6 and its ligands in the pathogenesis and potentially the treatment of inflammatory and autoimmune diseases, like psoriasis and multiple sclerosis. Its potential advantage over anti TNF biologics in predisposing to lesser risk of tuberculosis and other serious systemic infections or adverse effects makes it a potential valuable asset in the armamentarium of anti-psoriasis drugs.

The revascularization of blood vessels after myocardial infarction can lead to serious myocardial damage. Previous studies showed that radioprotective 105 kDa protein (RP105) is a specific negative regulator of myocardial ischemia reperfusion injury (MIRI). RP105 can modulate the Toll‑like receptor (TLR)2/TLR4 signaling pathways. However, the synergistic effect of TLR2/4 regulated by RP105 during MIRI requires further investigation. To determine this effect, a MIRI model was established in rats in the present study. The expression of RP105 was depleted by transfecting RP105‑siRNA and then detected using western blotting. Furthermore, the myocardium tissue was stained with the hematoxylin and eosin staining. Knockdown of RP105 promoted the activity of serum myocardial enzymes during MIRI and increased myocardial infarction. The present results indicated that knockdown of RP105 activated the TLR2/4 signaling pathway by modulating the myeloid differentiation primary response 88 and NF‑κB signaling pathways. Furthermore, decreased expression of RP105 promoted myocardial cell apoptosis, which induced the damage of myocardial ischemic reperfusion. The present results suggested both TLR2 and TLR4 as key targets of RP105, thus RP105 may be a promising candidate to facilitate the development of novel therapeutic strategies for MIRI.

TIM-3 has been considered as a target in cancer immunotherapy. In T cells, inhibitory as well as activating functions have been ascribed to this molecule. Its role may therefore depend on the state of T cells and on the presence of interaction partners capable to perform functional pairing. Carcinoembryonic antigen-related cell adhesion molecule (CEACAM1) has been proposed to bind TIM-3 and to regulate its function. Using a T cell reporter platform we confirmed CEACAM1-mediated inhibition, but CEACAM1 did not functionally engage TIM-3. TIM-3 and CEACAM1 coexpression was limited to a small subset of activated T cells. Moreover, results obtained in extensive binding studies were not in support of an interaction between TIM-3 and CEACAM1. Cytoplasmic sequences derived from TIM-3 induced inhibitory signaling in our human T cell reporter system. Our results indicate that TIM-3 functions are independent of CEACAM1 and that this receptor has the capability to promote inhibitory signaling pathways in human T cells., (© 2020 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Junín virus (JUNV) is one of five New World mammarenaviruses (NWMs) that causes fatal hemorrhagic disease in humans and is the etiological agent of Argentine hemorrhagic fever (AHF). The pathogenesis underlying AHF is poorly understood; however, a prolonged, elevated interferon-α (IFN-α) response is associated with a negative disease outcome. A feature of all NWMs that cause viral hemorrhagic fever is the use of human transferrin receptor 1 (hTfR1) for cellular entry. Here, we show that mice expressing hTfR1 develop a lethal disease course marked by an increase in serum IFN-α concentration when challenged with JUNV. Further, we provide evidence that the type I IFN response is central to the development of severe JUNV disease in hTfR1 mice. Our findings identify hTfR1-mediated entry and the type I IFN response as key factors in the pathogenesis of JUNV infection in mice., Competing Interests: BH, ES, KB, AV, BG No competing interests declared, MP is a shareholder of Klyss Biotech, Inc. The Regents of the University of California licensed Dr. Penichet’s technology to this firm. The author has no other competing interests to declare., (© 2020, Hickerson et al.)

The function of natural killer (NK) cells, defending against virus infection and tumour progression, is regulated by multiple activating and inhibiting receptors expressed on NK cells, among which sialic acid-bind immunoglobulin-like lectins (Siglecs) act as a vital inhibitory group. Previous studies have shown that Siglec7 and Siglec9 are expressed on NK cells, which negatively regulate the function of NK cells and modulate the immune response through the interaction of sialic acid-containing ligands. Siglec7 and Siglec9 are very similar in distribution, gene encoding, protein sequences, ligand affinity, and functions in regulating the immune system against virus and cancers, but differences still exist between them. In this review, we aim to discuss the similarities and differences between Siglec7 and Siglec9 and analyze their functions in virus infection and tumour progression in order to develop better anti-viral and anti-tumor immunotherapy in the future., Competing Interests: The authors declare that they have no conflict of interest., (Copyright © 2020 Yayun Zheng et al.)

