A Bioassay to Estimate Root Penetration by Nematodes

An in vitro bioassay with a 96-well microtiter plate was used to study the effect of lectins on burrowing nematode penetration of citrus roots. In each well, one 4-mm root segment, excised from the zone of elongation of rough lemon roots, was buried in 0.88 g dry sand. Addition of a Radopholus citrophilus suspension containing ca. 300 nematodes in 50 μ1 test solution completely moistened the sand in each well. The technique assured uniform treatment concentration throughout the medium. Within 16-24 hours, burrowing nematodes penetrated citrus root pieces, primarily through the cut ends. The lectins (100 μg/ml) Concanavalin A (Con A), soybean agglutinin (SBA), wheat germ agglutinin (WGA), and Lotus tetragonolobus agglutinin (LOT) stimulated an increase in penetration of citrus root segments by Radopholus citrophilus. Concentrations as low as 12.5 μg/ml Con A, LOT, and WGA stimulated burrowing nematode penetration of citrus roots. Heat denaturation of the lectins reversed their effect on penetration; however, incubation of nematodes in lectin (25 μg/ml) with 25 mM competitive sugars did not. The reason for enhanced penetration associated with lectins is unclear.     

Effect of lectins on the invasion of Ichthyophthirius theront to channel catfish tissue.

This study determined the effects of lectin binding to theronts of Ichthyophthirius multifiliis on theront immobilization, invasion, trophont development and survival in channel catfish Ictalurus punctatus excised fins in vitro. Soybean agglutinin (SBA), lentil agglutinin (LCA), gorse agglutinin (UEA-I) and wheat germ agglutinin (WGA) were used to treat theronts. Percentages of theronts immobilized by 4 lectins ranged from 12.0 to 19.4% at a concentration of 1000 microg ml(-1). These lectins bound more than half of the theronts at a concentration of 50 microg ml(-1). More theronts were labeled by SBA and WGA than by lectin LCA at concentrations of 50 and 100 microg ml(-1), respectively. The binding of these lectins to theronts indicated that monosaccharides (D-galactose, L-fucose, D-mannose and D-glucose) and amino sugar derivatives (N-acetylgalactosamine and N-acetylglucosamine) were present on the surface of theronts. Invasion was reduced significantly for theronts treated with LCA, UEA-I and WGA. No difference in invasion was found between control and SBA bound theronts (p > 0.05). The binding of lectin LCA, UEA-I and WGA to theronts significantly reduced the development of trophonts (p < 0.05). The mean volumes of trophonts labeled with these 3 lectins were smaller than volumes in control trophonts from 8 to 48 h after exposure. Survival was lower in trophonts labeled with lectins than in control trophonts at 48 h after exposure.     

Effect of lectins on the transport of food ingredients in Caco-2 cell cultures

We investigated the effect of several lectins, such as soy bean lectin (SBA), concanavalin A (Con A), and wheat germ agglutinin (WGA), on the transport of some food ingredients (isoflavones, quercetin glycosides, carnosine/anserine) across Caco-2 cell monolayers. After incubation of food ingredients (0.03 approximately 2 mmol/L) in the presence or absence of lectins (1 approximately 180 microg/ml) on the apical side, aliquots were taken from the apical and basolateral solution, and were subjected to HPLC analysis. We also examined the effect of lectins on the permeability of the tight junction by measuring the transepithelial electrical resistance (TER) value of the Caco-2 cell monolayer. Isoflavones, which was not transported to the basolateral solution without lectins, could be transported in the presence of lectins, whereas their aglycones were detected at the same levels with or without the lectin treatment. The transport of quercetin glycosides also increased in the presence of lectins, however, that of peptides was not affected by the lectins. Con A and WGA, but SBA, decreased the TER value, indicating that Con A and WGA increased the transport via paracellular pathway, whereas SBA did via a different pathway.     

