Pseudomonas aeruginosa resistance of monosaccharide-functionalized glass surfaces.

Preventing microorganism colonization on a surface is a great challenge in the conception of medical, food and marine devices. Here, we describe the formation of carbohydrate functionalized glass surfaces with D-glucose, D-galactose and D-mannose and how they efficiently affected the bacterial attachment. The carbohydrate entities were covalently attached to the pre-functionalized surface by click chemistry thanks the copper catalysed alkyl-azide cycloaddition. Water contact angle and X-ray photoelectron spectroscopy characterisations showed a homogeneous and quantitative cycloaddition at the scale of microorganisms. The adhesion assays with Pseudomonas aeruginosa, used as model of opportunistic pathogen, indicated a significant diminution of almost 40% of the bacterial accumulation on glycosidic surfaces with respect to initial surface. This activity was further compared with a surface presenting a simple hydroxyl residue. Exploration of specific interactions through Lectin A deficient Pseudomonas aeruginosa mutant strain provided new evidences that Lectin A was involved in biofilm maturation, rather than bacterial attachment. Subsequently, the determination of surface free energy and the adhesion free energy between surfaces and bacterial cell wall showed that the adhesion was thermodynamically unfavourable.

Alteration of salivary glycopatterns in oral lichen planus.

BACKGROUND: Oral lichen planus (OLP) is one of the most common oral mucosal lesions affecting 0.5-2% of the adult population. It is difficult to distinguish between OLP and other oral mucosal diseases. Structural changes in the glycans of saliva proteins might be reliable indicators of OLP. However, little is known about the alteration of salivary glycopatterns during OLP. OBJECTIVE: We aimed to investigate the alterations of salivary protein glycosylation related to OLP. MATERIAL AND METHODS: Twenty-eight patients with OLP and 30 age- and sex-matched healthy volunteers (HVs) were enrolled in the test group to probe the difference of salivary glycopatterns using lectin microarrays. The lectin blotting were further utilized to validate the expression of certain glycans. RESULTS: The glycoproteins recognized by three lectins [Aleuria aurantia lectin (AAL); Phytolacca americana (PWM); Phaseolus vulgaris agglutinin (E + L), (PHA-E + L)] were mainly increasing in the saliva of OLP. Meanwhile, these glycoproteins also exhibited significant age-associated alterations. CONCLUSIONS: This study provided a new basic insight into salivary glycopatterns in OLP and helped to develop new potential biomarkers for diagnosis of OLP.

Lectin-mediated reversible immobilization of human cells into a glycosylated macroporous protein hydrogel as a cell culture matrix.

3D cell culture is a helpful approach to study cell-cell interaction in a native-like environment, but is often limited due the challenge of retrieving cells from the material. In this study, we present the use of recombinant lectin B, a sugar-binding protein with four binding cavities, to enable reversible cell integration into a macroporous protein hydrogel matrix. By functionalizing hydrogel precursors with saccharose, lectin B can both bind to sugar moieties on the cellular surface as well as to the modified hydrogel network. Confocal microscopy and flow cytometry analysis revealed cells to be integrated into the network and to adhere and proliferate. Furthermore, the specificity and reversibility was investigated by using a recombinantly produced yellow fluorescent - lectin B fusion protein and a variety of sugars with diverging affinities for lectin B at different concentrations and elution times. Cells could be eluted within minutes by addition of L-fucose to the cell-loaded hydrogels to make cells available for further analysis.

