Frances A. Spring

Learn More
Erythroid progenitors differentiate in erythroblastic islands, bone marrow niches composed of erythroblasts surrounding a central macrophage. Evidence suggests that within islands adhesive interactions regulate erythropoiesis and apoptosis. We are exploring whether erythroid intercellular adhesion molecule 4 (ICAM-4), an immunoglobulin superfamily member,(More)
The CD47 glycoprotein was isolated from human erythrocytes by immunoprecipitation using monoclonal antibody (mAb) BRIC-125. Enzymic deglycosylation of the protein showed it contained N-linked oligosaccharides, and trypsin proteolysis of the protein in situ in the erythrocyte membrane cleaved it into two portions, one of which was glycosylated. Both the(More)
The expression of decay accelerating factor (DAF) was investigated in human fetal and extra-fetal tissues using a panel of mAb directed against different epitopes on the DAF molecule. By immunostaining, extensive reactivity was observed on the placental trophoblast epithelium and this was confined exclusively to sites of direct contact with maternal blood(More)
Intercellular adhesion molecule-4 (ICAM-4), a newly characterized adhesion molecule, is expressed early in human erythropoiesis and functions as a ligand for binding alpha4beta1 and alphaV integrin-expressing cells. Within the bone marrow, erythroblasts surround central macrophages forming erythroblastic islands. Evidence suggests that these islands are(More)
The LW blood group glycoprotein, ICAM-4, is a member of the intercellular adhesion molecule (ICAM) family expressed in erythroid cells. To begin to address the function of this molecule, ligands for ICAM-4 on hemopoietic and nonhemopoietic cell lines were identified. Peptide inhibition studies suggest that adhesion of cell lines to an ICAM-4-Fc construct is(More)
Intercellular adhesion molecule-4 (ICAM-4, syn. LW glycoprotein) interacts with the integrins alpha(L)beta(2), alpha(M)beta(2), A(4)beta(1), the alpha(V) family, and alpha(IIb)beta(3). Systematic mutagenesis of surface-exposed residues conserved between human and murine ICAM-4 defined 12 single amino-acid changes that affect the interaction of ICAM-4 with(More)
Blood group antigens are structural variants in surface carbohydrate or amino acid polymorphisms on extracellular domains of membrane proteins. The red cell water channel-forming integral protein (Aquaporin CHIP) is a homotetramer with only one N-glycosylated subunit, however no CHIP-associated blood group antigens have yet been identified. Immunoblotting,(More)
The cell-surface glycoproteins CD44 and CD58 are involved in cell adhesion reactions. In this paper 12 monoclonal antibodies in CD44 and two in CD58 are described. Competitive binding assays using CD44 antibodies identified three distinct epitope groups. Antibodies in Group 1 and, with one exception (BRIC 214), antibodies in group 2, but not antibodies in(More)
1. We have shown that the Dia antigen of the Diego blood group system is associated with the presence of red cell band 3 Memphis, but not all band 3 Memphis samples carry the Dia antigen. 2. The band 3 Memphis associated with the Dia antigen was covalently labelled by 4,4'-di-isothiocyanato-1,2-diphenylethane-2,2'-disulphonic acid (H2DIDS) more readily than(More)
The Lutheran blood group glycoprotein, first discovered on erythrocytes, is widely expressed in human tissues. It is a ligand for the alpha5 subunit of Laminin 511/521, an extracellular matrix protein. This interaction may contribute to vaso-occlusive events that are an important cause of morbidity in sickle cell disease. Using x-ray crystallography,(More)