NEAT1: Culprit lncRNA linking PIG-C, MSLN, and CD80 in triple-negative breast cancer

BACKGROUND

Breast cancer (BC) is the most common cancer in women. Despite the effectiveness of conventional therapies, they cause detrimental side effects. Glycosyl-Phosphatidyl-Inositol (GPI) pathway is a conserved pathway that culminates in the generation of GPI anchored proteins (GPI-AP). Phosphatidyl-Inositol-Glycan Biosynthesis Class C (PIG-C) is the first step in GPI pathway and upon its overexpression, Mesothelin (MSLN); an oncogenic GPI-AP, expression is induced. Therefore, blocking GPI pathway is a potential therapy through which multiple pathways can be rectified. Recombinant GPI-CD80 proved to be a potent immunostimulatory protein and currently being evaluated as tumor vaccine. In fact, CD80 is a unique immunomodulator that binds to CD28, CTLA-4 and PD-L1. Furthermore, research advancement showed that non-coding RNAs (ncRNAs) are key epigenetic modulators. Therefore, epigenetic tuning of GPI-APs remains an unexplored area. This study aims at investigating the potential role of ncRNAs in regulating MSLN, PIG-C and CD80 in BC.

METHODS

Potential ncRNAs were filtered by bioinformatics algorithms. MDA-MB-231 cells were transfected with RNA oligonucleotides. Surface CD80 and MSLN were assessed by FACS and immunofluorescence. Gene expression was tested by q-PCR.

RESULTS

PIG-C gene was overexpressed in TNBC and its manipulation altered MSLN surface level. Aligning with bioinformatics analysis, miR-2355 manipulated PIG-C and MSLN expression, while miR-455 manipulated CD80 expression. NEAT1 sponged both miRNAs. Paradoxically, NEAT1 lowered PIG-C gene expression while increased MSLN gene expression.

CONCLUSION

This study unravels novel immunotherapeutic targets for TNBC. NEAT1 is potential immunomodulator by sponging several miRNAs. Finally, this study highlights GPI pathway applications, therefore integrating epigenetics, post-translational modifications and immunomodulation.

Dual Role of HIV-1 Envelope Signal Peptide in Immune Evasion

HIV-1 Env signal peptide (SP) is an important contributor to Env functions. Env is generated from Vpu/Env encoded bicistronic mRNA such that the 5′ end of Env-N-terminus, that encodes for Env-SP overlaps with 3′ end of Vpu. Env SP displays high sequence diversity, which translates into high variability in Vpu sequence. This study aimed to understand the effect of sequence polymorphism in the Vpu-Env overlapping region (VEOR) on the functions of two vital viral proteins: Vpu and Env. We used infectious molecular clone pNL4.3-CMU06 and swapped its SP (or VEOR) with that from other HIV-1 isolates. Swapping VEOR did not affect virus production in the absence of tetherin however, presence of tetherin significantly altered the release of virus progeny. VEOR also altered Vpu’s ability to downregulate CD4 and tetherin. We next tested the effect of these swaps on Env functions. Analyzing the binding of monoclonal antibodies to membrane embedded Env revealed changes in the antigenic landscape of swapped Envs. These swaps affected the oligosaccharide composition of Env-N-glycans as shown by changes in DC-SIGN-mediated virus transmission. Our study suggests that genetic diversity in VEOR plays an important role in the differential pathogenesis and also assist in immune evasion by altering Env epitope exposure.

CD109 expression in tumor cells and stroma correlates with progression and prognosis in pancreatic cancer

CD109 is a glycosylphosphatidylinositol-anchored glycoprotein, whose expression is upregulated in some types of malignant tumors. High levels of CD109 in tumor cells have been reported to correlate with poor prognosis; however, significance of CD109 stromal expression in human malignancy has not been elucidated. In this study, we investigated the tumorigenic properties of CD109 in pancreatic ductal adenocarcinoma (PDAC). Immunohistochemical analysis of 92 PDAC surgical specimens revealed that positive CD109 expression in tumor cells was significantly associated with poor prognosis (disease-free survival, p = 0.003; overall survival, p = 0.002), and was an independent prognostic factor (disease-free survival, p = 0.0173; overall survival, p = 0.0104) in PDAC. Furthermore, CD109 expression was detected in the stroma surrounding tumor cells, similar to that of α-smooth muscle actin, a histological marker of cancer-associated fibroblasts. The stromal CD109 expression significantly correlated with tumor progression in PDAC (TNM stage, p = 0.033; N factor, p = 0.024; lymphatic invasion, p = 0.028). In addition, combined assessment of CD109 in tumor cells and stroma could identify the better prognosis group of patients from the entire patient population. In MIA PaCa-2 PDAC cell line, we demonstrated the involvement of CD109 in tumor cell motility, but not in PANC-1. Taken together, CD109 not only in the tumor cells but also in the stroma is involved in the progression and prognosis of PDAC, and may serve as a useful prognostic marker in PDAC.

Elucidating the clinical spectrum and molecular basis of HYAL2 deficiency

PURPOSE

We previously defined biallelic HYAL2 variants causing a novel disorder in 2 families, involving orofacial clefting, facial dysmorphism, congenital heart disease, and ocular abnormalities, with Hyal2 knockout mice displaying similar phenotypes. In this study, we better define the phenotype and pathologic disease mechanism.

METHODS

Clinical and genomic investigations were undertaken alongside molecular studies, including immunoblotting and immunofluorescence analyses of variant/wild-type human HYAL2 expressed in mouse fibroblasts, and in silico modeling of putative pathogenic variants.

RESULTS

Ten newly identified individuals with this condition were investigated, and they were associated with 9 novel pathogenic variants. Clinical studies defined genotype-phenotype correlations and confirmed a recognizable craniofacial phenotype in addition to myopia, cleft lip/palate, and congenital cardiac anomalies as the most consistent manifestations of the condition. In silico modeling of missense variants identified likely deleterious effects on protein folding. Consistent with this, functional studies indicated that these variants cause protein instability and a concomitant cell surface absence of HYAL2 protein.

CONCLUSION

These studies confirm an association between HYAL2 alterations and syndromic cleft lip/palate, provide experimental evidence for the pathogenicity of missense alleles, enable further insights into the pathomolecular basis of the disease, and delineate the core and variable clinical outcomes of the condition.

Elevated ATP via enhanced miRNA-30b, 30c, and 30e downregulates the expression of CD73 in CD8+ T cells of HIV-infected individuals

CD8⁺ T cells play a crucial role against chronic viral infections, however, their effector functions are influenced by the expression of co-stimulatory/inhibitory receptors. For example, CD73 works with CD39 to convert highly inflammatory ATP to adenosine. However, its expression on T cells in the context of viral infections has not been well defined. Here, we analyzed the expression of CD73 on human T cells in a cohort of 102 HIV-infected individuals including those on antiretroviral therapy (ART), ART-naïve, and long-term non-progressors who were not on ART. We found that the frequency of CD73⁺ T cells was markedly lower among T cell subsets (e.g. naïve, effector or memory) in the peripheral blood of all HIV-infected individuals. Notably, CD73 was decreased at the cell surface, intracellular and gene levels. Functionally, CD8⁺CD73⁺ T cells exhibited decreased cytokine expression (TNF-α, IFN-γ and IL-2) upon global or antigen-specific stimulation and impaired expression of cytolytic molecules at the gene and protein levels. In contrast, CD8⁺CD73⁺ T cells expressed elevated levels of homing receptors such as CCR7, α4β7 integrin, which suggests a migratory advantage for these cells as observed in vitro. We also observed significant migration of CD73⁺CD8⁺ T cells into the cerebrospinal fluids of multiple sclerosis (MS) patients at the time of disease relapse. Moreover, we found that elevated levels of ATP in the plasma of HIV-infected individuals upregulates the expression of miRNA30b-e in T cells in vitro. In turn, inhibition of miRNAs (30b, 30c and 30e) resulted in significant upregulation of CD73 mRNA in CD8⁺ T cells. Therefore, we provide a novel mechanism for the downregulation of CD73 via ATP-induced upregulation of miRNA30b, 30c and 30e in HIV infection. Finally, these observations imply that ATP-mediated downregulation of CD73 mainly occurs via its receptor, P2X1/P2RX1. Our results may in part explain why HIV-infected individuals have reduced risk of developing MS considering the role of CD73 for efficient T cell entry into the central nervous system.

CD8⁺ T cells (killer T cells) play an important role against chronic viral infections, however, their functional properties get compromised during the course of HIV infection. CD73, is one of molecules that influences T cell functions, however, its role in the context of viral infections has not been well defined. Here, we analyzed the expression of CD73 on T cells in a cohort of 102 HIV-infected individuals including those on antiretroviral therapy (ART), ART-naïve, and long-term non-progressors who were not on ART. We found that the frequency of T cells expressing this molecule was markedly lower among different T cell subsets obtained from the blood of HIV-infected individuals. Notably, CD73 was decreased at the intracellular protein and gene levels. Furthermore, we found that T cells expressing this molecule (CD73) had impaired functional properties. In contrast, we observed that T cells expressing CD73 had elevated levels of homing receptors, which suggests a migratory advantage for these cells. This was also supported by increased CD73⁺ T cells in the cerebrospinal fluids of multiple sclerosis patients when they experienced disease replace. Moreover, we found that the elevated level of ATP in the plasma of HIV-infected individuals is responsible for the upregulation of miRNA30b, 30c and 30e, resulting in reduced expression of CD73.

