Identification of a novel immune prognostic model in gastric cancer.

PURPOSE: The tumor immune microenvironment (TIME) is now considered as an important factor during gastric cancer (GC) development. This study identified a novel immune-related risk model for predicting prognosis and assessing the immune status of GC patients. METHODS: Transcriptomic data were obtained from the TCGA database. The differential expressed immune-related genes (IRGs) were identified through the ImmPort portal. Enrichment analysis was performed to explore the potential molecular mechanism of these IRGs. By the Cox regression analysis, we constructed the immune prognostic model. Then, the association between the model and the immune microenvironment was estimated. The model was validated in the GSE84433 dataset. RESULTS: Totally, we identified 222 differentially expressed IRGs. These IRGs were closely correlated with immune response and immune signaling pathways. Through the Cox regression analysis, we developed the immune prognostic model based on the expression of seven IRGs (CXCL3, NOX4, PROC, FAM19A4, RNASE2, IGHD2-15, CGB5). Patients were stratified into two groups according to immune-related risk scores. Survival analysis indicated that the prognosis of high-risk patients was poorer than low-risk patients. Moreover, the immune-related risk score was an independent prognostic biomarker. More importantly, we found that the infiltration level of immunosuppressive cells and the expression of inhibitory immune checkpoints were higher in high-risk patients. The immune microenvironment tended to be a suppressive status in patients with high-risk scores. CONCLUSION: This study demonstrated that our model had predictive value for prognosis and the TIME in GC. It might be a robust tool to improve personalized patient management.

Galectins, Eosinophiles, and Macrophages May Contribute to Schistosoma japonicum Egg-Induced Immunopathology in a Mouse Model.

Schistosomiasis is a severe public health problem, which can cause tissue fibrosis and can even be fatal. Previous studies have proven that galectins and different kinds of cells involve in the regulation of tissue fibrosis process. In this study, outbred Kunming mice were infected with Schistosoma japonicum (S. japonicum). Our results showed that compared with uninfected mice, there were severe egg granulomatous inflammation and tissue fibrosis in the livers, spleens, and large intestines of S. japonicum-infected mice at 8 weeks post-infection (p.i.), and the number of eosinophils by hematoxylin and eosin staining and CD68 macrophage-positive area by immunohistochemical staining were significantly increased. Detected by using quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR), at 8 weeks after S. japonicum infection, the mRNA expression levels of galectin (Gal)-1, Gal-3, CD69, eosinophil protein X (EPX), and chitinase 3-like protein 3 (Ym1) were significantly increased in liver, spleen, and large intestine; eotaxin-1 (CCL11) and eosinophil cationic protein were significantly increased in both liver and spleen; eotaxin-2 (CCL24) and Arginase1 (Arg1) were significantly increased in both spleen and large intestine; and CD200R was significantly increased in both liver and large intestine. However, interleukin (IL)-1ß and inducible nitric oxide synthase (iNOS) were only significantly increased in liver. The M2/M1 ratio of CD200R/CD86 genes was significantly increased in liver, and ratios of Ym1/IL-1ß and Ym1/iNOS were significantly increased in liver, spleen, and large intestine of S. japonicum-infected mice. Ex vivo study further confirmed that the levels of Gal-1, Gal-3, CD200R, Arg1, and Ym1 were significantly increased, and the ratios of CD200R/CD86 and Ym1/IL-1ß were significantly increased in peritoneal macrophages isolated from S. japonicum-infected mice at 8 weeks p.i. In addition, correlation analysis showed that significant positive correlations existed between mRNA levels of Gal-1/Gal-3 and EPX in liver, between Gal-3 and Ym1 in both liver and large intestine, and between Gal-3 and CD200R in peritoneal macrophages of S. japonicum-infected mice. Our data suggested that Gal-1, Gal-3, eosinophils, and macrophages are likely involved in the development of egg granulomatous response and fibrosis induced by S. japonicum infection.

Relationship between SNPs and expression level for candidate genes in rheumatoid arthritis.

