Application of Lectin Array Technology for Biobetter Characterization: Its Correlation with FcγRIII Binding and ADCC.

Background: Inflammation plays a key role in the progression of atherosclerotic plaque for peripheral artery disease (PAD). Immunoglobulin G (IgG) glycosylation could modulate immunological effector functions and has been explored as biomarkers for various diseases. Methods: Lectin microarray was applied to analyze the expression profile of serum IgG glycosylation in patients with lower-extremity peripheral artery disease (LEPAD), carotid artery stenosis (CAS), abdominal aortic aneurysm (AAA), and healthy controls. Lectin blot was performed to validate the differences. Results: SNA (Sambucus nigra agglutinin) binding (preferred sialic acid) was significantly higher in the LEPAD (3.21 ± 2.06) and AAA (3.34 ± 2.42) groups compared to the CAS (2.47 ± 1.45) group. Significantly higher binding levels of ConA (Concanavalin A) (preferred mannose) and PSA (Pisum sativum agglutinin) (preferred fucose) were also observed in LEPAD compared to CAS patients. Among LEPAD patients, a significant lower binding level of Black bean crude (preferred GalNAc) was present for dyslipidemia patients. A higher binding level of MNA-M (Morniga M agglutinin) (preferred Mannose) and Jacalin-AIA (Artocarpus integrifolia agglutinin) (preferred Galβ3GalNAc) was observed for Fontaine severe patients. Higher binding levels of PHA-E (Phaseolus vulgaris Erythroagglutinin) and PHA-L (Phaseolus vulgaris Leucoagglutinin) (preferred Galβ4GlcNAc) were observed for diabetic patients, and higher binding of ASA (Allium sativum agglutinin) (preferred Mannose) was present in patients with hypertension. The level of high-sensitivity C-reactive protein (hsCRP) was positively associated with LTL (Lotus tetragonolobus lectin) (r = 0.44), PSA (r = 0.44), LCA (Lens Culinaris agglutinin) (r = 0.39), SNA (r = 0.57), and CSA (Cytisus sscoparius agglutinin) (r = 0.56). For CAS, symptomatic patients had lower binding levels of AAL (Aleuria aurantia lectin) (preferred fucose) and IAA (Iberis amara agglutinin) (preferred GalNAc). Blood total cholesterol level was positively associated with SNA-I (r = 0.36) and SBA (Soybean agglutinin) (r = r = 0.35). Creatinine levels were positively associated with lectins including, but not limited to, MNA-M (r = 0.42), CSA (r = 0.45), GHA (Glechoma hederacea agglutinin) (r = 0.42), and MNA-G (Morniga G agglutinin) (r = 0.45). Conclusion: LEPAD patients had increased IgG binding levels of SNA and ConA compared to CAS, which could provide potential diagnostic value. Fontaine severity was associated with Mannose-rich IgG N-glycan, while diabetic LEPAD correlated with bisecting GlcNAc. The levels of hsCRP and creatinine were positively associated with IgG fucosylation and galactosylation. Changes in IgG glycosylation may play important roles in PAD pathogenesis and progression.

In this study, we aimed to explore the effectiveness of selenium on the chondrocyte glycoprotein glycosylation which plays important roles in the pathogenesis of Kashin-Beck disease (KBD). Cartilage samples were collected from KBD patients after total knee replacement surgery. Chondrocytes were cultured with sodium selenium. The group of chondrocytes which were cultured without adding sodium selenium was considered as control group. Lectin microarray was used to screen the differences in lectin levels between KBD and KBD with selenium groups. Stronger signals for Bandeiraea simplicifolia (BS-I), Hippeastrum hybrid lectin (HHL), Pisum sativum agglutinin (PSA), Psophocarpus tetragonolobus lectin I (PTL-I), Psophocarpus tetragonolobus lectin II (PTL-II), Sophora japonica agglutinin (SJA), Lotus tetragonolobus lectin (LTL), and Triticum vulgaris (WGA) were observed in the KBD group. Meanwhile, Aleuria aurantia lectin (AAL), Lens culinaris agglutinin (LCA), Lycopersicon esculentum (tomato) lectin (LEL), Peanut agglutinin (PNA), and Sambucus nigra lectin (SNA) signals were lower in the KBD group. Selenium may have the function of influence the expression levels of carbohydrate chains Galα1,3-Gal, high mannose, and GlcNAc.