Dexamethasone sensitizes to ferroptosis by glucocorticoid receptor-induced dipeptidase-1 expression and glutathione depletion

Dexamethasone is widely used as an immunosuppressive therapy and recently as COVID-19 treatment. Here, we demonstrate that dexamethasone sensitizes to ferroptosis, a form of iron-catalyzed necrosis, previously suggested to contribute to diseases such as acute kidney injury, myocardial infarction, and stroke, all of which are triggered by glutathione (GSH) depletion. GSH levels were significantly decreased by dexamethasone. Mechanistically, we identified that dexamethasone up-regulated the GSH metabolism regulating protein dipeptidase-1 (DPEP1) in a glucocorticoid receptor (GR)-dependent manner. DPEP1 knockdown reversed the phenotype of dexamethasone-induced ferroptosis sensitization. Ferroptosis inhibitors, the DPEP1 inhibitor cilastatin, or genetic DPEP1 inactivation reversed the dexamethasone-induced increase in tubular necrosis in freshly isolated renal tubules. Our data indicate that dexamethasone sensitizes to ferroptosis by a GR-mediated increase in DPEP1 expression and GSH depletion. Together, we identified a previously unknown mechanism of glucocorticoid-mediated sensitization to ferroptosis bearing clinical and therapeutic implications.

Low MICA Gene Expression Confers an Increased Risk of Graves' Disease: A Mendelian Randomization Study

Background: Expression of natural killer group 2 member D (NKG2D) ligand (NKG2DL) plays a major role as a "danger signal" on stressed cells to promote removal of the latter by NKG2D-expressing cytotoxic lymphocytes. NKG2DL expression has been found in peripheral immune cells as well, such as in macrophages; however, the effect of this expression is yet to be determined. Methods: We determined instrumental variables (IVs; R² <0.01 in linkage disequilibrium), explaining the major variance in major histocompatibility complex class I chain-related protein A (MICA) and B (MICB) gene expression levels from the expression-quantitative trait locus (eQTL) of NKG2DLs based on the RNA-seq analysis of peripheral blood mononuclear cells (PBMCs) from 381 Japanese. Simultaneously, the target outcomes were filtered by PheWAS from 58 health risks, using a community-based cohort study composed of 44,739 Japanese residents. Finally, we estimated the causal effect of gene expression levels on the outcomes using the Mendelian randomization approach. Results: We determined nine and four IVs, explaining 87.6% and 33.0% of MICA and MICB gene expression levels, respectively. In the association test, we identified 10 or 13 significant outcomes associated with the MICA or MICB eQTLs, respectively, as well as the causal effect of MICA expression on Graves' disease (GD) (p = 4.2 × 10^-3; odds ratio per 1 S.D. difference in the expression: 0.983 [confidence interval: 0.971-0.995]), using the weighted median estimator, without significant pleiotropy (p > 0.05), and the results were consistent across the sensitivity analyses. Conclusions: Our study provide novel evidence associating NKG2DL expression with GD, an autoimmune thyroiditis; direction of the effect indicated the immunoregulatory role of MICA expression in PBMCs, suggesting the importance of further functional assays in inflammatory diseases.

Circulating Interleukin-6 and CD16 positive monocytes increase following angioplasty of an arteriovenous fistula

Arteriovenous fistulas are the ideal form of vascular access that allows provision of haemodialysis. Stenotic lesions caused by neointimal hyperplasia commonly occur resulting in patients requiring a fistuloplasty. This is effective but there is a high recurrence rate. We sought to investigate the effects of a fistuloplasty on monocyte populations. Blood samples were taken from patients before and after their fistuloplasty procedure. Samples were analysed using flow cytometry, ELISA and Luminex assays. Univariate cox regression was carried out to investigate associations with post fistuloplasty patency. At 1-2 days post fistuloplasty, the proportion of classical (CD14++CD16-) monocytes decreased (p < 0.001), whilst intermediate (CD14++CD16+) and non-classical (CD14+CD16+) monocytes increased (both p < 0.01) in a cohort of 20 patients. A time course study carried out in 5 patients showed that this was due to an increase in absolute numbers of non-classical and intermediate monocytes. Higher levels of non-classical monocytes pre-fistuloplasty were associated with an increased risk for patency loss (p < 0.05). We measured 41 soluble factors in plasma samples taken before a fistuloplasty in 54 patients, with paired post-fistuloplasty samples (1-2 days) available in 30 patients. After correcting for false discovery, the only factor with a significant change in level was IL-6 (P = 0.0003, q = 0.0124). In a further time-course study in 6 patients, peak level of IL-6 occurred 2-3 h post fistuloplasty. This study demonstrates that there is a systemic inflammatory response to the fistuloplasty procedure and that monocyte subsets and IL-6 may be important in the pathophysiology of restenosis.

NT5E mutation in sisters who underwent aortic valve replacements for aortic stenosis

Mutations of the NT5E gene encoding the cluster of differentiation 73 (CD73) protein have been found in patients with characteristic calcification of joints and arteries (CALJA). CD73 plays a protective role against aortic valve calcification; therefore, its deletion results in aortic valve calcification. However, to date, there are no reports of a patient with CALJA with aortic stenosis. In this study, we describe 2 extremely rare cases of sisters with identical NT5E gene mutation patterns, both of whom developed late-onset severe aortic stenosis and limb ischaemia. Both patients underwent aortic valve replacement and bilateral distal arterial bypass surgeries successfully. They were genetically diagnosed with CALJA based on the NT5E mutation. Our report suggests that NT5E mutations should be considered in patients requiring aortic valve replacement for a calcified aortic valve and bypass surgery for specific calcified and occluded arteries.

Multidimension Analysis of the Prognostic Value, Immune Regulatory Function, and ceRNA Network of LY6E in Individuals with Colorectal Cancer

BACKGROUND

Lymphocyte antigen 6 complex, locus E (LY6E) is abnormally expressed in several cancers and is associated with poor outcomes. However, the biological role of LY6E in colorectal cancer (CRC) remains largely unknown. Hence, we aimed to evaluate the expression levels, prognostic value, biological functions, and immune effects of LY6E via pan-cancer and CRC analyses using multiple databases.

METHODS

We analyzed the expression pattern of LY6E in various cancers. The prognostic value of LY6E expression was identified using the Kaplan-Meier analysis and the Cox regression models. We used gene set enrichment analysis (GSEA) to identify the potential functions of LY6E. Correlations between the LY6E expression and various factors, including LY6E methylation level, copy number variation (CNV), microsatellite instability (MSI), and immune checkpoint genes, were also analyzed. The levels of LY6E expression and immune infiltration were analyzed using CIBERSORT. We constructed a regulatory network that was in compliance with the competing endogenous RNA (ceRNA) hypothesis. A ceRNA expression-based nomogram was established. Real-time PCR (qRT-PCR) was applied to validate the expression of LY6E-related ceRNA in CRC cell lines.

RESULTS

LY6E is overexpressed in several tumor types, including CRC, and patients with high expression levels of LY6E have a poor prognosis. The Kaplan-Meier analysis and Cox regression analysis showed that LY6E could be considered a favorable prognostic factor in TCGA and GEO cohort. The results of GSEA showed that high LY6E expression levels were associated with immune-related pathways, such as those involved in antigen processing and presentation and the intestinal immune network for IgA production. Six methylation sites of LY6E that were associated with prognostic survival were screened. Moreover, the high levels of LY6E expression were correlated with copy number gain, microsatellite instability high, and immunotherapy response. The results of CIBERSORT analysis demonstrated that the LY6E expression levels were correlated with the infiltration of multiple immune cells, especially T cells. Then, we constructed a ceRNA network (LINC00963/miR-92a-3p/LY6E) and validated it using qRT-PCR. A predictive ceRNA-based nomogram was established and validated.

CONCLUSION

The oncogenic LY6E may serve as a promising marker for the diagnosis and treatment of CRC.

APOBEC3, TRIM5α, and BST2 polymorphisms in healthy individuals of various populations with special references to its impact on HIV transmission

AIDS restriction genes (ARGs) like APOBEC3, TRIM5α, and BST2 can act as immunological detectors of the innate protective mechanism of the body. ARGs influence the course of viral pathogenesis and progression of the disease. The infection caused by different viruses including HIV activates the innate immune receptors leading to production of proinflammatory cytokines, interferons and signals that recruit and activate cells involved in the process of inflammation following induction of adaptive immunity. Differential expression of genes involved in viral infection decide the fate and subsequent susceptibility to infection and its clinical outcome. Nevertheless, comprehensive reports on the incidence of genetic polymorphism of APOBEC3s, TRIM5α, and BST-2 in the general population and its association with pathological conditions have not been described well. Therefore, the occurrence of APOBEC3, TRIM5α, and BST2 polymorphism in healthy individuals and its impact on HIV transmission was analyzed. We conducted an extensive search using the several databases including, EMBASE, PubMed (Medline), and Google Scholar. APOBEC3-D, -F, -G, and -H out of the seven human APOBEC3s, help in the control of viral infection. Amongst various restriction factors, TRIM5α and BST-2 also restrict the viral infection followed by the development of the disease. In the current review, a brief account of the polymorphism in the APOBEC3G, TRIM5α, and BST2 genes are explored among different populations along with the interaction of APOBEC3G with Vif protein. Furthermore, this review specifically focus on ARGs polymorphism (APOBEC3G, TRIM5α, and BST2) associated with HIV transmission.