Background: The diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) relies on flow cytometric demonstration of loss of glycosyl-phosphatidyl inositol (GPI)-anchored proteins from red blood cells (RBC) and white blood cells (WBC). High-sensitivity multiparameter assays have been developed to detect loss of GPI-linked structures on PNH neutrophils and monocytes. High-sensitivity assays to detect PNH phenotypes in RBCs have also been developed that rely on the loss of GPI-linked CD59 on CD235a-gated mature RBCs. The latter is used to delineate PNH Type III (total loss of CD59) and PNH Type II RBCs (partial loss of CD59) from normal (Type I) RBCs. However, it is often very difficult to delineate these subsets, especially in patients with large PNH clones who continue to receive RBC transfusions, even while on eculizumab therapy., Methods: We have added allophycocyanin (APC)-conjugated CD71 to the existing CD235aFITC/CD59PE RBC assay allowing simultaneous delineation and quantification of PNH Type III and Type II immature RBCs (iRBCs)., Results: We analyzed 24 medium to large-clone PNH samples (>10% PNH WBC clone size) for PNH Neutrophil, PNH Monocyte, Type III and Type II PNH iRBCs, and where possible, Type III and Type II PNH RBCs. The ability to delineate PNH Type III, Type II, and Type I iRBCs was more objective compared to that in mature RBCs. Additionally, total PNH iRBC clone sizes were very similar to PNH WBC clone sizes., Conclusions: Addition of CD71 significantly improves the ability to analyze PNH clone sizes in the RBC lineage, regardless of patient hemolytic and/or transfusion status., (© 2019 International Clinical Cytometry Society.)

Thyroid cancer is one of the common malignancies of the endocrine system and the number of thyroid cancer cases is increasing constantly. Significant work has focused on the molecular mechanisms of thyroid cancer, but many mechanisms remain undiscovered. In this study, we employed a comprehensive analysis of whole-transcriptome resequencing derived from paired papillary thyroid cancer (PTC) and normal thyroid tissues. We performed a massive parallel whole-transcriptome resequencing of matched PTC and normal thyroid tissues in 19 patients and found that integrin subunit alpha 7 (ITGA7) was downregulated in thyroid tumor tissues, but the function of ITGA7 in this cancer is still unclear. We also discovered that ITGA7 gene in thyroid cancer tissues was downregulated compared to paired adjacent non-tumor tissues by real-time quantitative polymerase chain reaction. After transfection with small interfering RNA to knock down ITGA7, the abilities of colony formation, proliferation, migration, and invasion were enhanced in PTC cell lines (TPC1 and KTC-1). Meanwhile, ITGA7 knockdown decreased apoptotic cell death in thyroid cells but promoted the expressions of N-cadherin and vimentin and decreased E-cadherin expression by epithelial-to-mesenchymal transition, which may induce invasion and migration. In conclusion, these results indicated that ITGA7 is involved in the progress of PTC and might act as a tumor suppressor gene., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Both miRNAs and A-to-I RNA editing, a widespread nucleotide modification mechanism, have recently emerged as key players in cancer pathophysiology. However, the functional impact of RNA editing of miRNAs in cancer remains largely unexplored. Here, we focused on an ADAR2-catalyzed RNA editing site within the miR-379-5p seed region. This site was under-edited in tumors relative to normal tissues, with a high editing level being correlated with better patient survival times across cancer types. We demonstrated that in contrast to wild-type miRNA, edited miR-379-5p inhibited cell proliferation and promoted apoptosis in diverse tumor contexts in vitro, which was due to the ability of edited but not wild-type miR-379-5p to target CD97. Importantly, through nanoliposomal delivery, edited miR-379-5p mimics significantly inhibited tumor growth and extended survival of mice. Our study indicates a role of RNA editing in diversifying miRNA function during cancer progression and highlights the translational potential of edited miRNAs as a new class of cancer therapeutics.

