RESUMEN
BACKGROUND: Antigen exposure is one of the major exogenous factors modulating human immunocompetence acquisition. Decline in family size and improvements in public health and hygiene in developed countries, may deprive the immune system of appropriate antigen input by diminishing infectious stimuli. Probiotics are a large group of microorganisms defined by their beneficial effects on human health and with stimulating effects on different functions of the immune system. AIM OF THE STUDY: We conducted a double-blind, placebo-controlled trial to determine if probiotics maintain their immune-stimulating effects in a population of 162 children with a high index of natural exposure to microorganisms. Children were to ingest for at least 4 months one of two products, low-fat milk fermented by Streptococcus thermophilus (control product) or low-fat milk fermented by S. thermophilus and Lactobacillus casei, with Lactobacillus acidophilus, oligofructose and inulin added after the fermentation process (test product). According to their age, children were vaccinated with DTP-Hib vaccine or a 23-valent anti-pneumococcal vaccine. RESULTS: Final analysis of results was done in 70 children in each group, showing that the rate of immunoglobulin and isoagglutinin acquisition was similar in both groups. There was no difference between groups in antibody levels neither before nor after vaccination. Days of fever and number of episodes of infection were not statistically different in either group. CONCLUSIONS: Supplementation of standard fermented milk with additional probiotics was not of benefit. The high natural rate of early microbial exposure in infants and children from a population of low socio-economic status living in a "less hygienic environment" may account for the absence of an additional immune-stimulating effect by supplementary probiotics.
Asunto(s)
Aglutininas/inmunología , Formación de Anticuerpos/inmunología , Suplementos Dietéticos , Inmunoglobulinas/inmunología , Probióticos/farmacología , Aglutininas/sangre , Aglutininas/efectos de los fármacos , Formación de Anticuerpos/efectos de los fármacos , Niño , Preescolar , Método Doble Ciego , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Inmunoglobulinas/sangre , Inmunoglobulinas/efectos de los fármacos , Lactante , Lactobacillus acidophilus/inmunología , Lacticaseibacillus casei/inmunología , Masculino , Factores Socioeconómicos , Streptococcus thermophilus/inmunologíaRESUMEN
The effects of pH on Clitoria ternatea agglutinin (CTA) were studied by spectroscopy, size-exclusion chromatography, and by measuring carbohydrate specificity. At pH 2.6, CTA lacks well-defined tertiary structure, as seen by fluorescence and near-UV CD spectra. Far-UV CD spectra show retention of 50% native-like secondary structure. The mean residue ellipticity at 217 nm plotted against pH showed a transition around pH 4.0 with loss of secondary structure leading to the formation of an acid-unfolded state. This state is relatively less denatured than the state induced by 6 M guanidine hydrochloride. With a further decrease in pH, this unfolded state regains ~75% secondary structure at pH 1.2, leading to the formation of the A-state with native-like near-UV CD spectral features. Enhanced 8-anilino-1-naphthalene-sulfonate binding was observed in A-state, indicating a "molten-globule" like conformation with exposed hydrophobic residues. Acrylamide quenching data exhibit reduced accessibility of quencher to tryptophan, suggesting a compact conformation at low pH. Size-exclusion chromatography shows the presence of a compact intermediate with hydrodynamic size corresponding to a monomer. Thermal denaturation of the native state was cooperative single-step transition and of the A-state was non-cooperative two-step transition. A-State regains 72% of the carbohydrate-binding activity.
Asunto(s)
Ácidos/farmacología , Aglutininas/efectos de los fármacos , Clitoria/química , Venenos de Cnidarios/química , Aglutininas/química , Aglutininas/fisiología , Dicroismo Circular , Conformación Proteica , Pliegue de ProteínaRESUMEN
OBJECTIVE: Preoperative reduction of isoagglutinins leads to successful ABO-incompatible (ABOi) renal transplantation. The strategy includes pretransplantation plasmapheresis, more potent immunosuppressive drugs, splenectomy, and anti-CD20 antibody. It has been reported that low isoagglutinin antibody titers posttransplant were observed among ABOi renal transplants with favorable outcome. The isoagglutinin titers may increase slightly when plasmapheresis is discontinued; however, it never returns to the pretreatment level under immunosuppressive therapy. This raises the question of what occurs to the isoagglutinin titer in ABO-compatible renal transplants under maintenance immunosuppressive pharmacotherapy. METHODS: We analyzed 10 renal transplant recipients, including seven living and three cadaveric donors. Patients were treated with basiliximab (20 mg) intravenously on day 0 and day 4. Maintenance immunosuppressive therapy involved a calcineurin inhibitor, mycophenolate mofetil, and steroid. Anti-human globulin isoagglutinin titers were routinely examined 1 day before and day 0 and 1, 2, 3, 4, 8, 12, and 24 weeks posttransplant. No ALG or intravenous immunoglobulin or plasmapheresis treatment was provided in the follow-up period. RESULTS: Our preliminary data showed nearly no influence on isoagglutinin titer levels in 6-month follow-up under maintenance immunosuppressive therapy. In addition, no significant difference in isoagglutinin titer was observed between tacrolimus and cyclosporine groups. CONCLUSION: Maintenance immunosuppressive pharmacotherapy did not affect isoagglutinin titer levels in ABO-compatible kidney transplants. Further study is needed to investigate the mechanisms of persistent low-level isoagglutinin titers among successful ABOi renal transplantation patients.