The impact of CD160 deficiency on alloreactive CD8 T cell responses and allograft rejection

CD160 is a member of the immunoglobulin superfamily with a pattern of expression mainly restricted to cytotoxic cells. To assess the functional relevance of the HVEM/CD160 signaling pathway in allogeneic cytotoxic responses, exon 2 of the CD160 gene was targeted by CRISPR/Cas9 to generate CD160 deficient mice. Next, we evaluated the impact of CD160 deficiency in the course of an alloreactive response. To that aim, parental donor WT (wild-type) or CD160 KO (knock-out) T cells were adoptively transferred into non-irradiated semiallogeneic F1 recipients, in which donor alloreactive CD160 KO CD4 T cells and CD8 T cells clonally expanded less vigorously than in WT T cell counterparts. This differential proliferative response rate at the early phase of T cell expansion influenced the course of CD8 T cell differentiation and the composition of the effector T cell pool that led to a significant decreased of the memory precursor effector cells (MPECs) / short-lived effector cells (SLECs) ratio in CD160 KO CD8 T cells compared to WT CD8 T cells. Despite these differences in T cell proliferation and differentiation, allogeneic MHC class I mismatched (bm1) skin allograft survival in CD160 KO recipients was comparable to that of WT recipients. However, the administration of CTLA-4.Ig showed an enhanced survival trend of bm1 skin allografts in CD160 KO with respect to WT recipients. Finally, CD160 deficient NK cells were as proficient as CD160 WT NK cells in rejecting allogeneic cellular allografts or MHC class I deficient tumor cells. CD160 may represent a CD28 alternative costimulatory molecule for the modulation of allogeneic CD8 T cell responses either in combination with costimulation blockade or by direct targeting of alloreactive CD8 T cells that upregulate CD160 expression in response to alloantigen stimulation.

New Mutations in HFE2 and TFR2 Genes Causing Non HFE-Related Hereditary Hemochromatosis

Hereditary hemochromatosis (HH) is an iron metabolism disease clinically characterized by excessive iron deposition in parenchymal organs such as liver, heart, pancreas, and joints. It is caused by mutations in at least five different genes. HFE hemochromatosis is the most common type of hemochromatosis, while non-HFE related hemochromatosis are rare cases. Here, we describe six new patients of non-HFE related HH from five different families. Two families (Family 1 and 2) have novel nonsense mutations in the HFE2 gene have novel nonsense mutations (p.Arg63Ter and Asp36ThrfsTer96). Three families have mutations in the TFR2 gene, one case has one previously unreported mutation (Family A-p.Asp680Tyr) and two cases have known pathogenic mutations (Family B and D-p.Trp781Ter and p.Gln672Ter respectively). Clinical, biochemical, and genetic data are discussed in all these cases. These rare cases of non-HFE related hereditary hemochromatosis highlight the importance of an earlier molecular diagnosis in a specialized center to prevent serious clinical complications.

The neutrophil protein CD177 is a novel PDPN receptor that regulates human cancer-associated fibroblast physiology

The cancer-associated fibroblast (CAF) marker podoplanin (PDPN) is generally correlated with poor clinical outcomes in cancer patients and thus represents a promising therapeutic target. Despite its biomedical relevance, basic aspects of PDPN biology such as its cellular functions and cell surface ligands remain poorly uncharacterized, thus challenging drug development. Here, we utilize a high throughput platform to elucidate the PDPN cell surface interactome, and uncover the neutrophil protein CD177 as a new binding partner. Quantitative proteomics analysis of the CAF phosphoproteome reveals a role for PDPN in cell signaling, growth and actomyosin contractility, among other processes. Moreover, cellular assays demonstrate that CD177 is a functional antagonist, recapitulating the phenotype observed in PDPN-deficient CAFs. In sum, starting from the unbiased elucidation of the PDPN co-receptome, our work provides insights into PDPN functions and reveals the PDPN/CD177 axis as a possible modulator of fibroblast physiology in the tumor microenvironment.

HVEM structures and mutants reveal distinct functions of binding to LIGHT and BTLA/CD160

HVEM is a TNF (tumor necrosis factor) receptor contributing to a broad range of immune functions involving diverse cell types. It interacts with a TNF ligand, LIGHT, and immunoglobulin (Ig) superfamily members BTLA and CD160. Assessing the functional impact of HVEM binding to specific ligands in different settings has been complicated by the multiple interactions of HVEM and HVEM binding partners. To dissect the molecular basis for multiple functions, we determined crystal structures that reveal the distinct HVEM surfaces that engage LIGHT or BTLA/CD160, including the human HVEM-LIGHT-CD160 ternary complex, with HVEM interacting simultaneously with both binding partners. Based on these structures, we generated mouse HVEM mutants that selectively recognized either the TNF or Ig ligands in vitro. Knockin mice expressing these muteins maintain expression of all the proteins in the HVEM network, yet they demonstrate selective functions for LIGHT in the clearance of bacteria in the intestine and for the Ig ligands in the amelioration of liver inflammation.

Val109Asp Polymorphism of the Omentin-1 Gene and Incidence of Knee Osteoarthritis in a Chinese Han Population: A Correlation Analysis

Objective

To investigate the correlation of the Val109Asp polymorphism of the omentin-1 gene with the risk and severity of knee osteoarthritis (KOA) in a Chinese Han population.

Methods

This study enrolled 383 patients with primary KOA and 460 healthy controls. The genotypes were determined by the detection of single nucleotide polymorphism. To explore the interaction between omentin-1 gene polymorphism and obesity and age, the body mass index (BMI) of 25 kg/m² and the age of 55 years old were preset as the cut-off value of stratified analysis. Furthermore, enzyme-linked immunosorbent assay was used to determine the levels of omentin-1, interleukin (IL)-1β, IL-6 in peripheral blood and synovial fluid and the contents of IL-1β, IL-6, metalloproteinase (MMP)-13 and collagen (COL)-II in the supernatant of knee joint cartilage tissue.

Results

The Val109Asp polymorphism of the omentin-1 gene showed no obvious correlation with KOA. Compared with Asp/Asp genotype carriers with BMI <25 kg/m² and age <55 years old, Val109 allele carriers with BMI≥25 kg/m² and age ≥55 years old had obviously increased risk of KOA (adjusted OR = 1.416, p = 0.042; adjusted OR = 1.735, p = 0.038, respectively). In the KOA group, only the omentin-1 levels were significantly lower in the plasma and synovial fluid of Ala/Ala genotype carriers than in those of Asp/Asp genotype carriers. Meanwhile, the proportion of patients with moderate–severe K-L Classification, the levels of IL-1β, IL-6 in synovial fluid and the expression levels of IL-1β, IL-6 and MMP-13 in cartilage tissue significantly increased (p < 0.05). By contrast, the expression level of COL-II in cartilage tissue significantly decreased (p < 0.05).

Conclusions

The Val109Asp polymorphism of the omentin-1 gene may not be the primary pathogenic factor of KOA in Chinese. The Val/Val genotype can be regarded as a potential biomarker for the risk of KOA progression.

Role of Intestinal Alkaline Phosphatase in Innate Immunity

Intestinal alkaline phosphatase (IAP) is a multi-functional protein that has been demonstrated to primarily protect the gut. The role of IAP in maintaining intestinal homeostasis is underscored by the observation that IAP expression is defective in many gastrointestinal-related disorders such as inflammatory bowel disease IBD, necrotizing enterocolitis, and metabolic syndrome and that exogenous IAP supplementation improves the outcomes associated with these disorders. Additionally, studies using transgenic IAP-knock out (IAP-KO) mouse models further support the importance of the defensive role of IAP in the intestine. Supplementation of exogenous IAP and cellular overexpression of IAP have also been used in vitro to dissect out the downstream mechanisms of this protein in mammalian cell lines. Some of the innate immune functions of IAP include lipopolysaccharide (LPS) detoxification, protection of gut barrier integrity, regulation of gut microbial communities and its anti-inflammatory roles. A novel function of IAP recently identified is the induction of autophagy. Due to its critical role in the gut physiology and its excellent safety profile, IAP has been used in phase 2a clinical trials for treating conditions such as sepsis-associated acute kidney injury. Many excellent reviews discuss the role of IAP in physiology and pathophysiology and here we extend these to include recent updates on this important host defense protein and discuss its role in innate immunity via its effects on bacteria as well as on host cells. We will also discuss the relationship between IAP and autophagy and how these two pathways may act in concert to protect the gut.

Identification of Novel Mutations by Targeted NGS Panel in Patients with Hyperferritinemia

BACKGROUND

Several inherited diseases cause hyperferritinemia with or without iron overload. Differential diagnosis is complex and requires an extensive work-up. Currently, a clinical-guided approach to genetic tests is performed based on gene-by-gene sequencing. Although reasonable, this approach is expensive and time-consuming and Next Generation Sequencing (NGS) technology may provide cheaper and quicker large-scale DNA sequencing.

METHODS

We analysed 36 patients with non-HFE-related hyperferritinemia. Liver iron concentration was measured in 33 by magnetic resonance. A panel of 25 iron related genes was designed using SureDesign software. Custom libraries were generated and then sequenced using Ion Torrent PGM.

RESULTS

We identified six novel mutations in SLC40A1, three novel and one known mutation in TFR2, one known mutation and a de-novo deletion in HJV, and a novel mutation in HAMP in ten patients. In silico analyses supported the pathogenic role of the mutations.

CONCLUSIONS

Our results support the use of an NGS-based panel in selected patients with hyperferritinemia in a tertiary center for iron metabolism disorders. However, 26 out of 36 patients did not show genetic variants that can individually explain hyperferritinemia and/or iron overload suggesting the existence of other genetic defects or gene-gene and gene-environment interactions needing further studies.

