Influence of intraperitoneal injection of three types of hydrogel beads on expression of carbohydrate-binding sites in spleen macrophages

et al. 2000

APMIS

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Deficiencies in adhesion molecules or their counter-receptors in humans may have severe consequences as exemplified by leukocyte adhesion deficiency (LAD) I or II syndromes. Because such diseases occur with great rarity, animal models are valuable for studying the role of particular adhesion molecules and their natural ligands in immunity. We studied selected immune parameters and general health in mice with a defect in the sialyl-Lewis X antigen (selectin ligand) caused by disruption of the gene encoding alpha(1,3)fucosyltransferase VII (Fuc-TVII). Leukocytes from Fuc-TVII -/- and control mice were tested for adherence to cellophane membranes or polymer particles in vivo and phagocytic activity in vitro. While no difference in adherence was found, the number of neutrophil granulocytes in exudate induced by intraperitoneal injection of polymer beads was reduced in knock-out mice. Moreover, the phagocytic activity in Fuc-TVII -/- mice was significantly reduced. These animals have splenomegaly due to increased hematopoiesis and reduced weight but do not exhibit clinical signs of immunodeficiency. In conclusion, the lack of Fuc-TVII activity leads to several morphological and functional abnormalities without an impact on survival rate.

Section: Discussionsupporting

confidence: 85%

Reduced phagocytic activity of polymorphonuclear leukocytes in α(1,3) fucosyltransferase VII‐deficient mice

Bartůňková

Malý

et al. 2000

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Untitled

Journal of Materials Science: Materials in Medicine

Petrovický

Zach

et al. 1999

A lesion in the dorsoposterior part of the rat brain septum is known to exert an inhibitory effect on the delayed skin hypersensitivity and incorporation of radiolabeled thymidine into the lymphoid organs. To determine whether distinct properties of macrophages will also be modulated by this type of injury, we have focused upon the monitoring of expression of sugar receptors (lectins). In this study we show a reduction in the number of macrophages expressing carbohydrate-binding sites for asialoglycoproteins (beta-D-galactoside), alpha-D-mannoside and alpha-D-mannoside-6-phosphate in spleen macrophages after the lesion of the dorsoposterior septum of the brain in the rat. The number of ED-1+ macrophages was not influenced. The intraperitoneal injection of beads prepared from the copolymer of 2-hydroxyethyl methacrylate with dimethyl aminoethyl methacrylate (30 wt %) elevated significantly the number of ED-1+ spleen macrophages and number of macrophages with binding site(s) recognizing asialoglycoproteins and alpha-D-mannoside-6-phosphate, respectively. These results indicate that a foreign-body reaction appears to be able to mediate a phenotypic restoration of lectin expression by spleen macrophages altered by the brain lesion. It can be suggested that, for example, a probable production of cytokines by the inflammatory cells colonizing the implanted beads plays a role in this process.

Anionic Polymers for Implantation

Annals of the New York Academy of Sciences

Vacı́k

1997

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Synthetic polymers are more and more frequently used in clinical medicine for the reconstruction of seriously damaged tissues and organs. Unfortunately, they are recognized by immune cells. This process includes the adsorption of bioactive proteins such as fibronectin, vitronectin, complement, fibrinogen or immunoglobulins on foreign surfaces and their recognition by receptors on immune cells.' This usually influences the activity and phenotypic characteristics of immune cells colonizing the implant.Numerous data from the area of anti-infectious immunity demonstrated the distinct effect of chemistry of the surface of bacterial cells on their recognition by non-specific immunity. Bacteria containing the anionic sialic acids in both, monomeric and polymeric form are known as poor activators of the alternative complement pathway, which is also of a great importance in the non-self recognition of synthetic materials2 Sialic acids are a quite wide family of derivatives of Nacetylneuraminic acid, which are characterized by the presence of carboxylate anions and are normally expressed on the surface of cells in vertebrates. This monosaccharide is recognized by specific populations of macrophages in lymphatic nodes and in the spleen by endogenous lectin sialoadhesin which is participating in immune cell maturation in lymphoid organs.' However, the knowledge about the sialoadhesin expression in inflammatory macrophages is only minimal.In this study we demonstrate the N-acetylneuraminic acid (Neu)-binding sites in inflammatory macrophages colonizing the surface of implants in the rat, to estimate the binding capacity of macrophages for this anionic monosaccharide with described biomimetic properties.The effect of carboxylate anions on hydrogel supports or implants on monocyte adhesion in vitro and macrophage adhesion and fusion on surfaces of strips subcutaneously implanted into the rat was tested for a better understanding of the effect of this anion on the non-self recognition of synthetic hydrogels. An intraperitoneal injection of beads prepared from the same polymers was used for the phenotypic characterization of red pulp spleen macrophages and so for an estimation for any "This research was supported by grant No 304/93/0666 of the Grant Agency of the Czech Republic.Tel: +420 2 24 91 50 03; Fax: +420 2 29 76 92.Tel: +420 2 36 03 41; Fax: +420 2 36 79 81. 95