Kinetics of antibody-dependent binding of haptenated phospholipid vesicles to a macrophage-related cell line

Antibody-bearing fluorescent liposomes containing methotrexate became bound to cells expressing determinants recognized by the antibody. The number ofbound liposomes could be evaluated by fluorometry, and the internalization of liposomes was evaluated by the methotrexate-mediated inhibition of radiolabeled deoxyuridine incorporation. The effect of methotrexate transferred from the liposomes into the cells was a function not of the number of liposomes bound but of the nature of the cells and of the target molecules. Liposomes bearing antibodies with specificity for the H-2Kor Mr 94,000 and 180,000 molecules were much more effective at drug delivery into T than B cells, even though these determinants were expressed by both cell types. B cells were more sensitive to the effect of methotrexate in anti-H-2

Section: Lated T and B Cellsmentioning

confidence: 99%

Differential endocytosis of T and B lymphocyte surface molecules evaluated with antibody-bearing fluorescent liposomes containing methotrexate.

Machy¹,

Barbet²,

Leserman³

1982

“…Several in vitro studies have demonstrated that, for efficient uptake of liposomes by Fc receptor (FcR)-bearing peritoneal macrophages (24) or macrophage-like tumor cells (25,26), it was necessary to opsonize liposomes with passively administered antibodies to liposome-bound ligands. As part of the present experiments, mice either received antidinitrophenyl (anti-DNP) mAbs ofdifferent IgG subclasses passively or were immunized to respond to DNP.…”

Section: Introductionmentioning

confidence: 99%

Immune clearance of liposomes inhibited by an anti-Fc receptor antibody in vivo.

Aragnol¹,

Leserman²

1986

In a study designed to evaluate the potential for in vivo manipulation of the circulation and tissue distribution of injected liposomes, mice were passively injected with antidinitrophenyl (anti-DNP) monoclonal antibodies of the IgG2a or IgG2b subclasses or were immunized with the nitrophenyl hapten bound to a protein carrier. They were then injected i.v. with 12'I-and carboxyfluorescein-labeled, DNPbearing liposomes. Circulation time of the DNP-bearing liposomes was markedly reduced in actively and passively immune mice, with increased deposition of liposomes in the liver. The increased clearance of liposomes could be abrogated by injection of a monoclonal antibody directed against the murine IgG Fc receptor (2.4G2). The results suggest that clearance of ligand-bearing reagent in the face of an immune response may be modified by specific immunologic manipulation in vivo.

“…Unilamellar phospholipid vesicles were prepared by the ether injection method described previously (2). Vesicles (=--1 ,am diameter) were resuspended in 0.15 M NaCl at 0.25 mM lipid after centrifugation at 12,000 X g for 30 min.…”

Section: -mentioning

confidence: 99%

“…Such reconstituted lipid bilayer membranes are usually in the form of multilamellar liposomes or single-shell vesicles. In some studies the question has arisen as to whether the spherical shape (e.g., radius of curvature 0.5 um), membrane flexibility, or both, of these vesicles or liposomes might play a significant role when cell membrane-reconstituted target membrane contact is involved in binding and triggering (2)(3)(4). For this reason we have been motivated to study the specific binding and triggering of cellular components of the immune system by lipid monolayer membranes attached to a planar glass surface.…”

mentioning

confidence: 99%

“…For this reason we have been motivated to study the specific binding and triggering of cellular components of the immune system by lipid monolayer membranes attached to a planar glass surface. In the present work, the specific antibody-dependent interactions of macrophages with the supported membranes have been studied, and the results have been compared with previous studies ofsimilar interactions of macrophages with vesicle membranes (2)(3)(4).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Specific antibody-dependent interactions between macrophages and lipid haptens in planar lipid monolayers.

Hafeman¹,

Tscharner²,

McConnell³

1981

The binding of -guinea pig peritoneal macrophages to planar lipid monolayers on alkylated glass is shown to be highly specific, requiring lipid hapten in the monolayer and specific anti-hapten IgG antibody. This is true for both "fluid" and "solid" monolayer membranes, in which the lateral diffusion coefficients of fluorescent lipid probes and bound fluorescent antibodies differ by at least two orders of magnitude. The region of the (macrophage membrane)-(monolayer membrane) contact is readily observed by using an epifluorescence microscope and fluoresceinated IgG antibodies or fluorescent lipids. The fluorescence intensity of IgG antibodies bound to lipid haptens in fluid monolayer membranes in the region of the (macrophage membrane)-(monolayer membrane) contact was significantly enhanced in the early stages of binding (first 10 min at 24TC), due to a diffusive flux of the fluorescent antibodies into the region of membrane-membrane contact. Cellular activation takes place immediately during a 10-min warm-up to 37C and can be recognized by rapid symmetrical cell spreading, the formation of"black holes" around the cells (probably due to superoxide-facilitated photochemical bleaching of the fluorophore), and the release of the-lysozomal enzyme cathepsin B. Specific antibody-dependent [1-"C]-glucose oxidation by these macrophages on fluid and solid monolayers is quite similar to that reported previously for fluid and solid bilayer vesicle target membranes. These results are significant for understanding the molecular interactions between membranes that are necessary for a macrophage cytotoxic response.Reconstituted lipid bilayer membranes containing specific antigens or lipid haptens have been used successfully in a number of studies of cell surface recognition by cellular and humoral components ofthe immune system (for examples ofrecent work and references to earlier literature, see ref. 1). Such reconstituted lipid bilayer membranes are usually in the form of multilamellar liposomes or single-shell vesicles. In some studies the question has arisen as to whether the spherical shape (e.g., radius of curvature 0.5 um), membrane flexibility, or both, of these vesicles or liposomes might play a significant role when cell membrane-reconstituted target membrane contact is involved in binding and triggering (2-4). For this reason we have been motivated to study the specific binding and triggering of cellular components of the immune system by lipid monolayer membranes attached to a planar glass surface. In the present work, the specific antibody-dependent interactions of macrophages with the supported membranes have been studied, and the results have been compared with previous studies ofsimilar interactions of macrophages with vesicle membranes (2-4).A second motivation for the present work has been a desire to use the-fluorescence microscope to visualize molecular events that take place at the interface between a cellular membrane and a reconstituted membrane during the course of a specific functional interact...