Therapeutically expanded human regulatory T-cells are super-suppressive due to HIF1A induced expression of CD73

The adoptive transfer of regulatory T-cells (Tregs) is a promising therapeutic approach in transplantation and autoimmunity. However, because large cell numbers are needed to achieve a therapeutic effect, in vitro expansion is required. By comparing their function, phenotype and transcriptomic profile against ex vivo Tregs, we demonstrate that expanded human Tregs switch their metabolism to aerobic glycolysis and show enhanced suppressive function through hypoxia-inducible factor 1-alpha (HIF1A) driven acquisition of CD73 expression. In conjunction with CD39, CD73 expression enables expanded Tregs to convert ATP to immunosuppressive adenosine. We conclude that for maximum therapeutic benefit, Treg expansion protocols should be optimised for CD39/CD73 co-expression.

NRN1 and CAT Gene Polymorphisms, Complex Noise, and Lifestyles interactively Affect the Risk of Noise-induced Hearing Loss

OBJECTIVE

The effects of interactions between genetic and environmental factors on the noise-induced hearing loss (NIHL) are still unclear. This study aimed to assess interactions among gene polymorphisms, noise metrics, and lifestyles on the risk of NIHL.

METHODS

A case-control study was conducted using 307 patients with NIHL and 307 matched healthy individuals from five manufacturing industries. General demographic data, lifestyle details, and noise exposure levels were recorded. The Kompetitive allele-specific polymerase chain reaction (KASP) was used to analyze the genotypes of 18 SNPs.

RESULTS

GMDR model demonstrated a relevant interaction between NRN1 rs3805789 and CAT rs7943316 (P = 0.0107). Subjects with T allele of rs3805789 or T allele of rs7943316 had higher risks of NIHL than those with the SNP pair of rs3805789-CC and rs7943316-AA (P < 0.05). There was an interaction among rs3805789, rs7943316, and kurtosis (P = 0.0010). Subjects exposed to complex noise and carrying both rs3805789-CT and rs7943316-TT or rs3805789-CT/TT and rs7943316-AA had higher risks of NIHL than those exposed to steady noise and carrying both rs3805789-CC and rs7943316-AA (P < 0.05). The best six-locus model involving NRN1 rs3805789, CAT rs7943316, smoking, video volume, physical exercise, and working pressure for the risk of NIHL was found to be the interaction (P = 0.0010). An interaction was also found among smoking, video volume, physical exercise, working pressure, and kurtosis (P = 0.0107).

CONCLUSION

Concurrence of NRN1 and CAT constitutes a genetic risk factor for NIHL. Complex noise exposure significantly increases the risk of NIHL in subjects with a high genetic risk score. Interactions between genes and lifestyles as well as noise metrics and lifestyles affect the risk of NIHL.

Deficiency of Omentin-1 leads to delayed fracture healing through excessive inflammation and reduced CD31hiEmcnhi vessels

Fracture healing is a complicated process affected by many factors, such as inflammatory responses and angiogenesis. Omentin-1 is an adipokine with anti-inflammatory properties, but whether omentin-1 affects the fracture healing process is still unknown. Here, by using global omentin-1 knockout (omentin-1^-/-) mice, we demonstrated that omentin-1 deficiency resulted in delayed fracture healing in mice, accompanied by increased inflammation and osteoclast formation, and decreased production of platelet-derived growth factor-BB (PDGF-BB) and osteogenesis-promoting vessels that are strongly positive for CD31 and Endomucin (CD31^hiEmcn^hi) in the fracture area. In vitro, omentin-1 treatment suppressed the ability of the tumor necrosis factor-α (TNF-α)-activated macrophages to stimulate multi-nuclear osteoclast formation, resulting in a significant increase in the generation of mono-nuclear preosteoclasts and PDGF-BB, a pro-angiogenic protein that is abundantly secreted by preosteoclasts. PDGF-BB significantly augmented endothelial cell proliferation, tube formation and migration, whereas direct treatment with omentin-1 did not induce obvious effects on angiogenesis activities of endothelial cells. Our study suggests a positive role of omentin-1 in fracture healing, which may be associated with the inhibition of inflammation and stimulation of preosteoclast PDGF-BB-mediated promotion of CD31^hiEmcn^hi vessel formation.

Hepatocyte neogenin is required for hemojuvelin-mediated hepcidin expression and iron homeostasis in mice

Neogenin (NEO1) is a ubiquitously expressed multifunctional transmembrane protein. It interacts with hemojuvelin (HJV), a BMP coreceptor that plays a pivotal role in hepatic hepcidin expression. Earlier studies suggest that the function of HJV relies on its interaction with NEO1. However, the role of NEO1 in iron homeostasis remains controversial because of the lack of an appropriate animal model. Here, we generated a hepatocyte-specific Neo1 knockout (Neo1fl/fl;Alb-Cre+) mouse model that circumvented the developmental and lethality issues of the global Neo1 mutant. Results show that ablation of hepatocyte Neo1 decreased hepcidin expression and caused iron overload. This iron overload did not result from altered iron utilization by erythropoiesis. Replacement studies revealed that expression of the Neo1L1046E mutant that does not interact with Hjv, was unable to correct the decreased hepcidin expression and high serum iron in Neo1fl/fl;Alb-Cre+ mice. In Hjv-/- mice, expression of HjvA183R mutant that has reduced interaction with Neo1, also displayed a blunted induction of hepcidin expression. These observations indicate that Neo1-Hjv interaction is essential for hepcidin expression. Further analyses suggest that the Hjv binding triggered the cleavage of the Neo1 cytoplasmic domain by a protease, which resulted in accumulation of truncated Neo1 on the plasma membrane. Additional studies did not support that Neo1 functions by inhibiting Hjv shedding as previously proposed. Together, our data favor a model in which Neo1 interaction with Hjv leads to accumulation of cleaved Neo1 on the plasma membrane, where Neo1 acts as a scaffold to induce the Bmp signaling and hepcidin expression.

Associations between CD160 polymorphisms and autoimmune thyroid disease: a case-control study

BACKGROUND

Recent researches suggest that the CD160/HVEM/LIGHT/BTLA signaling pathway may contribute to the pathogeneses of autoimmune diseases, but the relationship between CD160 polymorphisms and autoimmune thyroid disease (AITD) has not been reported yet. This study aimed to evaluate the associations between CD160 polymorphisms and AITD.

METHODS

A total of 1017 patients with AITD (634 Graves' disease and 383 Hashimoto's thyroiditis) and 856 unrelated healthy controls were recruited into our study. Odds ratios (ORs) with 95% confidence interval (95%CI) were calculated through logistic regression analyses. The CD160 SNPs were detected using Hi-SNP high-throughput genotyping.

RESULTS

There was a statistically significant difference between Graves' disease patients and the control group with respect to both the genotype distribution (P = 0.014) and allele frequency of rs744877 (P = 0.034). A significant association of CD160 rs744877 with AITD was observed before adjusted age and gender under a dominant model (OR = 0.79, 95%CI 0.66-0.95; P = 0.013) and an additive model (OR = 0.77, 95%CI 0.64-0.94, P = 0.008), and was also observed after adjusted age and gender under a dominant model (OR = 0.78, 95%CI 0.65-0.95; P = 0.011) and an additive model (OR = 0.76, 95%CI 0.63-0.93, P = 0.007). A significant association of rs744877 with Graves' disease was observed under an allele model (OR = 0.84, 95%CI 0.71-0.98, P = 0.027), a dominant model (OR = 0.74, 95%CI 0.60-0.91; P = 0.005), and an additive model (OR = 0.72, 95%CI 0.58-0.90, P = 0.004). Multivariate logistic regression analyses suggested that the association remained significant after adjustment for age and gender. However, rs744877 was not related to Hashimoto's thyroiditis. Furthermore, CD160 rs3766526 was not significantly related to either Graves' disease or Hashimoto's thyroiditis.

CONCLUSION

This is the first identification of the association of CD160 rs744877 with Graves' disease. Our findings add new data to the genetic contribution to Graves' disease susceptibility and support the crucial role of the CD160/HVEM/LIGHT/BTLA pathway in the pathogenesis of Graves' disease.

miRNA-132/212 Gene-Deletion Aggravates the Effect of Oxygen-Glucose Deprivation on Synaptic Functions in the Female Mouse Hippocampus

Cerebral ischemia and its sequelae, which include memory impairment, constitute a leading cause of disability worldwide. Micro-RNAs (miRNA) are evolutionarily conserved short-length/noncoding RNA molecules recently implicated in adaptive/maladaptive neuronal responses to ischemia. Previous research independently implicated the miRNA-132/212 cluster in cholinergic signaling and synaptic transmission, and in adaptive/protective mechanisms of neuronal responses to hypoxia. However, the putative role of miRNA-132/212 in the response of synaptic transmission to ischemia remained unexplored. Using hippocampal slices from female miRNA-132/212 double-knockout mice in an established electrophysiological model of ischemia, we here describe that miRNA-132/212 gene-deletion aggravated the deleterious effect of repeated oxygen-glucose deprivation insults on synaptic transmission in the dentate gyrus, a brain region crucial for learning and memory functions. We also examined the effect of miRNA-132/212 gene-deletion on the expression of key mediators in cholinergic signaling that are implicated in both adaptive responses to ischemia and hippocampal neural signaling. miRNA-132/212 gene-deletion significantly altered hippocampal AChE and mAChR-M1, but not α7-nAChR or MeCP2 expression. The effects of miRNA-132/212 gene-deletion on hippocampal synaptic transmission and levels of cholinergic-signaling elements suggest the existence of a miRNA-132/212-dependent adaptive mechanism safeguarding the functional integrity of synaptic functions in the acute phase of cerebral ischemia.