Trypanosoma rhodesiense Bloodstream Trypomastigote and Culture Procyclic Cell Surface Carbohydrates1, 2, 3

Bloodstream trypomastigote and culture procyclic (insect midgut) forms of a cloned T. rhodesiense variant (WRATat 1) were tested for agglutination with the lectins concanavalin A (Con A), phytohemagglutinin P (PP), soybean agglutinin (SBA), fucose binding protein (FBP), wheat germ agglutinin (WGA), and castor bean lectin (RCA). Fluorescence-microscopic localization of lectin binding to both formalin-fixed trypomastigotes and red cells was determined with fluorescein isothiocyanate (FITC)-conjugated Con A, SBA, FBP, WGA, RCA, PNA (peanut agglutinin), DBA (Dolichos bifloris), and UEA (Ulex europaeus) lectins. Electron microscopic localization of lectin binding sites on bloodstream trypomastigotes was accomplished by the Con A-horseradish peroxidase-diaminobenzidine (HRP-DAB) technique, and by a Con A-biotin/avidin-ferritin method. Trypomastigotes, isolated by centrifugation or filtration through DEAE-cellulose or thawed after cryopreservation, were agglutinated by the lectins Con A and PP with agglutination strength scored as Con A < PP. No agglutination was observed in control preparations or with the lectins WGA, FBA or SBA. Red cells were agglutinated by all the lectins tested. Formalin-fixed bloodstream trypomastigotes bound FITC-Con A and FITC-RCA but not FITC-WGA, -SBA, -PNA, -UEA or -DBA lectins. All FITC-labeled lectins bound to red cells. Con A receptors, visualized by Con A-HRP-DAB and Con A-biotin/avidin-ferritin techniques, were distributed uniformly on T. rhodesiense bloodstream forms. No lectin receptors were visualized on control preparations. Culture procyclics lacked a cell surface coat and were agglutinated by Con A and WGA but not RCA, SBA, PP and FBP. Procyclics were not agglutinated by lectins in the presence of competing sugar at 0.25 M. The expression of lectin binding cell surface saccharides of T. rhodesiense WRATat 1 is related to the parasite stage. Sugars resembling α-D-mannose are on the surface of bloodstream trypomastigotes and culture procyclics; n-acetyl-D-galactosamine and D-galactose residues are on bloodstream forms; and n-acetyl-D-glucosamine-like sugars are on procyclic stages.     

Trypanosoma rhodesiense bloodstream trypomastigote and culture procyclic cell surface carbohydrates

Bloodstream trypomastigote and culture procyclic (insect midgut) forms of a cloned T. rhodesiense variant (WRAT at 1) were tested for agglutination with the lectins concanavalin A (Con A), phytohemagglutinin P (PP), soybean agglutinin (SBA), fucose binding protein (FBP), wheat germ agglutinin (WGA), and castor bean lectin (RCA). Fluorescence-microscopic localization of lectin binding to both formalin-fixed trypomastigotes and red cells was determined with fluorescein isothiocyanate (FITC)-conjugated Con A, SBA, FBP, WGA, RCA, PNA (peanut agglutinin), DBA (Dolichos bifloris), and UEA (Ulex europaeus) lectins. Electron microscopic localization of lectin binding sites on bloodstream trypomastigotes was accomplished by the Con A-horseradish peroxidase-diamino-benzidine (HRP-DAB) technique, and by a Con A-biotin/avidin-ferritin method. Trypomastigotes, isolated by centrifugation or filtration through DEAE-cellulose or thawed after cryopreservation, were agglutinated by the lectins Con A and PP with agglutination strength scored as Con A greater than PP. No agglutination was observed in control preparations or with the lectins WGA, FBA or SBA. Red cells were agglutinated by all the lectins tested. Formalin-fixed bloodstream trypomastigotes bound FITC-Con A and FITC-RCA but not FITC-WAG, -SBA, -PNA, -UEA or -DBA lectins. All FITC-labeled lectins bound to red cells. Con A receptors, visualized by Con A-HRP-DAB and Con A-biotin/avidin-ferritin techniques, were distributed uniformly on T. rhodesiense bloodstream forms. No lectin receptors were visualized on control preparations. Culture procyclics lacked a cell surface coat and were agglutinated by Con A and WGA but not RCA, SBA, PP and FBP. Procyclics were not agglutinated by lectins in the presence of competing sugar at 0.25 M.(ABSTRACT TRUNCATED AT 250 WORDS)     

Characterization of Carbohydrates on the Surface of Second-stage Juveniles of Meloidogyne spp.

