Are grape juices more erosive than orange juices?

AIMS: To evaluate the chemical characteristics of grape and orange juices, and their erosive potential in the decrease of microhardness and the loss of enamel structure. METHODS: Five grape and orange juices were evaluated for pH, titratable acidity, calcium, phosphate, and fluoride concentration. De-ionised water and Cola soft drink were used as a negative and positive control, respectively. Twelve specimens of bovine enamel were immersed in beverages for 10 min at 37 °C, 3 times/day for 7 days. Erosive potential was quantified using microhardness and loss of enamel structure. Anova One Way, Student's t test, Multiple Regression and Spearman Correlation (p < 0.05) were used to analyse the results. RESULTS: Powdered grape juice showed the lowest pH (3.18 ± 0.03) and pure grape juice presented the highest titratable acidity (5.48 ± 0.06 mL NaOH/100 mL). Fresh orange juice and soya-based grape juice revealed the lowest calcium (0.77 ± 0.12 mmol/L) and phosphate concentrations (0.35 ± 0.06 mmol/L), respectively. Among juices, powdered orange juice caused the greatest decrease in surface microhardness (SMH) (127.99 ± 40.47 ΔSMH) and grape juice from concentrate caused the greatest loss of enamel structure (13.30 ± 3.56 µm). CONCLUSIONS: All of the evaluated juices contributed to dental erosion. Grape juices presented greater erosive potential than orange juices. Pure, powdered and concentrated grape juices showed similar loss of enamel structure to the Cola soft drink. The erosive potential of beverages was statistically correlated to pH, titratable acidity, calcium, phosphate and fluoride concentrations.

Follow-up of the development of femoral degeneration lesions in broilers / Seguimiento del desarrollo de lesiones por degeneración en pollos de engorde

A study was carried out in the experimental facilities of FMVZ/UNESP-Botucatu, with the aim of following-up the development and the incidence of femoral degeneration (FD). A total of 305 one-day-old male broilers were housed in six pens of 5m² each. Histological analyses of femur head collected when broilers were 0, 7, 14, 21, 28, 35, and 42 days of age were carried out. At 42 days of age, 30 birds were taken to the experimental processing plant of FMVZ for leg gross examination. Ten legs per FD score where selected, and histologically analyzed to determine the most probable age at the beginning of the lesions, and to standardize femoral degeneration lesion scores. The histological results showed that cell architecture started to disorganize at 21 days of age in the resting and proliferation zones, and that angiogenesis increased, invading the joint cartilage, The gross lesion indexes due to femoral degeneration were 22.5 percent, 42.5%, and 65% at 28, 35, and 42 days of age, respectively.

Se realizó un estudio en las instalaciones experimentales de FMVZ/UNESP-Botucatu, con el objetivo de seguir el desarrollo y la incidencia de degeneración femoral (DF) en pollos. Se utilizaron 305 polluelos de un día, machos, distribuidos en seis corrales de 5m² cada uno. Se analizaron cortes histológicos de cabezas de fémur recolectadas a los 0, 7, 14, 21, 28, 35 y 42 días de edad. A los 40 días de edad, se llevaron 30 aves al Matadero Experimental de FMVZ, para análisis macroscópico de las piernas. Se escogieron 10 muslos por escore de DF, y se analizaron histológicamente para determinar la edad más probable del inicio de la lesión y estandarizar los escores de lesión por degeneración femoral. Los resultados histológicos indicaron que a los 21 días ocurre el inicio de la desorganización celular en la zona de reposo y de proliferación, además del aumento de la angiogénesis, invadiendo el cartílago articular. Microscópicamente, el índice de lesión por degeneración femoral fue del 22.5 por ciento, 42.5% y 65% a los 28, 35 y 42 días de edad, respectivamente.