Intracellular Sequestration of the NKG2D Ligand MIC B by Species F Adenovirus

The enteric human adenoviruses of species F (HAdVs-F), which comprise HAdV-F40 and HAdV-F41, are significant pathogens that cause acute gastroenteritis in children worldwide. The early transcription unit 3 (E3) of HAdVs-F is markedly different from that of all other HAdV species. To date, the E3 proteins unique to HAdVs-F have not been characterized and the mechanism by which HAdVs-F evade immune defenses in the gastrointestinal (GI) tract is poorly understood. Here, we show that HAdV-F41 infection of human intestinal HCT116 cells upregulated the expression of MHC class I-related chain A (MIC A) and MIC B relative to uninfected cells. Our results also showed that, for MIC B, this response did not however result in a significant increase of MIC B on the cell surface. Instead, MIC B was largely sequestered intracellularly. Thus, although HAdV-F41 infection of HCT116 cells upregulated MIC B expression, the ligand remained inside infected cells. A similar observation could not be made for MIC A in these cells. Our preliminary findings represent a novel function of HAdVs-F that may enable these viruses to evade immune surveillance by natural killer (NK) cells in the infected gut, thereby paving the way for the future investigation of their unique E3 proteins.

Methylation of NRN1 is a novel synthetic lethal marker of PI3K-Akt-mTOR and ATR inhibitors in esophageal cancer

Wnt, PI3K-Akt-mTOR, and NF-κB pathways were reported to be involved in DNA damage repair (DDR). DDR-deficient cancers become critically dependent on backup DNA repair pathways. Neuritin 1 (NRN1) is reported to be involved in PI3K-Akt-mTOR, and its role in DDR remains unclear. Methylation-specific PCR, siRNA, flow cytometry, esophageal cancer cell lines, and xenograft mouse models were used to examine the role of NRN1 in esophageal cancer. The expression of NRN1 is frequently repressed by promoter region methylation in human esophageal cancer cells. NRN1 was methylated in 50.4% (510/1012) of primary esophageal cancer samples. NRN1 methylation is associated significantly with age (P < .001), tumor size (P < .01), TNM stage (P < .001), differentiation (P < .001) and alcohol consumption (P < .05). We found that NRN1 methylation is an independent prognostic factor for poor 5-y overall survival (P < .001). NRN1 inhibits colony formation, cell proliferation, migration, and invasion, and induces apoptosis and G1/S arrest in esophageal cancer cells. NRN1 suppresses KYSE150 and KYSE30 cells xenografts growth in nude mice. PI3K signaling is reported to activate ATR signaling by targeting CHK1, the downstream component of ATR. By analyzing the synthetic efficiency of NVP-BEZ235 (PI3K inhibitor) and VE-822 (an ATR inhibitor), we found that the combination of NVP-BEZ235 and VE-822 increased cytotoxicity in NRN1 methylated esophageal cancer cells, as well as KYSE150 cell xenografts. In conclusion, NRN1 suppresses esophageal cancer growth both in vitro and in vivo by inhibiting PI3K-Akt-mTOR signaling. Methylation of NRN1 is a novel synthetic lethal marker for PI3K-Akt-mTOR and ATR inhibitors in human esophageal cancer.

Two RECK Splice Variants (Long and Short) Are Differentially Expressed in Patients with Stable and Unstable Coronary Artery Disease: A Pilot Study

Primary prevention is crucial for coronary heart disease (CAD) and the identification of new reliable biomarkers might help risk stratification or predict adverse coronary events. Alternative splicing (AS) is a less investigated genetic factors implicated in CAD etiology. We performed an RNA-seq study on PBMCs from CAD patients and control subjects (CTR) and observed 113 differentially regulated AS events (24 up and 89 downregulated) in 86 genes. The RECK (Reversion-inducing-cysteine-rich protein with Kazal motifs) gene was further analyzed in a larger case study (24 CTR subjects, 72 CAD and 32 AMI patients) for its Splicing-Index FC (FC = −2.64; p = 0.0217), the AS event involving an exon (exon 18), and its role in vascular inflammation and remodeling. We observed a significant downregulation of Long RECK splice variant (containing exon 18) in PBMCs of AMI compared to CTR subjects (FC = −3.3; p < 0.005). Interestingly, the Short RECK splice variant (lacking exon 18) was under-expressed in AMI compared to both CTR (FC = −4.5; p < 0.0001) and CAD patients (FC = −4.2; p < 0.0001). A ROC curve, constructed combining Long and Short RECK expression data, shows an AUC = 0.81 (p < 0.001) to distinguish AMI from stable CAD patients. A significant negative correlation between Long RECK and triglycerides in CTR group and a positive correlation in the AMI group was found. The combined evaluation of Long and Short RECK expression levels is a potential genomic biomarker for the discrimination of AMI from CAD patients. Our results underline the relevance of deeper studies on the expression of these two splice variants to elucidate their functional role in CAD development and progression.

Human intelectin-1 (ITLN1) genetic variation and intestinal expression

Intelectins are ancient carbohydrate binding proteins, spanning chordate evolution and implicated in multiple human diseases. Previous GWAS have linked SNPs in ITLN1 (also known as omentin) with susceptibility to Crohn's disease (CD); however, analysis of possible functional significance of SNPs at this locus is lacking. Using the Ensembl database, pairwise linkage disequilibrium (LD) analyses indicated that several disease-associated SNPs at the ITLN1 locus, including SNPs in CD244 and Ly9, were in LD. The alleles comprising the risk haplotype are the major alleles in European (67%), but minor alleles in African superpopulations. Neither ITLN1 mRNA nor protein abundance in intestinal tissue, which we confirm as goblet-cell derived, was altered in the CD samples overall nor when samples were analyzed according to genotype. Moreover, the missense variant V109D does not influence ITLN1 glycan binding to the glycan β-D-galactofuranose or protein-protein oligomerization. Taken together, our data are an important step in defining the role(s) of the CD-risk haplotype by determining that risk is unlikely to be due to changes in ITLN1 carbohydrate recognition, protein oligomerization, or expression levels in intestinal mucosa. Our findings suggest that the relationship between the genomic data and disease arises from changes in CD244 or Ly9 biology, differences in ITLN1 expression in other tissues, or an alteration in ITLN1 interaction with other proteins.

Functional landscape of SARS-CoV-2 cellular restriction

A deficient interferon (IFN) response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been implicated as a determinant of severe coronavirus disease 2019 (COVID-19). To identify the molecular effectors that govern IFN control of SARS-CoV-2 infection, we conducted a large-scale gain-of-function analysis that evaluated the impact of human IFN-stimulated genes (ISGs) on viral replication. A limited subset of ISGs were found to control viral infection, including endosomal factors inhibiting viral entry, RNA binding proteins suppressing viral RNA synthesis, and a highly enriched cluster of endoplasmic reticulum (ER)/Golgi-resident ISGs inhibiting viral assembly/egress. These included broad-acting antiviral ISGs and eight ISGs that specifically inhibited SARS-CoV-2 and SARS-CoV-1 replication. Among the broad-acting ISGs was BST2/tetherin, which impeded viral release and is antagonized by SARS-CoV-2 Orf7a protein. Overall, these data illuminate a set of ISGs that underlie innate immune control of SARS-CoV-2/SARS-CoV-1 infection, which will facilitate the understanding of host determinants that impact disease severity and offer potential therapeutic strategies for COVID-19.

FLA14 is required for pollen development and preventing premature pollen germination under high humidity in Arabidopsis

BACKGROUND

As an important subfamily of arabinogalactan proteins (AGPs), fasciclin-like AGPs (FLAs) contribute to various aspects of growth, development and adaptation, yet their function remains largely elusive. Despite the diversity of FLAs, only two members, Arabidopsis FLA3 and rice MTR1, are reported to be involved in sexual reproduction. In this study, another Arabidopsis FLA-encoding gene, FLA14, was identified, and its role was investigated.

RESULTS

Arabidopsis FLA14 was found to be a pollen grain-specific gene. Expression results from fusion with green fluorescent protein showed that FLA14 was localized along the cell membrane and in Hechtian strands. A loss-of-function mutant of FLA14 showed no discernible defects during male gametogenesis, but precocious pollen germination occurred inside the mature anthers under high moisture conditions. Overexpression of FLA14 caused 39.2% abnormal pollen grains with a shrunken and withered appearance, leading to largely reduced fertility with short mature siliques and lower seed set. Cytological and ultramicroscopic observation showed that ectopic expression of FLA14 caused disruption at the uninucleate stage, resulting in either collapsed pollen with absent intine or pollen of normal appearance but with a thickened intine.

CONCLUSIONS

Taken together, our data suggest a role for FLA14 in pollen development and preventing premature pollen germination inside the anthers under high relative humidity in Arabidopsis.

