Article

Naturally occurring anti-band 3 antibodies bind to protein rather than to carbohydrate on band 3.

Laboratory for Biochemistry, Swiss Federal Institute of Technology, ETH-Zentrum, Zurich.
Journal of Biological Chemistry (Impact Factor: 4.65). 12/1993; 268(31):23562-6.
Source: PubMed

ABSTRACT Naturally occurring anti-band 3 antibodies were affinity purified from pooled human IgG (Sandoglobulin) (Lutz, H. U., Flepp, R., and Stringaro-Wipf, G. (1984) J. Immunol. 133, 2610-2618). They bound to the major integral membrane protein of human red blood cells and its 55-kDa NH2-terminal chymotryptic fragment but not to the carbohydrate-rich 38-kDa fragment on blots. Likewise, neither an endo-beta-galactosidase nor a neuraminidase treatment of band 3 on intact red cells reduced their binding to the blotted antigen. Lactoferrin (10 micrograms/ml) had no significant effect on their binding to band 3 and to its 55-kDa chymotryptic fragment. Even in the presence of 20 micrograms/ml lactoferrin anti-band 3 antibodies bound specifically to chymotrypsin-pretreated and oxidatively stressed red cells. Thus, naturally occurring anti-band 3 antibodies bind to protein rather than carbohydrate within band 3 protein, irrespectively of whether the antibodies were depleted of anti-idiotypic and other IgG-reactive antibodies or not.

0 Bookmarks
 · 
99 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Immunoglobulins may have been developed in evolution to provide specificity for clearing body waste in the first animals with three germ layers. Tissue homeostasis in vertebrates comprises clearance of proteins released from lysed cells, elimination of altered plasma proteins, of senescent and apoptotic cells. Rather specific IgM and IgG naturally occurring antibodies (NAbs) to cytoplasmic and cytoskeletal proteins bind to proteins released from lysing cells and the IgG NAbs are slightly upregulated upon demand. Some of these NAbs along with complement have devastating effects when massive amounts of intracellular proteins are released during an infarct or an ischemia/reperfusion experiment. IgM NAbs to neoepitopes on plasma proteins/lipids help clear denatured proteins and are protective. IgG NAbs to an exposed protein, band 3 from red blood cells, bind to oligomerized band 3 and due to an affinity for C3 within their framework preferentially form C3b2-IgG complexes from nascent C3b. Thus, anti-band 3 NAbs gain potency by using avidity and generating a potent precursor of the amplifying C3 convertase. IgM NAbs to neoepitopes, which are generated by oxidized lipids forming Schiff bases with proteins, are protective and help clear this waste in atherosclerosis, but IgG antibodies (NAbs?) of the same specificity promote disease.
    Journal of Autoimmunity 01/2008; 29(4):287-94. · 8.15 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Naturally occurring anti-band 3 antibodies (anti-band 3 NAbs) are directed against the 55-kDa chymotryptic fragment of the anion transport protein (band 3) of red blood cells (RBCs). They bind to senescent and oxidatively stressed RBCs and induce their selective clearance. These IgG NAbs exist at low concentrations, and have a weak affinity that prevents them from actively recruiting second binding sites. Cellular senescence or oxidative damage induces a cascade of biochemical events that results in the detachment of band 3 from the cytoskeleton and in clustering of band 3 protein by bound hemichromes and Syk kinase. Clustered band 3 proteins allow bivalent binding of anti-band 3 NAbs. Bivalently bound anti-band 3 NAbs have the unique capacity to stimulate C3b deposition by preferentially generating C3b2-IgG complexes, which act as potent C3 convertase precursors of the alternative complement pathway. Antibody binding not only to clustered, but also to oligomerized band 3 protein further increases if the human plasma also contains induced anti-lactoferrin antibodies. These bind to the polylactosaminyl oligosaccharide, a carbohydrate that exists in lactoferrin and in the 38-kDa fragment of band 3 protein. Anti-lactoferrin antibodies are found primarily in plasma of patients with autoimmune diseases and who have anti-neutrophil cytoplasmic antibodies (ANCA).
    Transfusion Medicine and Hemotherapy 10/2012; 39(5):321-327. · 1.59 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This review focuses on the analysis and evaluation of the diverse senescence markers suggested to prime red blood cells (RBC) for clearance in humans. These tags develop in the course of biochemical and structural alterations accompanying RBC aging, as the decrease of activities of multiple enzymes, the gradual accumulation of oxidative damage, the loss of membrane in form of microvesicles, the redistribution of ions and alterations in cell volume, density, and deformability. The actual tags represent the penultimate galactosyl residues, revealed by desialylation of glycophorins, or the aggregates of the anion exchanger (band 3 protein) to which anti-galactose antibodies bind in the first and anti-band 3 naturally occurring antibodies (NAbs) in the second case. While anti-band 3 NAbs bind to the carbohydrate-free portion of band 3 aggregates in healthy humans, induced anti-lactoferrin antibodies bind to the carbohydrate-containing portion of band 3 and along with anti-band 3 NAbs may accelerated clearance of senescent RBC in patients with anti-neutrophil cytoplasmic antibodies (ANCA). Exoplasmically accessible phosphatidylserine (PS) and the alterations in the interplay between CD47 on RBC and its receptor on macrophages, signal regulatory protein alpha (SIRPalpha protein), were also reported to induce erythrocyte clearance. We discuss the relevance of each mechanism and analyze the strength of the data.
    Frontiers in Physiology 01/2013; 4:387.

Full-text (2 Sources)

View
39 Downloads
Available from
Jun 6, 2014