Femur mineral density of broilers with femoral degeneration fed high nutritional density diets / Densidad mineral del fémur de pollos de engorde con degeneración femoral alimentados con dietas de alta densidad nutricional

A study was carried out in the experimental facilities of FMVZ/UNESP-Botucatu, with the aim of following-up the development and the incidence of femoral degeneration (FD). A total of 305 one-day-old male broilers were housed in six pens of 5m² each. A completely randomized experimental design, with 3 treatments (T1traditional nutritional density diet; T2high nutritional density diet) of 3 replicates each was applied. Femoral head of the broilers were submitted to gross examination at 0, 7, 14, 21, 28, 35, and 42 days of aged. At 42 days of age, 60 birds (30 per treatment) were submitted to the Veterinary Hospital of FMVZ to determine bone mineral density by radiography. Birds were then sacrificed for gross examination of the legs, and FD scoring. Five legs per treatment within each FD score were submitted to computed tomography for femur head integrity and bone mineral density. Treatments did not influence FD incidence, and the first gross FD lesions appeared when birds were 28 days old. It was concluded that radiographic optical densitometry and computed tomography are efficient methods to evaluate femoral degeneration, and both techniques expressed the same profile. In addition, using radiographic optical densitometry and computed tomography, these results also allowed us to establish bone mineral density value ranges within each gross FD score. These finding may provide an excellent non-invasive tool to describe femoral degeneration.

Se realizó un estudio en las instalaciones experimentales de FMVZ/UNESP-Botucatu, con el objetivo de seguir el desarrollo y la incidencia de degeneración femoral en pollos. Se utilizaron 305 polluelos de un día, machos, distribuidos en seis corrales de 5m² cada uno. Se adoptó un delineamiento experimental totalmente al azar, con dos tratamientos de 3 repeticiones cada uno. Se alimentaron las aves del T1 con dietas con densidad nutricional convencional, mientras el T2 consistió de una dieta con alta densidad nutricional. Se realizaron análisis macroscópicos de la cabeza del fémur de aves de 0, 7, 14, 21, 28, 35 y 42 días de edad. A los 42 días de edad, se llevaron 60 aves (30 por tratamiento) al Hospital Veterinario de FMVZ, para hacer radiografías para el análisis de la densidad mineral ósea. Posteriormente, se sacrificaron los pollos para el análisis macroscópico de las piernas y se atribuyeron puntajes para DF. Se seleccionaron cinco muslos por tratamiento dentro de cada puntaje de DF, que fueron sometidas a tomografía para evaluación de la integridad y de la densidad ósea de la cabeza del fémur. Los tratamientos no tuvieron influencia en la incidencia de DF, y a partir de los 28 días de vida, las aves presentaron lesiones macroscópicas. Se estableció que la densitometría ósea y la tomografía son métodos eficaces para evaluar la DF, además que ambos expresan el mismo perfil. Por otra parte, se encontraron intervalos de valores para densidad mineral ósea obtenida por densitometría óptica radiográfica y por tomografía en función de los puntajes macroscópicos de DF. Esos hallazgos son una importante herramienta no invasiva para la caracterización de degeneración femoral.

Prevalência, necessidade de tratamento e fatores predisponentes do traumatismo na dentição permanente de escolares de 11 a 13 anos de idade / Prevalence, treatment needs, and predisposing factors for traumatic injuries to permanent dentition in 11-13-year-old schoolchildren

Este estudo objetivou determinar a prevalência do traumatismo dentário na dentição permanente e observar associações com fatores predisponentes. Foi realizado um estudo transversal com escolares de 11 a 13 anos de Biguaçu, Santa Catarina, Brasil. Os exames foram realizados por um cirurgião-dentista utilizando os mesmos critérios do Children's Dental Health Survey do Reino Unido. Foram observados tipo de dano, tratamento providenciado e necessidade, overjet incisal, adequabilidade da cobertura labial, idade, sexo e nível de educação dos pais. Foram examinadas 2.260 crianças e as prevalências encontradas foram: 10,4 por cento, 10,6 por cento e 11,2 por cento aos 11, 12 e 13 anos, respectivamente. A necessidade de tratamento foi de 6,3 incisivos por mil examinados. Escolares do sexo masculino e com overjetmaior que 5mm tiveram mais traumatismo dentário do que escolares do sexo feminino e com overjetincisal até 5mm. Cobertura labial inadequada e nível de educação dos pais não estiveram estatisticamente associados com o traumatismo dentário. Concluiu-se que ser do sexo masculino ou ter um overjetincisal maior do que 5mm aumenta a chance de sofrer traumatismo dentário.