Fluorescent conjugates of the lectins soybean agglutinin (SBA), Concanavalin A (Con A), wheat germ agglutinin (WGA), Lotus tetragonolobus agglutinin (LOT), and Limulus polyphemus agglutinin (LPA) bound primarily to amphidial openings and amphidial secretions of viable, preinfective second-stage juveniles (J2) of Meloidogyne incognita races 1 and 3 (Mil, Mi3) and M. javanica (Mj). No substantial difference in fluorescent lectin binding was observed among the populations examined. Binding of only LOT and LPA were inhibited in the presence of 0.1 M competitive sugar. Structural differences in amphidial carbohydrate complexes among populations of Mi 1, Mi3, and Mj were revealed by glycohydrolase treatment of preinfective J2 and subsequent labeling with fluorescent lectins. A quantitative microfiltration enzyme-linked lectin assay revealed previously undetected differences in lectin binding to nonglycohydrolase-treated J2. Freinfective J2 of Mj bound the greatest amount of SBA, LOT, and WGA, whereas J2 of Mil bound the most LPA.     

Lectin-binding properties of the neuroepithelium of the vomeronasal organ, olfactory epithelium proper and the septal organ of Masera in mice (semithin section study)

The apical border of the vomeronasal neuroepithelium, the olfactory epithelium proper, and the septal organ possess varying lectin-binding properties. This can be judged by their ability to bind a peculiar lectin and/or by their reactivity to the given lectin. The following lectins have been used: Triticum vulgaris agglutinin (WGA), Ulex europeus agglutinin (UEA-1), Arachis hypogea agglutinin (PNA), Lymbus polyphenus agglutinin (LPA), Glycine soja agglutinin (SBA) and Dolchos diflerus agglutinin (DBA). But if the apical border of the vomeronasal neuroepithelium possesses certain binding areas for all the lectins investigated, the olfactory epithelium proper and the septal organ are not able to bind some of them.     

D-galactose-binding lectins induce a differential response of blood platelets

Platelets are strongly aggregated by 50 μg/ml of soybean agglutinin (SBA), $\text{Cytisus scoparius}$ agglutinin (CSA I), and peanut agglutinin (PNA). The effects of SBA, CSA I, and PNA require pretreatment of the platelets with neuraminidase and are inhibited by D-galactose. PNA is the only one of these lectins which simultaneously induces the secretion and the concomitant shape change of platelets. Cytochalasin B enhances the effect of PNA but is inactive with SBA and CSA I. Thus the saccharide specificity of the lectins does not determine the kind of the platelet response for which additional binding properties of these lectins may be crucial.     

Lectin-induced blockage of developmental processes in preimplantation mouse embryos in vitro

