Participation of concanavalin A binding sites in the interaction between Trypanosoma cruzi and macrophages

1983 ◽  
Vol 62 (1) ◽  
pp. 287-299
Author(s):  
M.N. Meirelles ◽  
A. Martinez-Palomo ◽  
T. Souto-Padron ◽  
W. De Souza

Untreated mouse peritoneal macrophages as well as macrophages treated with concanavalin A (ConA) were incubated in the presence of untreated or ConA-treated epimastigotes and trypomastigotes of Trypanosoma cruzi. Treatment of epimastigotes or trypomastigotes with ConA increased or decreased their uptake by macrophages, respectively. Treatment of their macrophages with ConA reduced by 70% and increased by five times the ingestion of epimastigotes and trypomastigotes, respectively. These results are discussed in relation to previous studies on the mobility of ConA receptors in the membrane of the parasite. Using fluorescein- or ferritin-labelled ConA we observed that ConA binding sites located on the plasma membrane of macrophages are internalized during endocytosis of T. cruzi, and observed in association with the membrane of the endocytic vacuole. Vacuoles without parasites showed a uniform distribution of ConA binding sites, while these sites were distributed in patches in vacuoles containing parasites. These results, in association with others previously reported, suggest the involvement of glycoproteins and/or glycolipids localized on the cell surface of T. cruzi and macrophages during the T. cruzi-macrophage interaction.

1981 ◽  
Vol 29 (7) ◽  
pp. 858-863 ◽  
Author(s):  
K Takata ◽  
F Nishiyama ◽  
H Hirano

Cationized ferritin (CF) binding, and its effect on the concanavalin A (Con A) binding pattern were studied by the double technique in monkey peritoneal macrophages. CF particles formed clumps and were internalized when cells were incubated at 37 degrees C. Such cells were fixed, and the Con A binding sites were visualized by the Con A-horseradish peroxidase (HRP) method. Using the same specimen, the distribution of CF particles and the Con A-HRP product was observed under an electron microscope. The redistribution and internalization of CF particles did not affect the continuous label of the cell surface Con A binding sites. These observations suggest the independent mobility of cell surface anionic sites and Con A binding sites.


1989 ◽  
Vol 92 (1) ◽  
pp. 85-91
Author(s):  
W.F. Patton ◽  
M.R. Dhanak ◽  
B.S. Jacobson

The plasma membrane proteins of Dictyostelium discoideum were characterized with respect to their partitioning into the Triton-insoluble cytoskeleton fraction of the cell during concanavalin A-induced capping. Two fractions of plasma membrane-associated concanavalin A were identified; one that immediately associated with the cytoskeleton fraction via cell surface glycoproteins, and one that partitioned with the cytoskeleton only after extensive cell surface glycoprotein cross-linking. Three major classes of polypeptides were found in the plasma membrane that differed with respect to their partitioning properties into the cytoskeleton fraction. The temporal order of association of the polypeptides with the cytoskeleton during concanavalin A-induced capping corresponded to the strength of their association with the cytoskeleton fraction as determined by pH and ionic strength elution from unligated cytoskeletons.


Parasitology ◽  
2019 ◽  
Vol 147 (3) ◽  
pp. 310-321
Author(s):  
Roberta Ferreira Cura das Neves ◽  
Camila Marques Adade ◽  
Anne Cristine Silva Fernandes ◽  
Angela Hampshire Lopes ◽  
Thaïs Souto-Padrón

AbstractCapping and shedding of ectodomains in Trypanosoma cruzi may be triggered by different ligands. Here, we analysed the mobility and shedding of cell surface components of living trypomastigotes of the Y strain and the CL Brener clone in the presence of poly-L-lysine, cationized ferritin (CF) and Concanavalin A (Con A). Poly-L-lysine and CF caused intense shedding in Y strain parasites. Shedding was less intense in CL Brener trypomastigotes, and approximately 10% of these parasites did not show any decrease in poly L-lysine or CF labelling. Binding of Con A induced low-intensity shedding in Y strain and redistribution of Con A-binding sites in CL Brener parasites. Trypomastigotes of the Y strain showed intense labelling with anti-〈-galactosyl antibodies, resulting in the lysis of approximately 30% of their population, in contrast with what was observed in CL Brener parasites. Incubation with Con A and CF protected trypomastigotes of the Y strain from lysis by anti-αGal. The last treatment did not interfere with the survival of the CL Brener parasites. This study corroborates with the idea that a ligand can differentially modulate the cell surface of T. cruzi, depending on the strain used, resulting in variable immune system responses and recognition by host cells.