Host response to viral infection is a highly regulated process involving engagement of various host factors, cytokines, chemokines, and stimulatory signals that pave the way for an antiviral immune response. The response is manifested in terms of viral sequestration, phagocytosis, and inhibition of genome replication, and, finally, if required, lymphocyte-mediated clearance of virally infected cells. During this process, cross-talk between viral and host factors can shape disease outcomes and immunopathology. Bone marrow stromal antigen 2 ( BST-2 ), also know as tetherin, is induced by type I interferon produced in response to viral infections, as well as in certain cancers. BST-2 has been shown to be a host restriction factor of virus multiplication through its ability to physically tether budding virions and restrict viral spread. However, BST-2 has other roles in the host antiviral response. This review focuses on the diverse functions of BST-2 and its downstream signaling pathways in regulating host immune responses.

Cholinergic neurons in the central nervous system play a vital role in higher brain functions, such as learning and memory. Choline is essential for the synthesis of the neurotransmitter acetylcholine by cholinergic neurons. The synthesis and metabolism of acetylcholine are important mechanisms for regulating neuronal activity. Choline is a positively charged quaternary ammonium compound that requires transporters to pass through the plasma membrane. Currently, there are three groups of choline transporters with different characteristics, such as affinity for choline, tissue distribution, and sodium dependence. They include (I) polyspecific organic cation transporters (OCT1-3: SLC22A1-3) with a low affinity for choline, (II) high-affinity choline transporter 1 (CHT1: SLC5A7), and (III) choline transporter-like proteins (CTL1-5: SLC44A1-5). Brain microvascular endothelial cells, which comprise part of the blood-brain barrier, take up extracellular choline via intermediate-affinity choline transporter-like protein 1 (CTL1) and low-affinity CTL2 transporters. CTL2 is responsible for excreting a high concentration of choline taken up by the brain microvascular endothelial cells on the brain side of the blood-brain barrier. CTL2 is also highly expressed in mitochondria and may be involved in the oxidative pathway of choline metabolism. Therefore, CTL1- and CTL2-mediated choline transport to the brain through the blood-brain barrier plays an essential role in various functions of the central nervous system by acting as the rate-limiting step of cholinergic neuronal activity.

Human semaphorin 4D (SEMA4D), a type I integral membrane glycoprotein, regulates key cellular functions (e.g. cell-cell communication, platelet activation). Its 120 kDa extracellular region can be shed from the membrane to release soluble SEMA4D (sSEMA4D). Studies on circulating sSEMA4D levels are mostly performed with poorly characterized assays and use serum and plasma as matrix. We developed and validated a sandwich ELISA utilizing two monoclonal antibodies with resolved epitopes and determined affinities. Human serum and plasma samples were analyzed, and the influence of protease activity on sSEMA4D concentration was tested by collecting samples in the presence of the protease inhibitor TAPI-1. Both antibodies recognize conformational epitopes in the sema domain. Validation for plasma (EDTA, citrate, heparin) showed valid specificity, precision, accuracy, dilution linearity, and robustness. The assay shows a calibration range from 62.5 to 2000 pmol/L with a quantification limit of 31 pmol/L. sSEMA4D was significantly higher in serum than in plasma, whereas serum and plasma levels from samples collected in the presence of TAPI-1 showed no statistical difference. This ELISA provides a reliable tool for the quantification of sSEMA4D in human plasma. Serum is not recommended as matrix due to the accumulation of shed SEMA4D during blood coagulation altering serum sSEMA4D levels., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Background and Aims: CD8 + T-cells have been attributed both atherogenic and atheroprotective properties, but analysis of CD8 + T-cells has mostly been restricted to the circulation and secondary lymphoid organs. The atherosclerotic lesion, however, is a complex microenvironment containing a plethora of inflammatory signals, which may affect CD8 + T-cell activation. Here, we address how this environment affects the functionality of CD8 + T-cells., Methods and Results: We compared the cytokine production of CD8 + T-cells derived from spleens and enzymatically digested aortas of apoE -/- mice with advanced atherosclerosis by flow cytometry. Aortic CD8 + T-cells produced decreased amounts of IFN-γ and TNF-α compared to their systemic counterparts. The observed dysfunctional phenotype of the lesion-derived CD8 + T-cells was not associated with classical exhaustion markers, but with increased expression of the ectonucleotidase CD39. Indeed, pharmacological inhibition of CD39 in apoE -/- mice partly restored cytokine production by CD8 + T-cells. Using a bone-marrow transplantation approach, we show that TCR signaling is required to induce CD39 expression on CD8 + T-cells in atherosclerotic lesions. Importantly, analysis of human endarterectomy samples showed a strong microenvironment specific upregulation of CD39 on CD8 + T-cells in the plaques of human patients compared to matched blood samples., Conclusions: Our results suggest that the continuous TCR signaling in the atherosclerotic environment in the vessel wall induces an immune regulatory CD8 + T-cell phenotype that is associated with decreased cytokine production through increased CD39 expression in both a murine atherosclerotic model and in atherosclerosis patients. This provides a new understanding of immune regulation by CD8 + T-cells in atherosclerosis., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

