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PubMed1978

Effects of wheat germ agglutinin and concanavalin A on parameters of highly purified sodium-potassium adenosine triphosphatases from Squalus acanthias and Electrophorus electricus.

The effects of two lectins, wheat germ agglutinin and concanavalin A, were studied on a variety of parameters of two highly purified (Na+ + K+)-ATPases (ATP phosphohydrolase, EC 3.6.1.3), from the rectal salt gland of Squalus acanthias and from the electroplax of Electrophorus electricus. Both lectins agglutinated the rectal gland enzyme equally, but wheat germ agglutinin inhibited (Na+ + K+)-ATPase activity much more. The electroplax enzyme was only marginally agglutinated and inhibited by the lectins. Neuraminidase treatment of the rectal gland (Na+ + K+)-ATPase had no effect on germ agglutinin inhibition. The inhibition of the rectal gland (Na+ + K+)-ATPase by wheat germ agglutinin could be reversed by N,N'-diacetylchitobiose, which has a high affinity for wheat germ agglutinin. Neither ouabain inhibition nor ouabain binding to the rectal gland enzyme was affected by wheat germ agglutinin. The p-nitrophenylphosphatase activity of the rectal gland enzyme was not inhibited by wheat germ agglutinin. Na+-ATPase activity, which reflects ATP binding and phosphorylation at the substrate site was inhibited by wheat germ agglutinin and this inhibition was reversed by potassium. Evidence is cited (Pennington, J. and Hokin, L.E., in preparation) that the inhibition of the (Na+ + K+)-ATPase by wheat germ agglutinin is due to binding to the glycoprotein subunit.

Animals↗
PubMed1976

Structure and toxicity of pure ricinus agglutinin.

Highly purified ricinus agglutinin was found to inhibit protein synthesis in HeLa cells. This effect could be prevented by the addition of the specific antiricinus agglutinin serum, whereas specific anti-ricin serum did not protect the cells, demonstrating that the toxic effect of ricinus agglutinin is not due to contamination with ricin. After reduction of ricinus agglutinin with 2-mercaptoethanol in the presence of 0.5 M galactose the constituent peptide chains were separated by chromatography on a DE-52 column. The B'-chain passed through the column, whereas the A'-chain bound and was eluted with a salt gradient. The B'-chain was further purified by chromatography on a CM-52 column. The shortest chain, the A'-chain, was found to inhibit cell-free protein synthesis whereas the B'-chain did not have this ability. On the other hand, the B'-chain was able to induce agglutination of erythrocytes when tested together with anti-ricinus agglutinin serum indicating that the "b'-chains bind to the cells. Ouchterlony immunodiffusion tests with crude anti-ricin and anti-ricinus agglutinin sera revealed that the two constituent chains of ricinus agglutinin are immunologically partial identical and that they also show reaction or partial identity with both chains of the toxic lectin ricin. The data indicate that a similar structure-function relationship exists in ricinus agglutinin as in ricin. The reason for the much lower toxicity of ricinus agglutinin than of ricin in living animals is discussed.

HeLa Cells↗
PubMed1988

Cell-cell recognition in yeast: isolation of intact alpha-agglutinin from Saccharomyces kluyveri.

The heat-labile sexual agglutinin from Saccharomyces kluyveri strain 17 (alpha-agglutinin) has been isolated in an apparently intact form from wild-type and mnn1 (glycosylation-defective) cells. The wild-type agglutinin is polydisperse, due to variable degrees of glycosylation, and migrates on native gels with an apparent mass of greater than 400 kDa, whereas under denaturing conditions it appears somewhat smaller. The mnn1 agglutinin is also heterogeneous but has a lower molecular mass due to the presence of shorter N- and O-linked polymannose chains. Both agglutinins are converted sequentially by proteolysis to active fragments of approximately equal to 150 and 60 kDa, but the rate of proteolysis of the more highly glycosylated wild-type agglutinin is much slower than that of the mnn1 agglutinin. The 60-kDa fragment was isolated by HPLC and found to contain 46% carbohydrate as mannose, all of which was linked to serine and threonine. Thus, the N-linked oligosaccharides are restricted to that part of the agglutinin molecule that presumably anchors the agglutinin in the cell wall.

