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PubMed1982

Isolation of human suppressor T cells by peanut agglutinin.

Peanut agglutinin (PNA) is a plant lectin which has been used for the separation of suppressor T cells in mice. The present study was carried out to determine whether PNA would be useful in the isolation of human suppressor T cells. Normal human peripheral blood mononuclear cells (PBMC) were activated by concanavalin A (Con A) and the resultant blastoid cells were then incubated with PNA-coated autologous erythrocytes to induce the rosette formation. The PNA rosette-forming cells (15-18% of Con A-activated PBMC) were separated from non-rosette-forming cells by differential centrifugation. The rosette-forming cells suppressed pokeweed mitogen-induced polyclonal immunoglobulin synthesis by 2- to 5-fold. This degree of suppression was greater than that seen with non-rosette-forming cells or with unseparated Con A-activated cells. Our data indicate that PNA rosette fractionation provides a simple and useful method for the isolation of human suppressor T cells.

Cell Separation↗
PubMed1988

Binding of peanut agglutinin on fresh and organ-cultured porcine corneal tissue.

To investigate the binding of peanut-agglutinin (PNA) on porcine corneal tissue, several methods of tissue processing were used. In cryostat sections of postmortem tissue, PNA labeling of epithelial cell membranes was detected. In the stroma, a fibrillar structure parallel to the corneal surface was found. The anterior part of Descemet's membrane was strongly positive, whereas the posterior Descemet membrane was negative. The endothelium was faintly positive. After 3 days of organ culture, the epithelial and endothelial staining patterns were not significantly changed. The stromal fibrils detected by PNA staining showed a considerable spatial disarrangement due to the stromal hydration.

Animals↗
PubMed1986

Wheat germ and peanut agglutinin binding to normal, dysplastic and neoplastic cervical epithelium.

Binding of wheat germ agglutinin (WGA) and peanut agglutinin (PNA) was studied cytochemically in 43 cervical specimens covering a range of lesions from moderate atypia to invasive carcinoma. Normal squamous epithelium showed weak binding of WGA and negative reaction with PNA. Atypical squamous epithelium was characterized by moderate binding of WGA and PNA, while malignant lesions demonstrated strong affinity to both lectins. In adenocarcinoma in situ, WGA and PNA binding was reduced by comparison with normal glandular epithelium, that was strongly positive.

Adenocarcinoma↗
PubMedDate not supplied

Peanut oil reduces diet-induced atherosclerosis in cynomolgus monkeys.

The atherogenicity of dietary peanut oil (PO) was examined in cynomolgus monkeys fed semipurified diets for 15 months. Four groups of six monkeys were fed diets containing 0.22 mg/kcal (0.1%) cholesterol and 0%, 5%, 10%, or 20% PO. An additional group was fed 2.0% cholesterol and 20% PO to serve as a literature control. Increasing the concentration of PO in the diet was associated with significant decreases in total plasma cholesterol (p less than 0.05) and the total/HDL cholesterol ratio (p less than 0.05) and an increase in the terminal HDL cholesterol concentration (p less than 0.05). Intimal thickness and composition were determined from cross sections of the thoracic aorta and the iliac and coronary arteries. Increasing dietary PO was associated with decreases in thickness (p less than 0.005), lipid (p less than 0.001), and smooth muscle cells (p less than 0.005) in the aortic intima. Aortic intimal lipid was positively correlated with the ratio of total to HDL cholesterol (r2 = 0.78, p less than 0.05). Monkeys fed 2.0% cholesterol and 20% PO revealed extensive atherosclerosis in all three arterial sites compared with those of any other group. Whereas the dietary fat effect was most demonstrable in the aorta, dietary cholesterol had a greater effect on the iliac and coronary arteries than it did on the aorta. Under these circumstances, dietary PO was not atherogenic in cynomolgus monkeys when fed with a concentration of cholesterol equivalent to that consumed by humans.

Animals↗
PubMed1981

Discrete Distribution of binding sites for Dolichos biflorus agglutinin (DBA) and for peanut agglutinin (PNA) in mouse organ tissues.

The distribution of binding sites for two lectins with different specificities was studied in adult mice by staining paraffin sections with lectins labeled either with fluorescein isothiocyanate or horseradish peroxidase. Binding sites for Dolichos biflorus agglutinin, a lectin specific to terminal alpha-N-acetylgalactosamine residue, were detected only in several restricted regions, such as collecting tubules and Bowman's capsules of the kidney, bile ducts, pancreatic ducts, sperms, oocytes, some secreting cells, and the secreted mucin itself. Binding sites for peanut agglutinin (PNA), a lectin specific to terminal beta-galactosyl residue, were distributed more widely. However, differentiation-dependent alterations in the expression of PNA binding sites have been observed in two types of cell lineage. During the course of spermatogenesis, the binding sites were expressed at the stage of spermatocytes. In the epithelium of esophagus, the binding sites were present in cells of the superficial layer.