Decrease in interleukin-21 in children suffering with severe atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a kind of eczema with an inflammatory, relapsing, non-contagious, and pruritic skin disorder. It is associated with the local infiltration of T helper type 2 (Th2) cells that secrete interleukin (IL)-4 and IL-5. IL-21 is a member of IL-2 family cytokine mainly expressed by activated CD4+ T lymphocytes. Until now, there is no clinical research in the expression of IL-21 in patients with AD. METHODS: We analyzed serum levels of total immunoglobulin E (IgE), allergen-specific IgE, and cytokines IL-4, IL-5, IFN-γ, IL-17, and IL-21 in AD cases and controls. In addition, cytokine levels in the culture supernatants of peripheral blood mononuclear cells stimulated with anti-CD3 and anti-CD28 Abs, phytohemagglutin (PHA), or pokeweed mitogen (PWM) were measured. We also assessed clinical skin severity by Scoring of Atopic Dermatitis (SCORAD) index. RESULTS: Our results showed that serum total IgE in the case group was significantly higher than that of control group (365.449 ± 52.945 and 39.243 ± 7.605 IU/ml, respectively). Logistic regression analysis system reveals serum levels of IL-21 and IFN-γ are significantly correlated. However, IL-21 and IL-4, IL-21 and IL-5, as well as IL-21 and IL-17 showed no correlation. CONCLUSION: A significantly decreased level of IL-21 was observed in children suffering with severe AD compared with controls, suggesting that IL-21 may play a role in AD.

Effect of infection with bovine leukosis virus on lymphocyte proliferation and apoptosis in dairy cattle.

OBJECTIVE: To determine effects of infection with bovine leukosis virus (BLV) on lymphocyte proliferation and apoptosis in dairy cattle. ANIMALS: 27 adult Holstein cows. PROCEDURES: Peripheral blood mononuclear cells (PBMCs) were isolated from whole blood from lactating Holstein cows seronegative for BLV (n = 9 cows), seropositive for BLV and aleukemic (aleukemic; 9), and seropositive for BLV and persistently lymphocytotic (PL; 9). Isolated PBMCs were assayed for mitogen-induced proliferation and were analyzed by means of flow cytometry. The PBMCs from a subset of each group were assayed for apoptosis, caspase-9 activity, and expression of selected genes related to apoptosis. RESULTS: PL cows had significantly higher total lymphocyte counts and significantly lower proportions of T-lymphocyte populations than did BLV-negative and aleukemic cows. Both groups of BLV-infected cows had significantly higher proportions of B cells and major histocompatibility complex II-expressing cells than did BLV-negative cows. Proliferation with concanavalin A was significantly lower for PL cows, compared with proliferation for BLV-negative cows. Pokeweed mitogen-induced proliferation was significantly higher for aleukemic and PL cows than for BLV-negative cows. Gene expression of apoptosis-inhibitory proteins BCL2 and BCL2L1 was significantly higher for aleukemic cows and expression of BCL2 was significantly higher for PL cows than for BLV-negative cows. CONCLUSIONS AND CLINICAL RELEVANCE: Cattle infected with BLV had marked changes in PBMC populations accompanied by alterations in proliferation and apoptosis mechanisms. Because the relative distribution and function of lymphocyte populations are critical for immune competence, additional studies are needed to investigate the ability of BLV-infected cattle to respond to infectious challenge.

Early cerebrovascular and parenchymal events following prenatal exposure to the putative neurotoxin methylazoxymethanol.

One of the most common causes of neurological disabilities are malformations of cortical development (MCD). A useful animal model of MCD consists of prenatal exposure to methylazoxymethanol (MAM), resulting in a postnatal phenotype characterized by cytological aberrations reminiscent of human MCD. Although postnatal effects of MAM are likely a consequence of prenatal events, little is known on how the developing brain reacts to MAM. General assumption is the effects of prenatally administered MAM are short lived (24 h) and neuroblast-specific. MAM persisted for several days after exposure in utero in both maternal serum and fetal brain, but at levels lower than predicted by a neurotoxic action. MAM levels and time course were consistent with a different mechanism of indirect neuronal toxicity. The most prominent acute effects of MAM were cortical swelling associated with mild cortical disorganization and neurodegeneration occurring in absence of massive neuronal cell death. Delayed or aborted vasculogenesis was demonstrated by MAM's ability to hinder vessel formation. In vitro, MAM reduced synthesis and release of VEGF by endothelial cells. Decreased expression of VEGF, AQP1, and lectin-B was consistent with a vascular target in prenatal brain. The effects of MAM on cerebral blood vessels persisted postnatally, as indicated by capillary hypodensity in heterotopic areas of adult rat brain. In conclusion, these results show that MAM does not act only as a neurotoxin per se, but may additionally cause a short-lived toxic effect secondary to cerebrovascular dysfunction, possibly due to a direct anti-angiogenic effect of MAM itself.