Tumor Extracellular Matrix Stiffness Promptly Modulates the Phenotype and Gene Expression of Infiltrating T Lymphocytes

The immune system is a fine modulator of the tumor biology supporting or inhibiting its progression, growth, invasion and conveys the pharmacological treatment effect. Tumors, on their side, have developed escaping mechanisms from the immune system action ranging from the direct secretion of biochemical signals to an indirect reaction, in which the cellular actors of the tumor microenvironment (TME) collaborate to mechanically condition the extracellular matrix (ECM) making it inhospitable to immune cells. TME is composed of several cell lines besides cancer cells, including tumor-associated macrophages, cancer-associated fibroblasts, CD4+ and CD8+ lymphocytes, and innate immunity cells. These populations interface with each other to prepare a conservative response, capable of evading the defense mechanisms implemented by the host's immune system. The presence or absence, in particular, of cytotoxic CD8+ cells in the vicinity of the main tumor mass, is able to predict, respectively, the success or failure of drug therapy. Among various mechanisms of immunescaping, in this study, we characterized the modulation of the phenotypic profile of CD4+ and CD8+ cells in resting and activated states, in response to the mechanical pressure exerted by a three-dimensional in vitro system, able to recapitulate the rheological and stiffness properties of the tumor ECM.

CD73 expression in normal, hyperplastic, and neoplastic thyroid: a systematic evaluation revealing CD73 overexpression as a feature of papillary carcinomas

CD73 converts AMP to adenosine, an immunosuppressive metabolite that promotes tumorigenesis. This study presents a systematic evaluation of CD73 expression in benign, hyperplastic, and neoplastic thyroid. CD73 expression was assessed by immunohistochemistry in 142 thyroid samples. CD73 was expressed in normal thyroid (3/6) and goiter (5/6), with an apical pattern and mild intensity. Apical and mild CD73 expression was also present in oncocytic cell adenomas/carcinomas (9/10; 5/8) and in follicular adenomas/carcinomas (12/18; 23/27). In contrast, papillary thyroid carcinomas featured extensive and intense CD73 staining (49/50) (vs. normal thyroid/goiter, p < 0.001). Seven of nine anaplastic carcinomas were CD73-positive with heterogeneous extensiveness of staining. Medullary and poorly differentiated carcinomas were mostly CD73-negative (1/6; 2/2). These results were corroborated by NT5E mRNA profiling. Papillary carcinomas feature enhanced CD73 protein and mRNA expression with distinct and intense staining, more pronounced in the invasive fronts of the tumors.

Circulating adiponectin mediates the association between omentin gene polymorphism and cardiometabolic health in Asian Indians

BACKGROUND

Plasma omentin levels have been shown to be associated with circulating adiponectin concentrations and cardiometabolic disease-related outcomes. In this study, we aim to examine the association of omentin gene polymorphism with serum adiponectin levels and cardiometabolic health status using a genetic approach, and investigate whether these associations are modified by lifestyle factors.

METHODS

The study included 945 normal glucose tolerant and 941 unrelated individuals with type 2 diabetes randomly selected from the Chennai Urban Rural Epidemiology Study (CURES), in southern India. Study participants were classified into cardiometabolically healthy and unhealthy, where cardiometabolically healthy were those without hypertension, diabetes, and dyslipidemia. Fasting serum adiponectin levels were measured by radioimmunoassay. The omentin A326T (rs2274907) single nucleotide polymorphism (SNP) was screened by polymerase chain reaction-restriction fragment length polymorphism and direct sequencing.

RESULTS

The 'A' allele of the omentin SNP was significantly associated with lower adiponectin concentrations after adjusting for age, sex, body mass index (BMI), waist circumference (WC) and cardiometabolic health status (p = 1.90 x 10-47). There was also a significant association between circulating adiponectin concentrations and cardiometabolic health status after adjusting for age, sex, BMI, WC and Omentin SNP (p = 7.47x10-10). However, after adjusting for age, sex, BMI, WC and adiponectin levels, the association of 'A' allele with cardiometabolic health status disappeared (p = 0.79) suggesting that adiponectin serves as a mediator of the association between omentin SNP and cardiometabolic health status. There were no significant interactions between the SNP and dietary factors on adiponectin levels and cardiometabolic health status (p>0.25, for all comparisons).

CONCLUSIONS

Our findings show that adiponectin might function as a mechanistic link between omentin SNP and increased risk of cardiometabolic diseases independent of common and central obesity in Asian Indians. Before strategies to promote adiponectin modulation could be implemented, further studies are required to confirm the molecular mechanisms involved in this triangular relationship between omentin gene, adiponectin and cardiometabolic diseases.

CD109-GP130 interaction drives glioblastoma stem cell plasticity and chemoresistance through STAT3 activity

Glioma stem cells (GSCs) drive propagation and therapeutic resistance of glioblastomas, the most aggressive diffuse brain tumors. However, the molecular mechanisms that maintain the stemness and promote therapy resistance remain poorly understood. Here we report CD109/STAT3 axis as crucial for the maintenance of stemness and tumorigenicity of GSCs and as a mediator of chemoresistance. Mechanistically, CD109 physically interacts with glycoprotein 130 to promote activation of the IL-6/STAT3 pathway in GSCs. Genetic depletion of CD109 abolished the stemness and self-renewal of GSCs and impaired tumorigenicity. Loss of stemness was accompanied with a phenotypic shift of GSCs to more differentiated astrocytic-like cells. Importantly, genetic or pharmacologic targeting of CD109/STAT3 axis sensitized the GSCs to chemotherapy, suggesting that targeting CD109/STAT3 axis has potential to overcome therapy resistance in glioblastoma.

ABCC6, Pyrophosphate and Ectopic Calcification: Therapeutic Solutions

Pathological (ectopic) mineralization of soft tissues occurs during aging, in several common conditions such as diabetes, hypercholesterolemia, and renal failure and in certain genetic disorders. Pseudoxanthoma elasticum (PXE), a multi-organ disease affecting dermal, ocular, and cardiovascular tissues, is a model for ectopic mineralization disorders. ABCC6 dysfunction is the primary cause of PXE, but also some cases of generalized arterial calcification of infancy (GACI). ABCC6 deficiency in mice underlies an inducible dystrophic cardiac calcification phenotype (DCC). These calcification diseases are part of a spectrum of mineralization disorders that also includes Calcification of Joints and Arteries (CALJA). Since the identification of ABCC6 as the “PXE gene” and the development of several animal models (mice, rat, and zebrafish), there has been significant progress in our understanding of the molecular genetics, the clinical phenotypes, and pathogenesis of these diseases, which share similarities with more common conditions with abnormal calcification. ABCC6 facilitates the cellular efflux of ATP, which is rapidly converted into inorganic pyrophosphate (PPi) and adenosine by the ectonucleotidases NPP1 and CD73 (NT5E). PPi is a potent endogenous inhibitor of calcification, whereas adenosine indirectly contributes to calcification inhibition by suppressing the synthesis of tissue non-specific alkaline phosphatase (TNAP). At present, therapies only exist to alleviate symptoms for both PXE and GACI; however, extensive studies have resulted in several novel approaches to treating PXE and GACI. This review seeks to summarize the role of ABCC6 in ectopic calcification in PXE and other calcification disorders, and discuss therapeutic strategies targeting various proteins in the pathway (ABCC6, NPP1, and TNAP) and direct inhibition of calcification via supplementation by various compounds.

Predicting anthropometric and metabolic traits with a genetic risk score for obesity in a sample of Pakistanis

Obesity is an outcome of multiple factors including environmental and genetic influences. Common obesity is a polygenic trait indicating that multiple genetic variants act synergistically to influence its expression. We constructed a genetic risk score (GRS) based on five genetic variants (MC4R rs17782313, BDNF rs6265, FTO rs1421085, TMEM18 rs7561317, and NEGR1 rs2815752) and examined its association with obesity-related traits in a sample of Pakistanis. The study involved 306 overweight/obese (OW/OB) and 300 normal-weight (NW) individuals. The age range of the study participants was 12-63 years. All anthropometric and metabolic parameters were measured for each participant via standard procedures and biochemical assays, respectively. The genetic variants were genotyped by allelic discrimination assays. The age- and gender-adjusted associations between the GRS and obesity-related anthropometric and metabolic measures were determined using linear regression analyses. The results showed that OW/OB individuals had significantly higher mean ranks of GRS than NW individuals. Moreover, a significant association of the GRS with obesity-related anthropometric traits was seen. However, the GRS did not appear to affect any obesity-related metabolic parameter. In conclusion, our findings indicate the combined effect of multiple genetic variants on the obesity-related anthropometric phenotypes in Pakistanis.

Tetherin/BST2, a physiologically and therapeutically relevant regulator of platelet receptor signalling

The reactivity of platelets, which play a key role in the pathogenesis of atherothrombosis, is tightly regulated. The integral membrane protein tetherin/bone marrow stromal antigen-2 (BST-2) regulates membrane organization, altering both lipid and protein distribution within the plasma membrane. Because membrane microdomains have an established role in platelet receptor biology, we sought to characterize the physiological relevance of tetherin/BST-2 in those cells. To characterize the potential importance of tetherin/BST-2 to platelet function, we used tetherin/BST-2-/- murine platelets. In the mice, we found enhanced function and signaling downstream of a subset of membrane microdomain-expressing receptors, including the P2Y12, TP thromboxane, thrombin, and GPVI receptors. Preliminary studies in humans have revealed that treatment with interferon-α (IFN-α), which upregulates platelet tetherin/BST-2 expression, also reduces adenosine diphosphate-stimulated platelet receptor function and reactivity. A more comprehensive understanding of how tetherin/BST-2 negatively regulates receptor function was provided in cell line experiments, where we focused on the therapeutically relevant P2Y12 receptor (P2Y12R). Tetherin/BST-2 expression reduced both P2Y12R activation and trafficking, which was accompanied by reduced receptor lateral mobility specifically within membrane microdomains. In fluorescence lifetime imaging-Förster resonance energy transfer (FLIM-FRET)-based experiments, agonist stimulation reduced basal association between P2Y12R and tetherin/BST-2. Notably, the glycosylphosphatidylinositol (GPI) anchor of tetherin/BST-2 was required for both receptor interaction and observed functional effects. In summary, we established, for the first time, a fundamental role of the ubiquitously expressed protein tetherin/BST-2 in negatively regulating membrane microdomain-expressed platelet receptor function.

