High-affinity binding measurements of antibodies to cell-surface-expressed antigens

2008 ◽  
Vol 373 (1) ◽  
pp. 52-60 ◽  
Author(s):  
Palaniswami Rathanaswami ◽  
John Babcook ◽  
Michael Gallo
Keyword(s):  
Cell Surface ◽  
Affinity Binding ◽  
High Affinity Binding ◽  
High Affinity

scholarly journals Polarized fibronectin secretion and localized matrix assembly sites correlate with subendothelial matrix formation

Blood ◽  
1990 ◽  
Vol 75 (12) ◽  
pp. 2335-2342 ◽  
Author(s):  
AP Kowalczyk ◽  
RH Tulloh ◽  
PJ McKeown-Longo
Keyword(s):  
Endothelial Cells ◽  
Cell Surface ◽  
Binding Sites ◽  
Affinity Binding ◽  
Apical Surface ◽  
Matrix Assembly ◽  
High Affinity Binding ◽  
High Affinity ◽  
Fibronectin Matrix ◽  
Subendothelial Matrix

Abstract Endothelial cells in vivo form the interface between the vascular and interstitial compartments and are strategically located to mediate vascular permeability and hemostasis. One mechanism endothelial cells use to maintain a nonthrombogenic surface is to polarize basement membrane constituents to the basolateral cell surface. In the present study, we began characterization of the mechanisms used by endothelial cells in the assembly of a subcellular fibronectin matrix. Immunofluorescence microscopy was used to localize extracellular matrix fibronectin in endothelial cell cultures. In contrast to preconfluent and newly confluent cultures, post-confluent cultures assembled a fibronectin matrix that was restricted to the basolateral cell surface. To determine if endothelial cells polarize fibronectin secretion, Millicell culture inserts were used to distinguish proteins secreted from apical and basal surfaces. Preconfluent and newly confluent cultures secreted fibronectin equally into apical and basal media. In contrast, post-confluent endothelial cells secreted fibronectin preferentially into the basal chamber. The degree to which fibronectin secretion was polarized varied with time in culture and with the ability of the monolayers to act as a barrier to the movement of 125I- fibronectin from the apical to basal chamber. In addition, high affinity binding sites for exogenous 125I-fibronectin were found to be present on the basolateral, but not apical, surface of post-confluent endothelial monolayers. These results indicate that subendothelial matrix assembly correlates with polarized fibronectin secretion, culture confluence, and expression of high affinity binding sites for fibronectin on the basolateral cell surface.

scholarly journals Polarized fibronectin secretion and localized matrix assembly sites correlate with subendothelial matrix formation

Blood ◽  
1990 ◽  
Vol 75 (12) ◽  
pp. 2335-2342
Author(s):  
AP Kowalczyk ◽  
RH Tulloh ◽  
PJ McKeown-Longo
Keyword(s):  
Endothelial Cells ◽  
Cell Surface ◽  
Binding Sites ◽  
Affinity Binding ◽  
Apical Surface ◽  
Matrix Assembly ◽  
High Affinity Binding ◽  
High Affinity ◽  
Fibronectin Matrix ◽  
Subendothelial Matrix

Endothelial cells in vivo form the interface between the vascular and interstitial compartments and are strategically located to mediate vascular permeability and hemostasis. One mechanism endothelial cells use to maintain a nonthrombogenic surface is to polarize basement membrane constituents to the basolateral cell surface. In the present study, we began characterization of the mechanisms used by endothelial cells in the assembly of a subcellular fibronectin matrix. Immunofluorescence microscopy was used to localize extracellular matrix fibronectin in endothelial cell cultures. In contrast to preconfluent and newly confluent cultures, post-confluent cultures assembled a fibronectin matrix that was restricted to the basolateral cell surface. To determine if endothelial cells polarize fibronectin secretion, Millicell culture inserts were used to distinguish proteins secreted from apical and basal surfaces. Preconfluent and newly confluent cultures secreted fibronectin equally into apical and basal media. In contrast, post-confluent endothelial cells secreted fibronectin preferentially into the basal chamber. The degree to which fibronectin secretion was polarized varied with time in culture and with the ability of the monolayers to act as a barrier to the movement of 125I- fibronectin from the apical to basal chamber. In addition, high affinity binding sites for exogenous 125I-fibronectin were found to be present on the basolateral, but not apical, surface of post-confluent endothelial monolayers. These results indicate that subendothelial matrix assembly correlates with polarized fibronectin secretion, culture confluence, and expression of high affinity binding sites for fibronectin on the basolateral cell surface.