The cellular protein bone marrow stromal antigen-2 (BST-2)/tetherin acts against a variety of enveloped viruses by restricting their release from the plasma membrane. The HIV-1 accessory protein Vpu counteracts BST-2 by downregulating it from the cell surface and displacing it from virion assembly sites. Previous comparisons of Vpus from transmitted/founder viruses and between viruses isolated during acute and chronic infection led to the identification of a tryptophan at position 76 in Vpu (W76) as a key determinant for the displacement of BST-2 from virion assembly sites. Although present in Vpus from clades B, D, and G, W76 is absent from Vpus from clades A, C, and H. Mutagenesis of the C-terminal region of Vpu from two clade C viruses led to the identification of a conserved LL sequence that is functionally analogous to W76 of clade B. Alanine substitution of these leucines partially impaired virion release. This impairment was even greater when the mutations were combined with mutations of the Vpu β-TrCP binding site, resulting in Vpu proteins that induced high surface levels of BST-2 and reduced the efficiency of virion release to less than that of virus lacking vpu Microscopy confirmed that these C-terminal leucines in clade C Vpu, like W76 in clade B, contribute to virion release by supporting the displacement of BST-2 from virion assembly sites. These results suggest that although encoded differently, the ability of Vpu to displace BST-2 from sites of virion assembly on the plasma membrane is evolutionarily conserved among clade B and C HIV-1 isolates. IMPORTANCE Although targeted by a variety of restriction mechanisms, HIV-1 establishes chronic infection in most cases, in part due to the counteraction of these host defenses by viral accessory proteins. Using conserved motifs, the accessory proteins exploit the cellular machinery to degrade or mistraffic host restriction factors, thereby counteracting them. The Vpu protein counteracts the virion-tethering factor BST-2 in part by displacing it from virion assembly sites along the plasma membrane, but a previously identified determinant of that activity is clade specific at the level of protein sequence and not found in the clade C viruses that dominate the pandemic. Here, we show that clade C Vpu provides this activity via a leucine-containing sequence rather than the tryptophan-containing sequence found in clade B Vpu. This difference seems likely to reflect the different evolutionary paths taken by clade B and clade C HIV-1 in human populations., (Copyright © 2019 American Society for Microbiology.)

Impact Statement: This review will provide a summary of recent advances in choline transport research and highlight important novel areas of focus in the field.

