N-glycan structures of Wisteria floribunda agglutinin-positive Mac2 binding protein in the serum of patients with liver fibrosis†.

The extent of liver fibrosis predicts prognosis and is important for determining treatment strategies for chronic hepatitis. During the fibrosis progression, serum levels of Mac2 binding protein (M2BP) increase and the N-glycan structure changes to enable binding to Wisteria floribunda agglutinin (WFA) lectin. As a novel diagnostic marker, glycosylation isomer of M2BP (M2BPGi) has been developed. However, its glycan structures recognized by WFA are unclear. In this study, we analyzed site-specific N-glycan structures of serum M2BP using Glyco-RIDGE (Glycan heterogeneity-based Relational IDentification of Glycopeptide signals on Elution profile) method. We evaluated five sample types: (1) M2BP immunoprecipitated from normal healthy sera (NHS-IP(+)), (2) M2BP immunoprecipitated from sera of patients with liver cirrhosis (stage 4; F4-IP(+)), (3) M2BP captured with WFA from serum of patients with liver cirrhosis (stage 4; F4-WFA(+)), (4) recombinant M2BP produced by HEK293 cells (rM2BP) and (5) WFA-captured rM2BP (rM2BP-WFA(+)). In NHS-IP(+) M2BP, bi-antennary N-glycan was the main structure, and LacNAc extended to its branches. In F4-IP(+) M2BP, many branched structures, including tri-antennary and tetra-antennary N-glycans, were found. F4-WFA(+) showed a remarkable increase in branched structures relative to the quantity before enrichment. In recombinant M2BP, both no sialylated-LacdiNAc and -branched LacNAc structures were emerged. The LacdiNAc structure was not found in serum M2BP. Glycosidase-assisted HISCL assays suggest that reactivity with WFA of both serum and recombinant M2BP depends on unsialylated and branched LacNAc and in part of recombinant depends on LacdiNAc. On M2BPGi, the highly branched LacNAc, probably dense cluster of LacNAc, would be recognized by WFA.

Multi-serum glycobiomarkers improves the diagnosis and prognostic prediction of cholangiocarcinoma.

BACKGROUND: Aberrant glycosylation has been reported to play important roles in progression of cholangiocarcinoma (CCA) and hence the aberrant expressed glycans are beneficial markers for diagnosis and prognostic prediction of CCA. METHODS: Five CCA-associated glycobiomarkers-carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen-S27 (CA-S27), CCA-associated carbohydrate antigen (CCA-CA), WFA-positive MUC1 (WFA+-MUC1), and WFA-positive M2BP (WFA+-M2BP), in the sera from CCA patients (N = 138) were determined in comparison with non-CCA control subjects (N = 246). RESULTS: Receiver operating characteristic analysis suggested the significance of each glycobiomarker in discriminating CCA from non-CCA with area under curve of 0.580-0.777. High levels of CA19-9, CCA-CA, CA-S27, or WFA+-MUC1 were associated with poor prognosis and poor survival of CCA patients. Combination of these glycobiomarkers and graded as a GlycoBiomarker (GB)-score could increase the power of the tests in diagnosis than an individual marker with 81% of sensitivity, specificity and accuracy. CONCLUSIONS: According to the GB-score, these glycobiomarkers not only increased diagnostic power but also discriminated survival of patients indicating the diagnostic and prognostic values of GB-score.

Correction: Serum Wisteria floribunda agglutinin-positive Mac-2-binding protein levels predict the presence of fibrotic nonalcoholic steatohepatitis (NASH) and NASH cirrhosis.

[This corrects the article DOI: 10.1371/journal.pone.0202226.].

Serum Wisteria floribunda agglutinin-positive Mac-2-binding protein levels predict the presence of fibrotic nonalcoholic steatohepatitis (NASH) and NASH cirrhosis.