Animals↗
PubMed1983

Light microscopic histochemical detection of terminal galactose and N-acetylgalactosamine residues in rodent complex carbohydrates using a galactose oxidase--Schiff sequence and peanut lectin--horseradish peroxidase conjugate.

A technique was investigated for the direct visualization on paraffin sections of galactose and N-acetylgalactosamine residues terminating saccharide chains in complex carbohydrates. Sections were incubated with the enzyme galactose oxidase (GO), which oxidizes the C-6 hydroxyl of galactose or N-acetylgalactosamine (GalNAc) residues, and the resulting aldehyde was visualized by its reaction with Schiff's reagent. Submaxillary and sublingual glands, pancreas, stomach, duodenum, and ileum from mice and rats were stained with the GO-Schiff sequence and results were compared with staining by a peanut lectin-horseradish peroxidase (PL-HRP) conjugate that binds selectively to terminal galactose and preferentially to the terminal dimer beta-D-Gal-(1 leads to 3)-D-GalNAc. Three classes of reactive sites were revealed: 1) those reactive with both GO-Schiff and PL-HRP, 2) those stained with the GO-Schiff sequence but unreactive with PL-HRP, and 3) those GO-Schiff unreactive but PL-HRP positive. Based on the carbohydrate binding specificity of GO and PL, it is suggested that tissue complex carbohydrates in group one contain terminal beta-galactose residues with unmodified hydroxyls at C-2, C-4, and C-6, whereas those in group two contain terminal GalNAc residues. The structure of oligosaccharides in group 3 sites remains enigmatic.

Acetylgalactosamine↗
PubMed1988

Ultrastructural visualization of selective peanut agglutinin binding sites in rat osteoclasts.

We investigated the distribution of concanavalin A (ConA)-reactive alpha-D-mannosyl and alpha-D-glucosyl groups and peanut agglutinin (PNA)-reactive beta-D-galactose-(1----3)-N-acetyl-D-galactosamine residues on the surface of osteoclasts with pre-embedment ultrastructural lectin cytochemistry after aldehyde fixation of the metaphyses of the rat tibiae. By routine morphology, the plasma membrane of the ruffled border of the osteoclast was distinguished from the rest of the cell membrane, with the exception of the membrane of coated pits, by its characteristic thick coat at its cytoplasmic surface. Cytochemistry, using ConA in combination with horseradish peroxidase (ConA-HRP) and PNA conjugated to HRP, showed that binding of ConA was distributed over the entire cell surface of osteoclasts. In contrast, intense binding of PNA was limited to the membranes of the ruffled border and coated pits, whereas the remainder of the cell membrane stained weakly or not at all. These results demonstrate that preferential PNA binding sites of the cell surface correspond to coated membranes associated with osteoclastic endocytosis.

Animals↗
PubMed1990

Binding of T-antigen-bearing neoglycoprotein and peanut agglutinin to cultured tumor cells and breast carcinomas.

Chemical conjugation of appropriate carbohydrate ligands to an inert labeled carrier renders probes available to screen for the presence of respective binding sites. A set with a certain plant lectin and a suitable neoglycoprotein can thus determine complementary parts of a potentially relevant glycobiological interaction system. Owing to the interest in the peanut agglutinin-reactive T-antigen, we performed chemical synthesis of the respective disaccharide structure to serve as glycohistochemical ligand and established refinements of the synthetic patway. Coupling of the derivatized monomers had to be performed in the presence of sodium sulfate for optimal results. Complete removal of the protective groups from the p-nitrophenyl derivative of the N-acetylgalactosamine moiety was achieved under mild conditions with 2,3-dichloro-5,6-dicyanobenzoquinone without affecting any other functional groups. Specific binding sites for the synthetic neoglycoprotein as well as for the plant lectin were demonstrated in cell lines of human breast carcinoma colon adenocarcinoma, and erythroleukemia. ABC reagents in conjunction with DAB as peroxidase substrate were used to visualize specific binding sites. Binding complied with the accepted criteria for specificity. Moreover, carbohydrate-specific binding sites were detected in sections of nine out of 14 cases with malignant breast lesions. The percentage of positive tumor cells with both neoglycoprotein and lectin was similar in each of the individual sections, regardless of quantitative variations between cases, lectin staining intensity often being more pronounced. The reactivity pattern in sections of primary and metastatic lesions was not significantly correlated with the lymph node status. This study emphasized that custom synthesis of saccharides and histochemical application of the resulting neoglycoprotein has a remarkable potential for complementary assessment of endogenous binding sites for carbohydrate structures, localized by external tools such as plant lectins, as a step to elucidate the importance of a putative proteincarbohydrate interaction.