OBJECTIVES: The study of polymorphisms of genes differentially expressed may lead to the identification of putative causal genetic variants in multifactorial diseases such as rheumatoid arthritis (RA). Based on preceding transcriptomic results, we genotyped 10 single nucleotide polymorphisms (SNPs) belonging to six genes (S100A8, RNASE2, PGLYRP1, RUNX3, IL2RB, and LY96) showing the highest fold change (> 1.9) when level of expression was compared between RA patients and controls. These SNPs were then analysed to evaluate their role in RA. METHOD: The relationship between gene expression and genotypes of SNPs was first investigated by Kruskal-Wallis and Mann-Whitney tests in RA patients and controls. The genetic association of these SNPs with RA were then analysed using family-based association tests in trio families. RESULTS: We found that RNASE2 gene expression was related to rs2013109 genotypes in 14 RA patients (p = 0.030). The association study in a discovery sample of 200 French trio families revealed a significant association with RA for one SNP, PGLYRP1-rs2041992 (p = 0.019); this association was stronger in trios where RA patients carried the HLA-DRB1 shared epitope (SE) (p = 0.003). However, this association was not found in a replication sample of 240 European trio families (p = 0.6). CONCLUSIONS: Family-based association tests did not reveal an association between RA and any SNP of the candidate genes tested. However, RNASE2 gene expression was differentially expressed in RA patients considering a sequence polymorphism. This result led us to highlight the potential disease-specific regulation for this candidate gene in RA.

Eosinophil associated genes in the inflammatory bowel disease 4 region: correlation to inflammatory bowel disease revealed.

AIM: To study the association between inflammatory bowel disease (IBD) and genetic variations in eosinophil protein X (EPX) and eosinophil cationic protein (ECP). METHODS: DNA was extracted from ethylene diamine tetraacetic acid blood of 587 patients with Crohn's disease (CD), 592 with ulcerative colitis (UC) and 300 healthy subjects. The EPX405 (G > C, rs2013109), ECP434 (G > C, rs2073342) and ECP562 (G > C, rs2233860) gene polymorphisms were analysed, by the 5'-nuclease allelic discrimination assay. For determination of intracellular content of EPX and ECP in granulocytes, 39 blood samples was collected and extracted with a buffer containing cetyltrimethylammonium bromide. The intracellular content of EPX was analysed using an enzyme-linked immunosorbent assay. The intracellular content of ECP was analysed with the UniCAP(®) system as described by the manufacturer. Statistical tests for calculations of results were χ(2) test, Fisher's exact test, ANOVA, Student-Newman-Keuls test, and Kaplan-Meier survival curve with Log-rank test for trend, the probability values of P < 0.05 were considered statistically significant. RESULTS: The genotype frequency for males with UC and with an age of disease onset of ≥ 45 years (n = 57) was for ECP434 and ECP562, GG = 37%, GC = 60%, CC = 4% and GG = 51%, GC = 49%, CC = 0% respectively. This was significantly different from the healthy subject's genotype frequencies of ECP434 (GG = 57%, GC = 38%, CC = 5%; P = 0.010) and ECP562 (GG = 68%, GC = 29%,CC = 3%; P = 0.009). The genotype frequencies for females, with an age of disease onset of ≥ 45 years with CD (n = 62), was for the ECP434 and ECP562 genotypes GG = 37%, GC = 52%, CC = 11% and GG = 48%, GC = 47% and CC = 5% respectively. This was also statistically different from healthy controls for both ECP434 (P = 0.010) and ECP562 (P = 0.013). The intracellular protein concentration of EPX and ECP was calculated in µg/10(6) eosinophils and then correlated to the EPX 405 genotypes. The protein content of EPX was highest in the patients with the CC genotype of EPX405 (GG = 4.65, GC = 5.93, and CC = 6.57) and for ECP in the patients with the GG genotype of EPX405 (GG = 2.70, GC = 2.47 and CC = 1.90). ANOVA test demonstrated a difference in intracellular protein content for EPX (P = 0.009) and ECP (P = 0.022). The age of disease onset was linked to haplotypes of the EPX405, ECP434 and ECP562 genotypes. Kaplan Maier curve showed a difference between haplotype distributions for the females with CD (P = 0.003). The highest age of disease onset was seen in females with the EPX405CC, ECP434GC, ECP562CC haplotype (34 years) and the lowest in females with the EPX405GC, ECP434GC, ECP562GG haplotype (21 years). For males with UC there was also a difference between the highest and lowest age of the disease onset (EPX405CC, ECP434CC, ECP562CC, mean 24 years vs EPX405GC, ECP434GC, ECP562GG, mean 34 years, P = 0.0009). The relative risk for UC patients with ECP434 or ECP562-GC/CC genotypes to develop dysplasia/cancer was 2.5 (95%CI: 1.2-5.4, P = 0.01) and 2.5 (95%CI: 1.1-5.4, P = 0.02) respectively, compared to patients carrying the GG-genotypes. CONCLUSION: Polymorphisms of EPX and ECP are associated to IBD in an age and gender dependent manner, suggesting an essential role of eosinophils in the pathophysiology of IBD.

