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Bull Exp Biol Med ; 167(1): 120-122, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31183643


We optimized the method of isolation of antibodies from placental tissue of a conventionally healthy patient. Four protocols of antibody isolation were evaluated and a protocol with tissue grinding (without homogenization) and successive elution of the antibodies with acidic and alkaline buffers was recommended for use. The repertoire of the isolated antibodies was characterized using a glycan array. Partial coincidence of the specificity of the isolated antibodies with antibodies in the peripheral blood was demonstrated, which indicates their possible association with carbohydrate antigens in the placenta. Identification of potential molecular targets of resident antibodies in the placenta is necessary for understanding the mechanisms of formation of immunological tolerance to the fetus.

Biochemistry (Mosc) ; 84(6): 608-616, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31238860


The repertoire of antiglycan antibodies of peripheral blood was studied using a microarray containing 487 glycan antigens: fragments of mammalian glycans (N- and O-chains of glycoproteins, as well as glycolipids) and also bacterial polysaccharides. The sera samples correspond to the third, sixth, and twelfth months of life. The infants were divided into four groups according to their nutrition type: breast milk, standard formula, and partially or extensively hydrolyzed formula. During the first year of life, the total amount of IgG decreased; presumably, the lifetime of maternal IgG in the newborns' bloodstream is much greater than is generally assumed. At the same time, the IgM content was low during the first six months and increased significantly by the twelfth month. The antiglycan IgM repertoire of one-year-old infants was still different from that of their mothers, as well as from the repertoire of unrelated donors, in particular, by the absence of antibodies against the Galß1-3GlcNAc (LeC) disaccharide, which is found in almost all healthy humans. It is noteworthy that the level of IgM of breast-fed infants was significantly lower than that of formula-fed by the twelfth month.

Autoanticorpos/imunologia , Polissacarídeos/imunologia , Adulto , Autoanticorpos/sangue , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Lactente , Alimentos Infantis , Recém-Nascido , Mães
Mol Immunol ; 106: 63-68, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30583222


Sepharose matrix without immobilized ligands binds antibodies from human blood serum or immunoglobulin preparations. The eluted antibodies bind bacterial polysaccharides having no structural similarity to agarose (Sepharose is a cross-linked polysaccharide agarose) with a high affinity. It is concluded that the identified antibodies are capable of recognizing spatial rather than linear epitopes of bacterial polysaccharides. This side activity of Sepharose matrix should be taken into account in isolating target antibodies and other proteins from human blood.

Anticorpos Antibacterianos/isolamento & purificação , Polissacarídeos Bacterianos/química , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Humanos , Polissacarídeos Bacterianos/imunologia , Sefarose/química
Biochemistry (Mosc) ; 80(7): 820-35, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26541997


It is generally accepted that the generation of antibodies proceeds due to immunization of an organism by alien antigens, and the level and affinity of antibodies are directly correlated to the presence of immunogen. At the same time, vast experimental material has been obtained providing evidence of antibodies whose level remains unchanged and affinity is constant during a lifetime. In contrast to the first, adaptive immunoglobulins, the latter are named natural antibodies (nAbs). The nAbs are produced by B1 cells, whereas adaptive Abs are produced by B2. This review summarizes general data on nAbs and presents in more detail data on antigens of carbohydrate origin. Hypotheses on the origin of nAbs and their activation mechanisms are discussed. We present our thoughts on this matter supported by our experimental data on nAbs to glycans.

Anticorpos/imunologia , Antígenos/imunologia , Imunidade Adaptativa/imunologia , Animais , Formação de Anticorpos/imunologia , Humanos , Imunização , Polissacarídeos/imunologia
Glycoconj J ; 31(1): 7-12, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24065176


Galectins are multifunctional effectors, for example acting as regulators of cell growth via protein-glycan interactions. The observation of capacity to kill bacteria for two tandem-repeat-type galectins, which target histo-blood epitopes toward this end (Stowell et al. Nat. Med. 16:295-301, 2010), prompted us to establish an array with bacterial polysaccharides. We addressed the question whether sugar determinants other than ß-galactosides may be docking sites, using human galectins-4, -8, and -9. Positive controls with histo-blood group ABH-epitopes and the E. coli 086 polysaccharide ascertained the suitability of the set-up. Significant signal generation, depending on type of galectin and polysacchride, was obtained. Presence of cognate ß-galactoside-related epitopes within a polysaccharide chain or its branch will not automatically establish binding properties, and structural constellations lacking galactosides, like rhamnan, were found to be active. These data establish the array as valuable screening tool, giving direction to further functional and structural studies.

Galectinas/metabolismo , Polissacarídeos Bacterianos/metabolismo , Sítios de Ligação , Epitopos/metabolismo , Galactosídeos/química , Galectinas/química , Humanos , Polissacarídeos Bacterianos/química , Ligação Proteica , Sequências Repetitivas de Aminoácidos , Ramnose/química