Kinetics↗
PubMed1993

Cell surface anchorage and ligand-binding domains of the Saccharomyces cerevisiae cell adhesion protein alpha-agglutinin, a member of the immunoglobulin superfamily.

alpha-Agglutinin is a cell adhesion glycoprotein expressed on the cell wall of Saccharomyces cerevisiae alpha cells. Binding of alpha-agglutinin to its ligand a-agglutinin, expressed by a cells, mediates cell-cell contact during mating. Analysis of truncations of the 650-amino-acid alpha-agglutinin structural gene AG alpha 1 delineated functional domains of alpha-agglutinin. Removal of the C-terminal hydrophobic sequence allowed efficient secretion of the protein and loss of cell surface attachment. This cell surface anchorage domain was necessary for linkage to a glycosyl phosphatidylinositol anchor. A construct expressing the N-terminal 350 amino acid residues retained full a-agglutinin-binding activity, localizing the binding domain to the N-terminal portion of alpha-agglutinin. A 278-residue N-terminal peptide was inactive; therefore, the binding domain includes residues between 278 and 350. The segment of alpha-agglutinin between amino acid residues 217 and 308 showed significant structural and sequence similarity to a consensus sequence for immunoglobulin superfamily variable-type domains. The similarity of the alpha-agglutinin-binding domain to mammalian cell adhesion proteins suggests that this structure is a highly conserved feature of adhesion proteins in diverse eukaryotes.

Amino Acid Sequence↗
PubMed1976

Opposing effects of mitogenic and nonmitogenic lectins on lymphocyte activation. Evidence that wheat germ agglutinin produces a negative signal.

In an effort to clarify the mechanism by which certain plant lectins induce lymphocyte activation, we have studied amino acid (amino[14C]isobutyric acid) uptake in purified human lymphocytes exposed to mitogenic and nonmitogenic lectins. In confirmation of earlier work, mitogenic lectins (concanavalin A and two phytohemagglutinins) produced a dose-related, 2- to 10-fold increase in aminoisobutyric acid transport. Changes occurred as early as 2 hours and reached a maximum after 18 hours. The stimulation by concanavalin A was inhibited by alpha-methyl-D-mannoside but not by other selected monosaccharides, indicating that the effect is modulated through specific carbohydrate receptors. In contrast to the stimulation with concanavalin A and phytohemagglutinin, the nonmitogen wheat germ agglutinin inhibited aminoisobutyric acid transport, both in the presence and absence of the mitogenic lectins. The inhibition was seen over a broad wheat germ agglutinin dose range, was prevented by N-acetylglucosamine, a known inhibitor of wheat germ agglutinin binding, and did not appear to be associated with cytotoxicity. Comparative binding studies with radiolabeled concanavalin A and wheat germ agglutinin demonstrated that differences in transport occurred in cells containing comparable numbers of bound lectin molecules indicating that the failure of wheat germ agglutinin to stimulate a response was not a result of ineffective binding. The lack of stimulation by wheat germ agglutinin was not due to its inability to interact multivalently with membrane receptors since this lectin is divalent, produces capping and agglutination, and continues to inhibit aminoisobutyric acid transport even after the minimum valence was increased to 4 by cross-linking with glutaraldehyde. In contrast both divalent and tetravalent concanavalin A produced stimulation. Competitive binding studies with soluble wheat germ agglutinin or lectin attached to 300 A latex spheres revealed little or no competition for binding sites with radiolabeled concanavalin A, suggesting the two lectins are interacting with different receptors. This was further suggested by kinetic studies of aminoisobutyric acid transport which indicated that wheat germ agglutinin was probably affecting both the Vmax and Km of transport, whereas concanavalin A affected only the Vmax. While the mechanism by which concanavalin A and wheat germ agglutinin produce opposing effects on amino acid transport is not clear, since the two lectins appear to be interacting with different surface receptors we would suggest that they are perturbing microanatomically and functionally different domains on the lymphocyte plasma membrane.