Trigeminal P2X3 receptor expression differs from dorsal root ganglion and is modulated by deep tissue inflammation.

The distribution and modulation of the P2X(3) receptor was studied in trigeminal ganglion neurons to provide insight into the role of ATP in craniofacial sensory mechanisms. Binding to the d-galactose specific lectin IB4 was found in 73% of P2X(3)-positive neurons while only 16% of IB4 neurons expressed P2X(3). Neurons expressing P2X(3) alone were significantly larger than IB4-or IB4/P2X(3)-positive neurons. Investigation of target-specificity revealed that 22% of trigeminal ganglion muscle afferent neurons were positive for P2X(3) versus 16% of cutaneous afferent neurons. Muscle P2X(3) afferents were significantly smaller than the overall muscle afferent population while P2X(3) cutaneous afferent neurons were not. Presumptive heteromeric (P2X(2/3)) muscle afferent neurons were also identified and comprised 77% of the P2X(3) muscle afferent population. Muscle afferent neurons co-expressed P2X(3) with either calcitonin gene-related peptide (15%) or substance P (4%). The number of P2X(3)-positive muscle afferent neurons significantly increased one and four days following complete Freund's adjuvant-induced masseter muscle inflammation, but significantly decreased after 12 days. These results indicate that within trigeminal ganglia: (1) the P2X(3) receptor is expressed in both small and medium-sized neurons; (2) the P2X(3) receptor is not exclusively expressed in IB4 neurons; (3) P2X(3) is co-expressed with neuropeptides; (4) differences in the proportion of cutaneous versus muscle P2X(3) afferents are not apparent. Trigeminal P2X(3) neurons therefore differ markedly from dorsal root ganglion P2X(3) afferents. This study also shows that deep tissue inflammation modulates expression of the P2X(3) receptor and thus may warrant exploration as a target for therapeutic intervention.

Spinal-supraspinal serotonergic circuits regulating neuropathic pain and its treatment with gabapentin.

Not all neuropathic pain patients gain relief from current therapies that include the anticonvulsant, gabapentin, thought to modulate calcium channel function. We report a neural circuit that is permissive for the effectiveness of gabapentin. Substance P-saporin (SP-SAP) was used to selectively ablate superficial dorsal horn neurons expressing the neurokinin-1 receptor for substance P. These neurons project to the brain as shown by retrograde labelling and engage descending brainstem serotonergic influences that enhance spinal excitability via a facilitatory action on 5HT(3) receptors. We show the integrity of this pathway following nerve injury contributes to the behavioural allodynia, neuronal plasticity of deep dorsal horn neurons and the injury-specific actions of gabapentin. Thus SP-SAP attenuated the tactile and cold hypersensitivity and abnormal neuronal coding (including spontaneous activity, expansion of receptive field size) seen after spinal nerve ligation. Furthermore the powerful actions of gabapentin after neuropathy were blocked by either ablation of NK-1 expressing neurones or 5HT(3) receptor antagonism using ondansetron. Remarkably, 5HT(3) receptor activation provided a state-dependency (independent of that produced by neuropathy) allowing GBP to powerfully inhibit in normal uninjured animals. This circuit is therefore a crucial determinant of the abnormal neuronal and behavioural manifestations of neuropathy and importantly, the efficacy of gabapentin. As this spino-bulbo-spinal circuit contacts areas of the brain implicated in the affective components of pain, this loop may represent a route by which emotions can influence the degree of pain in a patient, as well as the effectiveness of the drug treatment. These hypotheses are testable in patients.

Influence of fish oil supplementation on growth and immune system characteristics of cattle.