Proinflammatory activity of glycosylphosphatidylinositol anchors derived from Trypanosoma cruzi: structural and functional analyses.

A strong activation of macrophages is observed during acute infection with Trypanosoma cruzi. Little is known, however, about the parasite molecules that are responsible for this early activation of innate immunity. Recent studies have shown the stimulatory activity of protozoan-derived glycosylphosphatidylinositol (GPI) anchors on cultured macrophages. In this review, we provide a detailed analysis of the correlation between structure and proinflammatory activity by T. cruzi-derived GPI anchors. We also cover the studies that have identified the Toll-like receptor 2 as a functional GPI receptor and have partially characterized signaling pathways triggered by T. cruzi-derived GPI anchors, which lead to the synthesis of proinflammatory cytokines in macrophages. Finally, we discuss the implications of these findings in resistance and pathogenesis during the infection with T. cruzi.

Activation of Toll-like receptor-2 by glycosylphosphatidylinositol anchors from a protozoan parasite.

Glycosylphosphatidylinositol (GPI) anchors and glycoinositolphospholipids (GIPLs) from parasitic protozoa have been shown to exert a wide variety of effects on cells of the host innate immune system. However, the receptor(s) that are triggered by these protozoan glycolipids has not been identified. Here we present evidence that Trypanosoma cruzi-derived GPI anchors and GIPLs trigger CD25 expression on Chinese hamster ovary-K1 cells transfected with CD14 and Toll-like receptor-2 (TLR-2), but not wild-type (TLR-2-deficient) Chinese hamster ovary cells. The protozoan-derived GPI anchors and GIPLs containing alkylacylglycerol and saturated fatty acid chains or ceramide were found to be active in a concentration range of 100 nM to 1 microM. More importantly, the GPI anchors purified from T. cruzi trypomastigotes, which contain a longer glycan core and unsaturated fatty acids in the sn-2 position of the alkylacylglycerolipid component, triggered TLR-2 at subnanomolar concentrations. We performed experiments with macrophages from TLR-2 knockout and TLR-4 knockout mice, and found that TLR-2 expression appears to be essential for induction of IL-12, TNF-alpha, and NO by GPI anchors derived from T. cruzi trypomastigotes. Thus, highly purified GPI anchors from T. cruzi parasites are potent activators of TLR-2 from both mouse and human origin. The activation of TLR-2 may initiate host innate defense mechanisms and inflammatory response during protozoan infection, and may provide new strategies for immune intervention during protozoan infections.

The mucin-like glycoprotein super-family of Trypanosoma cruzi: structure and biological roles.

Trypanosoma cruzi expresses at its surface large amounts of mucin-like glycoproteins. The T. cruzi mucins (TcMUC), a group of highly glycosylated GPI-anchored proteins rich in Thr, Ser, and Pro residues, are expressed in high copy numbers in both insect and mammalian stages of the parasite. These molecules are encoded by a multigene family and contain a unique type of glycosylation consisting of several sialylated O-glycans linked to the protein backbone via N-acetylglucosamine residues. The TcMUC are important because of their role in host cell invasion and the ability to induce secretion of proinflammatory cytokines and nitric oxide in activated macrophages. The TcMUC are also significant in being the major substrate for the cell surface trans-sialidase. In this review, we summarize the recent knowledge on the molecular structure and function of this family of T. cruzi glycoproteins.

