scholarly journals MECHANISMS UNDERLYING BINDING OF IMMUNE COMPLEXES TO MACROPHAGES

1971 ◽  
Vol 133 (3) ◽  
pp. 589-601 ◽  
Author(s):  
Julia M. Phillips-Quagliata ◽  
Bernard B. Levine ◽  
Franco Quagliata ◽  
Jonathan W. Uhr

The mechanism of binding of immune complexes to macrophages was investigated using purified antibody and haptens of different valences. Antibody alone bound to macrophages; enhancement of binding occurred when polyvalent and divalent haptens were present at equivalence but did not occur in great antigen excess. Monovalent hapten did not increase the binding of antibody at any concentration ratio tried, though it inhibited the enhancement due to oligovalent hapten. Ultracentrifuged normal rabbit globulin also inhibited the binding of complexes indicating the presence of exposed binding sites on the uncomplexed molecules. Complexes bound more strongly than antibody alone as determined from elution studies. These results support the hypothesis that the enhancement of antibody binding to macrophages in the presence of antigen is due to increased energy of binding resulting from summation of individual binding sites already exposed on the antibody molecules. It was also possible, by saturating the macrophages with gamma globulin, to estimate the number of binding sites per cell; this was calculated to be approximately 2 million per alveolar macrophage.

1976 ◽  
Vol 35 (02) ◽  
pp. 274-288 ◽  
Author(s):  
Judith Pool ◽  
Rosemary Biggs ◽  
R. G Miller

SummaryThe theoretical basis for determining the number of antibody sites on antigen molecules is examined. The theoretical considerations are applied to factor VIII molecules. Examples based on data available at the Oxford Haemophilia Centre are calculated to illustrate the approach. It is concluded that there are few sites on each factor VIII molecule for human antibody. The three antibodies for which reasonable data were available suggest 1–3 sites for human antibody. The data for rabbit antibody suggest 5–6 sites per factor VIII molecule.


1984 ◽  
Vol 51 (03) ◽  
pp. 349-353 ◽  
Author(s):  
C Caranobe ◽  
P Sié ◽  
F Fernandez ◽  
J Pris ◽  
S Moatti ◽  
...  

SummaryA simultaneous investigation of the kinetics of serotonin (5 HT) uptake and of binding sites was carried out in the platelets of normal subjects and of 10 patients affected with various types of myeloproliferative disorders (MD). The 5 HT uptake was analysed according to the Lineweaver-Burk and the Eadie-Hofstee methods. With the two methods, the patient’s platelets exhibited a dramatic reduction of the Vi max and of the Km; in some patients the Eadie-Hofstee analysis revealed that a passive diffusion phenomenon is superimposed on the active 5 HT uptake at least for the higher concentration used. The binding data were analysed with the Scatchard method. Two classes of binding sites (high affinity - low capacity, low affinity - high capacity) were found in normal subjects and patients. Pharmacological studies with imipramine, a specific inhibitor of 5 HT uptake, suggested that both the sites are involved in 5 HT uptake. The number of both binding sites was significantly decreased in patient’s platelets while the affinity constants of these binding sites were not significantly reduced in comparison with those of the control subjects. No correlations were found between Vi max, Km and the number of binding sites. These results suggest that a reduction in the number of platelet membrane acceptors for 5 HT commonly occurs in myeloproliferative disorders but does not provide a full explanation of the uptake defect.


1993 ◽  
Vol 2 (2) ◽  
pp. 175-182 ◽  
Author(s):  
Christian Schwab ◽  
Andrea Twardek ◽  
Hans Rudolf Bosshard ◽  
Terence P. Lo ◽  
Gary D. Brayer

PLoS ONE ◽  
2015 ◽  
Vol 10 (2) ◽  
pp. e0115582 ◽  
Author(s):  
Silvia Ratto-Kim ◽  
Mark S. de Souza ◽  
Jeffrey R. Currier ◽  
Nicos Karasavvas ◽  
John Sidney ◽  
...  

Microbiology ◽  
1987 ◽  
Vol 133 (4) ◽  
pp. 825-833 ◽  
Author(s):  
I. J. Nicolson ◽  
A. C. F. Perry ◽  
M. Virji ◽  
J. E. Heckels ◽  
J. R. Saunders

1988 ◽  
Vol 66 (12) ◽  
pp. 1258-1264
Author(s):  
Patrick J. McIlroy

The effect of various salts on the binding of human choriogonadotropin to rat luteal membranes has been examined. Increasing salt concentrations had biphasic effects, initially increasing binding, then decreasing it. With NaCl, these effects were on both the affinity and the number of receptor sites. The affinity increased with increasing NaCl concentrations, to a maximum at 40 mM, and then decreased. Above 40 mM NaCl, the number of binding sites increased. NaCl also altered the effects of Mg2+ and guanyl nucleotides. At low ionic strength, Mg2+ was necessary to observe binding. Guanine nucleotides modulated this binding by decreasing the affinity. At 40 mM NaCl, Mg2+ increased receptor number without altering affinity. Guanyl nucleotides modulated this binding by reducing the number of sites to that observed in the absence of Mg2+. At 150 mM NaCl, Mg2+ and guanine nucleotides had no effect. The results suggest the presence of two pools of human choriogonadotropin receptor in rat corpus luteum, one coupled to the guanine nucleotide regulatory protein (Ns) and being Mg2+ dependent and guanine nucleotide sensitive, and the other not coupled to Ns and being Mg2+ independent and guanine nucleotide insensitive.


1988 ◽  
Vol 118 (2) ◽  
pp. 227-232 ◽  
Author(s):  
L. G. Guijarro ◽  
E. Arilla

ABSTRACT Atrophy of the exocrine pancreas was induced in rabbits by pancreatic duct ligation. Somatostatin concentration and binding in cytosol from rabbit duodenal mucosa were studied after 6 and 14 weeks of pancreatic duct ligation. Somatostatin-like immunoreactivity was significantly increased in the duodenal mucosa in both periods. Scatchard analysis showed a parallel increase in the number of binding sites rather than a change in their affinity. The physiological significance of these findings remains to be clarified. J. Endocr. (1988) 118, 227–232


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