Changes of glycoconjugates in granulosa cells during follicular atresia were examined by lectin histochemical and biochemical techniques. Twenty-four lectins were used to visualize the different glycoconjugates of granulosa cells in frozen sections of the pig ovary. Four lectins showed stronger staining of the granulosa cells in atretic than in healthy follicles. Very strong and/or strong staining with Sambucus sieboldiana agglutinin (SSA) was seen in scattered granulosa cells of atretic follicles, but those of healthy follicles were not stained with this lectin. In atretic follicles, very strong-moderate diffuse staining was seen with Aleuria aurantia lectin (AAL), Pisum sativum agglutinin (PSA) and Lens culinaris agglutinin (LCA) in granulosa cells, in contrast with very weak staining in those of healthy follicles. Furthermore, lectin blot analysis with three lectins (SSA, AAL, and PSA) indicated several glycoproteins with increased staining in atretic relative to healthy follicles for these three lectins. Especially, two SSA-positive glycoproteins (62 and 64 kD) of granulosa cells in atretic follicles were specific and characteristic which were not detected in those in healthy follicles. These results suggest that changes of some glycoconjugates in granulosa cells may be involved in granulosa cell apoptosis and follicular atresia.

The aim of this study was to use a lectin microarray to detect differential glycan profiling of serous glycoprotein in iron overload thalassemia patients. This study enrolled iron overload α/β-thalassemia patients and no iron overload α/β-thalassemia patients. Lectin microarray was used to detect the alteration of protein glycosylation. The reliability of the lectin microarray results was verified by the lectin blotting technique. Expression level of hepcidin, erythropoietin, ferritin, and transferrin were measured by western blotting. Data were analyzed using the SPSS 16.0 software. In this study, 19 differentiating lectins were screened from the iron overload α-thalassemia group, and 15 were screened from the iron overload β-thalassemia group. The agglutinin blotting technique demonstrated that the results of the Aleuria aurantia lectin (AAL), Lens culinaris agglutinin (LCA), and Wheat germ agglutinin (WGA) agglutinin affinity for serum glycoproteins were consistent with the results of the lectin microarray. In iron overload thalassemia groups, expression levels of erythropoietin and ferritin were increased, but hepcidin and transferrin were significantly reduced. The differentially expressed glycoprotein database of iron overload thalassemia was successfully created, and the specific glycan patterns of serous glycoprotein might be efficient biomarkers for diagnosis or progression of iron overload thalassemia.

BackgroundWe previously reported increased levels of protein-linked fucosylation with the development of liver cancer and identified many of the proteins containing the altered glycan structures. One such protein is alpha-1-antitrypsin (A1AT). To advance these studies, we performed N-linked glycan analysis on the five major isoforms of A1AT and completed a comprehensive study of the glycosylation of A1AT found in healthy controls, patients with hepatitis C- (HCV) induced liver cirrhosis, and in patients infected with HCV with a diagnosis of hepatocellular carcinoma (HCC).Methodology/Principal FindingsPatients with liver cirrhosis and liver cancer had increased levels of triantennary glycan-containing outer arm (α-1,3) fucosylation. Increases in core (α-1,6) fucosylation were observed only on A1AT from patients with cancer. We performed a lectin fluorophore-linked immunosorbent assay using Aleuria Aurantia lectin (AAL), specific for core and outer arm fucosylation in over 400 patients with liver disease. AAL-reactive A1AT was able to detect HCC with a sensitivity of 70% and a specificity of 86%, which was greater than that observed with the current marker of HCC, alpha-fetoprotein. Glycosylation analysis of the false positives was performed; results indicated that these patients had increases in outer arm fucosylation but not in core fucosylation, suggesting that core fucosylation is cancer specific.Conclusions/SignificanceThis report details the stepwise change in the glycosylation of A1AT with the progression from liver cirrhosis to cancer and identifies core fucosylation on A1AT as an HCC specific modification.