Requirement of mitogen-activated protein kinases and I kappa B phosphorylation for induction of proinflammatory cytokines synthesis by macrophages indicates functional similarity of receptors triggered by glycosylphosphatidylinositol anchors from parasitic protozoa and bacterial lipopolysaccharide.

In the present study, we evaluated the ability of GPI-anchored mucin-like glycoproteins purified from Trypanosoma cruzi trypomastigotes (tGPI-mucin) to trigger phosphorylation of different mitogen-activated protein kinases (MAPKs) and related transcription factors in inflammatory macrophages. Kinetic experiments show that the peak of extracellular signal-related kinase (ERK)-1/ERK-2, stress-activated protein kinase (SAPK) kinase-1/mitogen-activated protein kinase (MAPK) kinase-4, and p38/SAPK-2, phosphorylation occurs between 15 and 30 min after macrophage stimulation with tGPI-mucin or GPI anchors highly purified from tGPI-mucins (tGPI). The use of the specific inhibitors of ERK-1/ERK-2 (PD 98059) and p38/SAPK-2 (SB 203580) phosphorylation also indicates the role of MAPKs, with possible involvement of cAMP response element binding protein, in triggering TNF-alpha and IL-12 synthesis by IFN-gamma-primed-macrophages exposed to tGPI or tGPI-mucin. In addition, tGPI-mucin and tGPI were able to induce phosphorylation of I kappa B, and the use of SN50 peptide, an inhibitor of NF-kappa B translocation, resulted in 70% of TNF-alpha synthesis by macrophages exposed to tGPI-mucin. Finally, the similarity of patterns of MAPK and I kappa B phosphorylation, the concentration of drugs required to inhibit cytokine synthesis, as well as cross-tolerization exhibited by macrophages exposed to tGPI, tGPI-mucin, or bacterial LPS, suggest that receptors with the same functional properties are triggered by these different microbial glycoconjugates.

HeLp, a heme lipoprotein from the hemolymph of the cattle tick, Boophilus microplus.

The main protein of the hemolymph of the cattle tick Boophilus microplus has been isolated and shown to be a heme lipoprotein (HeLp). HeLp has an apparent molecular mass of 354,000 and contains two apoproteins (103 and 92 kDa) found in equal amounts. HeLp presents a pI of 5.8 and a density of 1.28 g/ml and contains 33% lipids, containing both neutral lipids and phospholipids, and 3% of sugars. A remarkable feature of HeLp is the abundance of cholesterol ester (35% of total lipids), a lipid not previously reported in invertebrate lipoproteins. Western blot analysis showed HeLp in hemolymph from adult females and males, but not in eggs. Although HeLp contains 2 heme molecules, it is capable of binding 6 additional molecules of heme. Boophilus feeds large amount of blood, and we recently showed that this tick is unable to perform de novo synthesis of heme (Braz, G. R. C., Coelho, H. S. L., Masuda, H., and Oliveira, P. L. (1999) Curr. Biol. 9, 703-706). Injection of tick females with (55)Fe-labeled heme-HeLp indicated that this protein transports heme from hemolymph to tissues. HeLp is suggested to be an essential adaptation to the loss of the heme synthesis pathway.

Highly purified glycosylphosphatidylinositols from Trypanosoma cruzi are potent proinflammatory agents.

Intracellular protozoan parasites are potent stimulators of cell-mediated immunity. The induction of macrophage proinflammatory cytokines by Trypanosoma cruzi is considered to be important in controlling the infection and the outcome of Chagas' disease. Here we show that the potent tumour necrosis factor-alpha-, interleukin-12- and nitric oxide-inducing activities of T.cruzi trypomastigote mucins were recovered quantitatively in a highly purified and characterized glycosylphosphatidylinositol (GPI) anchor fraction of this material. The bioactive trypomastigote GPI fraction was compared with a relatively inactive GPI fraction prepared from T. cruzi epimastigote mucins. The trypomastigote GPI structures were found to contain additional galactose residues and unsaturated, instead of saturated, fatty acids in the sn-2 position of the alkylacylglycerolipid component. The latter feature is essential for the extreme potency of the trypomastigote GPI fraction, which is at least as active as bacterial endotoxin and Mycoplasma lipopeptide and, therefore, one of the most potent microbial proinflammatory agents known.