OBJECTIVE: The race for finding effective treatments for nonalcoholic fatty liver disease (NAFLD) has been slowed down by the high screen-failure rate for including patients in trials due to the lack of a noninvasive biomarker that can identify patients with significant disease. Recently, Wisteria floribunda agglutinin-positive Mac-2-binding protein (WFA+ -M2BP) has shown promise in predicting liver fibrosis. The aims of this study were to evaluate the utility of WFA+ -M2BP as a biomarker to sub-classify patients with NAFLD according to their disease severity and to assess its correlation with histologic features of NAFLD. METHODS: Patients undergoing biopsy for clinical suspicion of NAFLD and healthy controls were included. Patients with NAFLD were classified into: NAFL, early NASH (F0-F1), fibrotic NASH (F2-F3), and NASH cirrhosis (F4). Levels of WFA+ -M2BP in sera was measured by a HISCL™ M2BPGi™ assay kit using an automated immunoanalyzer (HISCL™-800; Sysmex, Kobe, Japan). Analysis of covariance was used to assess difference in WFA+ -M2BP between the groups and Spearman's correlation coefficients were used to assess correlation with histological features. RESULTS: Our cohort consisted of 20 healthy controls and 198 patients with biopsy-proven NAFLD divided as follows: 52 with NAFL, 62 with early NASH, 52 with fibrotic NASH, and 32 with NASH cirrhosis. WFA+ -M2BP level was found to be significantly increased in the fibrotic NASH and NASH cirrhosis groups compared to healthy controls and those with early NAFLD after adjusting for age, gender and BMI. Furthermore, patients with NASH cirrhosis had significantly higher WFA+ -M2BP levels (2.4[1.5, 4.2] C.O.I (Cut-off Index)) than those with fibrotic NASH (1.2[0.79, 1.9]), p < 0.001. WFA+ -M2BP level had moderate correlation with inflammation, ballooning and NAFLD activity score and strong correlation with fibrosis stage. Additionally, ROC curve analysis demonstrated that WFA+ -M2BP accurately differentiated F2-4 from F0-F1. CONCLUSION: In a large cohort of patients with the full spectrum of NAFLD, WFA+ -M2BP levels predicted the presence of advanced disease and correlated strongly with fibrosis stage.

Reconstruction of a robust glycodiagnostic agent supported by multiple lectin-assisted glycan profiling.

PURPOSE: Wisteria floribunda agglutinin positive human Mac-2-binding protein (WFA(+)-hM2BP) was recently validated as a liver fibrosis glycobiomarker with a fully automated lectin-antibody sandwich immunoassay. In this study, we supplied recombinant WFA(+)-hM2BP as the standard glycoprotein and the overlaid antibody to enhance the robustness of WFA(+)-hM2BP quantification. EXPERIMENTAL DESIGN: The optimum conditions for producing recombinant WFA(+)-hM2BP were selected by cell glycome analysis based on a lectin microarray. Interlot variability of recombinant WFA(+)-hM2BP was determined using an antibody-overlay lectin microarray. Screening of anti-M2BP mAb was completed by incorporating a WFA-antibody sandwich ELISA and an antibody-overlay lectin microarray. RESULTS: The lectin microarray analysis revealed that human embryonic kidney 293 cells efficiently and stably produced WFA(+)-hM2BP in DMEM containing 10% FCS without any variation in the M2BP glycosylation level. A spiking experiment with recombinant WFA(+)-hM2BP was mostly effective for antibody screening. The reconstituted sandwich immunoassay was useful for the continuous quantification and cutoff index expression of serum WFA(+)-hM2BP. CONCLUSIONS AND CLINICAL RELEVANCE: The multiple use of lectin-assisted glycan profiling enabled us to construct a reliable sandwich assay kit for monitoring liver fibrosis in patients with viral hepatitis. This will assist in the development pipeline for other glycodiagnostic agents.

Comparison of LecT-Hepa and FibroScan for assessment of liver fibrosis in hepatitis B virus infected patients with different ALT levels.

BACKGROUND: FibroScan is one of the noninvasive techniques based on the transient elastography that can assess the progression of liver fibrosis in chronic hepatitis patients in daily clinical practice. Recently, LecT-Hepa was validated as a serological glycomarker correlating well with the fibrosis stage determined by liver biopsy, and was superior to many other noninvasive biochemical markers and tests. We compared the reliability of LecT-Hepa with that of FibroScan for evaluation of liver fibrosis. METHODS: The effects of increased alanine aminotransferase (ALT) activities on LecT-Hepa and FibroScan were investigated. RESULTS: The areas under the receiver-operating characteristic curves, sensitivity and specificity for detecting cirrhosis, which is one of the outcomes of fibrosis estimation, were 0.82, 72.5% and 78.2% of LecT-Hepa, 0.85, 87.0% and 74.1% of FibroScan; these did not differ significantly. The count distribution of LecT-Hepa in non-cirrhosis group or cirrhosis group did not differ between the patients grouped according to their ALT levels, whereas that of FibroScan was substantially affected. CONCLUSION: LecT-Hepa was confirmed as a reliable noninvasive test for the evaluation of liver fibrosis in hepatitis B virus-infected patients with comparable performance to that of FibroScan and proved to be unaffected by inflammation.