A study was conducted to determine the effects of supplemental fish oil on growth performance and immune system characteristics of beef calves. The grazing phase (78 d) used 48 yearling crossbred steers (231 +/- 22 kg initial BW) grazing 0.45-ha mixed-grass pastures (four per treatment) supplemented with 1.82 kg/d (as-fed basis) of the diets. Diets consisted of 1) corn-based supplement; 2) corn-based supplement with 1.5% (as-fed basis) fish oil; 3) wheat midd-based supplement; and 4) wheat midd-based supplement with 1.5% fish oil. On d 78, all calves were bled by jugular venipuncture, and blastogenic response of peripheral blood lymphocytes to phytohemagglutinin, concanavalin A, and pokeweed mitogen was measured. Fish oil supplementation negatively affected ADG with the corn-based supplement, but it had no effect when added to the wheat midd-based supplement (base-supplement x fish oil interaction; P < 0.03). Isolated lymphocytes from calves fed the corn-based supplement with fish oil had a greater response to stimulation with concanavalin A than did lymphocytes from calves fed the corn-based supplement alone, but there was no effect of fish oil addition to the wheat midd-based supplement (base-supplement x fish oil interaction; P < 0.01). During the growing phase, the 48 steers (352 +/- 32 kg initial BW) from the grazing phase were moved to drylot pens and were stratified by BW and previous dietary treatment (three calves per pen; eight pens per dietary treatment) for a 56-d growing trial. Dietary treatments consisted of 1) control, and 2) the control diet with 3% (as-fed basis) fish oil. Calves supplemented with fish oil had decreased ADG, ADFI, and G:F (P < or = 0.02) compared with controls. Fish oil supplementation during the grazing phase modulated the immune system; however, the decreased growth performance associated with fish oil in both trials may limit its practical use as an immune stimulant.

Similarity between protein-protein and protein-carbohydrate interactions, revealed by two crystal structures of lectins from the roots of pokeweed.

The roots of pokeweed (Phytolacca americana) are known to contain the lectins designated PL-A, PL-B, PL-C, PL-D1, and PL-D2. Of these lectins, the crystal structures of two PLs, the ligand-free PL-C and the complex of PL-D2 with tri-N-acetylchitotriose, have been determined at 1.8A resolution. The polypeptide chains of PL-C and PL-D2 form three and two repetitive chitin-binding domains, respectively. In the crystal structure of the PL-D2 complex, one trisaccharide molecule is shared mainly between two neighboring molecules related to each other by a crystallographic 2(1)-screw axis, and infinite helical chains of complexed molecules are generated by the sharing of ligand molecules. The crystal structure of PL-C reveals that the molecule is a dimer of two identical subunits, whose polypeptide chains are located in a head-to-tail fashion by a molecular 2-fold axis. Three putative carbohydrate-binding sites in each subunit are located in the dimer interface. The dimerization of PL-C is performed through the hydrophobic interactions between the carbohydrate-binding sites of the opposite domains in the dimer, leading to a distinct dimerization mode from that of wheat-germ agglutinin. Three aromatic residues in each carbohydrate-binding site of PL-C are involved in the dimerization. These residues correspond to the residues that interact mainly with the trisaccharide in the PL-D2 complex and appear to mimic the saccharide residues in the complex. Consequently, the present structure of the PL-C dimer has no room for accommodating carbohydrate. The quaternary structure of PL-C formed through these putative carbohydrate-binding residues may lead to the lack of hemagglutinating activity.

Effects on functions of ovine blood mononuclear cells for each of several fatty acids at concentrations found in plasma of healthy and ketotic ewes.

