Sialic Acid Binding Sites: Role in Hemagglutination by
            <i>Mycoplasma gallisepticum</i>

Gesner, Bertram M.; Thomas, Lewis

doi:10.1126/science.151.3710.590

Cited by 74 publications

(31 citation statements)

References 4 publications

(1 reference statement)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For example, M. synoviae and M. gallisepticum both utilize sialylated glycoproteins on eukaryotic cell surface membranes as receptors for cytadherence mediated by adhesins such as the vlhA system hemagglutinins [40]. Since receptor desialylation reduces or abolishes cytadherence by M. synoviae, M. gallisepticum, and M. canis [32,41,42], it is predictable that a functional balance between the amount of sialidase activity and receptor binding affinity must be essential to promote both colonization and transmission of these mycoplasmas. Strains with comparatively higher sialidase activity would be expected to possess higher-affinity adhesins [43].…”

Section: Discussionmentioning

confidence: 99%

Genetic variation in sialidase and linkage to N-acetylneuraminate catabolism in Mycoplasma synoviae

May

Brown

2008

Microbial Pathogenesis

View full text Add to dashboard Cite

We explored the genetic basis for intraspecific variation in mycoplasmal sialidase activity that correlates with virulence, and its potentially advantageous linkage to nutrient catabolism. Polymorphism in N-acetylneuraminate scavenging and degradation genes (sialidase, Nacetylneuraminate lyase, N-acetylmannosamine kinase, N-acetylmannosamine-6-phosphate epimerase, N-acetylglucosamine-6-phosphate deacetylase, and glucosamine-6-phosphate deaminase) was evident among eight strains of the avian pathogen Mycoplasma synoviae. Most differences were single nucleotide polymorphisms, ranging from 0.34 ± 0.04 substitutions per 100 bp for N-acetylmannosamine kinase to 0.65 ± 0.03 for the single-copy sialidase gene nanI. Missense mutations were twice as common as silent mutations in nanI; 26% resulted in amino acids dissimilar to consensus; and there was a 12-base deletion near the nanI promoter in strain WVU1853 T , supporting a complex genetic basis for differences in sialidase activity. Two strains had identical frameshifts in the N-acetylneuraminate lyase gene nanA, resulting in nonsense mutations, and both had downstream deletions in nanA. Such genetic lesions uncouple extracellular liberation of sialic acid from generation of fructose-6-phosphate and pyruvate via intracellular N-acetylneuraminate degradation. Retention of nanI by such strains, but not others in the M. synoviae phylogenetic cluster, is evidence that sialidase has an important non-nutritional role in the ecology of M. synoviae and certain other mycoplasmas.

show abstract

Section: Discussionmentioning

confidence: 99%

Genetic variation in sialidase and linkage to N-acetylneuraminate catabolism in Mycoplasma synoviae

May

Brown

2008

Microbial Pathogenesis

View full text Add to dashboard Cite

show abstract

“…The NC proline assay has been described in detail (4). Briefly, 103 [3H]proline-labeled Meth A target cells were allowed to adhere to the wells of a 96-well microplate (Falcon), for 24 hr, in 0.15 ml of RPMI 1640 medium supplemented with 10% heat-inactivated fetal calf serum, 1% L-glutamine, 1% penicillin/streptomycin, and 1% nonessential amino acids. The sugars, diluted in this medium, were added in 50-,gl amounts, followed by the effector spleen cells at 100:1, 50:1, and 10:1 effector-to-target (E:T) ratios.…”

mentioning

confidence: 99%

“…The sugars, diluted in this medium, were added in 50-,gl amounts, followed by the effector spleen cells at 100:1, 50:1, and 10:1 effector-to-target (E:T) ratios. The plates were incubated for 24 hr at 37-C in 5% CO2 in air and washed extensively, and the wells were punched into scintillation vials. Hyamine hydroxide and scintillation fluid were added and the radioactivities were determined.…”

mentioning

confidence: 99%

Natural cytotoxic cells against solid tumors in mice: blocking of cytotoxicity by D-mannose.

Stutman¹,

Dien²,

Wisun³

et al. 1980

Proc. Natl. Acad. Sci. U.S.A.