Recent Developments in New Therapeutic Agents against Alzheimer and Parkinson Diseases: In-Silico Approaches

Neurodegenerative diseases (ND), including Alzheimer's (AD) and Parkinson's Disease (PD), are becoming increasingly more common and are recognized as a social problem in modern societies. These disorders are characterized by a progressive neurodegeneration and are considered one of the main causes of disability and mortality worldwide. Currently, there is no existing cure for AD nor PD and the clinically used drugs aim only at symptomatic relief, and are not capable of stopping neurodegeneration. Over the last years, several drug candidates reached clinical trials phases, but they were suspended, mainly because of the unsatisfactory pharmacological benefits. Recently, the number of compounds developed using in silico approaches has been increasing at a promising rate, mainly evaluating the affinity for several macromolecular targets and applying filters to exclude compounds with potentially unfavorable pharmacokinetics. Thus, in this review, an overview of the current therapeutics in use for these two ND, the main targets in drug development, and the primary studies published in the last five years that used in silico approaches to design novel drug candidates for AD and PD treatment will be presented. In addition, future perspectives for the treatment of these ND will also be briefly discussed.

Neuritin inhibits astrogliosis to ameliorate diabetic cognitive dysfunction

Earlier, it was shown that reversing the downregulation of neuritin expression in the brain improves central neuropathy in diabetic rats. We investigated the protective mechanism of neuritin in diabetic cognitive dysfunction via astrocytes. Further, the impact of the overexpression of neuritin in the cortex and the hippocampus on diabetic cognitive dysfunction and astrogliosis in type 2 diabetic (db/db) mice was assessed. Antagonists were used to inhibit the JAK2/STAT3 signaling pathway in U-118MG, an astrocyte cell line. Immunofluorescence, Western blotting, and real-time PCR were performed. Neuritin overexpression in the hippocampus of db/db mice significantly ameliorated cognitive dysfunction, hippocampal neuronal impairment, and synaptic plasticity deterioration, and inhibited astrogliosis and the JAK2/STAT3 signaling pathway in the hippocampus. Neuritin suppressed the JAK2/STAT3 signaling pathway to inhibit lipopolysaccharide-induced gliosis in U-118MG cells. It was observed that neuritin regulates the JAK2/STAT3 signaling pathway in astrocytes to inhibit astrogliosis and improve diabetic cognitive dysfunction.

Modulatory effects of caffeic acid on purinergic and cholinergic systems and oxi-inflammatory parameters of streptozotocin-induced diabetic rats

Diabetes mellitus (DM) is a metabolic disorder characterized by a chronic hyperglycemia state, increased oxidative stress parameters, and inflammatory processes.

AIMS

To evaluate the effect of caffeic acid (CA) on ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase) and adenosine deaminase (ADA) enzymatic activity and expression of the A2A receptor of the purinergic system, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymatic activity and expression of the α7nAChR receptor of the cholinergic system as well as inflammatory and oxidative parameters in diabetic rats.

METHODS

Diabetes was induced by a single dose intraperitoneally of streptozotocin (STZ, 55 mg/kg). Animals were divided into six groups (n = 10): control/oil; control/CA 10 mg/kg; control/CA 50 mg/kg; diabetic/oil; diabetic/CA 10 mg/kg; and diabetic/CA 50 mg/kg treated for thirty days by gavage.

RESULTS

CA treatment reduced ATP and ADP hydrolysis (lymphocytes) and ATP levels (serum), and reversed the increase in ADA and AChE (lymphocytes), BuChE (serum), and myeloperoxidase (MPO, plasma) activities in diabetic rats. CA treatment did not attenuate the increase in IL-1β and IL-6 gene expression (lymphocytes) in the diabetic state; however, it increased IL-10 and A2A gene expression, regardless of the animals' condition (healthy or diabetic), and α7nAChR gene expression. Additionally, CA attenuated the increase in oxidative stress markers and reversed the decrease in antioxidant parameters of diabetic animals.

CONCLUSION

Overall, our findings indicated that CA treatment positively modulated purinergic and cholinergic enzyme activities and receptor expression, and improved oxi-inflammatory parameters, thus suggesting that this phenolic acid could improve redox homeostasis dysregulation and purinergic and cholinergic signaling in the diabetic state.

Association of plasma fatty acids pattern with omentin gene expression in human adipose tissues: A cross-sectional study

BACKGROUND AND AIMS

Omentin, as an adipokine, has been reported to improve insulin resistance and inflammation may be related to fatty acids (FAs). Plasma FAs can be used as biomarkers of dietary FAs and endogenous FA exposure. We aimed to evaluate the association between plasma FAs pattern and omentin gene expression in adipose tissue (AT).

METHODS AND RESULTS

Visceral and subcutaneous AT and fasting blood were gathered from 97 adults aged >18 years. Participants were already admitted to hospitals for elective abdominal surgery. Dietary intakes were assessed using a food frequency questionnaire. The relative omentin gene expression in visceral and subcutaneous AT was measured by Real-Time PCR and plasma FAs was determined by gas chromatography. The principal component analysis was performed to derive the FAs pattern from plasma individual FAs. Three patterns were derived from plasma FAs, 1) high de-novo lipogenesis (DNL), 2) high trans saturated fatty acids (SFA), and docosahexaenoic acid (trans-SFA/DHA), and 3) high long-chain SFA (LC-SFA). After adjustment for age, sex, and insulin concentration, only the LC-SFA pattern was associated with omentin gene expression in visceral AT (β = 2.25, P = 0.03). Other patterns were not associated with omentin gene expression in visceral and subcutaneous AT.

CONCLUSION

A pattern characterized by high levels of myristic acid (14:0), heptadecanoic acid (17:0), pentadecanoic acid (15:0), and Cis_heptadecanoic acid (17:1), which named LC-SFA was related to omentin gene expression in visceral AT.

Novel Associations of BST1 and LAMP3 With REM Sleep Behavior Disorder

OBJECTIVE

To examine the role of genes identified through genome-wide association studies (GWASs) of Parkinson disease (PD) in the risk of isolated REM sleep behavior disorder (iRBD).

METHODS

We fully sequenced 25 genes previously identified in GWASs of PD in a total of 1,039 patients with iRBD and 1,852 controls. The role of rare heterozygous variants in these genes was examined with burden tests. The contribution of biallelic variants was further tested. To examine the potential effect of rare nonsynonymous BST1 variants on the protein structure, we performed in silico structural analysis. Finally, we examined the association of common variants using logistic regression adjusted for age and sex.

RESULTS

We found an association between rare heterozygous nonsynonymous variants in BST1 and iRBD (p = 0.0003 at coverage >50× and 0.0004 at >30×), driven mainly by 3 nonsynonymous variants (p.V85M, p.I101V, and p.V272M) found in 22 (1.2%) controls vs 2 (0.2%) patients. All 3 variants seem to be loss-of-function variants with a potential effect on the protein structure and stability. Rare noncoding heterozygous variants in LAMP3 were also associated with iRBD (p = 0.0006 at >30×). We found no association between rare heterozygous variants in the rest of genes and iRBD. Several carriers of biallelic variants were identified, yet there was no overrepresentation in iRBD.

CONCLUSION

Our results suggest that rare coding variants in BST1 and rare noncoding variants in LAMP3 are associated with iRBD. Additional studies are required to replicate these results and to examine whether loss of function of BST1 could be a therapeutic target.

Generating tumor-selective conditionally active biologic anti-CTLA4 antibodies via protein-associated chemical switches

Anticytotoxic T lymphocyte-associated protein 4 (CTLA4) antibodies have shown potent antitumor activity, but systemic immune activation leads to severe immune-related adverse events, limiting clinical usage. We developed novel, conditionally active biologic (CAB) anti-CTLA4 antibodies that are active only in the acidic tumor microenvironment. In healthy tissue, this binding is reversibly inhibited by a novel mechanism using physiological chemicals as protein-associated chemical switches (PaCS). No enzymes or potentially immunogenic covalent modifications to the antibody are required for activation in the tumor. The novel anti-CTLA4 antibodies show similar efficacy in animal models compared to an analog of a marketed anti-CTLA4 biologic, but have markedly reduced toxicity in nonhuman primates (in combination with an anti-PD1 checkpoint inhibitor), indicating a widened therapeutic index (TI). The PaCS encompass mechanisms that are applicable to a wide array of antibody formats (e.g., ADC, bispecifics) and antigens. Examples shown here include antibodies to EpCAM, Her2, Nectin4, CD73, and CD3. Existing antibodies can be engineered readily to be made sensitive to PaCS, and the inhibitory activity can be optimized for each antigen's varying expression level and tissue distribution. PaCS can modulate diverse physiological molecular interactions and are applicable to various pathologic conditions, enabling differential CAB antibody activities in normal versus disease microenvironments.

High-dimensional analysis of the adenosine pathway in high-grade serous ovarian cancer

BACKGROUND

Hydrolysis of extracellular ATP to adenosine (eADO) is an important immune checkpoint in cancer immunology. We here investigated the impact of the eADO pathway in high-grade serous ovarian cancer (HGSC) using multiparametric platforms.