Aminoisobutyric Acids↗
PubMed1988

Quantitation of lectin binding sites in human colon mucins by use of peanut and wheat germ agglutinins.

We have developed a novel method for quantitation of lectin binding sites in mucins derived from colon tissues. Binding of peanut agglutinin and wheat germ agglutinin was measured in extracts from normal and malignant human colon epithelium. Binding of wheat germ agglutinin was used as an estimate of the total mucin present in the tissue extract. Peanut agglutinin was found to bind to mucin from normal colon, but at levels that may be difficult to appreciate by fluorescence microscopy. The yield of mucin extracted from colon cancer was more variable than that from normal colon, and the binding ratio of peanut agglutinin to wheat germ agglutinin was greater in extracts from tumors than in normal tissues. Our findings confirm the histological observation that peanut agglutinin binds more avidly to mucins from colon cancer than to those from normal colon. The finding of peanut agglutinin binding sites in mucins front normal colon was not expected. The quantitative technique may have detected small numbers of binding sites not readily appreciable by fluorescence microscopy. Alternatively, the chromatographic method for measuring lectin binding may be sufficiently sensitive to detect nonspecific binding of the lectin to terminal galactose residues other than the Thomsen-Friedenreich antigen.

Arachis↗
PubMed1993

Stage-specific binding of peanut agglutinin to aggregates of degenerating photoreceptor cells in the rd mouse retina.

Peanut agglutinin, a lectin with high binding affinity for galactose-galactosamine disaccharide, was used to monitor changes in the photoreceptor cell layer of mice with inherited retinal degeneration. Mice homozygous for the retinal degeneration (rd) gene exhibit a rapid loss of rod photoreceptor cells in the first postnatal month. Previous studies have shown that aggregates of peanut agglutinin-binding cells are observed in the outer nuclear layer in the retinal degenerative mouse at between postnatal days 10 and 18, a period during which massive photoreceptor degeneration occurs in this mutant. This study was performed to determine whether these peanut agglutinin-positive cell clusters represent degenerating photoreceptor cells or, alternatively, macrophages that have migrated into the photoreceptor cell layer. Electron microscopic cytochemistry, using horseradish-peroxidase-conjugated peanut agglutinin, was used to trace cellular processes of peanut-agglutinin-stained cell clusters. Additionally, macrophage-specific antibodies were employed to determine whether macrophages were present in the clusters. The cell clusters did not react with macrophage-specific antibodies. However, processes of cells in peanut-agglutinin-bound clusters could be traced by electron microscopic serial sections to both the outer limiting membrane and the outer synaptic layer. These results provide strong evidence that peanut-agglutinin-bound cells seen during this stage of degeneration in the rd mouse are degenerating photoreceptor cells. Since peanut agglutinin has been shown to bind preferentially to cone, but not to rod, photoreceptor cells, the results also suggest that the clusters may be aggregates of degenerating cones.

Animals↗
PubMed1991

Effects of denervation on the distribution of peanut agglutinin binding molecules in frog muscles.

The extracellular matrix has been shown to play an important role in the differentiation of neuromuscular junctions during reinnervation in frogs. Peanut agglutinin, a lectin, is known to specifically bind to some glycoconjugates in the extracellular matrix at the frog neuromuscular junction and myotendinous junction. In order to determine if innervation has any role in regulating the specific binding of peanut agglutinin at neuromuscular junctions and myotendinous junctions, the distribution of peanut agglutinin binding was examined in muscles chronically denervated for various periods. Short-term denervated muscles (less than or equal to 2 months) showed no changes in peanut binding agglutinin binding at neuromuscular junctions and no extrajunctional binding. In contrast, long-term denervation (greater than 2 months - 7.5 months) resulted in altered peanut agglutinin distribution and a substantial reduction or a total loss in its binding at denervated neuromuscular junctions; binding at myotendinous junctions was not affected. Results of electron microscopic studies suggest that the presence of Schwann cells at denervated endplates delays the loss of peanut agglutinin binding. Reinnervation restores normal peanut agglutinin binding at neuromuscular junctions following long-term denervation. This report demonstrates that although the distribution of peanut agglutinin binding molecules is unchanged short-term denervation, intact innervation is necessary for the long-term maintenance of these molecules at neuromuscular junctions.