Lymphocyte activation gene-3 (LAG-3) is an inhibitory receptor expressed by CD4 + T cells and tempers their homeostatic expansion. Because CD4 + T cell proliferation is tightly coupled to bioenergetics, we investigate the role of LAG-3 in modulating naive CD4 + T cell metabolism. LAG-3 deficiency enhances the metabolic profile of naive CD4 + T cells by elevating levels of mitochondrial biogenesis. In vivo, LAG-3 blockade partially restores expansion and the metabolic phenotype of wild-type CD4 + T cells to levels of Lag3 -/- CD4 + T cells, solidifying that LAG-3 controls these processes. Lag3 -/- CD4 + T cells also demonstrate greater signal transducer and activator of transcription 5 (STAT5) activation, enabling resistance to interleukin-7 (IL-7) deprivation. These results implicate this pathway as a target of LAG-3-mediated inhibition. Additionally, enhancement of STAT5 activation, as a result of LAG-3 deficiency, contributes to greater activation potential in these cells. These results identify an additional mode of regulation elicited by LAG-3 in controlling CD4 + T cell responses., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objective: The aim of this study was to evaluate the expression of Twist and E-cadherin in lower lip squamous cell carcinoma (LLSCC) and their association with clinicopathologic parameters., Study Design: Fifty-nine cases of LLSCC were analyzed by applying immunohistochemistry techniques in a semiquantitative manner. The systems proposed by Bryne etal., Brandwein-Gensler etal., and Almangush etal. were applied for analysis of the histopathologic malignancy grading system., Results: Higher E-cadherin expression (general and membrane) was observed in cases presenting with disease-free survival after 5years of follow-up (P < .05). Higher Twist expression was observed in lesions classified as being in advanced stages, displaying recurrence, and having a high degree of malignancy. A significant negative correlation was detected between cytoplasmic Twist expression and membrane E-cadherin expression (P = .028). A statistically significant relationship was detected between high total Twist expression in tumors classified as high risk by Brandwein-Gensler etal., and no significant difference was observed among total, membrane, and cytoplasmic E-cadherin expressions in LLSCC cases and the 3 applied grading systems (P > .05)., Conclusions: The results of the present study suggest the potential involvement of Twist and E-cadherin in the modulation of events related to worse prognoses in LLSCC cases., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective- Leukocyte flux contributes to thrombus formation in deep veins under pathological conditions, but mechanisms that inhibit venous thrombosis are incompletely understood. Ectonucleotide di(tri)phosphohydrolase 1 ( ENTPD1 or Cd39), an ectoenzyme that catabolizes extracellular adenine nucleotides, is embedded on the surface of endothelial cells and leukocytes. We hypothesized that under venous stasis conditions, CD39 regulates inflammation at the vein:blood interface in a murine model of deep vein thrombosis. Approach and Results- CD39-null mice developed significantly larger venous thrombi under venous stasis, with more leukocyte recruitment compared with wild-type mice. Gene expression profiling of wild-type and Cd39-null mice revealed 76 differentially expressed inflammatory genes that were significantly upregulated in Cd39-deleted mice after venous thrombosis, and validation experiments confirmed high expression of several key inflammatory mediators. P-selectin, known to have proximal involvement in venous inflammatory and thrombotic events, was upregulated in Cd39-null mice. Inferior vena caval ligation resulted in thrombosis and a corresponding increase in both P-selectin and VWF (von Willebrand Factor) levels which were strikingly higher in mice lacking the Cd39 gene. These mice also manifest an increase in circulating platelet-leukocyte heteroaggregates suggesting heterotypic crosstalk between coagulation and inflammatory systems, which is amplified in the absence of CD39. Conclusions- These data suggest that CD39 mitigates the venous thromboinflammatory response to flow interruption.

Rationale: Endothelial barrier function depends on the proper localization and function of the adherens junction protein VE (vascular endothelial)-cadherin. Previous studies have suggested a functional relationship between integrin-mediated adhesion complexes and VE-cadherin yet the underlying molecular links are unclear. Binding of the cytoskeletal adaptor protein talin to the β-integrin cytoplasmic domain is a key final step in regulating the affinity of integrins for extracellular ligands (activation) but the role of integrin activation in VE-cadherin mediated endothelial barrier function is unknown., Objective: To test the requirement of talin-dependent activation of β1 integrin in VE-cadherin organization and endothelial cell (EC) barrier function., Methods and Results: EC-specific deletion of talin in adult mice resulted in impaired stability of intestinal microvascular blood vessels, hemorrhage, and death. Talin-deficient endothelium showed altered VE-cadherin organization at EC junctions in vivo. shRNA (short hairpin RNA)-mediated knockdown of talin1 expression in cultured ECs led to increased radial actin stress fibers, increased adherens junction width and increased endothelial monolayer permeability measured by electrical cell-substrate impedance sensing. Restoring β1-integrin activation in talin-deficient cells with a β1-integrin activating antibody normalized both VE-cadherin organization and EC barrier function. In addition, VE-cadherin organization was normalized by reexpression of talin or integrin activating talin head domain but not a talin head domain mutant that is selectively deficient in activating integrins., Conclusions: Talin-dependent activation of EC β1-integrin stabilizes VE-cadherin at endothelial junctions and promotes endothelial barrier function.