Asunto(s)
Aglutininas/fisiología , Anticuerpos Monoclonales/uso terapéutico , Inmunosupresores/farmacología , Inmunosupresores/uso terapéutico , Trasplante de Riñón/inmunología , Proteínas Recombinantes de Fusión/uso terapéutico , Sistema del Grupo Sanguíneo ABO , Aglutininas/efectos de los fármacos , Anticuerpos Monoclonales/farmacología , Basiliximab , Cadáver , Creatinina/sangre , Estudios de Seguimiento , Humanos , Terapia de Inmunosupresión/métodos , Donadores Vivos , Proteínas Recombinantes de Fusión/farmacología , Tacrolimus/uso terapéutico , Factores de Tiempo , Donantes de TejidosRESUMEN
In the current study it has been found that efrapeptins, secondary metabolites of entomopathogenic fungi Tolypocladium cylindrosporum, interfere with agglutinin. The effect of efrapeptins on G. mellonella agglutinin was tested using rabbit blood. The results revealed that the end point for control larvae were 12.5 whereas for treated larvae which injected with 5 microl of 5 microg efrapepins ml(-1) or 50 microg efrapepins ml(-1) the end points were 10.5 and 8.5, respectively. Considering that efrapeptins suppress agglutination this study suggest that efrapeptins may interfere with the ligand-receptor interactions that are likely to occur at the plasma membrane of specific haemocytes. It has been suggested that majority of interactions between cellular and humoral components of the insect immune system are receptor-mediated.
Asunto(s)
Aglutininas/efectos de los fármacos , Hongos Mitospóricos/patogenicidad , Mariposas Nocturnas/inmunología , Péptidos/farmacología , Animales , Catecol Oxidasa/metabolismo , Culicidae/crecimiento & desarrollo , Culicidae/microbiología , Precursores Enzimáticos/metabolismo , Control de Insectos/métodos , Larva , Hongos Mitospóricos/aislamiento & purificación , Mariposas Nocturnas/efectos de los fármacos , Mariposas Nocturnas/enzimología , Mariposas Nocturnas/crecimiento & desarrolloRESUMEN
BACKGROUND: It is believed that EDTA-dependent panagglutination is associated with free carboxylic acids that support reactions of rare autoagglutinins. CASE REPORT: An ABO typing discrepancy occurred in an 88-year-old patient. The specificity of his autoagglutinin was demonstrated by panel cell study and absorption tests using normal donors' red cells or immunoadsorbents coated with A, B, or O substances. Inhibition assays were performed to determine whether the autoagglutinin was inhibited by ionized calcium or carboxylic acids. The autoagglutinin had anti-B specificity when tested in the presence of EDTA. It was neutralized by group B secretor saliva and adsorbed by crystalline silica coated with simple B substances with or without EDTA, although it was absorbed by group B red cells only in the presence of EDTA. The agglutinating activity was stronger at 25 degrees C (titer 64) than at 37 degrees C (titer 16) and was destroyed by treatment of the serum with dithiothreitol, which suggests that the autoagglutinin is IgM. This activity also appeared in the patient's serum after dialysis and in an eluate obtained after adsorption with simple B substances, and it was inhibited by the addition of CaCl2 at 0.5 mM or higher concentrations. This suggests that the agglutination is not dependent on EDTA but, rather, on the concentration of ionized calcium. The autoagglutinin failed to react with group B red cells treated with glutaraldehyde for 10 minutes. CONCLUSION: An anti-B autoagglutinin was shown to have caused an ABO typing discrepancy in the presence of EDTA. These results suggest that autoagglutination requires an environment with low levels of ionized calcium, but not the presence of carboxyl groups.