OBJECTIVE: To assess effects on functions of peripheral blood mononuclear cells (PBMC) obtained from ewes for each of several fatty acids represented in ovine plasma at concentrations mimicking those of ketotic or healthy ewes. SAMPLE POPULATION: Blood samples obtained from 6 Sardinian ewes. PROCEDURE: The PBMC were cultured in media that contained oleic (OA), palmitic (PA), stearic (SA), linoleic (LA), or palmitoleic (POA) acid at concentrations similar to those of ketotic or healthy ewes. Synthesis of DNA was stimulated by use of concanavalin A or pokeweed mitogen (PWM). Secretion of IgM was stimulated by use of PWM. RESULTS: High concentrations (900, 450, and 225 micromol/L) of OA significantly inhibited DNA synthesis and IgM secretion of PBMC. Conversely, low concentrations (56 or 28 micromol/L) of OA significantly enhanced DNA synthesis of PBMC. High concentrations of PA (600, 300, 150, 75, 375, or 18.7 micromol/L) and SA (300, 150, or 75 micromol/L) significantly inhibited DNA synthesis of PBMC. High concentrations of PA (600, 300, 150, 75, 375, or 18.7 micromol/L) and SA (300, 150, 75, or 38 micromol/L) also significantly inhibited IgM secretion of PBMC. None of the concentrations of LA and POA affected PBMC functions. CONCLUSION AND CLINICAL RELEVANCE: Impaired immunoresponsiveness of ketotic ewes is likely associated with an increase of plasma concentrations of OA, PA, or SA and not with that of LA or POA. At physiologic concentrations, single fatty acids are likely to participate in modulation of immunoresponsiveness by exerting suppressive or stimulatory effects on immune cells.

Activation of indices of cell-mediated immunity in bipolar mania.

BACKGROUND: Evidence supports that macrophages as well as lymphocytes and their products may be involved in the pathophysiology of psychiatric disorders. Whether patients with bipolar disorder have activation or reduction of immunity during a manic episode remains unclear. METHODS: The purpose of this case-control study was to investigate the lymphocyte proliferation to phytohemagglutinin (PHA), concanavalin A, and pokeweed mitogen, and plasma levels of soluble interleukin-2 receptor (sIL-2R) and sIL-6R in patients with bipolar mania (DSM-III-R). The subjects were 23 physically healthy patients with Young Mania Rating Scale (YMRS) scores > or = 26 as well as aged < or = 45 years and 23 age- and gender-matched normal control subjects. The above immune variables were measured in acute mania and consequent remission (YMRS scores < or = 12) among bipolar patients. RESULTS: The lymphocyte proliferation to PHA and the plasma sIL-2R levels, but not sIL-6R, of bipolar patients were significantly higher in acute mania than in consequent remission. These elevations were not due to differences in medication status. Only in acute mania were the plasma sIL-2R levels of patients significantly higher than control subjects. A positive correlation between the changes of manic severity and plasma sIL-2R levels was observed. Remitted bipolar patients and normal control subjects did not differ in any of these measures. CONCLUSIONS: Cell-mediated immunity activation in bipolar mania was demonstrated and may be through a specifically state-dependent immune response.

Desialylation of T lymphocytes overcomes the monocyte dependency of pokeweed mitogen-induced T-cell activation.

Activation of T lymphocytes by pokeweed mitogen (PWM) is strictly monocyte (Mo)-dependent and results in T-cell mitogenesis and interleukin-2 (IL-2) secretion, coupled with an inability to utilize IL-2 due to an impaired expression of functional IL-2 receptor (IL-2R). Such IL-2R impairment could arise in PWM-activated T cells themselves or, alternatively, be the result of Mo-derived influences, as it is known that PWM binds Mo strongly and does not or poorly binds lymphocytes, and Mo becomes rapidly destroyed in PWM-stimulated cultures of blood mononuclear cells or T cells plus Mo. The present study investigated these possibilities. The results show for the first time that desialylation of T lymphocytes strongly increases their PWM-binding capacity and, in addition, overcomes the Mo requirement for PWM to induce T-cell mitogenesis and IL-2 secretion. Such secreted IL-2 levels were even higher that those found in cultures of Mo-dependent PWM-activated T lymphocytes but similarly to the latter, PWM-activated desialylated purified T lymphocytes exhibited negligible high-affinity IL-2 binding capacity and an inability to utilize the IL-2 they produced. These effects were not due to desialylation itself, as indicated by data obtained with peanut agglutinin, a lectin that becomes strongly reactive with desialylated T lymphocytes. The data clearly indicate the existence of PWM-related events capable of impairing the expression of functional IL-2R without affecting IL-2 secretion, and indicate that such events are due to mechanisms arising at the level of PWM-activated T cells themselves.