Background and Aims: CD71+ erythroid cells are enriched during pregnancy with immuno suppressive properties. We investigated the frequency and functionality of CD71+ erythroid cells in peripheral blood, cord blood, and placenta of inflammatory bowel disease [IBD] patients versus healthy controls [HCs]. We aimed to determine their role in IBD pathogenesis during pregnancy., Methods: Peripheral blood was collected at preconception, the first, second and third trimesters, and postpartum. Cord blood and placental tissues were collected at the time of birth. Cells from different specimens were subjected to immune-phenotyping and functional assays. CD71+ erythroid cells were purified for quantitative polymerase chain reaction [qPCR] analysis. Using an allogeneic mouse model of pregnancy, the effects of CD71+ erythroid cells depletion on intestinal homeostasis and dysbiosis was studied., Results: IBD patients had lower CD71+ erythroid cells during pregnancy compared with HCs. Placenta and cord blood CD71+ erythroid cells from IBD patients exhibited impaired functionality and expressed lower inhibitory molecules including VISTA, TGF-β, and reactive oxygen species [ROS]. Lower CD71+ erythroid cells were correlated with reduced regulatory T cells and increased immune-activation in IBD patients. Depletion of CD71+ erythroid cells in an allogeneic pregnancy model resulted in upregulation of TLRs, IL-6, and CXCL-1, and enhanced production of TNF-α, in intestinal tissues. In contrast, TGF-β gene expression was reduced. Excessive inflammatory response in the gut [e.g. TNF-α] affects intestinal integrity and CD71+ erythroid cells impact on the gut's bacterial composition., Conclusions: Reduced frequency and/or impaired functionality of CD71+ erythroid cells during pregnancy may predispose IBD patients to a more pro-inflammatory milieu in their gastrointestinal tract, characterised by lower Tregs, higher IL-6, and TNF-α, and dysbiosis.

A recent meta-analysis revealed the contribution of the SIGLEC6 locus to the risk of developing systemic lupus erythematosus (SLE). However, no specific Siglec (sialic acid-binding immunoglobulin-like lectin) genes (Siglecs) have been implicated in the pathogenesis of SLE. Here, we performed in silico analysis of the function of three major protective alleles in the locus and found that these alleles were expression quantitative trait loci that enhanced expression of the adjacent SIGLEC12 gene. These data suggest that SIGLEC12 may protect against the development of SLE in Asian populations. Consistent with human genetic data, we identified two missense mutations in lupus-prone B6.NZM Sle1/Sle2/Sle3 (Sle1-3) mice in Siglece, which is the murine Siglec with the greatest homology to human SIGLEC12. Since the mutations resulted in reduced binding of Siglec E to splenic cells, we evaluated whether Siglece -/- mice had SLE phenotypes. We found that Siglece -/- mice showed increased autoantibody production, glomerular immune complex deposition and severe renal pathology reminiscent of human SLE nephropathy. Our data demonstrate that the Siglec genes confer resistance to SLE in mice and humans.

HIV causes several forms of immune dysfunction that need to be addressed in a functional cure for HIV. Immune exhaustion describes a dysfunctional phenotype caused by chronic cellular activation. Lymphocyte activation gene-3 (LAG3) is one of several negative coreceptors known as immune checkpoints that contribute to this exhaustion phenotype. Antibodies targeting immune checkpoints are now used clinically to restore immunity against cancer and hold promise in restoring immunity during HIV infection. Here, we summarize current knowledge surrounding LAG3 and discuss its relevance during HIV infection and the potential for LAG3-targeting antibodies in a functional HIV cure., Competing Interests: The authors have declared that no competing interests exist.

