Interaction of lymphocytes with lipid bilayer membranes: a model for lymphocyte-mediated lysis of target cells.

Abstract

Horizontal li id bilayer membranes were used as a model system to study lymphocyte-mediated killing of target cells. Dinitrophenylated lipid bilayers can physically support dozens of lymphocytes for periods of over one hour without breakage or increasing the electrical conductance of the membrane. However, in the presence of antibody against Dnp, human lymphocytes rapidly induced increases in membrane conductance of several orders of magnitude without membrane breakage. Such ionic permeability increases occurred only when the membrane voltage was positive on the lymphocyte side, as would be the case with a target cell membrane. The lymphocyte and antibody dependence of this conductance increase parallels that observed for lymphocyte killing of antibody-coated target cells. The results are interpreted as evidence that the primary event in lymphocyte kiling of antibody-coated target cells is the creation of ion-conducting channels in the target membrane. Lymphocytes appear to play a major role in the immunologic rejection of foreign grafts and tumors. Since lymphocytes have also been shown to be able to destroy such foreign cells directly in vitro, interest has focused on the mechanism of this lymphocyte-induced killing (1). Several lines of evidence suggest that lymphocytes destroy their target cells by inducing a breakdown in the permeability barrier to small ions, leading to a subsequent colloid osmotic lysis. Morphological studies of the killing reactions have demonstrated that the cytolytic process is accompanied by a marked swelling of the dying cell (2). The study of target cells internally labeled with molecules of different sizes shows that the smaller molecules are released from the dying cell faster than those of high molecular weight (3-5). High concentrations of macromolecules have been shown to suppress the final release of 51Cr from the target cell (5, 6), but the interpretation of these findings is controversial (7). There has been no evidence to indicate whether the early permeability increase in the target membrane is caused directly by the attacking lymphocyte or is a secondary consequence of some other primary injury.In order to study the ability of lymphocytes to induce permeability changes in a foreign membrane, we have studied the interaction of human lymphocytes with artificial lipid bilayer membranes. Such "black lipid membranes" have been used extensively to model the permeability properties of naturally occurring membranes and have been especially useful in studying the properties of membrane active drugs (8,9). The ionic permeability of such membranes can conveniently be studied by electrical measurements. In the present studies we have used an antigenic lipid to form a bilayer membrane, and have examined the ability of nonimmune lymphocytes to induce permeability changes in the presence of antibody bound to the membrane. This system is a model for the antibody-dependent (but complement-independent) killing of target cells mediated (10). Dnp-phosphatidylethanolamine (Dnp-PE) ...

Charge clusters and the orientation of membrane proteins

“…Asymmetrical conductances have been attributed to such effects on antibiotic ionophores (Ehrenstein & Lecar, 1977), toxins (Finkelstein, Rubin & Tzeng, 1976;Schein, Kagan & Finkelstein, 1978;Blumenthal & Klausner, 1982), lipids (McLaughlin & Harary, 1974), cellular transport molecules (Schein, Colombini & Finkelstein, 1976;Blumenthal & Shamoo, 1979), immune cytotoxic factors (Henkart & Blumenthal, 1975;Michaels, Abramovitz, Hammer & Mayer, 1976), and "gating" components of the sodium and potassium channels of nerve (Hodgkin & Huxley, 1952;Miller & Rosenberg, 1979).…”

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

“…We have also attempted to provide a quantitative analysis of the kinetic results. Other studies of specific antibody-dependent interactions between cells of the immune system and haptenated lipid membranes include work by Geiger & Schreiber (1979), Henkart & Blumenthal (1975), and Hafeman et al (1979).…”

Triggering of the macrophage and neutrophil respiratory burst by antibody bound to a spin-label phospholipid hapten in model lipid bilayer membranes

“…Lipid membranes that are "solid" at 37 °C (dipalmitoylphosphatidylcholine, DPPC) are much more effective, per vesicle bound, than are "fluid" membranes (dimyristoylphosphatidylcholine, DMPC). Vesicle membranes .^^.t present a variety of studies have been reported on the interactions of various components of the immune system with model membranes (lipid bilayers forming vesicles or liposomes) containing specific haptens or antigens (Esser et al, 1979;Finberg et al, 1978;Geiger & Schreiber, 1979;Hale et al, 1980;Kinsky & Nicolotti, 1977; Hafeman et al, 1979; Henkart & Blumenthal, 1975;Henry et al, 1978;Hollander et al, 1979;Lewis & McConnell, 1978;Loh et al, 1979;McConnell, 1978;Parce et al, 1978Parce et al, , 1980. Some of these studies have described a dependence of immune response on the physical-chemical properties of the host bilayer membranes (Esser et al, 1979;Hafeman et al, 1979; Lewis & McConnell, 1978; Parce et al, 1980;McConnell, 1978).…”