Adenocarcinoma↗
PubMed2003

Expression of peanut agglutinin-binding mucin-type glycoprotein in human esophageal squamous cell carcinoma as a marker.

BACKGROUND: The TF (Thomson-Friedenreich) blood group antigen behaves as an onco-foetal carcinoma-associated antigen, showing increased expression in malignancies and its detection and quantification can be used in serologic diagnosis mainly in adenocarcinomas. This study was undertaken to analyze the sera and tissue level detectable mucin-type glycoprotein (TF-antigen) by Peanut agglutinin (PNA) and its diagnostic index in serum as well tissues of human esophageal squamous cell carcinoma as marker. RESULTS: We examined 100 patients for serological analysis by Enzyme Linked Lectin Assay (ELISA) and demonstrated a sensitivity of 87.5%, specificity of 90% and a positive predictive value of 95%. The immuno-histochemical localization of TF antigen by Fluorescence Antigen Technique (FAT) in 25 specimens of normal esophageal squamous epithelium specimens and 92 specimens with different grades of, allowed a quicker and more precise identification of its increased expression and this did not correlate with gender and tumor size. There was a positive correlation between membrane bound TF antigen expression with different histological progression, from well differentiated to poorly differentiated, determined by PNA binding. Specimens showed morphological changes and a pronounced increase in PNA binding in Golgi apparatus, secretory granules of the cytosol of well differentiated and an increased cell membrane labeling in moderately and poorly differentiated, when compared with ESCC and normal tissues. CONCLUSION: The authors propose that the expression of TF-antigen in human may play an important role during tumorigenesis establishing it as a chemically well-defined carcinoma-associated antigen. Identification of the circulating TF-antigen as a reactive form and as a cryptic form in the healthy individuals, using PNA-ELLA and Immunohistochemical analysis of TF antigen by FAT is positively correlated with the different histological grades as a simple and cost-effective method for the early diagnosis of ESCC. The present study reveals that, during tumorigenesis, an aberrant glycosylation takes place in Golgi apparatus leading to over secretion of TF antigen into the cytoplasm along with mucin granules and later into cell membrane. We suggest that the further characterization of TF antigen may unravel pathogenetic aspects of this silent disease.

Adult↗
PubMed1990

Patterning of chick brain vesicles as revealed by peanut agglutinin and cholinesterases.

Differentiation of individual rhombomeres of the chicken hindbrain directly follows the emergence of primary brain vesicles. Immediately after the constriction of the prosencephalon at HH9, a series of vesicles of decreasing size is established almost simultaneously between HH9 and HH10, including mesencephalon, four preotic (R2-R5) and one postotic (R6/R7) rhombomeres. Thereby, the cranial neural tube is ventrally embedded in a mesodermal PNA-binding matrix that particularly accumulates underneath vesicular constriction sites, as demonstrated for the segregation of the prosencephalon at HH9 and the cerebellar rhombomere R1 from R2 at HH13. The subsequent period of hindbrain differentiation is analyzed by cholinesterase (AChE, BChE) and peanut lectin histochemistry, by the BrdU and the neurite-specific G4 antibodies. Preotically, differentiation of two pairs of rhombomeres (R4 + R5, R2 + R3) starts in R4, immediately followed by R2. The caudal rhombomeres of both pairs are delayed (R5, R3). Then the postotic rhombomere is subdivided, whereby R7 differentiates before R6. Thus, the development in the direct vicinity of the otic vesicle is delayed (R5, R6). R7 is the last rhombomere that is demarcated caudally. Based on these findings, we postulate two processes that may regulate rhombomere formation in the chicken embryo: (a) an early rostrocaudal wave establishing the major brain vesicles, (b) a superimposed pairwise segmentation emanating rostrally and caudally from the otic vesicle. The segregation of the cerebellar rhombomere is a late step.

Animals↗
PubMed1995

CD44 is the major peanut lectin-binding glycoprotein of human epidermal keratinocytes and plays a role in intercellular adhesion.