Ionizing radiation (IR) is a conventional cancer therapeutic, to which cancer cells develop radioresistance with exposure. The residual cancer cells after radiation treatment also have increased metastatic potential. The mechanisms by which cancer cells develop radioresistance and gain metastatic potential are still unknown. In this study acute IR exposure induced cancer cell senescence and apoptosis, but after long-term IR exposure, cancer cells exhibited radioresistance. The proliferation of radioresistant cells was retarded, and most cells were arrested in G0/G1 phase. The radioresistant cells simultaneously showed resistance to further IR-induced apoptosis, premature senescence, and epithelial to mesenchymal transformation (EMT). Acute IR exposure steadily elevated CDC6 protein levels due to the attenuation of ubiquitination, while CDC6 overexpression was observed in the radioresistant cells because the insufficiency of CDC6 phosphorylation blocked protein translocation from nucleus to cytoplasm, resulting in subcellular protein accumulation when the cells were arrested in G0/G1 phase. CDC6 ectopic overexpression in CNE2 cells resulted in apoptosis resistance, G0/G1 cell cycle arrest, premature senescence, and EMT, similar to the characteristics of radioresistant CNE2-R cells. Targeting CDC6 with siRNA promoted IR-induced senescence, sensitized cancer cells to IR-induced apoptosis, and reversed EMT. Furthermore, CDC6 depletion synergistically repressed the growth of CNE2-R xenografts when combined with IR. The study describes for the first time cell models for IR-induced senescence, apoptosis resistance, and EMT, three major mechanisms by which radioresistance develops. CDC6 is a novel radioresistance switch regulating senescence, apoptosis, and EMT. These studies suggest that CDC6 high KI67 low represents a new diagnostic marker of radiosensitivity, and CDC6 represents a new therapeutic target for cancer radiosensitization.

The metabolic syndrome describes a group of signs that increase the likelihood for developing type 2 diabetes mellitus, cardiovascular diseases and some types of cancer. The action of insulin depends on its binding to membrane receptors on its target cells. We wonder if blood insulin could travel bound to proteins and if, in the presence of hyperinsulinemia, a soluble insulin receptor might be generated. We used young adult Wistar rats (which have no predisposition to obesity or diabetes), whose drinking water was added 20 % of sugar and that were fed a standard diet ad libitum for two and six months. They were compared with control rats under the same conditions, but that had running water for consumption. At two months, the rats developed central obesity, moderate hypertension, high triglyceride levels, hyperinsulinemia, glucose intolerance and insulin resistance, i.e. metabolic syndrome. Electrophoresis of the rats' plasma proteins was performed, followed by Western Blot (WB) for insulin and for the outer portion of the insulin receptor. The bands corresponding to insulin and to the receptor external part were at the same molecular weight level, 25-fold higher than that of free insulin. We demonstrated that insulin, both in control animals and in those with hyperinsulinemia, travels bound to the receptor outer portion (ectodomain), which we called soluble insulin receptor, and that is released al higher amounts in response to plasma insulin increase; in rats with metabolic syndrome and hyperinsulinemia, plasma levels are much higher than in controls. Soluble insulin receptor increase in blood might be an early sign of metabolic syndrome., (Copyright: © 2019 Permanyer.)

Purpose: Gonadotroph tumours are the most abundant of the clinically silent pituitary tumours. There is a lack of reliable prognostic markers predicting their clinical course. Our aim was to determine the level of E-cadherin and N-cadherin in a cohort of clinically silent gonadotroph pituitary tumours, and compare them to the rate of reintervention., Methods: Tumour tissue from primary surgery was retrospectively investigated and compared with clinical data. Immunohistochemical (N = 105) and real time-qPCR (N = 85) analyses for the levels of N-cadherin and the extra- and intracellular domains of E-cadherin were performed. The immunoreactive scores (IRS) and mRNA relative quantity were compared to the rate of reintervention., Results: The tumours presented a high IRS for N-cadherin (Median 12 (IQR 12-12)) and almost no immunoreactivity for the extracellular domain of E-cadherin (Median 0 (IQR 0-0)). The membranous staining for the intracellular domain of E-cadherin varied (Median 6 (IQR 4-6). Reduced membranous expression of the intracellular domain of E-cadherin was associated with nuclear presence of the same domain. Nuclear staining for the intracellular domain of E-cadherin was associated with a lower rate of reintervention (p = 0.01)., Conclusion: We found that silent gonadotroph tumours presented high IRS for N-cadherin and low IRS for the extracellular domain of E-cadherin. A substantial proportion of the tumours presented nuclear staining for the intracellular domain of E-cadherin, accompanied by a reduced membranous expression of the intracellular domain of E-cadherin. Absence of nuclear staining for the intracellular domain of E-cadherin served as an independent predictor of reintervention.