LecT-Hepa: A triplex lectin-antibody sandwich immunoassay for estimating the progression dynamics of liver fibrosis assisted by a bedside clinical chemistry analyzer and an automated pretreatment machine.

BACKGROUND: A quantitative analysis of glyco-alteration in serum glycoproteins provides glyco-parameters for estimating the progression of liver fibrosis. In the analysis of glycans, a manual pretreatment process for clinical specimens leads to a complicated manipulation and loss-of-clinical implementation of the assay. METHOD: We evaluated an automated triplex lectin-antibody sandwich immunoassay assisted by an automated protein purification system (ED-01) and a bedside clinical chemistry analyzer (HISCL) for the acquisition of two glyco-parameters (AOL/DSA and MAL/DSA) derived from a fibrosis-related glyco-alteration of serum alpha1-acid glycoprotein (AGP). RESULTS: We adjusted the auto-machines with their accuracy set to CV <5.0% (ED-01) and <1.0% (HISCL). AGP samples were enriched from 275 serum specimens. Two glyco-parameters obtained by HISCL showed a linear correlation with that from a reported assay (R>0.90). The formula for monitoring fibrosis (LecT-Hepa) was given by a combination of the glyco-parameters. This correlated with the fibrosis stage from biopsy (R=0.68) and diagnosed severe fibrosis and cirrhosis. It was superior to that of FIB-4 index. CONCLUSIONS: We automated a multilectin-assisted immunoassay with an order of magnitude reduction of operation time without any loss-of-accuracy. LecT-Hepa is a reliable method to assess fibrosis-dynamics from moderate fibrosis to cirrhosis.

HMGA1a is involved in specific splice site regulation of human immunodeficiency virus type 1.

Human immunodeficiency virus type 1 (HIV-1) utilizes a highly complex splice site regulation system, taking advantage of host proteins, to express its own viral protein in an orderly way. We show here that one of the host proteins, high mobility group A protein 1a (HMGA1a), is involved in splice site regulation of 3' splice site 2 (A2) and 5'splice site 3 (D3) of HIV-1 genomic RNA. shRNA knockdown of HMGA1 in HeLa cells resulting in a decrease of HMGA1 showed a significant decrease of Vpr mRNA. RNA electrophoretic mobility shift assays showed HMGA1a specifically binds to a sequence adjacently upstream D3. In vitro splicing using heterologous pre-mRNA with A2 and D3, showed HMGA1a induced a splicing intermediate which decreased when an RNA decoy of the HMGA1a binding site was added. RT-PCR of in vitro splicing products revealed that HMGA1a induced an incomplete splicing product resulting from usage of A2 but inhibition of D3, which is reminiscent of the splicing pattern necessary for Vpr mRNA formation. HMGA1a interacted with hnRNPA1 shown by coimmunoprecipitation and supershifted U1 snRNP in an RNA electrophoretic mobility shift assay. We conclude that HMGA1a anchors U1 snRNP to inhibit D3 function, and that HMGA1a inhibits hnRNPA1 function on exon splicing silencer of Vpr (ESSV) to activate A2 function. We show here for the first time that HMGA1a is involved in specific splice site regulation of HIV-1.

A recombinant vesicular stomatitis virus encoding HIV-1 receptors and human OX40 ligand efficiently eliminates HIV-1-infected CD4-positive T cells expressing OX40.

OX40 protein is highly expressed on activated CD4-positive T cells that are susceptible for human immunodeficiency virus type 1 (HIV-1) infection. To target and kill HIV-1-infected OX40(+) T cells, we used a recombinant vesicular stomatitis virus (rVSV) lacking its envelope glycoprotein (ΔG) and instead expressing HIV-1 receptors CD4/CXCR4 and OX40 ligand (OX40L). Expression of OX40L as well as HIV-1 receptors on the VSV particles led to specific infection of OX40(+) T cells, including primary cells, either acutely or chronically infected with X4 HIV-1. Consequently, the rVSV rapidly eliminated these infected cells and caused a marked reduction of HIV-1 viral load in culture. Inclusion of the OX40L gene in the VSV recombinant led to significantly better infection and HIV-1 elimination compared with an rVSVΔG expressing only HIV-1 receptors. A novel rVSVΔG encoding both HIV-1 receptors and OX40L has a potentially greater therapeutic value than an rVSVΔG expressing only HIV-1 receptors.