Although binding of peanut agglutinin (PNA) to keratinocytes is often used as a marker of terminal differentiation, the identity of the PNA-binding glycoproteins has been unclear. We now show that an antiserum raised against the glycoproteins recognises isoforms of CD44, the most abundant of which could be labelled with [35S]sulphate, indicating the presence of glycosaminoglycan side chains. RT-PCR analysis showed that keratinocytes expressed at least 5 forms of CD44 containing different numbers of exons from the variable region of the extracellular domain and also expressed the standard 'haemopoietic' form of CD44 which lacks the variable exons. Standard and variant isoforms of CD44 were expressed both by proliferating keratinocytes and cells undergoing terminal differentiation, although the level of CD44 mRNAs decreased when keratinocytes were placed in suspension to induce differentiation. The role of CD44 in intercellular adhesion was investigated by plating keratinocytes onto a rat pancreatic carcinoma line transfected with different CD44 isoforms. Keratinocyte adhesion to transfectants expressing variant exons 4-7 was greater than to cells expressing standard CD44 and could be inhibited with hyaluronan or digestion with hyaluronidase. These observations confirm earlier predictions that the PNA-binding glycoproteins of keratinocytes play a role in intercellular adhesion.

Animals↗
PubMed1989

Assay for sialidase using erythrocytes and peroxidase-labeled peanut lectin.

A rapid and sensitive sialidase assay method based on peroxidase-labeled peanut lectin (PNA) binding to desialylated erythrocyte is described. Formalinized sheep erythrocytes were used both as a stable substrate for sialidase and as a target for the lectin. In the case of sialidases from Vibrio cholerae and Arthrobacter ureafaciens, a linear relationship was observed between the amount of peroxidase-labeled PNA bound to erythrocytes and the enzyme amount. Binding of the lectin to sialidase-treated erythrocytes was completely prevented in the presence of 25 mM lactose and galactose. The method is particularly useful as a selective assay for sialidase which is active towards gangliosides or sialoglycoproteins, because a mammalian sialidase which is preferentially active towards sialooligosaccharides and sialoglycopeptides is not able to remove sialic acid from erythrocytes.

Animals↗
PubMed2004

Preparation and characterization of novel branched beta-cyclodextrins having beta-D-galactose residues on the non-reducing terminal of the side chains and their specific interactions with peanut (Arachis hypogaea) agglutinin.

Six novel branched beta-cyclodextrins (betaCDs) having beta-D-galactose residues on the non-reducing terminal of the sugar side chains, namely 6(1),6(4)-di-O-(beta-D-galactosyl)-betaCD (10), 6-O-(beta-D-galactosyl)-betaCD (11), 6(1),6(4)-di-O-(beta-lactosyl)-betaCD (14), 6-O-(beta-lactosyl)-betaCD (15), 6(1),6(4)-di-O-(4'-O-beta-D-galactosyl-beta-lactosyl)-betaCD (18), and 6-O-(4'-O-beta-D-galactosyl-beta-lactosyl)-betaCD (19), were chemically synthesized using the trichloroacetimidate method. The reaction products were separated by HPLC on an amino column into dibranched and monobranched betaCDs. Their structures were confirmed by mass spectrometry (MS) and two-dimensional (2D) NMR spectroscopic analysis. To study the length of the sugar side chains attached to the CD ring, which leads to differences in the functions of the branched CDs, interactions of these compounds with peanut (Arachis hypogaea) agglutinin (PNA) were investigated using an optical biosensor and an inhibition assay based on hemagglutination. The results showed that all branched betaCDs interacted with PNA, and the binding affinity was 18>14>10 and 19>15>11 when the derivatives were compared on the basis of side chain length.

Biosensing Techniques↗
PubMed1998

Peanut lectin-binding sites and mucins in benign and malignant colorectal tissues associated with schistomatosis.

An immunohistochemical and histochemical comparative study was carried out in benign and malignant colorectal tissues with and without schistosomiasis. This included a quantitative determination of peanut lectin (PNA)-binding sites and proliferating cell nuclear antigen (PCNA) expression and histochemical detection of mucin changes. 133 cases were studied, including 70 cases of colorectal carcinoma associated with schistosomiasis (CCS) and 63 cases of colorectal carcinoma without schistosomiasis (CC). Significant differences were found in the type of mucin-containing carcinomas (MC) between CCS and CC. 65% of non-tumorous mucosa adjacent to MC of the CCS group expressed PNA-binding sites, significantly higher than those of the MC in the CC group (31%). The non-tumorous mucosa in cases of MC of the CCS group also showed a high percentage of sialomucin-predominant secretion (69%, vs 38% in MC of the CC group). Consistently, the presence of PNA-binding sites in MC tumors of the CCS group was increased, compared with that in the same subtype in the CC group (respectively 65% and 31% of strong positivity for PNA). However, no differences in expression of PNA and mucin changes were demonstrated in the surrounding mucosa and tumorous tissues of non-mucin-containing carcinomas (NMC) between CCS and CC. The expression of PCNA was not different between CCS and CC and their subtypes. Our findings suggest a close relationship between mucin-containing colorectal carcinomas and schistosomiasis japonica.