This study attempts to assess the developmental importance of cell surface glycoconjugates of preimplantation mouse embryos. This was done by incubating early embryos in various lectins and analyzing subsequent development. If specific cell surface glycoconjugates (lectin receptors) are linked to specific developmental processes, such as cell division, compaction, and blastocyst formation, then different lectins should block these different developmental processes. The results show that wheat-germ agglutinin (WGA; N-acetyl-D-glucosamine-specific) at 50 μg/ml prevents the cell division of four-cell embryos. However, this effect of WGA occurs only in embryos with intact zonae pellucidae. Concanavalin A (Con A; α-D-glucose and α-D-mannose-specific) treatment, 20 μg/ml, of four-cell or early eight-cell embryos prevents compaction, the first major change in cell shape in early mouse embryogenesis. Divalent succinly Con A does not affect development, suggesting that the Con A effect is due to crosslinking of cell surface glycoconjugates. Exposure of four-cell or early eight-cell embryos to 10 μg/ml Lotus Tetragonolobus puprureas agglutinin (LTA; α-L-fucose-specific) or 25 μg/ml Limulus polyphemus agglutinin (LPA; sialic acid-specific) allows compaction or development to the morula stage, but blocks blastocyst formation. All lectins tested retard cell division to some extent. Late morulae and early blastocysts are more resistant than earlier stages to all of the lectins studied. This study demonstrates that very low concentrations of these lectins affect different developmental processes, presumably based upon their sugar specificities.     

Lectin binding to newt epidermis: fluorescent localization and effects on motility

The ability of seven lectins to bind to newt epidermal cells and influence their motility was examined. Of the seven fluoresceinated lectins applied to frozen sections containing intact newt skin and migrating epidermis (wound epithelium), only Con A (concanavalin A), WGA (wheat germ agglutinin), and PNA (peanut agglutinin) produced detectable epidermal fluorescence. Con A and WGA each heavily labeled all layers of intact epidermis, but PNA bound only to the more superficial layers. In contrast to a single population of labeled cells in migrating epidermal sheets after treatment with Con A, there were both labeled and unlabeled cells after exposure to either WGA or PNA. The wound bed was labeled by both Con A and WGA, but not by PNA. DBA (Dolichos bifloris agglutinin), RCA I (Ricinus communis agglutinin), and UEA (Ulex europaeus agglutinin), did not produce significant fluorescence with either migrating or intact epidermis. In general, inhibitory effects on epidermal motility correlated with the binding studies. Thus, Con A, WGA, and PNA, the lectins which clearly bound to the epidermis, all produced a concentration-dependent depression in the rate of epidermal wound closure. RCA was somewhat paradoxical in that it was moderately inhibitory despite showing essentially no binding. The effects of SBA and UEA were equivocal. DBA had no effect. These results indicate that the inhibition of motility produced by Con A that we have described previously is not peculiar to this mannose-binding lectin, but is shared by at least one lectin with an affinity for D-GlcNAc (WGA), and one with an affinity for B-D-Gal(1-3)-D-GalNAc (PNA).(ABSTRACT TRUNCATED AT 250 WORDS)     

Search for the presence of lectin-binding sites on Toxoplasma gondii

Evidence for the presence of carbohydrate on the surface membrane of Toxoplasma gondii trophozoites and on the cell wall of toxoplasma brain cysts was sought by fluorescent lectin staining. Using FITC-conjugated preparations of Concanavalin A (Con A), wheat germ agglutinin (WGA), or soy bean agglutinin (SBA), we have failed to obtain evidence for the binding of these lectins on the surface of T. gondii trophozoites. In contrast, the three test lectins bound effectively and specifically to the wall of toxoplasma brain cysts. Prefixation of cysts with glutaraldehyde or brief trypsinization of cysts did not affect the intensity of cyst wall fluorescence when stained with FITC-conjugated Con A, SBA, or WGA. The results are interpreted to indicate that whereas exposed Con A, SBA, and WGA binding sites are associated with the wall of toxoplasma brain cysts, such lectin-binding saccharide residues are not present on the surface of trophozoites in exposed or reactive form.     

Changes in lectin-binding pattern in the digestive tract of Xenopus laevis during metamorphosis. I. Gastric region.