Animals↗
PubMed1986

Structural and conformational features that affect the interaction of polylactosaminoglycans with immobilized wheat germ agglutinin.

We examined the interaction between immobilized wheat germ agglutinin and the large, polylactosamine-containing glycans from human erythrocytes and human K-562 erythroleukemic cells. Three classes of interaction were identified. One class of glycan was merely retarded during chromatography. The other two classes were retained and could be distinguished by their ease of displacement with N-acetylglucosamine (GlcNAc); one was a moderate-affinity fraction displaced by 0.1 M GlcNAc and the other was a high-affinity fraction subsequently displaced by 1.0 M GlcNAc. A relatively small fraction of the K-562 polylactosamines were in the high-affinity class. We explored the role that fucose and sialic acid substitutions play in the strength of the lectin-glycan interaction. Although sialic acid is recognized by wheat germ agglutinin, sialylation was not required for the high-affinity interaction, and the presence of sialic acids actually prevented some glycans from binding with high affinity. In contrast, fucose is not part of the binding determinant, yet the removal of fucose resulted in decreased affinity. The possibility that some of these changes in affinity were the result of conformational changes was explored using matrices that had wheat germ agglutinin immobilized at different densities. At low wheat germ agglutinin densities, adult and fetal erythroglycans and K-562 glycophorin-like glycans were not retained by the matrix. As the density increased, the proportion of glycans that were retarded, and ultimately retained, increased. While these increases in the proportions retained occurred in parallel for the three different glycans, the apparent affinities of the glycan-lectin interactions differed. The glycophorin-like glycans were always readily displaced by 0.1 M GlcNAc, even at higher wheat germ agglutinin densities. In contrast, as the wheat germ agglutinin density increased, the proportion of erythroglycans that could be displaced by 0.1 M GlcNAc decreased; at 10 mg/ml immobilized wheat germ agglutinin, greater than 80% of the erythroglycans exhibited this tighter interaction. We suggest that this higher affinity interaction is the result of the large glycans spanning adjacent wheat germ agglutinin molecules, and is determined by the proximity of these molecules and the conformation of the glycans.

Amino Sugars↗
PubMed1976

Purification and characterization of the agglutinins from the sponge Axinella polypoides and a study of their combining sites.

The hemagglutinins from the sponge Axinella polypoides were isolated by affinity chromatography using Sepharose 4B as an absorbent and eluting with DGal. Further separation on DEAE-cellulose and preparative disc electrophoresis on polyacrylamide and agarose gave three fractions. The physicochemical properties and binding specificities of the two main agglutinins were studied. Homogeneity was tested by polyacrylamide electrophoresis and immunoelectrophoresis and by sedimentation analysis. In isoelectric focusing, agglutinin I (mol wt 21 000) showed two bands at pH 3.8 and 3.9. Agglutinin II (mol wt 15 000) showed one band at pH 3.9. Both agglutinins have a carbohydrate content of about 0.5%, are immunochemically unrelated, and differ in amino acid composition. Both precipitate A1, A2, B, Lea, and precursor I blood group substances but to different extents. Inhibition experiments revealed that both agglutinins are inhibited best by terminal nonreducing DGal glycosidically linked beta 1 leads to 6 or by p-nitrophenyl-betaDGal. DGal and DFuc are equally active but about 20 and 12 times less active with agglutinin I and agglutinin II, respectively. DGalNAc and LFuc were inactive even at much higher concentrations. Both agglutinins have similar specificities and react with the immunodominant determinants of blood group B and Lea but not with A and H substances; in A and H substances, reactivity is with side chains in which beta-linked DGal is unsubstituted at the nonreducing terminus. The Axinella polypoides lectins are compared with galactose-specific lectins of different origin and with the aggregation factor system is sponges.