1975 ◽  
Vol 23 (8) ◽  
pp. 607-617 ◽  
Author(s):  
T Amakawa ◽  
T Barka

The submandibular glands of 4-week-old rats were dissociated by a procedure involving digestions with collagenase and hyaluronidase, chelation of divalent cations and mechanical force. A suspension of single cells was obtained in low yield by centrifugation in a Ficoll-containing medium. Immediately after dissociation and after a culture period of 16-18 hr the dissociated cells were tested for agglutinability by concanavalin A (Con A). Using ferritin (tfer)-conjugated Con A the lectin binding by the isolated acinar cells was also studied. The dissociated cells were agglutinated by low concentrations of Con A and bound Fer-Con A molecules on their entire surface without any indication of polarization of the cell membrane. There was a considerable cell to cell variation in the amount of Fer-Con A binding which was, in general, sparse and patchy. The contact surfaces between agglutinated cells revealed a dense binding of Fer-Con A molecules irrespective of the types of cells participating in the agglutination reaction. Cells cultured for 16-18 hr were no longer agglutinated by Con A. As compared to the freshly dissociated cells the cultured acinar cells revealed a more uniform and denser binding of Fer-Con A molecules. Furthermore, there were more lectin molecules bound to the cell surface corresponding to the basal part of the cell, where the nucleus and most of the rough surface endoplasmic reticulum were located, than to the apical cell surface. It is suggested that the higher density of lectin-binding sites on the cell surface in the vicinity of the cisternae of the rough endoplasmic reticulum indicates insertion sites of newly synthesized membrane glycoproteins.


1982 ◽  
Vol 106 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Horst Robenek ◽  
Magdalena Marx ◽  
Elisabeth Peveling

1984 ◽  
Vol 32 (10) ◽  
pp. 1017-1027 ◽  
Author(s):  
H Robenek ◽  
G Schmitz ◽  
G Assmann

The topography and dynamics of receptors for acetylated (acetyl) and malondialdehyde-modified (MDA) low-density lipoprotein (LDL) in the plasma membrane of cultured mouse peritoneal macrophages were investigated using a new technique. Modified LDL labeled with gold particles was used to visualize LDL receptors in the plane of the plasma membrane in platinum-carbon surface replicas of critical point-dried cells. It was found that the native distribution of unoccupied acetyl-LDL receptors is diffuse, whereas unoccupied MDA-LDL receptors are preclustered in the plasma membrane. Competition and double labeling experiments suggest the existence of two distinct classes of receptor sites for acetyl-LDL and MDA-LDL.


1975 ◽  
Vol 142 (5) ◽  
pp. 1263-1282 ◽  
Author(s):  
F M Griffin ◽  
J A Griffin ◽  
J E Leider ◽  
S C Silverstein

These experiments were designed to evaluate the role of macrophage plasma membrane receptors for the third component of complement (C) and for the Fc portion of IgG in the ingestion phase of phagocytosis. Sheep erythrocyte (E) were coated with anti-E IgG [E(IgG)]; these E(IgG) were then attached to cultivated monolayers of mouse peritoneal macrophages under conditions which reversibly inhibit ingestion of E(IgG). The E(IgG)-macrophage complexes were further incubated under similar conditions with an antimacrophage IgG fraction which blocks Fc receptor-mediated ingestion but has no effect upon ingestion mediated by other phagocytic receptors. When these cultures were subsequently incubated under conditions optimal for particle ingestion, phagocytosis of the IgG-coated erythrocytes did not occur; the erythrocytes remained bound to the Fc receptors of the macrophage plasma membrane. To determine whether ligands must cover the entire surface of an attached particle to permit ingestion of that particle, C-coated E [E(IgM)C] were bound to the C receptors of thioglycollate-induced (activated) macrophages at 4 degrees C. E(IgM)C-macrophage complexes were then trypsinized at 4 degrees C, a procedure which resulted in cleavage of erythrocyte-bound C3b molecules to a form of C3 not recognized by the macrophage receptors for C3b. Under the conditions used, trypsin did not affect the attachment of E(IgM)C to the macrophage surface or the macrophage receptors for C3b. When these trypsin treated E(IgM)C-macrophage complexes were incubated at 37 degrees C, the bound E(IgM)C were not ingested; the erythrocytes remained attached to the macrophage plasma membrane via the macrophage's C receptors. These results indicate that attachment of a particle to specific receptors on the macrophage plasma membrane is not sufficient to trigger ingestion of that particle. Rather, ingestion requires the sequential, circumferential interaction of particle-bound ligands with specific plasma membrane receptors not involved in the initial attachment process.


1981 ◽  
Vol 1 (2) ◽  
pp. 128-135 ◽  
Author(s):  
P L Williamson ◽  
W A Massey ◽  
B M Phelps ◽  
R A Schlegel

Transformed murine hematopoietic cells of several lineages bound the fluorescent membrane probe merocyanine 540, whereas their normal counterparts did not. Similar selective binding was reproduced in artificial liposomes which bound this probe above their phase transition temperature, but not below it. The regions of the membrane to which merocyanine 540 binds along with the receptors for the lectin concanavalin A, but not the receptors for the lectin wheat germ agglutinin, were rearranged during the course of induced differentiation of erythroleukemia cells. Based on these findings, we propose a model of hematopoietic cell surface differentiation in which proteins such as concanavalin A receptors, which are destined for removal from the plasma membrane, are specifically associated with disordered, liquid-like lipid domains which can be visualized with merocyanine 540. For the specific case of erythroid differentiation, these domains and their associated proteins are collected at the region of the membrane where nuclear extrusion occurs and are eliminated from the reticulocyte plasma membrane by the enucleation event.


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