The distribution of structural and secretory glycoconjugates in the gastric region of metamorphosing Xenopus laevis was studied by the avidin-biotin-peroxidase (ABC) histochemical staining method using seven lectins (concanavalin A, Con A; Dolichos biflorus agglutinin, DBA; peanut agglutinin, PNA; Ricinus communis agglutinin I, RCA-I; soybean agglutinin, SBA; Ulex europeus agglutinin I, UEA-I; and wheat germ agglutinin, WGA). Throughout the larval period to stage 60, the epithelium consisting of surface cells and gland cells was stained in various patterns with all lectins examined, whereas the thin layer of connective tissue was positive only for RCA-I. At the beginning of metamorphic climax, the connective tissue became stained with Con A, SBA, and WGA, and its staining pattern varied with different lectins. The region just beneath the surface cells was strongly stained only with RCA-I. With the progression of development, both the epithelium and the connective tissue gradually changed their staining patterns. The surface cells, the gland cells, and the connective tissue conspicuously changed their staining patterns, respectively, for Con A and WGA; for Con A, PNA, RCA-I, SBA, and WGA; and for Con A, RCA-I, and WGA. At the completion of metamorphosis (stage 66), mucous neck cells became clearly identifiable in the epithelium, and their cytoplasm was strongly stained with DBA, PNA, RCA-I, and SBA. These results indicate that lectin histochemistry can provide good criteria for distinguishing among three epithelial cell types, namely, surface cells, gland cells, and mucous neck cells, and between adult and larval cells of each type.     

Lectin histochemistry of human skeletal muscle

Biotinyl derivatives of seven plant lectins-concanavalin A (Con A), peanut agglutinin (PNA), Ricinus communis agglutinin I (RCA I), Ulex europeus agglutinin I (UEA I), soybean agglutinin (SBA), Dolichos biflorus agglutinin (DBA), and wheat germ agglutinin (WGA)-were bound to cryostat sections of biopsied normal human muscle and visualized with avidin-horseradish peroxidase conjugates. A distinct staining pattern was observed with each lectin. The most general staining was observed with Con A, RCA I, and WGA, which permitted strong visualization of the plasmalemma-basement membrane unit, tubular profiles in the interior of muscle fibers, blood vessels, and connective tissue. PNA gave virtually no intracellular staining, while SBA and UEA I selectively stained blood vessels. DBA was unique in providing good visualization of myonuclei. In each case, lectin staining could be blocked by appropriate sugar inhibitors. Neuraminidase pretreatment of the cryostat sections altered the pattern of staining by all lectins except UEA I and Con A; staining with RCA I became stronger and that with WGA became less intense, while staining with PNA, SBA and DBA became stronger and more generalized, resembling that of RCA I. These effects of neuraminidase pretreatment are in conformity with the known structure of the oligosaccharide chains of membrane glycoproteins and specificities of the lectins involved.     

Carbohydrate determinants of organs of the reproductive tract of the mouse according to the results of using lectins with different specificities

Histotopography of lectin receptor sites in adult mice ovary, oviduct, uterus, testis and epididymis has been investigated on light-optic level by means of lectin-peroxidase technique. Paraffin sections are treated with peanut agglutinin (PNA), soybean agglutinin (SBA), wheat germ agglutinin (WGA) and Laburnum anagyroides lectin (LAL), conjugated with horseradish peroxidase. Concanavalin A (Con A) receptor sites are visualized by indirect method. The usefulness of lectins for selective histochemic evaluation of definite organ structures is demonstrated. Zona pellucida, luteocytes, oviductal and uterine epitheliocytes are rich in receptor sites for all lectin used in the investigation. The most intense binding to zonae pellucidae glycoconjugates possess WGA and LAL, to luteocytes--PNA, SBA and LAL, to oviductal and uterine epitheliocytes--Con A and LAL. The preferential SBA binding to the acrosomal system and plasma membranes of spermatogenic cells is demonstrated. Changes in lectin-binding patterns during the maturation of intraovarian oocytes and spermatogenic cells are also studied. The perspectives of practical application of the results obtained, as well as trends in further lectin histochemistry investigations of the reproductive system are discussed.     