Agglutinins↗
PubMed2001

Human salivary agglutinin binds to lung surfactant protein-D and is identical with scavenger receptor protein gp-340.

Salivary agglutinin is a 300-400 kDa salivary glycoprotein that binds to antigen B polypeptides of oral streptococci, thereby playing a role in their colonization and the development of caries. A mass spectrum was recorded of a trypsin digest of agglutinin. A dominant peak of 1460 Da was sequenced by quadrupole time-of-flight (Q-TOF) tandem MS. The sequence showed 100% identity with part of the scavenger receptor cysteine-rich ('SRCR') domain found in gp-340/DMBT1 (deleted in malignant brain tumours-1). The mass spectrum revealed 11 peaks with an identical mass as a computer-simulated trypsin digest of gp-340. gp-340 is a 340 kDa glycoprotein isolated from bronchoalveolar lavage fluid that binds specifically to lung surfactant protein-D. DMBT1 is a candidate tumour suppressor gene. A search in the human genome revealed only one copy of this gene. The molecular mass, as judged from SDS/PAGE and the amino acid composition of agglutinin, was found to be nearly identical with that of gp-340. It was shown by Western blotting that monoclonal antibodies against gp-340 reacted with salivary agglutinin, and monoclonals against agglutinin reacted with gp-340. It was demonstrated that gp-340 and agglutinin bound in a similar way to Streptococcus mutans and surfactant protein-D. Histochemically, the distribution of gp-340 in the submandibular salivary glands was identical with the agglutinin distribution, as shown in a previous paper [Takano, Bogert, Malamud, Lally and Hand (1991) Anat. Rec. 230, 307-318]. We conclude that agglutinin is identical with gp-340, and that this molecule interacts with S. mutans and surfactant protein-D.

Agglutinins↗
PubMed1985

Characterization of the purified Chlamydomonas minus agglutinin.

Chlamydomonas flagellar sexual agglutinins are responsible for the adhesion of opposite mating-type (plus and minus) gametes during the first stages of mating. Purification and partial characterization of the plus agglutinin was previously reported (Adair, W. S., C. J. Hwang, and U. W. Goodenough, 1983, Cell, 33:183-193). Here we characterize the purified minus molecule. We show it to be a high molecular weight, hydroxyproline-rich glycoprotein that migrates in the 3% stacking region of an SDS-polyacrylamide gel and is absent from two nonagglutinating minus mutants. Plus and minus agglutinins are remarkably similar, although nonidentical, in amino acid composition, molecular morphology, and reactivity in vivo and in vitro with monoclonal antibodies raised against the plus agglutinin. Moreover, the adhesiveness of both plus and minus agglutinins, when coupled to agarose beads, is abolished by thermolysin, trypsin, periodate, alkaline borohydride, reducing agents, or heat, but unaffected by exo- or endoglycosidases. The minus agglutinin, however, migrates just ahead of the plus molecule on SDS PAGE, is excluded from an anion-exchange (Mono Q) column, elutes earlier during hydrophobic interaction (Bio-gel TSK Phenyl 5PW) chromatography, and is sensitive to chymotrypsin digestion (unlike the plus agglutinin); therefore, it differs from the plus agglutinin in apparent molecular weight, net charge, relative hydrophobicity and proteolytic susceptibility. Nevertheless, our results generally demonstrate a high degree of homology between these complementary cell-cell recognition/adhesion molecules, which suggests that they are specified by genes that have a common evolutionary origin.

Agglutinins↗
PubMed1982

Removal of wheat-germ agglutinin increases protein synthesis in wheat-germ extracts.