Lung cancer is the most frequent cancer and the leading cause of cancer around the world. As one of the major types of lung cancer, lung squamous cell carcinoma (LUSC) is closely associated with smoking and shows poor sensitivity to therapy and prognosis. Although alteration of glycopatterns are reliable indicators of cancer, little is known about the alterations of protein glycosylation related to LUSC. In this study, we compared the differential expression levels of glycopatterns in seven pairs of LUSC tissues and normal pericarcinomatous tissues (PCTs) using lectin microarrays. Fluorescence-based lectin histochemistry and lectin blotting were utilized to validate and assess the expression and distribution of certain glycans in LUSC tissues and PCTs. And we further analyzed their total N-linked glycans using MALDI-TOF/TOF-MS to provide more information about the aberrant glycopatterns. The results showed that the expression level of the core fucosylation recognized by Pisum sativum agglutinin (PSA) and Lens culinaris agglutinin (LCA) was significantly increased in LUSC tissues compared with PCTs. There were 10 and 15 fucosylated N-linked glycans that were detected in PCTs and LUSC tissues respectively, 10 fucosylated N-glycans were common, while five fucosylated N-glycans were unique to LUSC tissues. And the abundance of the fucosylated N-glycans was increased from 40.9% (PCTs) to 48.3% (LUSC). These finding is helpful to elucidate the molecular mechanisms underlying the lung diseases and develop new treatment strategies.

BackgroundProstate-specific antigen (PSA) is commonly used as a serum biomarker for the detection of prostate cancer. However, levels of PSA in serum do not reliably distinguish aggressive prostate cancer from non-aggressive disease. Therefore, there is an urgent need for biomarkers that can differentiate aggressive prostate cancers from non-aggressive phenotypes. Fucosylation is one of the glycosylation-based protein modifications. Previously we demonstrated increased levels of serum fucosylated PSA in patients with aggressive prostate cancer using lectin selection followed by PSA immunoassay.MethodsWe developed two lectin-immunoassays, Lens culinaris agglutinin (LCA) and Aleuria aurantia lectin (AAL) followed by clinical PSA immunoassay and investigated the levels of PSA and its fucosylated glycoforms in serum specimens from prostate cancer patients with different Gleason scores. First, we developed standard curves for lectins enrichment, which were applied to lectin-immunoassay for fucosylated PSA–LCA and PSA–AAL quantification in serum samples.ResultsOur results showed that both LCA- and AAL-immunoassays detected elevated fucosylated PSA and were correlated with higher Gleason scores but only AAL-immunoassay detected an increased percentage of fucosylated PSA in patient serum with higher Gleason scores.ConclusionWe have developed quantitative lectin-immunoassays for serum fucosylated PSA. Our data demonstrated that fucosylated PSA–AAL, % fucosylated PSA–AAL and fucosylated PSA–LCA levels could be effective biomarkers to differentiate aggressive prostate cancer [especially Gleason 7 (4 + 3) or above] from non-aggressive disease. We believe that application of these lectin-immunoassays to a larger patient population is needed to evaluate the clinical utilities of fucosylated PSA using AAL–PSA and LCA–PSA for aggressive prostate cancer.

Lectin cytochemistry of the human autopsy cases of Creutzfeldt-Jakob disease and old cerebral infarction was performed on formalin-fixed, paraffin-embedded sections using 15 lectins. Reactive astrocytes showed a positive reaction with concanavalin A (Con A), Lens culinaris agglutinin (LCA) and Pisum sativum agglutinin (PSA), with common specificity for both mannose and glucose. However normal astrocytes demonstrated no or little cytochemical reaction for any of the lectins. Reactivity for the lectins in control sections was obviously reduced using the blocking sugars (0.1 mol/l D-mannose and 0.5 mol/l D-glucose for Con A, LCA, and PSA, and 0.5 M mol/l alpha-methyl mannopyranoside for Con A). The present data provide suggestive evidence that the reactivity for Con A, LCA, and PSA is increased in reactive astrocytes.