An insertion in loop L7 of human eosinophil-derived neurotoxin is crucial for its antiviral activity.

The human eosinophil granule ribonuclease, eosinophil-derived neurotoxin (EDN) has been shown to have antiviral activity against respiratory syncytial virus-B (RSV-B). Other closely related and more active RNases such as RNase A, onconase, and RNase k6 do not have any antiviral activity. A remarkable unique feature of EDN is a nine-residue insertion in its carboxy-terminal loop, L7 which is not present in RNase A, and differs in sequence from the corresponding loop in another eosinophil RNase, eosinophil cationic protein (ECP). ECP has a much lower antiviral activity as compared to EDN. The current study probed the role of loop L7 of EDN in its antiviral activity. Three residues in loop L7, Arg117, Pro120, and Gln122, which diverge between EDN, ECP, and RNase A, were mutated to alanine alone and in combination to generate single, double, and triple mutants. These mutants, despite having RNase activity had decreased antiviral activity towards RSV suggesting the involvement of loop L7 in the interaction of EDN with RSV. It appears that the mutations in loop L7 disrupt the interaction of protein with the viral capsid, thereby inhibiting its entry into the virions. The study demonstrates that besides the RNase activity, loop L7 is another important determinant for the antiviral activity of EDN.

A promising alternative anti-HBV agent: the targeted ribonuclease.

HBV-targeted ribonuclease (TR) is a fusion of HBV core protein (HBVc) and human eosinophil-derived neurotoxin (hEDN). Introduction of TR by transfection or transduction into HepG2.2.15 cells (a cell model of HBV infection) revealed that it significantly reduces serological markers of HBV replication (including HBsAg, HBeAg and HBV DNA) in cell supernatants, suggesting that the targeted ribonuclease inhibits HBV replication. To further our understanding of the molecular mechanism of the anti-HBV effect of TR, we expressed TR in E. coli and found that purified TR possesses RNase activity and targeting activity. Furthermore, the antiviral effect of TR depends both on an enzymatically active hEDN and on the core domain. In or out of HepG2.2.15 cells, TR coassembles with the wild-type capsid protein into particles with internal hEDN domains. Our data suggest an intracellular ribonuclease activation mechanism that, owing to the characteristics of HBV morphogenesis, is highly virus specific. HBV may therefore be particularly vulnerable to the capsid-targeted viral inactivation approach.

GATA transcription factors regulate the expression of the human eosinophil-derived neurotoxin (RNase 2) gene.

The transcription factors GATA-1 and GATA-2 have been implicated in promoting differentiation of eosinophilic leukocytes. In this study, we examined the roles of GATA-1 and GATA-2 in activating transcription of the secretory ribonuclease, the eosinophil-derived neurotoxin (EDN/RNase 2). Augmented expression of both GATA-1 and GATA-2 was detected in eosinophil promyelocyte HL-60 clone 15 cells in response to biochemical differentiation with butyric acid. Deletion or mutation of one or both of the two consensus GATA-binding sites in the extended 1000-bp 5' promoter of the EDN gene resulted in profound reduction in reporter gene activity. Antibody-augmented electrophoretic mobility shift and chromatin immunoprecipitation analyses indicate that GATA-1 and GATA-2 proteins bind to both functional GATA consensus sequences in the EDN promoter. Interestingly, RNA silencing of GATA-1 alone had no impact on EDN expression; silencing of GATA-2 resulted in diminished expression of EDN, and also diminished expression of GATA-1 in both butyric acid-induced HL-60 clone 15 cells and in differentiating human eosinophils derived from CD34(+) hematopoietic progenitors. Likewise, overexpression of GATA-2 in uninduced HL-60 clone 15 cells resulted in augmented transcription of both EDN and GATA-1. Taken together, our data suggest that GATA-2 functions directly via interactions with the EDN promoter and also indirectly, via its ability to regulate the expression of GATA-1 in differentiating eosinophils and eosinophil cell lines.

Transcriptional regulation of human eosinophil RNase2 by the liver-enriched hepatocyte nuclear factor 4.