A high degree of sequence homology in the putative carbohydrate recognition domains of pokeweed mitogen and wheat germ agglutinin: poly-N-acetyllactosamine-binding lectins from different species.

The complete amino acid sequence of a poly-N-acetyllactosamine-binding pokeweed mitogen 4 (Pa-4) was determined using a protein sequencer. After digestion of Pa-4 with endoproteinase Lys-C, Asp-N, Arg-C or Glu-C, the resulting peptides were separated by reversed-phase high-performance liquid chromatography (HPLC) and then subjected to sequence analysis using a protein sequencer. The complete amino acid sequence of Pa-4 was found to exhibit a high degree of homology with that of wheat germ agglutinin (WGA) regarding their overall sequences and the spatial arrangement of cysteine-glycine. Furthermore, the amino acid residues of WGA directly involved in carbohydrate-binding sites were found in the homologous region in Pa-4. This is the first report to show that lectins from different plant families (Phytolaccaceae for Pa-4 and Gramineae for WGA) possess homologous primary sequences.

Expression of pokeweed lectin binding in murine intestinal Paneth cells.

Pokeweed (Phytolacca americana) lectin was found to stain the secretory granules in epithelial Paneth cells of small intestine in mice and rats. The distribution of Paneth cells stained with this lectin was identical to that obtained by another immunohistochemical marker for lysozyme. However, in comparison with other immunohistochemical markers, Pokeweed lectin is a more robust method for identifying Paneth cells in histological sections and for studying their secretory granules. Co-expression of the Pokeweed lectin binding sites in some oligomucous cells within the crypts suggested a close developmental link between these two cell types. Only one other non-epithelial cell type was stained by this lectin, and these were migratory lymphocytes found within the villus epithelium and lamina propria. Approximately 20% of these lymphocyte cells were also positive for the expression of CD3+. Pokeweed lectin was therefore used to study changes in the frequency of Paneth cells and intra-epithelial lymphocytes in normal and immunologically compromised animals (following infection with a parasite worm Trichuris muris and in a model of graft-versus-host rejection). This study confirmed that the population of Paneth cells turns over slowly even during conditions of inflammation.

Human colorectal carcinoma-specific glycoconjugates detected by pokeweed mitogen lectin.

Pokeweed mitogen (PWM) lectin, known to bind branched poly-N-acetyllactosamines, has a highly selective affinity for human colorectal carcinomas. We performed light microscopic (LM) histochemistry with PWM lectin on paraffin sections of human colorectal tissues. In histological sections, normal mucosae and adenomas with mild dysplasia exhibited negative reaction (0/10, 0/13, respectively) with or without neuraminidase pre-digestion, whereas adenomas with moderate dysplasia showed a small increase in PWM lectin reactivity after neuraminidase digestion (4/23). In contrast, we observed a high incidence of positive reactivity in colorectal carcinoma without neuraminidase pre-digestion (38/44). After digestion with neuraminidase, there was increased reactivity of colorectal carcinomas in situ (7/12) and invasive carcinomas (13/32). These results imply that human colorectal carcinomas consistently contain substantial amounts of PWM-reactive branched poly-N-acetyllactosamine glycoconjugates structures. We also compared the staining patterns of PWM lectin and monoclonal antibodies (MAb) directed to Lewis X (LeX) or Lewis Y (LeY) antigen. PWM lectin reactivity was largely confined to the apical membranes of carcinoma tissues. MAb-LeX or MAb-LeY immunoreactivity was seen on the apical membranes and in the cytoplasm of both adenomas and carcinomas. Therefore, histochemical studies with this lectin should be useful for identification of carcinoma tissues and analysis of glycoconjugates associated with colorectal carcinoma.