METHODS

We performed a transcriptomic meta-analysis of eADO-producing CD39 and CD73, an eADO signaling gene signature, immune gene signatures and clinical outcomes in approximately 1200 patients with HGSC. Protein expression, localization and prognostic impact of CD39, CD73 and CD8 were then performed on approximately 1000 cases on tissue microarray, and tumor-infiltrating lymphocytes (TILs) were analyzed by flow cytometry and single-cell RNA sequencing on a subset of patients.

RESULTS

Concomitant CD39 and CD73 gene expression, as well as high levels of an eADO gene signature, were associated with worse prognosis in patients with HGSC, notably in the immunoregulatory molecular subtype, characterized by an immune-active microenvironment. CD39 was further associated with primary chemorefractory and chemoresistant human HGSC and platinum-based chemotherapy of murine HGSC was significantly more effective in CD39-deficient mice. At protein level, CD39 and CD73 were predominantly expressed by cancer-associated fibroblasts, and CD39 was expressed on severely exhausted, clonally expanded and putative tissue-resident memory TILs.

CONCLUSIONS

Our study revealed the clinical, immunological, subtype-specific impacts of eADO signaling in HGSC, unveiled the chemoprotective effect of CD39 and supports the evaluation of eADO-targeting agents in patients with ovarian cancer.

Mesothelin blockage by Amatuximab suppresses cell invasiveness, enhances gemcitabine sensitivity and regulates cancer cell stemness in mesothelin-positive pancreatic cancer cells

BACKGROUND

Mesothelin is a 40-kDa glycoprotein that is highly overexpressed in various types of cancers, however molecular mechanism of mesothelin has not been well-known. Amatuximab is a chimeric monoclonal IgG1/k antibody targeting mesothelin. We recently demonstrated that the combine therapy of Amatuximab and gemcitabine was effective for peritonitis of pancreatic cancer in mouse model.

METHODS

We discover the role and potential mechanism of mesothelin blockage by Amatuximab in human pancreatic cells both expressing high or low level of mesothelin in vitro experiment and peritonitis mouse model of pancreatic cancer.

RESULTS

Mesothelin blockage by Amatuximab lead to suppression of invasiveness and migration capacity in AsPC-1 and Capan-2 (high mesothelin expression) and reduce levels of pMET expression. The combination of Amatuximab and gemcitabine suppressed proliferation of AsPC-1 and Capan-2 more strongly than gemcitabine alone. These phenomena were not observed in Panc-1 and MIA Paca-2 (Mesothelin low expression). We previously demonstrated that Amatuximab reduced the peritoneal mass in mouse AsPC-1 peritonitis model and induced sherbet-like cancer cell aggregates, which were vanished by gemcitabine. In this study, we showed that the cancer stem cell related molecule such as ALDH1, CD44, c-MET, as well as proliferation related molecules, were suppressed in sherbet-like aggregates, but once sherbet-like aggregates attached to peritoneum, they expressed these molecules strongly without the morphological changes.

CONCLUSIONS

Our work suggested that Amatuximab inhibits the adhesion of cancer cells to peritoneum and suppresses the stemness and viability of those, that lead to enhance the sensitivity for gemcitabine.

Impact of Reck expression and promoter activity in neuronal in vitro differentiation

Reck (REversion-inducing Cysteine-rich protein with Kazal motifs) tumor suppressor gene encodes a multifunctional glycoprotein which inhibits the activity of several matrix metalloproteinases (MMPs), and has the ability to modulate the Notch and canonical Wnt pathways. Reck-deficient neuro-progenitor cells undergo precocious differentiation; however, modulation of Reck expression during progression of the neuronal differentiation process is yet to be characterized. In the present study, we demonstrate that Reck expression levels are increased during in vitro neuronal differentiation of PC12 pheochromocytoma cells and P19 murine teratocarcinoma cells and characterize mouse Reck promoter activity during this process. Increased Reck promoter activity was found upon induction of differentiation in PC12 cells, in accordance with its increased mRNA expression levels in mouse in vitro models. Interestingly, Reck overexpression, prior to the beginning of the differentiation protocol, led to diminished efficiency of the neuronal differentiation process. Taken together, our findings suggest that increased Reck expression at early stages of differentiation diminishes the number of neuron-like cells, which are positive for the beta-3 tubulin marker. Our data highlight the importance of Reck expression evaluation to optimize in vitro neuronal differentiation protocols.

Omentin-1: Protective impact on ischemic stroke via ameliorating atherosclerosis

Omentin-1, a newly identified adipokine, has recently been revealed as a novel biomarker for ischemic stroke (IS). Low circulating omentin-1 levels could indicate a high risk of IS, and elevated omentin-1 levels exert a favorable impact on cerebral ischemia. Furthermore, omentin-1 has anti-atherosclerotic, anti-inflammatory, and cardiovascular protective capabilities through the intracellular Akt/AMP-activated protein kinase (AMPK)/ nuclear factor-κB (NF-κB) and certain protein kinase (ERK, JNK, and p38) signaling pathways. Omentin-1 also alleviates endothelial cell dysfunction, improves revascularization via the Akt-endothelial nitric-oxide synthase (eNOS) regulatory axis, promotes endothelium-dependent vasodilation through endothelium-derived NO in an eNOS fashion, and inhibits VSMC proliferation by means of AMPK/ERK signaling pathways, VSMC migration via inactivation of the NADPH oxidase (NOX)/ROS/p38/HSP27 pathways and artery calcification via the PI3K-Akt pathway. These findings indicate that omentin-1 may be a negative mediator of IS. Pharmacologically, several lines of clinical evidence indicate that metformin and statins could elevate omentin-1 levels, although the specific mechanism has not been precisely delineated until now. This study is the first to summarize the comprehensive mechanisms between omentin-1 and atherosclerosis and to review the shielding effect of omentin-1 on IS. We shed light on omentin-1 as a novel therapeutic target for combating IS.

Human CD34-negative hematopoietic stem cells: The current understanding of their biological nature

Hematopoietic stem cell (HSC) heterogeneity and hierarchy are a current topic of interest, having major implications for clinical HSC transplantation and basic research on human HSCs. It was long believed that the most primitive HSCs in mammals, including mice and humans, were CD34 antigen positive (CD34⁺). However, 2 decades ago, it was reported that murine long-term multilineage reconstituting HSCs were lineage marker negative (Lin^-, i.e., c-kit⁺Sca-1⁺CD34^low/-), known as CD34^low/- KSL cells. In contrast, human CD34^- HSCs, a counterpart of murine CD34^low/- KSL cells, were hard to identify for a long time mainly because of their rarity. We previously identified very primitive human cord blood (CB)-derived CD34^- severe combined immunodeficiency (SCID)-repopulating cells (SRCs) using the intra-bone marrow injection method and proposed the new concept that CD34^- SRCs (HSCs) reside at the apex of the human HSC hierarchy. Through a series of studies, we identified two positive/enrichment markers: CD133 and GPI-80. The combination of these two markers enabled the development of an ultrahigh-resolution purification method for CD34^- as well as CD34⁺ HSCs and the successful purification of both HSCs at the single-cell level. Cell population purity is a crucial prerequisite for reliable biological and molecular analyses. Clonal analyses of highly purified human CD34^- HSCs have revealed their potent megakaryocyte/erythrocyte differentiation potential. Based on these observations, we propose a revised road map for the commitment of human CB-derived CD34^- HSCs. This review updates the current understanding of the stem cell nature of human CB-derived primitive CD34^- as well as CD34⁺ HSCs.

Discovery of natural product ellagic acid as a potent CD73 and CD39 dual inhibitor

The ATP-adenosine pathway has been recently identified as an attractive immune-oncology target and several drug candidates have been entered clinic trials. Inspired by the report of the first small-molecule CD73inhibitor AB680, we describe the discovery of natural product ellagic acid as a dual CD73 and CD39 inhibitor with an IC₅₀ value of 1.85 ± 0.21 μM and 0.50 ± 0.22 μM, respectively. The result of cytotoxicity assays indicated that ellagic acid is a valuable lead compound with low cytotoxicity effect for immune therapy.

Pseudorabies Virus Infection Causes Downregulation of Ligands for the Activating NK Cell Receptor NKG2D

Herpesviruses display a complex and carefully balanced interaction with important players in the antiviral immune response of immunocompetent natural hosts, including natural killer (NK) cells. With regard to NK cells, this delicate balance is illustrated on the one hand by severe herpesvirus disease reported in individuals with NK cell deficiencies and on the other hand by several NK cell evasion strategies described for herpesviruses. In the current study, we report that porcine cells infected with the porcine alphaherpesvirus pseudorabies virus (PRV) display a rapid and progressive downregulation of ligands for the major activating NK cell receptor NKG2D. This downregulation consists both of a downregulation of NKG2D ligands that are already expressed on the cell surface of an infected cell and an inhibition of cell surface expression of newly expressed NKG2D ligands. Flow cytometry and RT-qPCR assays showed that PRV infection results in downregulation of the porcine NKG2D ligand pULBP1 from the cell surface and a very substantial suppression of mRNA expression of pULBP1 and of another potential NKG2D ligand, pMIC2. Furthermore, PRV-induced NKG2D ligand downregulation was found to be independent of late viral gene expression. In conclusion, we report that PRV infection of host cells results in a very pronounced downregulation of ligands for the activating NK cell receptor NKG2D, representing an additional NK evasion strategy of PRV.