Isolation and characterization of glycosylphosphatidylinositol-anchored, mucin-like surface glycoproteins from bloodstream forms of the freshwater-fish parasite Trypanosoma carassii.

Wild and farmed freshwater fishes are widely and heavily parasitized by the haemoflagellate Trypanosoma carassii. In contrast, common carp, a natural host, can effectively control experimental infections by the production of specific anti-parasite antibodies. In this study we have identified and partially characterized mucin-like glycoproteins which are expressed in high abundance [(6. 0+/-1.7)x10(6) molecules.cell(-1)] at the surface of the bloodstream trypomastigote stage of the parasite. The polypeptide backbone of these glycoproteins is dominated by threonine, glycine, serine, alanine, valine and proline residues, and is modified at its C-terminus by a glycosylphosphatidylinositol membrane anchor. On average, each polypeptide carries carbohydrate chains composed of about 200 monosaccharide units (galactose, N-acetylglucosamine, xylose, sialic acid, fucose, mannose and arabinose), which are most probably O-linked to hydroxy amino acids. The mucin-like molecules are the target of the fish's humoral immune response, but do not undergo antigenic variation akin to that observed for the variant surface glycoprotein in salivarian trypanosomes. The results are discussed with reference to the differences between natural and experimental infections, and in relation to the recently delineated molecular phylogeny of trypanosomes.

Differential inhibitory mechanism of cyclic AMP on TNF-alpha and IL-12 synthesis by macrophages exposed to microbial stimuli.

Microbial stimuli such as bacterial lipopolysaccharide (LPS) or glycosylphosphatidylinositol-mucins derived from Trypanosoma cruzi trypomastigotes (tGPI-mucins) are effective stimulators of the synthesis of cytokines by macrophages. Here, we evaluated the ability of cyclic AMP mimetic or elevating agents to modulate TNF-alpha and IL-12 synthesis by murine inflammatory macrophages. Cholera Toxin (ChTx) inhibited tGPI-mucins (2.5 nM) or LPS (100 ng ml(-1)) induced TNF-alpha and IL-12(p40) synthesis in a concentration-dependent manner. Similarly, the cyclic AMP mimetics, 8-bromo cyclic AMP or dibutyryl cyclic AMP, or prostaglandin (PG) E2 inhibited the synthesis of both cytokines by macrophages exposed to microbial stimuli. The protein kinase A inhibitor H-89 partially reversed the inhibitory effects of dibutyryl cyclic AMP and PGE2 on both IL-12(p40) and TNF-alpha synthesis. Pretreatment of macrophages with dibutyryl cyclic AMP or ChTx augmented the synthesis of IL-10 triggered by microbial products. Elevation of cyclic AMP inhibited the synthesis of TNF-alpha, but not IL-12(p40), by inflammatory macrophages from IL-10 knockout mice. Kinetic studies showed that synthesis of both TNF-alpha and IL-10 peaked at 8 h and IL-12 at 24 h after stimulation with microbial stimuli. Together, our findings favour the hypothesis that the cyclic AMP inhibitory activity on IL-12(p40) but not on TNF-alpha synthesis is dependent on de novo protein synthesis, most likely involving IL-10, by macrophages stimulated with microbial products. Accordingly, dibutyryl cyclic AMP inhibited IL-12(p40) synthesis only when added before or at the same time of the stimuli. In contrast, the effect of this cyclic AMP analogue on TNF-alpha synthesis was protracted and observed even 2 h after the addition of the stimuli.

Glycosylphosphatidylinositol-anchored mucin-like glycoproteins isolated from Trypanosoma cruzi trypomastigotes initiate the synthesis of proinflammatory cytokines by macrophages.