Neospora caninum is an obligate intracellular parasite that causes abortion in ruminants. Different strains produce differences in the severity of disease outcomes. These differences may cause physiological or pathological changes in cells, modifying the intercellular interactions and intracellular transport pathways that could be evidenced by identifying the terminal sugars. This study aimed to characterize the oligosaccharide pattern in the bovine placenta and uterus after infection with tachyzoites of three different strains of N. caninum (Nc-1, Nc-6 Argentina and Nc Spain-7) during early gestation. Fourteen heifers were inoculated intravenously on day 70 of gestation with 2 × 108 N. caninum tachyzoites and samples of placentae and uteri were analysed by histology and lectin histochemistry. In the infected groups, severe placentitis was associated with changes in lectin binding in the vascular endothelium by Lens culinaris agglutinin (LCA), Pisum sativum agglutinin (PSA) and Ricinus communis I (RCA-I) lectins, in the epithelial cells of the endometrial glands by RCA-I, Dolichos biflorus agglutinin (DBA), succinylated wheat germ agglutinin, peanut agglutinin (PNA), concanavalin-A (CON-A), LCA, PSA and Phaseolus vulgaris erythroagglutinin (PHA-e), and in the trophoblast layer by PNA, CON-A, LCA, PSA, PHA-e, soybean agglutinin, RCA-I, DBA and Bandieraea simplicifolia agglutinin (BSA-I). The results suggest that N. caninum causes changes in the glycosylation pattern in the maternofetal interface tissues and might cause abortions in early gestation due to changes in the cellular structure of the placenta.

Background/aim We aimed to explore the roles of glycoprotein glycosylation in the pathogenesis of Kashin–Beck disease (KBD), and evaluated the effectiveness of sodium hyaluronate treatment. Materials and methods Blood and saliva were collected from KBD patients before and after the injection of sodium hyaluronate. Normal healthy subjects were included as controls. Saliva and serum lectin microarrays and saliva and serum microarray verifications were used to screen and confirm the differences in lectin levels among the three groups. Results In saliva lectin microarray, bindings to Sophora japonica agglutinin (SJA), Griffonia (Bandeiraea) simplicifolia lectin I (GSL-I), Euonymus europaeus lectin (EEL), Maackia amurensis lectin II (MAL-II), Sambucus nigra lectin (SNA), Hippeastrum hybrid lectin (HHL), and Aleuria aurantia lectin (AAL) were higher in the untreated KBD patients than in the control group. Increased levels of HHL, MAL-II, and GSL-I in the untreated KBD patients discriminated them in particular from the treated ones. Jacalin was lower in the untreated KBD patients compared to the treated KBD and control groups. In serum lectin microarray, HHL and peanut agglutinin (PNA) were increased in the untreated KBD group in comparison to the control one. AAL, Phaseolus vulgaris agglutinin (E+L) (PHA-E+L), and Psophocarpus tetragonolobus lectin I (PTL-I) were lower in the untreated KBD patients compared to the treated KBD and control groups. Hyaluronate treatment appeared to normalize SNA, AAL, and MAL-II levels in saliva, and HHL, PNA, AAL, PTL-I, and PHA-E+L levels in serum. Saliva reversed microarray verification confirmed significant differences between the groups in SNA and Jacalin, in particular for GSL-I levels, while serum reversed microarray verification indicated that HHL, PNA, and AAL levels returned to normal levels after the hyaluronate treatment. Lectin blot confirmed significant differences in HHL, AAL, and Jacalin in saliva, and HHL, PNA, PHA-E+L, and AAL in serum. Conclusion HHL in saliva and serum may be a valuable diagnostic biomarker of KBD, and it may be used as follow-up for the hyaluronate treatment.