Lectin binding to neural crest cells. Changes of the cell surface during differentiation in vitro

To examine possible changes in cell surface carbohydrates, fluorescent lectins were applied at various times during differentiation of neural crest cells in vitro. The pattern and intensity of binding of several lectins changed as the crest cells developed into melanocytes and adrenergic cells. Considerable amounts of concanavalin A (Con A) and wheat germ agglutinin (WGA) bound to all unpigmented cells throughout the culture period. Melanocytes, however, bound much less of these lectins. Soy bean agglutinin (SBA), unlike Con A and WGA, only bound later in development to unpigmented cells at about the time when catecholamines were detected histochemically. Binding of SBA could be induced in younger cultures by pretreating the cells with neuraminidase. Melanocytes, however, did not bind detectable amounts of SBA even if treated with neuraminidase. The SBA-binding sites were often concentrated on cytoplasmic extensions and on contact points between neighboring cells, even when receptor mobility was restricted by prefixation of the cells or adsorption of lectin at 0 degrees C. All three lectins bound to cell processes resembling nerve fibers in particularly high amounts.     

Lectin binding to rat spermatogenic cells: Effects of different fixation methods and proteolytic enzyme treatment

Summary The binding of a panel of eight different fluorescein-conjugated lectins to rat spermatogenic cells was investigated. Particular attention was paid to the effects of different fixation methods and proteolytic enzyme digestion on the staining pattern.Concanavalin A (Con A), wheatgerm agglutinin (WGA), succinylated WGA (s-WGA) and agglutinin from gorse (UEA I) stained the cytoplasm of most germ cells as well as the spermatid acrosome. In contrast, peanut agglutinin (PNA), castor bean agglutinin (RCAI) and soy bean agglutinin (SBA) mainly stained the acrosome. The staining pattern varied depending on the fixation method used. PNA was particularly sensitive to formalin fixation, while SBA, DBA and UEA I showed decreased binding and Con A, WGA, s-WGA and RCA I were insensitive to this type of fixation. Pepsin treatment of the sections before lectin staining caused marked changes in the staining pattern; staining with PNA in formalin-fixed tissue sections was particularly improved but there was also enhanced staining with SBA and horse gram agglutinin (DBA). On the other hand, in Bouin- and particularly in acetone-fixed tissue sections, pepsin treatment decreased the staining with several of the lectins, for example WGA and UEA I.     

A differential response elicited in macrophages on interaction with lectins

The interaction of several lectins, both native and chemically modified, with mouse peritoneal macrophages was studied. Surface distribution and interiorization of the lectins was assessed quantitatively using their radioactively-labeled derivatives, and qualitatively by employing fluorescein-labeled lectins. On the basis of their effect on the macrophages, the lectins tested fall into two classes: lectins that induce vacuole formation in the cells (concanavalin A (ConA), wax bean agglutinin (WBA) and wheat germ agglutinin (WGA)) and lectins that in their native form do not induce vacuolation (soybean agglutinin (SBA), peanut agglutinin (PNA) and the lectin from Lotus tetragonolobus (LT)). Neuraminidase treatment of the cells did not change their response to the lectins, though in the case of SBA and PNA binding was observed only with neuraminidase-treated macrophages. Incubation of the latter cells with SBA and subsequently with ConA resulted in significantly higher vacuolation than that observed with ConA alone. Glutaraldehyde-crosslinked polymers of SBA and of PNA, which are multivalent with respect to sugar binding, induced vacuolation in neuraminidase-treated macrophages. On the other hand, succinylation of ConA, which reduces the number of sugar binding sites per mole from four to two, abolished its ability to induce vacuole formation. These data suggest that multivalency of lectins and probably also their size are important factors in inducing vacuolation, by causing extensive crosslinkage of membrane receptors which is prerequisite for triggering of vacuole formation. Quantitative binding and internalization data indicate that vacuole formation is not directly related to the number of lectin receptors on the macrophages nor to the extent of their internalization.     