Asunto(s)
Sistema del Grupo Sanguíneo ABO/inmunología , Aglutininas/efectos de los fármacos , Ácido Edético/farmacología , Anciano , Anciano de 80 o más Años , Pruebas de Aglutinación , Aglutininas/inmunología , Calcio/inmunología , Calcio/fisiología , Cationes/inmunología , Cationes/farmacología , Sistema Libre de Células/efectos de los fármacos , Disacáridos/farmacocinética , Eritrocitos/efectos de los fármacos , Eritrocitos/inmunología , Eritrocitos/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Técnicas de Inmunoadsorción , Isoanticuerpos/sangre , Isoanticuerpos/inmunología , Masculino , Pruebas de Neutralización , Trisacáridos/farmacocinéticaRESUMEN
A cysteine protease inhibitor with an apparent Mr = 12,600, designated limulus (L)-cystatin, was isolated from hemocyte lysates of the Japanese horseshoe crab (Tachypleus tridentatus), using two steps of chromatography, including dextran sulfate-agarose, and carboxymethylated papain-agarose. L-cystatin inhibits amidolytic activity of papain by forming a noncovalent 1:1 complex with an equilibrium constant (Ki) of 0.08 nM. It also inhibits cathepsin L (Ki = 0.17 nM) and ficin (Ki = 0.52 nM), but not argingipain (a bacterial cysteine protease) and calpains. A cDNA for L-cystatin was isolated and the open reading frame coded for a mature protein of 114 amino acids, of which 99 residues were confirmed by peptide sequencing. L-cystatin shows significant sequence identities to members of the family 2 cystatin, such as bovine colostrum cystatin (33%) and human cystatin S (31%). Northern blotting revealed expression of the mRNA in hemocytes and slightly in heart but expression was negligible in hepatopancreas, intestine, stomach, and muscle. Immunoblotting revealed the localization to be in the large granules of hemocytes. Furthermore, L-cystatin has an antimicrobial activity against Gram-negative bacteria, which is much stronger than that of chicken egg white cystatin. These data suggest that the large granule-derived L-cystatin serves synergistically to accomplish an effective defense against invading microbes, together with other defense molecules that are released in response to external stimuli.
Asunto(s)
Cistatinas/química , Cistatinas/genética , Inhibidores de Cisteína Proteinasa/farmacología , Hemocitos/química , Cangrejos Herradura/química , Aglutininas/efectos de los fármacos , Secuencia de Aminoácidos , Animales , Antibacterianos/farmacología , Secuencia de Bases , Northern Blotting , Bovinos , Clonación Molecular , Cistatinas/farmacología , Inhibidores de Cisteína Proteinasa/química , Inhibidores de Cisteína Proteinasa/genética , ADN Complementario/química , ADN Complementario/genética , Hemocitos/ultraestructura , Cangrejos Herradura/citología , Humanos , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Papaína/antagonistas & inhibidores , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Fracciones Subcelulares/químicaRESUMEN
Sialylated or sulfated derivatives and acrylamide copolymers of blood group T-(Gal beta 1,3GalNAc alpha-) and Tn-(GalNAc alpha) haptens were studied for their interaction with the lectins of peanut (PNA), Agaricus bisporus-(ABA), Helix pomatia-(HPA) and Vicia villosa B4-(VVA), using asialo Cowper's gland mucin (ACGM), which contains both T and Tn epitopes, as the coating substrate in enzyme linked lectin assay. Both T and Tn copolymers (-40 haptens) showed high affinity and strict specificity; although the T-copolymer at 0.05-0.07 microM concentration caused 50% inhibition of interaction of either PNA or ABA with ACGM, there was little inhibition of the HPA and VVA interactions even at over 100 times that concentration. The Tn-copolymer at 0.02-0.05 microM inhibited HPA or VVA interaction with ACGM by 50% but gave virtually no inhibition of PNA and ABA binding. Sialyl, sulfate or methyl group substitution on C-6 of GalNAc of the T-haptene did not prevent interaction with PNA but almost abolished interaction with ABA. In contrast, sialyl or sulfate group on C-6 and sulfate on C-3 of Gal in Gal beta 1,3GalNAc alpha- inhibited almost completely the interaction of PNA with ACGM but had only a slight effect on the interaction of ABA; C-6 substitution with either sialic acid or sulfate on GalNAc alpha- almost abolished the interaction of both HPA and VVA with ACGM.(ABSTRACT TRUNCATED AT 250 WORDS)