Components of Trypanosoma cruzi able to induce the production of IL-12 and other proinflammatory cytokines by macrophages were identified. Murine inflammatory macrophages were cultured with live parasites or with cellular components from different developmental forms of T. cruzi (i.e., trypomastigotes, amastigotes, metacyclic trypomastigotes, and epimastigotes), and the cytokine levels were measured after 24 and 48 h. Our results indicate that live trypomastigotes or live amastigotes (but not live epimastigotes or live metacyclic trypomastigotes) as well as trypomastigote extracts (but not extracts derived from epimastigotes) induce IL-12 and TNF-alpha synthesis by macrophages. Such biological activity is enhanced in membrane preparations from trypomastigotes. Further enrichment of the trypomastigote-derived monokine-inducing factor was obtained by solvent extraction and hydrophobic-interaction chromatography. The resultant purified molecules are a family of closely related glycoconjugates with predominant species at 70 to 80 and 120 to 200 kDa. These molecules are composed of carbohydrate chains O-linked to a polypeptide backbone that is anchored to the trypomastigote membrane via a glycosylphosphatidylinositol structure. The trypomastigote-derived glycoconjugates are active in inducing cytokine synthesis by macrophages at concentrations of 100 ng/ml. These effects are highly potentiated by IFN-gamma. Mapping of the glycoconjugate molecules to characterize the structural requirements for macrophage activation suggested that nonsaturated acyl fatty acid chains and periodate-sensitive units from the glycosylphosphatidylinositol anchor are important elements for the infective trypomastigote form to initiate cytokine synthesis by macrophages.

Glycoconjugates isolated from Trypanosoma cruzi but not from Leishmania species membranes trigger nitric oxide synthesis as well as microbicidal activity in IFN-gamma-primed macrophages.

In the present study, we investigated the role of glycosylphosphatidylinositol-anchored mucin-like glycoproteins (GPI-mucins) from Trypanosoma cruzi trypomastigotes in triggering the synthesis of nitric oxide as well as the microbicidal activity in murine macrophages. Our results show that GPI-mucins isolated from trypomastigote membranes are potent inducers of nitric oxide synthesis by IFN-gamma-primed macrophages, even at concentrations as low as 10 ng/ml. Our data also indicate the important role of glycosylphosphatidylinositol anchors from GPI-mucins as the second signal responsible for induction of nitric oxide synthesis by macrophages. To further investigate the role of these parasite molecules in inducing parasiticidal function, we cultured macrophages in the presence or absence of trypomastigote GPI-mucins and/or IFN-gamma and then infected these cells with either Leishmania spp. or T. cruzi. IFN-gamma was sufficient to induce microbial activity in macrophages infected with T. cruzi trypomastigotes. In contrast, killing of different species of Leishmania was further enhanced when macrophages exposed to IFN-gamma were also costimulated with trypomastigote-derived GPI-mucins. Our results also indicate that different glycolipids obtained from Leishmania major or Leishmania donovani (i.e., lipophosphoglycans or glycoinositolphospholipids) were unable to potentiate nitric oxide synthesis and/or microbicidal activity displayed by IFN-gamma-primed macrophages.

Structure of the N-linked oligosaccharide of the main diagnostic antigen of the pathogenic fungus Paracoccidioides brasiliensis.

The major diagnostic antigen of Paracoccidioides brasiliensis is the exocellularly secreted 43,000 Da glycoprotein (gp43) which contains a single N-linked oligosaccharide chain. This oligosaccharide, although poorly immunogenic in man, is responsible for the cross-reactivity of the gp43 with sera from patients with histoplasmosis, and may have a role in fungal virulence. It contains a neutral high-mannose core (Man7GlcNAc2) to which a (1-->6)-linked alpha-D-Manp chain of variable length, substituted at the 2-O positions by single alpha-D-Manp residues, is attached. A terminal unit of beta-D-galactofuranose is (1-->6)-linked to one of the (1-->2)-linked mannosyl residues, either in the C or in the A arm of the oligosaccharide. The heterogeneity of the oligosaccharide is determined by the different sizes of the A arm and the sites of insertion of the beta-galactofuranosyl unit. The complete structure was determined by methylation analysis, 1H-NMR, mass spectrometry, acetolysis and mannosidase degradation. Electrospray mass spectrometry showed that the oligosaccharide comprises several subtypes ranging from Hex18GlcNAc2 to Hex10GlcNAc2 which accounts for the diffuse migration of the gp43 in polyacrylamide gels. The average size of the most frequent subtype is Hex13.6GlcNAc2. Dilute acid treatment to remove beta-D-Galf reduced the molecular masses of the majority of the subtypes by a single sugar unit.