Human eosinophil-derived neurotoxin (EDN, RNase2) and eosinophil cationic protein (ECP, RNase3) sequences possess as high as 92% identity in their promoter regions. The major difference within this region is a 34-nucleotide (34-nt) segment appeared only in the edn promoter. In addition, six discrete segments existed in the regulatory regions of both edn and ecp. Our previous study indicated that the 34-nt segment is responsive for higher transcription activity of edn in comparison with ecp, via binding to transcription activator Sp1. In this study, the roles of the six discrete segments in transcription regulation were investigated and the -350/-329 region (ednR2) was shown to be involved in the regulation of edn expression. When the ednR2 segment of edn was replaced with that of ecp, a significant decrease in edn promoter activity was detected. Supershift, chromatin immunoprecipitation, and DNA affinity precipitation assays further showed that a transcription factor HNF4 bound to the ednR2 region of edn promoter in vitro. Interestingly, HNF4 overexpression resulted in the reduction of edn promoter activity in HepG2 cells, due to involvement of both ednR2 and the 34-nt regions, and direct interaction between HNF4 and Sp1, which abolishes Sp1 binging to the 34-nt segment. Moreover, when the Sp1 was depleted in the cell, overexpressed HNF4 enhanced edn promoter activity. Our results provide novel mechanisms for HNF4 function as an activator to regulate edn promoter activity, which account for differential transcription regulation of human eosinophil RNases.

Adenoviral-vector mediated transfer of HBV-targeted ribonuclease can inhibit HBV replication in vivo.

Hepatitis B virus (HBV)-targeted ribonuclease (HBV-TR) is a fused protein of HBV core protein and a ribonuclease, human eosinophil-derived neurotoxin (hEDN). Our previous results showed that HBV-TR could effectively inhibit HBV replication in vitro. To test whether HBV-TR can inhibit HBV replication in vivo, we constructed a recombinant adenoviral vector expressing HBV-TR (Ad-TR) and used it to treat HBV-transgenic mice. Immunohistochemical staining showed that TR was expressed at varied levels in different tissues of Ad-TR-treated mice. Serum HBsAg concentration was decreased by 64.8% for the Ad-TR-treated mice compared with empty adenoviral vector-treated control mice. The amount of HBV-DNA in the livers of the Ad-TR-treated mice was 0.74 x 10(7) copies/mug of genomic DNA while the amount of HBV-DNA in the livers of the empty adenoviral vector-treated control mice was 2.86 x 10(7) copies/mug of genomic DNA. Serum HBV-DNA of Ad-TR-treated mice was also decreased by 71.4% compared with empty adenoviral vector-treated control mice. In addition, for some Ad-TR-treated mice, the expression of HBsAg in the liver cells turned negative. No discernible adverse effects were observed for Ad-TR-treated mice. Taken together, our results indicated that adenovirus mediated transfer of HBV-TR can inhibit HBV replication in vivo.

Transcriptional regulation of human eosinophil RNases by an evolutionary- conserved sequence motif in primate genome.

BACKGROUND: Human eosinophil-derived neurotoxin (edn) and eosinophil cationic protein (ecp) are members of a subfamily of primate ribonuclease (rnase) genes. Although they are generated by gene duplication event, distinct edn and ecp expression profile in various tissues have been reported. RESULTS: In this study, we obtained the upstream promoter sequences of several representative primate eosinophil rnases. Bioinformatic analysis revealed the presence of a shared 34-nucleotide (nt) sequence stretch located at -81 to -48 in all edn promoters and macaque ecp promoter. Such a unique sequence motif constituted a region essential for transactivation of human edn in hepatocellular carcinoma cells. Gel electrophoretic mobility shift assay, transient transfection and scanning mutagenesis experiments allowed us to identify binding sites for two transcription factors, Myc-associated zinc finger protein (MAZ) and SV-40 protein-1 (Sp1), within the 34-nt segment. Subsequent in vitro and in vivo binding assays demonstrated a direct molecular interaction between this 34-nt region and MAZ and Sp1. Interestingly, overexpression of MAZ and Sp1 respectively repressed and enhanced edn promoter activity. The regulatory transactivation motif was mapped to the evolutionarily conserved -74/-65 region of the edn promoter, which was guanidine-rich and critical for recognition by both transcription factors. CONCLUSION: Our results provide the first direct evidence that MAZ and Sp1 play important roles on the transcriptional activation of the human edn promoter through specific binding to a 34-nt segment present in representative primate eosinophil rnase promoters.