Degradation of Cell Surface Heparan Sulfates Decreases the High Affinity Binding of Basic FGF to Endothelial Cells, but Not to FRTL-5 Rat Thyroid Cells

Thyroid ◽  
1995 ◽  
Vol 5 (6) ◽  
pp. 455-460 ◽  
Author(s):  
NAOYA EMOTO ◽  
OSAMU ISOZAKI ◽  
EIJI OHMURA ◽  
KAZUO SHIZUME ◽  
TOSHIO TSUSHIMA ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Surface ◽  
Affinity Binding ◽  
Thyroid Cells ◽  
High Affinity Binding ◽  
Basic Fgf ◽  
High Affinity ◽  
Heparan Sulfates ◽  
Rat Thyroid

scholarly journals Endocytosis of sulphated proteoglycans by cultured skin fibroblasts

1978 ◽  
Vol 176 (3) ◽  
pp. 671-676 ◽  
Author(s):  
R Prinz ◽  
J Schwermann ◽  
E Buddecke ◽  
K von Figura
Keyword(s):  
Cell Surface ◽  
Binding Sites ◽  
Skin Fibroblasts ◽  
Affinity Binding ◽  
High Affinity Binding ◽  
Surface Receptors ◽  
High Affinity ◽  
Cultured Skin ◽  
Kinetics Of ◽  
Adsorptive Endocytosis

1. Human skin fibroblasts internalize homologous sulphated proteoglycans by adsorptive endocytosis. Endocytosis rate is half maximal when the concentration of the proteoglycans is 0.1 nM. At saturation, a single fibroblast may endocytose up to 8 × 10(6) proteoglycan molecules/h. 2. The kinetics of prote;glycan binding to the cell surface suggest the presence of 6 × 10(5) high-affinity binding sites per cell. The bulk of sulphated proteoglycans associates to low-affinity binding sites on the cell surface. 3. Glycosaminoglycans and other anionic macromolecules inhibit endocytosis of sulphated proteoglycans non-competitively. The lack of interaction of glycosaminoglycans with the cell-surface receptors for sulphated proteoglycans suggests that the protein core of proteoglycans is essential for binding to the cell surface. 4. The effects of trypsin, cell density, serum concentration and medium pH on endocytosis and degradation of endocytosed sulphated proteoglycans is described. 5. A comparison of the number of the high-affinity binding sites and the number of molecules endocytosed with respect to time suggests a recycling of the proteoglycan receptors between the cell surface and the endocytotic vesicles and/or the lysosomes.

scholarly journals Identification of a tumor cell receptor for VGVAPG, an elastin-derived chemotactic peptide.

1988 ◽  
Vol 107 (5) ◽  
pp. 1987-1993 ◽  
Author(s):  
C H Blood ◽  
J Sasse ◽  
P Brodt ◽  
B R Zetter
Keyword(s):  
Cell Surface ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Chemotactic Response ◽  
Cell Surface Receptor ◽  
Size Exclusion ◽  
Scatchard Analysis ◽  
Affinity Binding ◽  
High Affinity Binding ◽  
High Affinity

Extracellular matrix proteins and their proteolytic products have been shown to modulate cell motility. We have found that certain tumor cells display a chemotactic response to degradation products of the matrix protein elastin, and to an elastin-derived peptide, VGVAPG. The hexapeptide VGVAPG is a particularly potent chemotaxin for lung-colonizing Lewis lung carcinoma cells (line M27), with 5 nM VGVAPG eliciting maximal chemotactic response when assayed in 48-microwell chemotaxis chambers. Binding of the elastin-derived peptide to M27 cells was studied using a tyrosinated analog (Y-VGVAPG) to allow iodination. Scatchard analysis of [125I]Y-VGVAPG binding to viable M27 tumor cells at both 37 and 4 degrees C indicates the presence of a single class of high affinity binding sites. The dissociation constant obtained from these studies (2.7 X 10(-9) M) is equivalent to the concentration of VGVAPG required for chemotactic activity. The receptor molecule was identified as an Mr 59,000 species by covalent cross-linking of the radiolabeled ligand to the M27 tumor cell surface and subsequent analysis of the cross-linked material by electrophoresis and size-exclusion high performance liquid chromatography. These results suggest that M27 tumor cell chemotaxis to VGVAPG is initiated by high affinity binding of the peptide to a distinct cell surface receptor.

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