Biochemistry and molecular biology of the main diagnostic antigen of Paracoccidioides brasiliensis.

The 43,000 dalton glycoprotein of Paracoccidioides brasiliensis (gp 43) is the main exocellular antigen recognized by sera from patients with paracoccidioidomycosis in a variety of serological assays. Specific conformational peptide epitopes are recognized by the human antibodies as determined by antigen deglycosylation. Procedures for the purification of the gp43 using immunoaffinity chromatography have been described. The secretion of the gp43 as a function of the growth curve, its partial aggregation with a proteolytic enzyme, ability to bind laminin, as well as to form circulating immunocomplexes in vivo could play a role in pathogenesis. Crude antigenic preparations depleted of gp43 epitopes lost their ability to elicit positive skin tests. Accordingly, the purified gp43 molecule induced delayed hypersensitivity reactions in man and infected animals, caused a T-CD4-dependent proliferation of lymph node cells from mice immunized with it, and of peripheral blood lymphocytes from an individual sensitized to P. brasiliensis by prolonged contact with the fungus. To identify the immunodominant epitopes in both humoral and cellular reactions, the gp43 gene has been cloned, sequenced, and partly expressed. It bears peptide sequences homologous to those of beta-1,3-glucanases from Candida albicans and Saccharomyces cerevisiae but has no enzymatic activity itself. The molecular weight of the unglycosylated antigen is 42,227. A single N-linked oligosaccharide chain in the gp43 contains alpha-D-mannopyranosyl, beta-D-galactofuranosyl and N-acetylglucosaminyl units with the predominant ratio of 10:2:2, and characteristics of a high mannose type.

Complement-mediated lysis of Trypanosoma cruzi trypomastigotes by human anti-alpha-galactosyl antibodies.

Antibodies that lyse trypomastigotes in a complement-mediated reaction are believed to be the main participants in the protection against virulent Trypanosoma cruzi. Antibodies with a specificity for alpha-galactosyl-containing determinants--generally called antiGal--were studied to determine their role in the lysis of trypomastigote forms. The titers of antiGal markedly increase in Chagas's disease. In the present study we demonstrate binding of this antibody to T. cruzi and the complement-mediated lysis of trypomastigotes by antiGal. Lysis of metacyclic trypomastigotes by whole Chagasic (Ch) serum or isolated antiGal fractions was equally inhibited by alpha- but not by beta-galactosides. Most of the lytic power of the Ch antiGal as well as of the whole Ch serum was removed by absorption on Synsorb-linked Gal alpha 1, 3Gal beta 1, 4GlcNAc followed by rabbit erythrocyte absorption. The Ch antiGal had a lower affinity for melibiose bound to agarose than for the trisaccharide linked to Synsorb, and was several times more effective in the immunolysis of trypomastigotes than the corresponding antiGal from normal human serum. Lytic antibodies were partly absorbed by Serratia marcescens but not by Escherichia coli O111. A human volunteer immunized with an S. marcescens vaccine elicited a specific antiGal response that was lytic to trypomastigotes (70% lysis). We suggest that in vivo high-affinity antiGal antibody clones, as occur in Ch patients, may significantly contribute to the destruction of the parasite, whereas low-affinity antiGal clones are much less effective in the protection against T. cruzi infection.