Glycosidase inhibitors (castanospermine and swainsonine) and neuraminidase inhibit pokeweed mitogen-induced B cell maturation.

Castanospermine (CSP), an inhibitor of alpha-glucosidase, enhanced immunoglobulin (Ig) release in a Staphylococcus aureus Cowan I (SAC)-induced lymphocyte culture (Scand. J. Immunol. 1990. 32: 529). In a pokeweed mitogen (PWM)-human lymphocyte culture, unlike the SAC-stimulated system, CSP strongly decreased the number of IgG-, IgA- and IgM-secreting cells as well as that of Ig-bearing cells. Peripheral blood lymphocytes treated with swainsonine, a mannosidase II inhibitor, or with neuraminidase also showed a reduced response to PWM. In cross-culture experiments, only a mixture of B cells pretreated with either agent and untreated T cells showed such a suppressive effect. Adhesion was decreased between B cells treated with either agent and untreated T cells, but not between treated T cells and untreated B cells. These results demonstrate that a certain alteration in B cell membrane oligosaccharides inhibited the T cell-B cell adhesion in the PWM culture, leading to an arrest of B cell maturation. Considering that these inhibitors eventually prevent terminal sialic acid addition, the present study provides evidence that sialic acids on B cell surface oligosaccharides play a biological role in the T cell-B cell interaction.

Ascaris suum: stage-specific differences in lectin binding to the larval cuticle.

A glycosylated component with affinity for wheat germ agglutinin (specific binding to n-acetyl-D-glucosamine monomers and oligomers) and weak affinity for poke weed mitogen (specific binding to n-acetyl-D-glucosamine oligomers) was detected temporally on the surface of Ascaris suum larvae developing in vitro and on in vivo-derived larvae. The component was identified on the surface of in vitro-derived late second stage larvae, on all late third stage larvae (derived from pig lung), and all fourth stage larvae (obtained from pig intestines and from in vitro culture) of A. suum. None of the newly hatched first molt, L2, or early L3 bound any of the lectins tested. The component exhibited no affinity for concanavalin A (specific binding to alpha-D-mannosyl and alpha-D-glucosyl residues) or Dolichos biflorus lectin (specific binding to n-acetyl-D-galactosamine). A component with similar lectin binding specificities had previously been found on the cuticle of adult A. suum.

Bindings of the lectins Griffonia simplicifolia-1 and pokeweed mitogen mark discrete stages of myoepithelial-like differentiation of cell lines from the rat mammary gland.

Individual single-cell-cloned cell lines of the different rat mammary (Rama) cell types have been tested for their ability to bind the lectins Griffonia simplicifolia-1 (GS-1) and pokeweed mitogen (PWM) using fluorescent, histochemical, and radioactive assays. Myoepithelial-like cell lines isolated from neonatal rat mammary glands and from nonmetastasizing tumors strongly bind GS-1 and PWM, whereas the corresponding epithelial and fibroblastic cell lines do not. When the epithelial cell lines are grown on floating gels of polymerised rat tail collagen, the basally situated or peripheral cells are stained strongly with peroxidase-conjugated lectins, whereas the apically or luminally situated cells are unstained. The capacity of cell lines intermediate in morphology between epithelial and myoepithelial-like cells to bind to GS-1 is as follows: Rama 25 epithelial less than Rama 25-12 less than Rama 25-11 less than Rama 25-14 less than Rama 29 myoepithelial-like cells, the same order as for other markers of myoepithelial cells. Conjugated PWM, however, binds only to the myoepithelial-like cell lines. Treatment of Rama 25 epithelial cells with agents that disrupt microtubules accelerates their conversion to elongated, myoepithelial-like cells in culture. The binding of cells to GS-1 is observed prior to, and that to PWM after, the major morphological change. It is suggested that the stepwise appearances of carbohydrate receptors for GS-1 and PWM mark discrete stages in the differentiation of epithelial to myoepithelial-like cells in culture, in the same way that they mark similar differentiation stages in ductal development in mammary glands of prepubertal rats.