Effects of plant lectins on the adhesive properties of baby hamster kidney cells

We studied the effects of different lectins on the adhesive properties of baby hamster kidney (BHK) cells. The purpose of these studies was to learn more about the cell surface receptors involved in cell adhesion. Three adhesive phenomena were analyzed: 1) the adhesion of BHK cells to lectin-coated substrata; 2) the effects of lectins on the adhesion of cells to substrata coated by plasma fibronectin (pFN); and 3) the effects of lectins on the binding of pFN-coated beads to cells. Initial experiments with fluorescein-conjugated lectins indicated that concanavalin A (Con A), ricinus communis agglutinin I (RCA I), and wheat germ agglutinin (WGA) bound to BHK cells but peanut agglutinin (PNA), soybean agglutinin (SBA), and ulex europaeus agglutinin I (UEA I) dod not bind. All three of the lectins which bound to the cells promoted cell spreading on lectin substrata, and the morphology of the spread cells was similar to that observed with cells spread on pFN substrata. Protease treatment of the cells, however, was found to inhibit cell spreading on pFN substrata or WGA substrata more than on Con A substrata or RCA I substrata. In the experiment of cells with Con A or WGA inhibited cell spreading on pFN substrata, but RCA I treatment had no effect. Finally, treatment of cells with WGA inhibited binding to cells of pFN beads, but neither Con A nor RCA I affected this interaction. These results indicate that the lectins modify cellular adhesion in different ways, probably by interacting with different surface receptors. The possibility that the pFN receptor is a WGA receptor is discussed.     

Early events of secretory granule formation in the rat parotid acinar cell under the influence of isoproterenol. An ultrastructural and lectin cytochemical study

The events involved in the maturation process of acinar secretory granules of rat parotid gland were investigated ultrastructurally and cytochemically by using a battery of four lectins [Triticum vulgaris agglutinin (WGA), Ulex europaeus agglutinin I (UEA-I), Glycine max agglutinin (SBA), Arachys hypogaea agglutinin (PNA)]. In order to facilitate the study, parotid glands were chronically stimulated with isoproterenol to induce secretion. Specimens were embedded in the Lowicryl K4M resin. The trans-Golgi network (TGN) derived secretory granules, which we refer to as immature secretory granules, were found to be intermediate structures in the biogenesis process of the secretory granules in the rat parotid acinar cell. These early structures do not seem to be the immediate precursor of the mature secretory granules: in fact, a subsequent interaction process between these early immature granule forms and TGN elements seems to occur, leading, finally, to the mature granules. These findings could explain the origin of the polymorphic subpopulations of the secretory granules in the normal acinar cells of the rat parotid gland. The lectin staining patterns were characteristic of each lectin. Immature and mature secretory granules were labelled with WGA, SBA, PNA, and lightly with UEA-I. Cis and intermediate cisternae of the Golgi apparatus were labelled with WGA, and trans cisternae with WGA and SBA.     

Lectin binding ability of B-chronic lymphocytic leukaemia cells.

The binding of five fluorescein-labelled lectins: peanut agglutinin (PNA), lentil agglutinin (LEN), soybean agglutinin (SBA), wheat germ agglutinin (WGA) and asparagus pea agglutinin (ASP) to human B-cell chronic lymphocytic leukaemia (B-CLL) and B lymphocytes of normal donors was studied. The specificity of the fluorescence was demonstrated by inhibition with appropriate saccharides. The proportion of B cells was estimated using anti-B cell monoclonal antibody. Both leukaemic and normal B cells showed the binding ability of all except of one (ASP) studied lectins. We have found the differences in surface carbohydrate patterns between B-CLL and normal B lymphocytes. B-CLL cells showed the considerably lower ability to bind SBA and slightly higher expression of PNA and LEN receptors in comparison to normal B cells. The analysis of WGA binding allowed for recognizing two groups of CLL patients: one with high and the second one with low WGA receptor expression. The double marker studies revealed that B cells could simultaneously react with anti-B cell monoclonal antibody and fluorochrome labelled lectins.