Affinity chromatography of wheat germ extracts on a chitin column increased the rate and extent of protein synthesis, programmed by rabbit globin mRNA. Addition of purified wheat germ agglutinin to the chitin-treated extract reduced the rate of protein synthesis to about the levels seen in the untreated extracts. Experiments where the ratio of messenger to extract and the ratio of supernatant to ribosomes were varied, indicated that addition of wheat germ agglutinin reduced the amount of available ribosomes. Reduced and carboxymethylated wheat germ agglutinin failed to inhibit protein synthesis and was unable to bind to the ribosomes. However, labelled intact agglutinin was found to be bound to ribosomes. The bound agglutinin was not released by acid treatment. The inhibiting effect of wheat germ, agglutinin on protein synthesis could not be counteracted by addition of N-acetyl-D-glucosamine or sialic acid, whereas thiols partially diminished the inhibition. The data indicate that wheat germ agglutinin binds reversibly to ribosomes, probably through mixed disulfide formation, and that chitin treatment increases the ability of wheat germ extracts to support protein synthesis, at least in part, by removing the wheat germ agglutinin. The possibility that chitin treatment also removed other inhibitors of protein synthesis cannot be excluded.

Animals↗
PubMed1985

IgG-mediated haemolysis masquerading as cold agglutinin-induced anaemia complicating severe infection with mycoplasma pneumoniae.

Haemolytic anaemia complicating Mycoplasma infection has usually been attributed to IgM cold agglutinins. This report describes a patient with pneumonia due to Mycoplasma pneumoniae in whom severe haemolysis persisted despite declining thermal amplitude and titre of cold agglutinins as the infection resolved. Class-specific anti-globulin (Coombs) testing defined an IgG warm agglutinin coating the patient's erythrocytes that was distinct from the IgM cold agglutinin identified by Sephadex G-200 gel filtration and dithiothreitol inactivation. Monoclonal IgM(gamma) and IgK(k) circulating proteins were identified and immuno-electrophoresis of the cold agglutinin-containing cryoglobulin fraction identified the cold agglutinin as an IgM(gamma). In this patient initially presumed to have cold agglutinin induced haemolysis secondary to Mycoplasma infection, an IgG warm agglutinin was identified as the aetiology for the patient's haemolysis, underscoring the clinical relevance of careful evaluation of the mechanism of haemolysis accompanying Mycoplasma pneumonia.

Agglutinins↗
PubMed1994

Selective inhibition of a step of myotube formation with wheat germ agglutinin in a murine myoblast cell line, C2C12.

Myoblast cells, C2C12, which is an established cell line from satellite cells of skeletal muscle of C3H mouse, start to fuse and form multinucleated cells (myotubes) and begin to express creatine phosphokinase and myosin, when culture medium is changed from the growth medium to the differentiation medium. Among the 12 lectins that we tested, wheat germ agglutinin apparently suppressed the myotube development judged by phase-contrast microscopy, but did not affect the induction of creatine phosphokinase activity. The addition of N-acetylglucosamine or N,N',N"-triacetylchitotriose, which is a specific ligand for wheat germ agglutinin, to the differentiation medium, recovered this apparently suppressive effect of wheat germ agglutinin on the myotube development. Tachypleus tridentatus (Japanese horseshoe crab) lectin that specifically recognizes N-acetylneuraminic acid, one of the sialic acids, showed no effect on the myotube development. It was suggested that wheat germ agglutinin suppressed the process through recognizing N-acetylglucosamine containing sugar. Surprisingly, even in the presence of wheat germ agglutinin, the ratio of mononucleated cell numbers to the genomic DNA content, which represents the fusion level, decreased after incubation in the differentiation medium, indicating that even when wheat germ agglutinin was present in the medium, cell fusion, which is the initial step of the myotube formation, occurred. Immunostaining with anti-skeletal muscle myosin antiserum confirmed that the myosin expressing cells actually fused and formed multinucleated cells. Their shape, however, was thin compared to that in the absence of wheat germ agglutinin. We propose that the membrane fusion step to form myotubes is composed of two distinct steps in C2C12; one fusion step is to form long and thin myotubes from mononucleated cells and the other one is to develop fat myotubes. Wheat germ agglutinin specifically inhibits the latter fusion step.