CCR4-expressing T cell tumors can be specifically controlled via delivery of toxins to chemokine receptors.

Expression of chemokine receptors by tumors, specifically CCR4 on cutaneous T cell lymphomas, is often associated with a poor disease outcome. To test the hypothesis that chemokine receptor-expressing tumors can be successfully controlled by delivering toxins through their chemokine receptors, we have generated fusion proteins designated chemotoxins: chemokines fused with toxic moieties that are nontoxic unless delivered into the cell cytosol. We demonstrate that chemokines fused with human RNase eosinophil-derived neurotoxin or with a truncated fragment of Pseudomonas exotoxin 38 are able to specifically kill tumors in vitro upon internalization through their respective chemokine receptors. Moreover, treatment with the thymus and activation-regulated chemokine (CCL17)-expressing chemotoxin efficiently eradicated CCR4-expressing cutaneous T cell lymphoma/leukemia established in NOD-SCID mice. Taken together, this work represents a novel concept that may allow control of growth and dissemination of tumors that use chemokine receptors to metastasize and circumvent immunosurveillance.

EGO, a novel, noncoding RNA gene, regulates eosinophil granule protein transcript expression.

Gene expression profiling of early eosinophil development shows increased transcript levels of proinflammatory cytokines, chemokines, transcription factors, and a novel gene, EGO (eosinophil granule ontogeny). EGO is nested within an intron of the inositol triphosphate receptor type 1 (ITPR1) gene and is conserved at the nucleotide level; however, the largest open reading frame (ORF) is 86 amino acids. Sucrose density gradients show that EGO is not associated with ribosomes and therefore is a noncoding RNA (ncRNA). EGO transcript levels rapidly increase following interleukin-5 (IL-5) stimulation of CD34(+) hematopoietic progenitors. EGO RNA also is highly expressed in human bone marrow and in mature eosinophils. RNA silencing of EGO results in decreased major basic protein (MBP) and eosinophil derived neurotoxin (EDN) mRNA expression in developing CD34(+) hematopoietic progenitors in vitro and in a CD34(+) cell line model. Therefore, EGO is a novel ncRNA gene expressed during eosinophil development and is necessary for normal MBP and EDN transcript expression.

Human ribonuclease A superfamily members, eosinophil-derived neurotoxin and pancreatic ribonuclease, induce dendritic cell maturation and activation.

A number of mammalian antimicrobial proteins produced by neutrophils and cells of epithelial origin have chemotactic and activating effects on host cells, including cells of the immune system. Eosinophil granules contain an antimicrobial protein known as eosinophil-derived neurotoxin (EDN), which belongs to the RNase A superfamily. EDN has antiviral and chemotactic activities in vitro. In this study, we show that EDN, and to a lesser extent human pancreatic RNase (hPR), another RNase A superfamily member, activates human dendritic cells (DCs), leading to the production of a variety of inflammatory cytokines, chemokines, growth factors, and soluble receptors. Human angiogenin, a RNase evolutionarily more distant to EDN and hPR, did not display such activating effects. Additionally, EDN and hPR also induced phenotypic and functional maturation DCs. These RNases were as efficacious as TNF-alpha, but induced a different set of cytokine mediators. Furthermore, EDN production by human macrophages could be induced by proinflammatory stimuli. The results reveal the DC-activating activity of EDN and hPR and suggest that they are likely participants of inflammatory and immune responses. A number of endogenous mediators in addition to EDN have been reported to have both chemotactic and activating effects on APCs, and can thus amplify innate and Ag-specific immune responses to danger signals. We therefore propose these mediators be considered as endogenous multifunctional immune alarmins.

[Construction and expression of prokaryotic expression vector for pTAT-HBV targeted ribonuclease fusion protein].

AIM: To construct Tat-HBV targeted ribonuclease fusion protein prokaryotic expression vector and express it in E.coli. METHODS: The cDNAs encoding HBV targeted ribonuclease, human eosinophil-derived neurotoxin and HBV core protein were respectively cloned into prokaryotic expression vector pTAT-HA. Recombinant plasmids were transformed into E.coli BL21(DE3) LysS, then the transformed cells were induced with IPTG. The expression of the fusion proteins were analyzed by SDS-PAGE and Western blot. RESULTS: The three recombinant plasmids were constructed and expressed after IPTG induction successfully. CONCLUSION: The obtained Tat-HBV targeted ribonuclease fusion protein has laid the foundation for using TR in therapy of HBV infection.