Recent findings regarding the cellular biology and immunology of BST-2 (also known as tetherin) indicate that its function could be exploited as a universal replication inhibitor of enveloped respiratory viruses (e.g., influenza, respiratory syncytial virus, etc.). BST-2 inhibits viral replication by preventing virus budding from the plasma membrane and by inducing an antiviral state in cells adjacent to infection via unique inflammatory signaling mechanisms. This review presents the first comprehensive summary of what is currently known about BST-2 anti-viral function against respiratory viruses, how these viruses construct countermeasures to antagonize BST-2, and how BST-2 function might be targeted to develop therapies to treat respiratory virus infections. The authors address the current gaps in knowledge, including the need for mechanistic understanding of BST-2 antagonism by respiratory viruses, that should be bridged to achieve that goal., (© 2018 WILEY Periodicals, Inc.)

The interaction between CD200 and its receptor CD200R1 is among the central regulators of microglia and macrophage phenotype. However, it remains to be established whether, in the context of a traumatic CNS injury, CD200R1 act as a negative regulator of these particular innate immune cells, and if the exogenous delivery of CD200 may ameliorate neurological deficits. In the present study, we first evaluated whether preventing the local interaction between the pair CD200-CD200R1, by using a selective blocking antibody against CD200R1, has a role on functional and inflammatory outcome after contusion-induced spinal cord injury (SCI) in mice. The injection of the αCD200R1, but not control IgG1, into the lesioned spinal cord immediately after the SCI worsened locomotor performance and exacerbated neuronal loss and demyelination. At the neuroimmunological level, we observed that microglial cells and macrophages showed increased levels of iNOS and Ly6C upon CD200R1 blockade, indicating that the disruption of CD200R1 drove these cells towards a more pro-inflammatory phenotype. Moreover, although CD200R1 blockade had no effect in the initial infiltration of neutrophils into the lesioned spinal cord, it significantly impaired their clearance, which is a key sign of excessive inflammation. Interestingly, intraparenchymal injection of recombinant CD200-His immediately after the injury induced neuroprotection and robust and long-lasting locomotor recovery. In conclusion, this study reveals that interaction of CD200-CD200R1 plays a crucial role in limiting inflammation and lesion progression after SCI, and that boosting the stimulation of this pathway may constitute a new therapeutic approach., (Copyright © 2018. Published by Elsevier Inc.)

Objective: High blood pressure (hypertension) is one of the most common cardiovascular diseases. In recent years, there were more and more studies on the function of inflammation in hypertension. CD68 mainly mediates the activation of cytokine interleukin-17 (IL-17) signaling pathway and participates in inflammatory responses. It has been studied the function of CD68 and IL-17 in hypertension, but it has not been reported whether it affected hypertension and vascular remodeling when macrophage CD68 expression inhibited. In this study, antisense-CD68 mice were used to study the effect and mechanism of angiotensin II-induced hypertensive vascular remodeling under specific suppression of macrophage CD68., Materials and Methods: Fifty 8-week-old male antisense-CD681 and C57 mice were divided into control and experimental group (angiotensin II group, 1000 ng•kg-1•min-1). After infusion of angiotensin II for 28 days, hematoxylin-eosin (HE) staining and immunohistochemical staining were used to observe the remodel of vascular. The changes of aortic inflammatory factors were detected by Real-time PCR (RT-PCR) and Western blotting., Results: By specifically inhibiting the expression of macrophage CD68, macrophage infiltration was mitigated in Ang II-induced hypertensive vascular remodeling model mouse, which also down-regulated the expression of vascular tissue inflammatory factor and activation of vascular smooth muscle cell p65., Conclusions: CD68 regulates the Ang II-induced hypertensive vascular remodeling through mediating macrophage inflammatory factor release.