Agglutinins↗
PubMed1991

Increase in cell surface wheat germ agglutinin binding in a rat hepatoma cell line dRLa 74 treated with concanavalin A.

Wheat germ agglutinin binding to a rat hepatoma cell line dRLa 74 treated with concanavalin A was studied. It increased depending on the concanavalin A concentration in the culture medium. The cells exhibited about twofold increase in wheat germ agglutinin-binding when pretreated with 50 micrograms/ml of concanavalin A for 48 h. The wheat germ agglutinin binding sites were shown to be localized at the cell surface by lectin-histochemistry. Wheat germ agglutinin blotting of microsomal membrane proteins showed a broad wheat germ agglutinin-reactive band with an apparent molecular weight of 90 to 100 kDa. Loss of wheat germ agglutinin binding to dRLa 74 cells and the glycoprotein after neuraminidase treatment suggested that wheat germ agglutinin reacted with cell surface sialyl residues of dRLa 74 cells. The induced change was reversible. Increased wheat germ agglutinin binding returned to the pretreatment level when the concanavalin A-treated cells were subcultured in the absence of concanavalin A. These observations suggest that environmental factors interacting with tumor cell surface sugar moieties may induce reversible epigenetic changes on cell surface carbohydrate structures.

Animals↗
PubMed2001

Relevance of low titers of cryoglobulins and cold-agglutinins in patients with isolated Raynaud phenomenon.

INTRODUCTION: A Raynaud phenomenon can be associated with cold agglutinins or cryoglobulins. Although cold agglutinins or cryoglobulins may lead to severe acral gangrene the finding of relevant titers is rare. Low titers of cold agglutinins or cryoglobulins are detected more frequently but are assumed to be without any importance. OBJECTIVES: To prove a possible diagnostic or prognostic role of low titers of cold agglutinins or cryoglobulins in patients presenting an isolated Raynaud phenomenon we did a retrospective analysis. SETTINGS AND SUBJECTS: In 306 patients (40+/-16 years, range: 15-83 years) with a mean duration of the history of an isolated Raynaud phenomenon of 48+/-73 months we did a clinical examination, an analysis of antinuclear antibodies, extractable antibodies, cold agglutinins, cryoglobulins, plasma and blood viscosity, erythrocyte aggregation and a nail fold capillaroscopy. RESULTS: Low titers of cold agglutinins were found in 49 patients and of cryoglobulins in 7 patients. The finding of such low titers was not associated with extensive clinical symptoms, duration of clinical symptoms, megacapillaries or haemorrhagies in capillaroscopy, pathologic plasma and blood viscosity and erythrocyte aggregation. The follow-up investigations (mean: 3.1+/-1.2 years, range: 3-7 years) revealed no development of a haematological, vasculitic or connective tissue disease in the subgroup of patients who only had low titers of cold agglutinins. CONCLUSION: The detection of low titers of cold agglutinins in patients with isolated Raynaud phenomenon is of no diagnostic or prognostic relevance.

Adolescent↗
PubMed1982

Induction of macrophage-mediated tumor lysis by an animal lectin, Sarcophaga peregrina agglutinin.

Several animal lectins, such as Sarcophaga peregrina agglutinin, Limulus polyhemus agglutinin, Helix pomatia agglutinin and Helix aspersa agglutinin, were tested for induction of tumor lysis mediated by macrophages. Among them, only S. peregrina agglutinin purified from the hemolymph of S. peregrina larvae lysed tumor cells in co-operation with macrophages from the peritoneal cavity of mice. S. peregrina agglutinin alone did not kill target tumor cells. Macrophages in the presence of this lectin could kill other syngeneic tumor cells. This lectin-dependent cytolysis by macrophages was inhibited by galactose, a sugar which is specifically recognized by S. peregrina agglutinin. These findings suggest that the animal lectin S. peregrina agglutinin is a ligand in macrophage-mediated cytolysis, inducing binding of effector macrophages to target cells which in turn triggers off lysis of the target cells.

Agglutinins↗