Antibiotics have traditionally been used for growth promotion in the pork industry; however, their use in animal feed has recently been limited because of human health concerns. The intestinal microbiota plays an important role in mediating many physiological functions such as digestion and animal growth. It was hypothesized that use of antibiotics as growth promotants and subsequent variations in intestinal microbiota induce significant changes in the intestinal glycoconjugate composition, which ultimately affects animal growth and disease susceptibility. The aim of this study was to characterize the lectin binding profiles of the ileum of weanling pigs in response to the absence of intestinal microbiota and to the use of the antibiotic chlortetracycline as growth promotant. Eighteen half-sib piglets obtained by cesarean section were divided into 3 treatment groups (n = 6) and maintained as control, antibiotic-fed, and gnotobiotic piglets until 5 wk of age. The glycoconjugate composition of the ileal tissues was examined by lectin histochemistry. Lycopersicon esculentum lectin, Jacalin, Pisum sativum agglutinin, Lens culinaris agglutinin (LCA), and Sambucus nigra lectin showed significant differences (P < 0.05) in binding intensities on the dome and villous epithelium between the treatment groups. Griffonia simplicifolia lectin I, Glycine maxi agglutinin, and Arachis hypogea agglutinin exhibited differences (P < 0.05) between treatment groups in lectin binding on goblet cells. Triticum vulgaris agglutinin, Pisum sativum agglutinin, and LCA showed significant differences (P < 0.05) in binding intensities on dome, corona, and follicular regions of the ileum among treatment groups of animals. Overall, ileal tissues from gnotobiotic piglets expressed significantly weaker (P < 0.05) lectin binding for many lectins compared with control and antibiotic groups. This suggests that the intestinal microbiota plays an important role in the expression of sugar moieties in the intestine. Lectins LCA, Phaseolus vulgaris Leucoagglutinin, and Maackia amurensis lectin II showed significant differences (P < 0.05) in lectin bindings between control and antibiotic-fed piglets. This indicates that chlortetracycline as a growth promotant induces biologically relevant changes in the lectin binding profile of the ileum. These findings will help in further understanding the role of the gut microbiota and the mechanisms of action of antibiotics as growth promotants in pigs.

The distribution of lectin bindings in the testis of babirusa, Babyrousa babyrussa (Suidae) was studied histochemically using 10 biotinylated lectins, Peanut agglutinin (PNA), Ricinus communis agglutinin (RCA I), Dolichos biflorus agglutinin (DBA), Vicia villosa agglutinin (VVA), Soybean agglutinin (SBA), Wheat germ agglutinin (WGA), Lens culinaris agglutinin (LCA), Pisum sativum agglutinin (PSA), Concanavalin A(Con A) and Ulex europaeus agglutinin (UEA I). Nine of 10 lectins showed a variety of staining patterns in the seminiferous epithelium and interstitial cells. The acrosome of Golgi-, cap- and acrosome-phase spermatids displayed various PNA, RCA I, VVA, SBA and WGA bindings, indicating the presence of glycoconjugates with D-galactose, N-acetyl-D-galactosamine and N-acetyl-D-glucosamine sugar residues respectively. No affinity was detected in the acrosome of late spermatids. LCA, PSA and Con A which have affinity for D-mannose and D-glucose sugar residues were positive in the cytoplasm of spermatids and spermatocytes. DBA was positive only in spermatogonia. In addition to DBA, positive binding in spermatogonia was found for VVA, WGA and Con A, suggesting the distribution of glycoconjugates with N-acetyl-D-galactosamine, N-acetyl-D-glucosamine, D-mannose and D-glucose sugar residues. Sertoli cells were stained intensely with RCA I, WGA and Con A. In Leydig cells, RCA I and Con A were strongly positive, while WGA, LCA and PSA reactions were weak to moderate. The present findings showed that the distribution pattern of lectin binding in the testis of babirusa is somewhat different from that of pig or other mammals reported previously.