Colorectal Neoplasms↗
PubMed1987

Specific labelling by peanut agglutinin of the outer acrosomal membrane of the human spermatozoon.

Experiments to bind fluorescein-conjugated Arachis hypogea (peanut) agglutinin (FITC-PNA) to washed human spermatozoa demonstrated that this lectin binds to the acrosome region in air-dried preparations. Since there was no binding when labelling was performed in suspension, and comparable labelling to that seen in air-dried preparations was seen when spermatozoa treated with saponin (to lyse the plasma membrane) were labelled in suspension, the lectin must bind to an intracellular structure, probably the outer acrosomal membrane. This was confirmed by ultrastructural localization of colloidal gold-conjugated lectin in saponin-treated spermatozoa. Treatment of spermatozoa with the detergent Nonidet P-40 caused a marked change in the binding pattern: more spermatozoa showed binding in the equatorial segment of the acrosome with no binding in the anterior cap region. A comparable, less marked, change was seen when spermatozoa were incubated overnight under conditions known to support the capacitation and spontaneous acrosome reactions. Treatment with the calcium ionophore A23187 for 1 h to induce acrosome reactions artificially in uncapacitated spermatozoa resulted in the appearance of patchy acrosome fluorescence. From these experiments it is concluded that PNA binds specifically to the outer acrosomal membrane, and that FITC-PNA-labelling may be used to monitor the human sperm acrosome reaction.

Acrosome↗
PubMed2002

Trypanosoma cruzi I and Trypanosoma cruzi II: recognition of sugar structures by Arachis hypogaea (peanut agglutinin) lectin.

Epimastigote culture forms of different isolates of Trypanosoma cruzi from different mammal hosts, humans, and vectors were tested with FITC-conjugated peanut agglutinin lectin (PNA-FITC). The parasites maintained in axenic medium, liver infusion tryptose. were evaluated by flow cytometric analyses; whereas T. cruzi I (Tcl), which is associated with the sylvatic transmission cycle, was labeled in high percentages with PNA (88-99.2%), T. cruzi II (TcII) (parasites associated with domiciliar cycle) and T. cruzi, zymodeme 3 (Tc/Z3) (also associated with the sylvatic cycle) were labeled in low percentages (TcII, 0-26% and Tc/Z3, 0-12.6%). It was demonstrated that it is possible to differentiate the 2 main T. cruzi subpopulations, TcI and TcII, using Arachis hypogaea. These results also showed a higher variability in TcII in terms of PNA binding.

Animals↗
PubMed1999

Changes in the distribution of peanut agglutinin (PNA) binding molecules during muscle reinnervation following nerve crush injury.

Peanut agglutinin (PNA) staining during muscle reinnervation following a crushing injury of the sciatic nerve was performed in reference to the neural profiles immunolabeled with the PGP 9.5 antibody. PNA staining in the normal controls exhibited dots, granules, or lines along the length of the nerve fibers in the nerve trunk, but was faint or absent in the motor endplate. At seven days post-crush, PNA staining was detected around the vacuolated neural structures in the disorganized nerve trunk, but was still faint or absent in the motor endplate. At twenty-one days post-crush, when PGP 9.5-positive regenerating axons appeared in most of the motor endplates, PNA staining, either faint or strong, followed the pathway of the nerve fibers delineated by PGP 9.5-like immunoreactivity. During reinnervation to the motor endplates, PNA staining displayed signs of remodeling in the nerve trunk, such as marked variations in density and profile in the nerve fiber-associated dots or patches; it increased in intensity in the connective tissue covering the area of the motor endplate, as well as in the junctional myofiber surface. The structures recognizable by PNA coincided with components of the connective tissue such as collagen fibers and capillaries. Results suggest that: 1) the expression of PNA-binding molecules is dependent on the state of innervation, and 2) the spatiotemporal relationship between neural profiles and PNA staining provides sequences of axonal extension and subsequent nerve terminal maturation during regeneration in the motor endplate.

Animals↗