100

View full text Add to dashboard Cite

Natural cytotoxic (NC) and natural killer (NK) cells have been defined by their ability to lyse certain solid or lymphoid tumor targets in vitro, without prior sensitization. Our present studies describe an attempt to characterize the structures involved in the effector-target recognition leading to tumor cell lysis. Addition of the monosaccharide D-mannose to the NC cell assay significantly blocked cytotoxicity of the fibrosarcoma Meth A target by the effector cells at 50 mM and lower concentrations. D-Galactose showed blocking activity in one of five experiments, only at 50 mM. L-Fucose, D-glucose, and N-acetyl-D-glucosamine did not affect NC cell cytotoxicity at similar concentrations. All of the sugars tested inhibited NK cell lysis of the lymphoma YAC-1 target. None of the sugars affected killing of the appropriate target by allosensitized cytotoxic T lymphocytes. The blocking of NC-mediated cytotoxicity was not due to a direct toxic action of the sugars on the effector cells. These findings suggest that, in the NC system, recognition involves lectin-like structures with a specificity for D-mannose (or D-galactose, or both), whereas, in the NK system, such lectin-like structures are less restricted. Such structures appear not to be involved in the specific cytotoxicity mediated by T cells.Although there has been extensive characterization of many features of natural cell-mediated cytotoxicity (CMC) in mice, especially of the "natural killer" (NK) type (1-3), little is known about the recognition structures or target sites involved in the effector-target cell interaction leading to lysis. In addition, when different tumor targets are studied, some heterogeneity of effector cells is found, and subtypes such as the "natural cytotoxic" (NC) cells, which react with adherent target cells derived from nonlymphoid tumors, have been described (4). In both the NK and NC systems, targets may be susceptible or resistant to lysis by such effector cells (1-4). Competitive ("cold-target") inhibition studies with NK cells (1-43) and assays that determine the binding of effector cells to sensitive targets (5) have suggested a certain degree of specificity of recognition. In addition, crude cell extracts, probably glycoprotein in nature, from NK-susceptible targets can inhibit or block the binding of effector NK cells to the appropriate susceptible target (6).In the present study we show that some simple sugars can Sugars. All the sugars tested (see Tables 1 and 2) were obtained from Sigma. Stock solutions were made in medium (see details below), and sterilized by filtration prior to use.NC Assay. The NC proline assay has been described in detail (4). Briefly, 103 [3H]proline-labeled Meth A target cells were allowed to adhere to the wells of a 96-well microplate (Falcon), for 24 hr, in 0.15 ml of RPMI 1640 medium supplemented with 10% heat-inactivated fetal calf serum, 1% L-glutamine, 1% penicillin/streptomycin, and 1% nonessential amino acids. The sugars, diluted in this medium, were added in 50-,gl amounts, fol...

show abstract

“…The finding that the agglutination factor is a carbohydratebinding protein is of particular interest because of evidence implicating carbohydrates in the mechanisms of cellular interactions in various systems, including microbe-host cell interactions (11)(12)(13)(16)(17)(18), mating reactions of bacteria (19),---i yeast (20), and Chlamydomonas (21), and cell-cell interactions in tissue formation (14,22,23).…”

mentioning

confidence: 99%

Developmentally Regulated, Carbohydrate-Binding Protein in Dictyostelium discoideum

Rosen

Kafka

Simpson

et al. 1973

Proc. Natl. Acad. Sci. U.S.A.

228

View full text Add to dashboard Cite

A carbohydrate-binding protein assayed by its ability to agglutinate formalinized sheep erythrocytes is synthesized between 3 and 9 hr after Dictyostelium discoideum cells are deprived of food, as the cells become cohesive. Agglutination of erythrocytes by this protein was inhibited by N-acetyl-D-galactosamine, D-galactose, and Lfucose, but other monosaccharides had little or no effect. The protein bound completely to Sepharose 4B, and was isolated in highly purified form by elution with D-galactose. It appears to be present on the surface of cohesive but not vegetative slime-mold cells. Previous work has demonstrated that a protein factor assayed by its activity in agglutinating formalinized sheep erythrocytes can be extracted in increasing amounts from D. discoideum cells as they differentiate after removal of food (3). In a 12-hr period over which the cells become progressively more cohesive, the specific activity of the agglutination factor in cell extracts increases by over 400-fold (3). In this report, we show that the appearance of the agglutination factor in D. discoideum is closely correlated with development of cell cohesiveness, as measured by a newly devised quantitative assay. We also show that the factor is a carbohydratebinding protein with a high degree of specificity. We present preliminary evidence that the factor is detectable on the surface of cohesive slime-mold cells. buffer consisting of 40 mM potassium phosphate buffer (pH 6.5) containing per liter 1.5 g of KCl, 0.61 g of MgSO4, and 0.5 g of streptomycin sulfate (4, 9). The Millipore filters and pads were, respectively, catalogue nos. AABPO4700 and AP100-4700. The cells were then kept in a moist atmosphere at 220. At intervals cells were harvested from the filter supports and assayed for cohesiveness; extracts were assayed for agglutination activity.D. discoideum strain A3 cells (mutant derived from NC-4) were grown in axenic culture (5). Growth-phase cells (vegetative) were tested for cohesiveness and extracts were assayed for agglutination activity.Cohesiveness Assay. Based on a procedure developed by Gerisch (6), we used roller-tube culturing to promote aggregation of cohesive slime-mold cells by passively bringing them into contact with one another independently of their chemotactic system. Particle-size analysis by a Coulter Electronic Particle Counter was used to determine the degree of aggregation. The procedure was as follows: (i) Harvested cells were washed twice in water at 40 and suspended in EDTA-phosphate buffer [16.7 mM Na2HPO4-KH2PO4, 10 mM EDTA (pH 6.2) ]. This buffer is slightly modified from one described by Gerisch (6). (ii) The suspension was dispersed into single cells by repeated pipetting through a fine-tipped pipette. Erythrocyte Agglutination Assay has been described (3). Briefly, the method was as follows: (i) Soluble crude extracts were prepared by homogenization of washed slime-mold cells 2554

show abstract

Sialic Acid Binding Sites: Role in Hemagglutination by Mycoplasma gallisepticum

Cited by 74 publications

References 4 publications

Genetic variation in sialidase and linkage to N-acetylneuraminate catabolism in Mycoplasma synoviae

Genetic variation in sialidase and linkage to N-acetylneuraminate catabolism in Mycoplasma synoviae

Natural cytotoxic cells against solid tumors in mice: blocking of cytotoxicity by D-mannose.

Developmentally Regulated, Carbohydrate-Binding Protein in Dictyostelium discoideum

Contact Info

Product

Resources

About