The N-glycosylation of human immunoglobulins, especially IgGs, plays a critical role in determining affinity of IgGs towards their effector (pro- and anti-inflammatory) receptors. However, it is still not clear whether altered glycosylation is involved in only antibody-dependent disorders like seropositive rheumatoid arthritis (RA) or also in pathologies with similar clinical manifestations, but no specific autoantibodies like seronegative RA. The clarification of that uncertainty was the aim of the current study. Another study aim was the detection of specific glycan forms responsible for altered exposure of native glycoepitopes. We studied sera from seropositive RA (n = 15) and seronegative RA (n = 12) patients for exposure of glycans in native IgG molecules, followed by determination of specific glycans by capillary electrophoresis with laser-induced fluorescent detection (CE-LIF). Aged-matched groups of normal healthy donors (NHD) and samples of intravenous immunoglobulin IgG preparations (IVIG) served as controls. There was significantly stronger binding of Lens culinaris agglutinin (LCA) and Aleuria aurantia lectin (AAL) lectins towards IgG from seropositive RA compared to seronegative RA or NHD. CE-LIF analysis revealed statistically significant increases in bisecting glycans FA2BG2 (p = .006) and FABG2S1 (p = .005) seropositive RA, accompanied by decrease of bisecting monogalactosylated glycan FA2(6)G1 (p = .074) and non-bisecting monosialylated glycan FA2(3)G1S1 (p = .055). The results suggest that seropositive RA is distinct from seronegative RA in terms of IgG glycan moieties, attributable to specific immunoglobulin molecules present in seropositive disease. These glycans were determined to be bisecting GlcNAc-bearing forms FA2BG2 and FABG2S1, and their appearance increased the availability of LCA and AAL lectin-binding sites in native IgG glycoepitopes.

Lectin affinity chromatography using concanavalin A (Con A), Helix pomatia agglutinin (HPA), Lycopersicon esculentum lectin (LEL), Aleuria aurantia lectin (AAL) and Lens culinaris agglutinin (LCA) was used to investigate the utility of narrow selectivity lectins in the characterization of plasma glycoproteome diversity and to recognize cancer associated aberrations in glycosylation. Following affinity chromatographic selection, proteins were tryptically digested, the peptide fragments separated by reversed phase chromatography (RPC), and fractions from RPC identified by tandem mass spectrometry. The diversity of glycosylation found with narrow selectivity lectins was generally 2/3 that of Con A and not related to protein abundance. Small groups of proteins were found with each of the affinity columns, HPA, LEL, AAL, and LCA, that changed 3-fold or more in concentration between normal and breast cancer patient plasma. Although the number of cancer patients examined was too small to validate cancer marker candidates, they are clearly worth examining in a larger, more diverse patient population.

The α(1,6)fucose residue attached to the N-glycoprotein core is suspected to play an essential role in the progression of several types of cancer. Lectins remain the first choice for probing glycan modifications, although they may lack specificity. Thus, efforts have been made to identify new lectins with a narrower core fucose (CF) detection profile. Here, we present a comparison of the classical Aleuria aurantia lectin (AAL), Lens culinaris agglutinin (LCA) and Aspergillus oryzae lectin (AOL) with the newer Pholiota squarrosa lectin (PhoSL), which has been described as being specific for core fucosylated N-glycans. To this end, we studied the binding profiles of the four lectins using mammalian glycan arrays from the Consortium of Functional Glycomics. To validate their glycan specificity, we probed AOL, LCA and PhoSL in western-blot assays using protein extracts from eight common colorectal cancer (CRC) lines and colorectal biopsies from a small cohort of patients with CRC. The results showed that (i) LCA and PhoSL were the most specific lectins for detecting the presence of CF in a concentration-dependent manner; (ii) PhoSL exhibited the highest N-glycan sequence restriction, with preferential binding to core fucosylated paucimannosidic-type N-glycans, (iii) the recognition ability of PhoSL was highly influenced by the presence of terminal N-acetyl-lactosamine; (iv) LCA bound to paucimannosidic, bi-antennary and tri-antennary core fucosylated N-glycans and (v) AOL and AAL exhibited broader specificity towards fucosylation. Together, our results support the choice of LCA as the most appropriate lectin for CF detection, as validated in protein extracts from CRC cell lines and tissue specimens from patients with CRC.